a <firstterm><acronym>TOAST</acronym> table</firstterm> that is separate from, but
associated with, the table containing the <acronym>TOAST</acronym> pointer datum
itself. These <firstterm>on-disk</firstterm> pointer datums are created by the
-<acronym>TOAST</acronym> management code (in <filename>access/heap/tuptoaster.c</filename>)
+<acronym>TOAST</acronym> management code (in <filename>access/common/toast_internals.c</filename>)
when a tuple to be stored on disk is too large to be stored as-is.
Further details appear in <xref linkend="storage-toast-ondisk"/>.
Alternatively, a <acronym>TOAST</acronym> pointer datum can contain a pointer to
top_builddir = ../../../..
include $(top_builddir)/src/Makefile.global
-OBJS = bufmask.o heaptuple.o indextuple.o printsimple.o printtup.o \
- relation.o reloptions.o scankey.o session.o tupconvert.o tupdesc.o
+OBJS = bufmask.o detoast.o heaptuple.o indextuple.o printsimple.o \
+ printtup.o relation.o reloptions.o scankey.o session.o toast_internals.o \
+ tupconvert.o tupdesc.o
include $(top_srcdir)/src/backend/common.mk
--- /dev/null
+/*-------------------------------------------------------------------------
+ *
+ * detoast.c
+ * Retrieve compressed or external variable size attributes.
+ *
+ * Copyright (c) 2000-2019, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ * src/backend/access/common/detoast.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "access/detoast.h"
+#include "access/genam.h"
+#include "access/heaptoast.h"
+#include "access/table.h"
+#include "access/toast_internals.h"
+#include "common/pg_lzcompress.h"
+#include "utils/expandeddatum.h"
+#include "utils/fmgroids.h"
+#include "utils/rel.h"
+
+static struct varlena *toast_fetch_datum(struct varlena *attr);
+static struct varlena *toast_fetch_datum_slice(struct varlena *attr,
+ int32 sliceoffset, int32 length);
+static struct varlena *toast_decompress_datum(struct varlena *attr);
+static struct varlena *toast_decompress_datum_slice(struct varlena *attr, int32 slicelength);
+
+/* ----------
+ * heap_tuple_fetch_attr -
+ *
+ * Public entry point to get back a toasted value from
+ * external source (possibly still in compressed format).
+ *
+ * This will return a datum that contains all the data internally, ie, not
+ * relying on external storage or memory, but it can still be compressed or
+ * have a short header. Note some callers assume that if the input is an
+ * EXTERNAL datum, the result will be a pfree'able chunk.
+ * ----------
+ */
+struct varlena *
+heap_tuple_fetch_attr(struct varlena *attr)
+{
+ struct varlena *result;
+
+ if (VARATT_IS_EXTERNAL_ONDISK(attr))
+ {
+ /*
+ * This is an external stored plain value
+ */
+ result = toast_fetch_datum(attr);
+ }
+ else if (VARATT_IS_EXTERNAL_INDIRECT(attr))
+ {
+ /*
+ * This is an indirect pointer --- dereference it
+ */
+ struct varatt_indirect redirect;
+
+ VARATT_EXTERNAL_GET_POINTER(redirect, attr);
+ attr = (struct varlena *) redirect.pointer;
+
+ /* nested indirect Datums aren't allowed */
+ Assert(!VARATT_IS_EXTERNAL_INDIRECT(attr));
+
+ /* recurse if value is still external in some other way */
+ if (VARATT_IS_EXTERNAL(attr))
+ return heap_tuple_fetch_attr(attr);
+
+ /*
+ * Copy into the caller's memory context, in case caller tries to
+ * pfree the result.
+ */
+ result = (struct varlena *) palloc(VARSIZE_ANY(attr));
+ memcpy(result, attr, VARSIZE_ANY(attr));
+ }
+ else if (VARATT_IS_EXTERNAL_EXPANDED(attr))
+ {
+ /*
+ * This is an expanded-object pointer --- get flat format
+ */
+ ExpandedObjectHeader *eoh;
+ Size resultsize;
+
+ eoh = DatumGetEOHP(PointerGetDatum(attr));
+ resultsize = EOH_get_flat_size(eoh);
+ result = (struct varlena *) palloc(resultsize);
+ EOH_flatten_into(eoh, (void *) result, resultsize);
+ }
+ else
+ {
+ /*
+ * This is a plain value inside of the main tuple - why am I called?
+ */
+ result = attr;
+ }
+
+ return result;
+}
+
+
+/* ----------
+ * heap_tuple_untoast_attr -
+ *
+ * Public entry point to get back a toasted value from compression
+ * or external storage. The result is always non-extended varlena form.
+ *
+ * Note some callers assume that if the input is an EXTERNAL or COMPRESSED
+ * datum, the result will be a pfree'able chunk.
+ * ----------
+ */
+struct varlena *
+heap_tuple_untoast_attr(struct varlena *attr)
+{
+ if (VARATT_IS_EXTERNAL_ONDISK(attr))
+ {
+ /*
+ * This is an externally stored datum --- fetch it back from there
+ */
+ attr = toast_fetch_datum(attr);
+ /* If it's compressed, decompress it */
+ if (VARATT_IS_COMPRESSED(attr))
+ {
+ struct varlena *tmp = attr;
+
+ attr = toast_decompress_datum(tmp);
+ pfree(tmp);
+ }
+ }
+ else if (VARATT_IS_EXTERNAL_INDIRECT(attr))
+ {
+ /*
+ * This is an indirect pointer --- dereference it
+ */
+ struct varatt_indirect redirect;
+
+ VARATT_EXTERNAL_GET_POINTER(redirect, attr);
+ attr = (struct varlena *) redirect.pointer;
+
+ /* nested indirect Datums aren't allowed */
+ Assert(!VARATT_IS_EXTERNAL_INDIRECT(attr));
+
+ /* recurse in case value is still extended in some other way */
+ attr = heap_tuple_untoast_attr(attr);
+
+ /* if it isn't, we'd better copy it */
+ if (attr == (struct varlena *) redirect.pointer)
+ {
+ struct varlena *result;
+
+ result = (struct varlena *) palloc(VARSIZE_ANY(attr));
+ memcpy(result, attr, VARSIZE_ANY(attr));
+ attr = result;
+ }
+ }
+ else if (VARATT_IS_EXTERNAL_EXPANDED(attr))
+ {
+ /*
+ * This is an expanded-object pointer --- get flat format
+ */
+ attr = heap_tuple_fetch_attr(attr);
+ /* flatteners are not allowed to produce compressed/short output */
+ Assert(!VARATT_IS_EXTENDED(attr));
+ }
+ else if (VARATT_IS_COMPRESSED(attr))
+ {
+ /*
+ * This is a compressed value inside of the main tuple
+ */
+ attr = toast_decompress_datum(attr);
+ }
+ else if (VARATT_IS_SHORT(attr))
+ {
+ /*
+ * This is a short-header varlena --- convert to 4-byte header format
+ */
+ Size data_size = VARSIZE_SHORT(attr) - VARHDRSZ_SHORT;
+ Size new_size = data_size + VARHDRSZ;
+ struct varlena *new_attr;
+
+ new_attr = (struct varlena *) palloc(new_size);
+ SET_VARSIZE(new_attr, new_size);
+ memcpy(VARDATA(new_attr), VARDATA_SHORT(attr), data_size);
+ attr = new_attr;
+ }
+
+ return attr;
+}
+
+
+/* ----------
+ * heap_tuple_untoast_attr_slice -
+ *
+ * Public entry point to get back part of a toasted value
+ * from compression or external storage.
+ * ----------
+ */
+struct varlena *
+heap_tuple_untoast_attr_slice(struct varlena *attr,
+ int32 sliceoffset, int32 slicelength)
+{
+ struct varlena *preslice;
+ struct varlena *result;
+ char *attrdata;
+ int32 attrsize;
+
+ if (VARATT_IS_EXTERNAL_ONDISK(attr))
+ {
+ struct varatt_external toast_pointer;
+
+ VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);
+
+ /* fast path for non-compressed external datums */
+ if (!VARATT_EXTERNAL_IS_COMPRESSED(toast_pointer))
+ return toast_fetch_datum_slice(attr, sliceoffset, slicelength);
+
+ /* fetch it back (compressed marker will get set automatically) */
+ preslice = toast_fetch_datum(attr);
+ }
+ else if (VARATT_IS_EXTERNAL_INDIRECT(attr))
+ {
+ struct varatt_indirect redirect;
+
+ VARATT_EXTERNAL_GET_POINTER(redirect, attr);
+
+ /* nested indirect Datums aren't allowed */
+ Assert(!VARATT_IS_EXTERNAL_INDIRECT(redirect.pointer));
+
+ return heap_tuple_untoast_attr_slice(redirect.pointer,
+ sliceoffset, slicelength);
+ }
+ else if (VARATT_IS_EXTERNAL_EXPANDED(attr))
+ {
+ /* pass it off to heap_tuple_fetch_attr to flatten */
+ preslice = heap_tuple_fetch_attr(attr);
+ }
+ else
+ preslice = attr;
+
+ Assert(!VARATT_IS_EXTERNAL(preslice));
+
+ if (VARATT_IS_COMPRESSED(preslice))
+ {
+ struct varlena *tmp = preslice;
+
+ /* Decompress enough to encompass the slice and the offset */
+ if (slicelength > 0 && sliceoffset >= 0)
+ preslice = toast_decompress_datum_slice(tmp, slicelength + sliceoffset);
+ else
+ preslice = toast_decompress_datum(tmp);
+
+ if (tmp != attr)
+ pfree(tmp);
+ }
+
+ if (VARATT_IS_SHORT(preslice))
+ {
+ attrdata = VARDATA_SHORT(preslice);
+ attrsize = VARSIZE_SHORT(preslice) - VARHDRSZ_SHORT;
+ }
+ else
+ {
+ attrdata = VARDATA(preslice);
+ attrsize = VARSIZE(preslice) - VARHDRSZ;
+ }
+
+ /* slicing of datum for compressed cases and plain value */
+
+ if (sliceoffset >= attrsize)
+ {
+ sliceoffset = 0;
+ slicelength = 0;
+ }
+
+ if (((sliceoffset + slicelength) > attrsize) || slicelength < 0)
+ slicelength = attrsize - sliceoffset;
+
+ result = (struct varlena *) palloc(slicelength + VARHDRSZ);
+ SET_VARSIZE(result, slicelength + VARHDRSZ);
+
+ memcpy(VARDATA(result), attrdata + sliceoffset, slicelength);
+
+ if (preslice != attr)
+ pfree(preslice);
+
+ return result;
+}
+
+/* ----------
+ * toast_fetch_datum -
+ *
+ * Reconstruct an in memory Datum from the chunks saved
+ * in the toast relation
+ * ----------
+ */
+static struct varlena *
+toast_fetch_datum(struct varlena *attr)
+{
+ Relation toastrel;
+ Relation *toastidxs;
+ ScanKeyData toastkey;
+ SysScanDesc toastscan;
+ HeapTuple ttup;
+ TupleDesc toasttupDesc;
+ struct varlena *result;
+ struct varatt_external toast_pointer;
+ int32 ressize;
+ int32 residx,
+ nextidx;
+ int32 numchunks;
+ Pointer chunk;
+ bool isnull;
+ char *chunkdata;
+ int32 chunksize;
+ int num_indexes;
+ int validIndex;
+ SnapshotData SnapshotToast;
+
+ if (!VARATT_IS_EXTERNAL_ONDISK(attr))
+ elog(ERROR, "toast_fetch_datum shouldn't be called for non-ondisk datums");
+
+ /* Must copy to access aligned fields */
+ VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);
+
+ ressize = toast_pointer.va_extsize;
+ numchunks = ((ressize - 1) / TOAST_MAX_CHUNK_SIZE) + 1;
+
+ result = (struct varlena *) palloc(ressize + VARHDRSZ);
+
+ if (VARATT_EXTERNAL_IS_COMPRESSED(toast_pointer))
+ SET_VARSIZE_COMPRESSED(result, ressize + VARHDRSZ);
+ else
+ SET_VARSIZE(result, ressize + VARHDRSZ);
+
+ /*
+ * Open the toast relation and its indexes
+ */
+ toastrel = table_open(toast_pointer.va_toastrelid, AccessShareLock);
+ toasttupDesc = toastrel->rd_att;
+
+ /* Look for the valid index of the toast relation */
+ validIndex = toast_open_indexes(toastrel,
+ AccessShareLock,
+ &toastidxs,
+ &num_indexes);
+
+ /*
+ * Setup a scan key to fetch from the index by va_valueid
+ */
+ ScanKeyInit(&toastkey,
+ (AttrNumber) 1,
+ BTEqualStrategyNumber, F_OIDEQ,
+ ObjectIdGetDatum(toast_pointer.va_valueid));
+
+ /*
+ * Read the chunks by index
+ *
+ * Note that because the index is actually on (valueid, chunkidx) we will
+ * see the chunks in chunkidx order, even though we didn't explicitly ask
+ * for it.
+ */
+ nextidx = 0;
+
+ init_toast_snapshot(&SnapshotToast);
+ toastscan = systable_beginscan_ordered(toastrel, toastidxs[validIndex],
+ &SnapshotToast, 1, &toastkey);
+ while ((ttup = systable_getnext_ordered(toastscan, ForwardScanDirection)) != NULL)
+ {
+ /*
+ * Have a chunk, extract the sequence number and the data
+ */
+ residx = DatumGetInt32(fastgetattr(ttup, 2, toasttupDesc, &isnull));
+ Assert(!isnull);
+ chunk = DatumGetPointer(fastgetattr(ttup, 3, toasttupDesc, &isnull));
+ Assert(!isnull);
+ if (!VARATT_IS_EXTENDED(chunk))
+ {
+ chunksize = VARSIZE(chunk) - VARHDRSZ;
+ chunkdata = VARDATA(chunk);
+ }
+ else if (VARATT_IS_SHORT(chunk))
+ {
+ /* could happen due to heap_form_tuple doing its thing */
+ chunksize = VARSIZE_SHORT(chunk) - VARHDRSZ_SHORT;
+ chunkdata = VARDATA_SHORT(chunk);
+ }
+ else
+ {
+ /* should never happen */
+ elog(ERROR, "found toasted toast chunk for toast value %u in %s",
+ toast_pointer.va_valueid,
+ RelationGetRelationName(toastrel));
+ chunksize = 0; /* keep compiler quiet */
+ chunkdata = NULL;
+ }
+
+ /*
+ * Some checks on the data we've found
+ */
+ if (residx != nextidx)
+ ereport(ERROR,
+ (errcode(ERRCODE_DATA_CORRUPTED),
+ errmsg_internal("unexpected chunk number %d (expected %d) for toast value %u in %s",
+ residx, nextidx,
+ toast_pointer.va_valueid,
+ RelationGetRelationName(toastrel))));
+ if (residx < numchunks - 1)
+ {
+ if (chunksize != TOAST_MAX_CHUNK_SIZE)
+ ereport(ERROR,
+ (errcode(ERRCODE_DATA_CORRUPTED),
+ errmsg_internal("unexpected chunk size %d (expected %d) in chunk %d of %d for toast value %u in %s",
+ chunksize, (int) TOAST_MAX_CHUNK_SIZE,
+ residx, numchunks,
+ toast_pointer.va_valueid,
+ RelationGetRelationName(toastrel))));
+ }
+ else if (residx == numchunks - 1)
+ {
+ if ((residx * TOAST_MAX_CHUNK_SIZE + chunksize) != ressize)
+ ereport(ERROR,
+ (errcode(ERRCODE_DATA_CORRUPTED),
+ errmsg_internal("unexpected chunk size %d (expected %d) in final chunk %d for toast value %u in %s",
+ chunksize,
+ (int) (ressize - residx * TOAST_MAX_CHUNK_SIZE),
+ residx,
+ toast_pointer.va_valueid,
+ RelationGetRelationName(toastrel))));
+ }
+ else
+ ereport(ERROR,
+ (errcode(ERRCODE_DATA_CORRUPTED),
+ errmsg_internal("unexpected chunk number %d (out of range %d..%d) for toast value %u in %s",
+ residx,
+ 0, numchunks - 1,
+ toast_pointer.va_valueid,
+ RelationGetRelationName(toastrel))));
+
+ /*
+ * Copy the data into proper place in our result
+ */
+ memcpy(VARDATA(result) + residx * TOAST_MAX_CHUNK_SIZE,
+ chunkdata,
+ chunksize);
+
+ nextidx++;
+ }
+
+ /*
+ * Final checks that we successfully fetched the datum
+ */
+ if (nextidx != numchunks)
+ ereport(ERROR,
+ (errcode(ERRCODE_DATA_CORRUPTED),
+ errmsg_internal("missing chunk number %d for toast value %u in %s",
+ nextidx,
+ toast_pointer.va_valueid,
+ RelationGetRelationName(toastrel))));
+
+ /*
+ * End scan and close relations
+ */
+ systable_endscan_ordered(toastscan);
+ toast_close_indexes(toastidxs, num_indexes, AccessShareLock);
+ table_close(toastrel, AccessShareLock);
+
+ return result;
+}
+
+/* ----------
+ * toast_fetch_datum_slice -
+ *
+ * Reconstruct a segment of a Datum from the chunks saved
+ * in the toast relation
+ *
+ * Note that this function only supports non-compressed external datums.
+ * ----------
+ */
+static struct varlena *
+toast_fetch_datum_slice(struct varlena *attr, int32 sliceoffset, int32 length)
+{
+ Relation toastrel;
+ Relation *toastidxs;
+ ScanKeyData toastkey[3];
+ int nscankeys;
+ SysScanDesc toastscan;
+ HeapTuple ttup;
+ TupleDesc toasttupDesc;
+ struct varlena *result;
+ struct varatt_external toast_pointer;
+ int32 attrsize;
+ int32 residx;
+ int32 nextidx;
+ int numchunks;
+ int startchunk;
+ int endchunk;
+ int32 startoffset;
+ int32 endoffset;
+ int totalchunks;
+ Pointer chunk;
+ bool isnull;
+ char *chunkdata;
+ int32 chunksize;
+ int32 chcpystrt;
+ int32 chcpyend;
+ int num_indexes;
+ int validIndex;
+ SnapshotData SnapshotToast;
+
+ if (!VARATT_IS_EXTERNAL_ONDISK(attr))
+ elog(ERROR, "toast_fetch_datum_slice shouldn't be called for non-ondisk datums");
+
+ /* Must copy to access aligned fields */
+ VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);
+
+ /*
+ * It's nonsense to fetch slices of a compressed datum -- this isn't lo_*
+ * we can't return a compressed datum which is meaningful to toast later
+ */
+ Assert(!VARATT_EXTERNAL_IS_COMPRESSED(toast_pointer));
+
+ attrsize = toast_pointer.va_extsize;
+ totalchunks = ((attrsize - 1) / TOAST_MAX_CHUNK_SIZE) + 1;
+
+ if (sliceoffset >= attrsize)
+ {
+ sliceoffset = 0;
+ length = 0;
+ }
+
+ if (((sliceoffset + length) > attrsize) || length < 0)
+ length = attrsize - sliceoffset;
+
+ result = (struct varlena *) palloc(length + VARHDRSZ);
+
+ SET_VARSIZE(result, length + VARHDRSZ);
+
+ if (length == 0)
+ return result; /* Can save a lot of work at this point! */
+
+ startchunk = sliceoffset / TOAST_MAX_CHUNK_SIZE;
+ endchunk = (sliceoffset + length - 1) / TOAST_MAX_CHUNK_SIZE;
+ numchunks = (endchunk - startchunk) + 1;
+
+ startoffset = sliceoffset % TOAST_MAX_CHUNK_SIZE;
+ endoffset = (sliceoffset + length - 1) % TOAST_MAX_CHUNK_SIZE;
+
+ /*
+ * Open the toast relation and its indexes
+ */
+ toastrel = table_open(toast_pointer.va_toastrelid, AccessShareLock);
+ toasttupDesc = toastrel->rd_att;
+
+ /* Look for the valid index of toast relation */
+ validIndex = toast_open_indexes(toastrel,
+ AccessShareLock,
+ &toastidxs,
+ &num_indexes);
+
+ /*
+ * Setup a scan key to fetch from the index. This is either two keys or
+ * three depending on the number of chunks.
+ */
+ ScanKeyInit(&toastkey[0],
+ (AttrNumber) 1,
+ BTEqualStrategyNumber, F_OIDEQ,
+ ObjectIdGetDatum(toast_pointer.va_valueid));
+
+ /*
+ * Use equality condition for one chunk, a range condition otherwise:
+ */
+ if (numchunks == 1)
+ {
+ ScanKeyInit(&toastkey[1],
+ (AttrNumber) 2,
+ BTEqualStrategyNumber, F_INT4EQ,
+ Int32GetDatum(startchunk));
+ nscankeys = 2;
+ }
+ else
+ {
+ ScanKeyInit(&toastkey[1],
+ (AttrNumber) 2,
+ BTGreaterEqualStrategyNumber, F_INT4GE,
+ Int32GetDatum(startchunk));
+ ScanKeyInit(&toastkey[2],
+ (AttrNumber) 2,
+ BTLessEqualStrategyNumber, F_INT4LE,
+ Int32GetDatum(endchunk));
+ nscankeys = 3;
+ }
+
+ /*
+ * Read the chunks by index
+ *
+ * The index is on (valueid, chunkidx) so they will come in order
+ */
+ init_toast_snapshot(&SnapshotToast);
+ nextidx = startchunk;
+ toastscan = systable_beginscan_ordered(toastrel, toastidxs[validIndex],
+ &SnapshotToast, nscankeys, toastkey);
+ while ((ttup = systable_getnext_ordered(toastscan, ForwardScanDirection)) != NULL)
+ {
+ /*
+ * Have a chunk, extract the sequence number and the data
+ */
+ residx = DatumGetInt32(fastgetattr(ttup, 2, toasttupDesc, &isnull));
+ Assert(!isnull);
+ chunk = DatumGetPointer(fastgetattr(ttup, 3, toasttupDesc, &isnull));
+ Assert(!isnull);
+ if (!VARATT_IS_EXTENDED(chunk))
+ {
+ chunksize = VARSIZE(chunk) - VARHDRSZ;
+ chunkdata = VARDATA(chunk);
+ }
+ else if (VARATT_IS_SHORT(chunk))
+ {
+ /* could happen due to heap_form_tuple doing its thing */
+ chunksize = VARSIZE_SHORT(chunk) - VARHDRSZ_SHORT;
+ chunkdata = VARDATA_SHORT(chunk);
+ }
+ else
+ {
+ /* should never happen */
+ elog(ERROR, "found toasted toast chunk for toast value %u in %s",
+ toast_pointer.va_valueid,
+ RelationGetRelationName(toastrel));
+ chunksize = 0; /* keep compiler quiet */
+ chunkdata = NULL;
+ }
+
+ /*
+ * Some checks on the data we've found
+ */
+ if ((residx != nextidx) || (residx > endchunk) || (residx < startchunk))
+ elog(ERROR, "unexpected chunk number %d (expected %d) for toast value %u in %s",
+ residx, nextidx,
+ toast_pointer.va_valueid,
+ RelationGetRelationName(toastrel));
+ if (residx < totalchunks - 1)
+ {
+ if (chunksize != TOAST_MAX_CHUNK_SIZE)
+ elog(ERROR, "unexpected chunk size %d (expected %d) in chunk %d of %d for toast value %u in %s when fetching slice",
+ chunksize, (int) TOAST_MAX_CHUNK_SIZE,
+ residx, totalchunks,
+ toast_pointer.va_valueid,
+ RelationGetRelationName(toastrel));
+ }
+ else if (residx == totalchunks - 1)
+ {
+ if ((residx * TOAST_MAX_CHUNK_SIZE + chunksize) != attrsize)
+ elog(ERROR, "unexpected chunk size %d (expected %d) in final chunk %d for toast value %u in %s when fetching slice",
+ chunksize,
+ (int) (attrsize - residx * TOAST_MAX_CHUNK_SIZE),
+ residx,
+ toast_pointer.va_valueid,
+ RelationGetRelationName(toastrel));
+ }
+ else
+ elog(ERROR, "unexpected chunk number %d (out of range %d..%d) for toast value %u in %s",
+ residx,
+ 0, totalchunks - 1,
+ toast_pointer.va_valueid,
+ RelationGetRelationName(toastrel));
+
+ /*
+ * Copy the data into proper place in our result
+ */
+ chcpystrt = 0;
+ chcpyend = chunksize - 1;
+ if (residx == startchunk)
+ chcpystrt = startoffset;
+ if (residx == endchunk)
+ chcpyend = endoffset;
+
+ memcpy(VARDATA(result) +
+ (residx * TOAST_MAX_CHUNK_SIZE - sliceoffset) + chcpystrt,
+ chunkdata + chcpystrt,
+ (chcpyend - chcpystrt) + 1);
+
+ nextidx++;
+ }
+
+ /*
+ * Final checks that we successfully fetched the datum
+ */
+ if (nextidx != (endchunk + 1))
+ elog(ERROR, "missing chunk number %d for toast value %u in %s",
+ nextidx,
+ toast_pointer.va_valueid,
+ RelationGetRelationName(toastrel));
+
+ /*
+ * End scan and close relations
+ */
+ systable_endscan_ordered(toastscan);
+ toast_close_indexes(toastidxs, num_indexes, AccessShareLock);
+ table_close(toastrel, AccessShareLock);
+
+ return result;
+}
+
+/* ----------
+ * toast_decompress_datum -
+ *
+ * Decompress a compressed version of a varlena datum
+ */
+static struct varlena *
+toast_decompress_datum(struct varlena *attr)
+{
+ struct varlena *result;
+
+ Assert(VARATT_IS_COMPRESSED(attr));
+
+ result = (struct varlena *)
+ palloc(TOAST_COMPRESS_RAWSIZE(attr) + VARHDRSZ);
+ SET_VARSIZE(result, TOAST_COMPRESS_RAWSIZE(attr) + VARHDRSZ);
+
+ if (pglz_decompress(TOAST_COMPRESS_RAWDATA(attr),
+ VARSIZE(attr) - TOAST_COMPRESS_HDRSZ,
+ VARDATA(result),
+ TOAST_COMPRESS_RAWSIZE(attr), true) < 0)
+ elog(ERROR, "compressed data is corrupted");
+
+ return result;
+}
+
+
+/* ----------
+ * toast_decompress_datum_slice -
+ *
+ * Decompress the front of a compressed version of a varlena datum.
+ * offset handling happens in heap_tuple_untoast_attr_slice.
+ * Here we just decompress a slice from the front.
+ */
+static struct varlena *
+toast_decompress_datum_slice(struct varlena *attr, int32 slicelength)
+{
+ struct varlena *result;
+ int32 rawsize;
+
+ Assert(VARATT_IS_COMPRESSED(attr));
+
+ result = (struct varlena *) palloc(slicelength + VARHDRSZ);
+
+ rawsize = pglz_decompress(TOAST_COMPRESS_RAWDATA(attr),
+ VARSIZE(attr) - TOAST_COMPRESS_HDRSZ,
+ VARDATA(result),
+ slicelength, false);
+ if (rawsize < 0)
+ elog(ERROR, "compressed data is corrupted");
+
+ SET_VARSIZE(result, rawsize + VARHDRSZ);
+ return result;
+}
+
+/* ----------
+ * toast_raw_datum_size -
+ *
+ * Return the raw (detoasted) size of a varlena datum
+ * (including the VARHDRSZ header)
+ * ----------
+ */
+Size
+toast_raw_datum_size(Datum value)
+{
+ struct varlena *attr = (struct varlena *) DatumGetPointer(value);
+ Size result;
+
+ if (VARATT_IS_EXTERNAL_ONDISK(attr))
+ {
+ /* va_rawsize is the size of the original datum -- including header */
+ struct varatt_external toast_pointer;
+
+ VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);
+ result = toast_pointer.va_rawsize;
+ }
+ else if (VARATT_IS_EXTERNAL_INDIRECT(attr))
+ {
+ struct varatt_indirect toast_pointer;
+
+ VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);
+
+ /* nested indirect Datums aren't allowed */
+ Assert(!VARATT_IS_EXTERNAL_INDIRECT(toast_pointer.pointer));
+
+ return toast_raw_datum_size(PointerGetDatum(toast_pointer.pointer));
+ }
+ else if (VARATT_IS_EXTERNAL_EXPANDED(attr))
+ {
+ result = EOH_get_flat_size(DatumGetEOHP(value));
+ }
+ else if (VARATT_IS_COMPRESSED(attr))
+ {
+ /* here, va_rawsize is just the payload size */
+ result = VARRAWSIZE_4B_C(attr) + VARHDRSZ;
+ }
+ else if (VARATT_IS_SHORT(attr))
+ {
+ /*
+ * we have to normalize the header length to VARHDRSZ or else the
+ * callers of this function will be confused.
+ */
+ result = VARSIZE_SHORT(attr) - VARHDRSZ_SHORT + VARHDRSZ;
+ }
+ else
+ {
+ /* plain untoasted datum */
+ result = VARSIZE(attr);
+ }
+ return result;
+}
+
+/* ----------
+ * toast_datum_size
+ *
+ * Return the physical storage size (possibly compressed) of a varlena datum
+ * ----------
+ */
+Size
+toast_datum_size(Datum value)
+{
+ struct varlena *attr = (struct varlena *) DatumGetPointer(value);
+ Size result;
+
+ if (VARATT_IS_EXTERNAL_ONDISK(attr))
+ {
+ /*
+ * Attribute is stored externally - return the extsize whether
+ * compressed or not. We do not count the size of the toast pointer
+ * ... should we?
+ */
+ struct varatt_external toast_pointer;
+
+ VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);
+ result = toast_pointer.va_extsize;
+ }
+ else if (VARATT_IS_EXTERNAL_INDIRECT(attr))
+ {
+ struct varatt_indirect toast_pointer;
+
+ VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);
+
+ /* nested indirect Datums aren't allowed */
+ Assert(!VARATT_IS_EXTERNAL_INDIRECT(attr));
+
+ return toast_datum_size(PointerGetDatum(toast_pointer.pointer));
+ }
+ else if (VARATT_IS_EXTERNAL_EXPANDED(attr))
+ {
+ result = EOH_get_flat_size(DatumGetEOHP(value));
+ }
+ else if (VARATT_IS_SHORT(attr))
+ {
+ result = VARSIZE_SHORT(attr);
+ }
+ else
+ {
+ /*
+ * Attribute is stored inline either compressed or not, just calculate
+ * the size of the datum in either case.
+ */
+ result = VARSIZE(attr);
+ }
+ return result;
+}
* (In performance-critical code paths we can use pg_detoast_datum_packed
* and the appropriate access macros to avoid that overhead.) Note that this
* conversion is performed directly in heap_form_tuple, without invoking
- * tuptoaster.c.
+ * heaptoast.c.
*
* This change will break any code that assumes it needn't detoast values
* that have been put into a tuple but never sent to disk. Hopefully there
#include "postgres.h"
+#include "access/heaptoast.h"
#include "access/sysattr.h"
#include "access/tupdesc_details.h"
-#include "access/tuptoaster.h"
#include "executor/tuptable.h"
#include "utils/expandeddatum.h"
#include "postgres.h"
+#include "access/detoast.h"
+#include "access/heaptoast.h"
#include "access/htup_details.h"
#include "access/itup.h"
-#include "access/tuptoaster.h"
+#include "access/toast_internals.h"
+/*
+ * This enables de-toasting of index entries. Needed until VACUUM is
+ * smart enough to rebuild indexes from scratch.
+ */
+#define TOAST_INDEX_HACK
/* ----------------------------------------------------------------
* index_ tuple interface routines
#include "access/gist_private.h"
#include "access/hash.h"
+#include "access/heaptoast.h"
#include "access/htup_details.h"
#include "access/nbtree.h"
#include "access/reloptions.h"
#include "access/spgist.h"
-#include "access/tuptoaster.h"
#include "catalog/pg_type.h"
#include "commands/defrem.h"
#include "commands/tablespace.h"
--- /dev/null
+/*-------------------------------------------------------------------------
+ *
+ * toast_internals.c
+ * Functions for internal use by the TOAST system.
+ *
+ * Copyright (c) 2000-2019, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ * src/backend/access/common/toast_internals.c
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "access/detoast.h"
+#include "access/genam.h"
+#include "access/heapam.h"
+#include "access/heaptoast.h"
+#include "access/table.h"
+#include "access/toast_internals.h"
+#include "access/xact.h"
+#include "catalog/catalog.h"
+#include "common/pg_lzcompress.h"
+#include "miscadmin.h"
+#include "utils/fmgroids.h"
+#include "utils/rel.h"
+#include "utils/snapmgr.h"
+
+static bool toastrel_valueid_exists(Relation toastrel, Oid valueid);
+static bool toastid_valueid_exists(Oid toastrelid, Oid valueid);
+
+/* ----------
+ * toast_compress_datum -
+ *
+ * Create a compressed version of a varlena datum
+ *
+ * If we fail (ie, compressed result is actually bigger than original)
+ * then return NULL. We must not use compressed data if it'd expand
+ * the tuple!
+ *
+ * We use VAR{SIZE,DATA}_ANY so we can handle short varlenas here without
+ * copying them. But we can't handle external or compressed datums.
+ * ----------
+ */
+Datum
+toast_compress_datum(Datum value)
+{
+ struct varlena *tmp;
+ int32 valsize = VARSIZE_ANY_EXHDR(DatumGetPointer(value));
+ int32 len;
+
+ Assert(!VARATT_IS_EXTERNAL(DatumGetPointer(value)));
+ Assert(!VARATT_IS_COMPRESSED(DatumGetPointer(value)));
+
+ /*
+ * No point in wasting a palloc cycle if value size is out of the allowed
+ * range for compression
+ */
+ if (valsize < PGLZ_strategy_default->min_input_size ||
+ valsize > PGLZ_strategy_default->max_input_size)
+ return PointerGetDatum(NULL);
+
+ tmp = (struct varlena *) palloc(PGLZ_MAX_OUTPUT(valsize) +
+ TOAST_COMPRESS_HDRSZ);
+
+ /*
+ * We recheck the actual size even if pglz_compress() reports success,
+ * because it might be satisfied with having saved as little as one byte
+ * in the compressed data --- which could turn into a net loss once you
+ * consider header and alignment padding. Worst case, the compressed
+ * format might require three padding bytes (plus header, which is
+ * included in VARSIZE(tmp)), whereas the uncompressed format would take
+ * only one header byte and no padding if the value is short enough. So
+ * we insist on a savings of more than 2 bytes to ensure we have a gain.
+ */
+ len = pglz_compress(VARDATA_ANY(DatumGetPointer(value)),
+ valsize,
+ TOAST_COMPRESS_RAWDATA(tmp),
+ PGLZ_strategy_default);
+ if (len >= 0 &&
+ len + TOAST_COMPRESS_HDRSZ < valsize - 2)
+ {
+ TOAST_COMPRESS_SET_RAWSIZE(tmp, valsize);
+ SET_VARSIZE_COMPRESSED(tmp, len + TOAST_COMPRESS_HDRSZ);
+ /* successful compression */
+ return PointerGetDatum(tmp);
+ }
+ else
+ {
+ /* incompressible data */
+ pfree(tmp);
+ return PointerGetDatum(NULL);
+ }
+}
+
+/* ----------
+ * toast_save_datum -
+ *
+ * Save one single datum into the secondary relation and return
+ * a Datum reference for it.
+ *
+ * rel: the main relation we're working with (not the toast rel!)
+ * value: datum to be pushed to toast storage
+ * oldexternal: if not NULL, toast pointer previously representing the datum
+ * options: options to be passed to heap_insert() for toast rows
+ * ----------
+ */
+Datum
+toast_save_datum(Relation rel, Datum value,
+ struct varlena *oldexternal, int options)
+{
+ Relation toastrel;
+ Relation *toastidxs;
+ HeapTuple toasttup;
+ TupleDesc toasttupDesc;
+ Datum t_values[3];
+ bool t_isnull[3];
+ CommandId mycid = GetCurrentCommandId(true);
+ struct varlena *result;
+ struct varatt_external toast_pointer;
+ union
+ {
+ struct varlena hdr;
+ /* this is to make the union big enough for a chunk: */
+ char data[TOAST_MAX_CHUNK_SIZE + VARHDRSZ];
+ /* ensure union is aligned well enough: */
+ int32 align_it;
+ } chunk_data;
+ int32 chunk_size;
+ int32 chunk_seq = 0;
+ char *data_p;
+ int32 data_todo;
+ Pointer dval = DatumGetPointer(value);
+ int num_indexes;
+ int validIndex;
+
+ Assert(!VARATT_IS_EXTERNAL(value));
+
+ /*
+ * Open the toast relation and its indexes. We can use the index to check
+ * uniqueness of the OID we assign to the toasted item, even though it has
+ * additional columns besides OID.
+ */
+ toastrel = table_open(rel->rd_rel->reltoastrelid, RowExclusiveLock);
+ toasttupDesc = toastrel->rd_att;
+
+ /* Open all the toast indexes and look for the valid one */
+ validIndex = toast_open_indexes(toastrel,
+ RowExclusiveLock,
+ &toastidxs,
+ &num_indexes);
+
+ /*
+ * Get the data pointer and length, and compute va_rawsize and va_extsize.
+ *
+ * va_rawsize is the size of the equivalent fully uncompressed datum, so
+ * we have to adjust for short headers.
+ *
+ * va_extsize is the actual size of the data payload in the toast records.
+ */
+ if (VARATT_IS_SHORT(dval))
+ {
+ data_p = VARDATA_SHORT(dval);
+ data_todo = VARSIZE_SHORT(dval) - VARHDRSZ_SHORT;
+ toast_pointer.va_rawsize = data_todo + VARHDRSZ; /* as if not short */
+ toast_pointer.va_extsize = data_todo;
+ }
+ else if (VARATT_IS_COMPRESSED(dval))
+ {
+ data_p = VARDATA(dval);
+ data_todo = VARSIZE(dval) - VARHDRSZ;
+ /* rawsize in a compressed datum is just the size of the payload */
+ toast_pointer.va_rawsize = VARRAWSIZE_4B_C(dval) + VARHDRSZ;
+ toast_pointer.va_extsize = data_todo;
+ /* Assert that the numbers look like it's compressed */
+ Assert(VARATT_EXTERNAL_IS_COMPRESSED(toast_pointer));
+ }
+ else
+ {
+ data_p = VARDATA(dval);
+ data_todo = VARSIZE(dval) - VARHDRSZ;
+ toast_pointer.va_rawsize = VARSIZE(dval);
+ toast_pointer.va_extsize = data_todo;
+ }
+
+ /*
+ * Insert the correct table OID into the result TOAST pointer.
+ *
+ * Normally this is the actual OID of the target toast table, but during
+ * table-rewriting operations such as CLUSTER, we have to insert the OID
+ * of the table's real permanent toast table instead. rd_toastoid is set
+ * if we have to substitute such an OID.
+ */
+ if (OidIsValid(rel->rd_toastoid))
+ toast_pointer.va_toastrelid = rel->rd_toastoid;
+ else
+ toast_pointer.va_toastrelid = RelationGetRelid(toastrel);
+
+ /*
+ * Choose an OID to use as the value ID for this toast value.
+ *
+ * Normally we just choose an unused OID within the toast table. But
+ * during table-rewriting operations where we are preserving an existing
+ * toast table OID, we want to preserve toast value OIDs too. So, if
+ * rd_toastoid is set and we had a prior external value from that same
+ * toast table, re-use its value ID. If we didn't have a prior external
+ * value (which is a corner case, but possible if the table's attstorage
+ * options have been changed), we have to pick a value ID that doesn't
+ * conflict with either new or existing toast value OIDs.
+ */
+ if (!OidIsValid(rel->rd_toastoid))
+ {
+ /* normal case: just choose an unused OID */
+ toast_pointer.va_valueid =
+ GetNewOidWithIndex(toastrel,
+ RelationGetRelid(toastidxs[validIndex]),
+ (AttrNumber) 1);
+ }
+ else
+ {
+ /* rewrite case: check to see if value was in old toast table */
+ toast_pointer.va_valueid = InvalidOid;
+ if (oldexternal != NULL)
+ {
+ struct varatt_external old_toast_pointer;
+
+ Assert(VARATT_IS_EXTERNAL_ONDISK(oldexternal));
+ /* Must copy to access aligned fields */
+ VARATT_EXTERNAL_GET_POINTER(old_toast_pointer, oldexternal);
+ if (old_toast_pointer.va_toastrelid == rel->rd_toastoid)
+ {
+ /* This value came from the old toast table; reuse its OID */
+ toast_pointer.va_valueid = old_toast_pointer.va_valueid;
+
+ /*
+ * There is a corner case here: the table rewrite might have
+ * to copy both live and recently-dead versions of a row, and
+ * those versions could easily reference the same toast value.
+ * When we copy the second or later version of such a row,
+ * reusing the OID will mean we select an OID that's already
+ * in the new toast table. Check for that, and if so, just
+ * fall through without writing the data again.
+ *
+ * While annoying and ugly-looking, this is a good thing
+ * because it ensures that we wind up with only one copy of
+ * the toast value when there is only one copy in the old
+ * toast table. Before we detected this case, we'd have made
+ * multiple copies, wasting space; and what's worse, the
+ * copies belonging to already-deleted heap tuples would not
+ * be reclaimed by VACUUM.
+ */
+ if (toastrel_valueid_exists(toastrel,
+ toast_pointer.va_valueid))
+ {
+ /* Match, so short-circuit the data storage loop below */
+ data_todo = 0;
+ }
+ }
+ }
+ if (toast_pointer.va_valueid == InvalidOid)
+ {
+ /*
+ * new value; must choose an OID that doesn't conflict in either
+ * old or new toast table
+ */
+ do
+ {
+ toast_pointer.va_valueid =
+ GetNewOidWithIndex(toastrel,
+ RelationGetRelid(toastidxs[validIndex]),
+ (AttrNumber) 1);
+ } while (toastid_valueid_exists(rel->rd_toastoid,
+ toast_pointer.va_valueid));
+ }
+ }
+
+ /*
+ * Initialize constant parts of the tuple data
+ */
+ t_values[0] = ObjectIdGetDatum(toast_pointer.va_valueid);
+ t_values[2] = PointerGetDatum(&chunk_data);
+ t_isnull[0] = false;
+ t_isnull[1] = false;
+ t_isnull[2] = false;
+
+ /*
+ * Split up the item into chunks
+ */
+ while (data_todo > 0)
+ {
+ int i;
+
+ CHECK_FOR_INTERRUPTS();
+
+ /*
+ * Calculate the size of this chunk
+ */
+ chunk_size = Min(TOAST_MAX_CHUNK_SIZE, data_todo);
+
+ /*
+ * Build a tuple and store it
+ */
+ t_values[1] = Int32GetDatum(chunk_seq++);
+ SET_VARSIZE(&chunk_data, chunk_size + VARHDRSZ);
+ memcpy(VARDATA(&chunk_data), data_p, chunk_size);
+ toasttup = heap_form_tuple(toasttupDesc, t_values, t_isnull);
+
+ heap_insert(toastrel, toasttup, mycid, options, NULL);
+
+ /*
+ * Create the index entry. We cheat a little here by not using
+ * FormIndexDatum: this relies on the knowledge that the index columns
+ * are the same as the initial columns of the table for all the
+ * indexes. We also cheat by not providing an IndexInfo: this is okay
+ * for now because btree doesn't need one, but we might have to be
+ * more honest someday.
+ *
+ * Note also that there had better not be any user-created index on
+ * the TOAST table, since we don't bother to update anything else.
+ */
+ for (i = 0; i < num_indexes; i++)
+ {
+ /* Only index relations marked as ready can be updated */
+ if (toastidxs[i]->rd_index->indisready)
+ index_insert(toastidxs[i], t_values, t_isnull,
+ &(toasttup->t_self),
+ toastrel,
+ toastidxs[i]->rd_index->indisunique ?
+ UNIQUE_CHECK_YES : UNIQUE_CHECK_NO,
+ NULL);
+ }
+
+ /*
+ * Free memory
+ */
+ heap_freetuple(toasttup);
+
+ /*
+ * Move on to next chunk
+ */
+ data_todo -= chunk_size;
+ data_p += chunk_size;
+ }
+
+ /*
+ * Done - close toast relation and its indexes
+ */
+ toast_close_indexes(toastidxs, num_indexes, RowExclusiveLock);
+ table_close(toastrel, RowExclusiveLock);
+
+ /*
+ * Create the TOAST pointer value that we'll return
+ */
+ result = (struct varlena *) palloc(TOAST_POINTER_SIZE);
+ SET_VARTAG_EXTERNAL(result, VARTAG_ONDISK);
+ memcpy(VARDATA_EXTERNAL(result), &toast_pointer, sizeof(toast_pointer));
+
+ return PointerGetDatum(result);
+}
+
+/* ----------
+ * toast_delete_datum -
+ *
+ * Delete a single external stored value.
+ * ----------
+ */
+void
+toast_delete_datum(Relation rel, Datum value, bool is_speculative)
+{
+ struct varlena *attr = (struct varlena *) DatumGetPointer(value);
+ struct varatt_external toast_pointer;
+ Relation toastrel;
+ Relation *toastidxs;
+ ScanKeyData toastkey;
+ SysScanDesc toastscan;
+ HeapTuple toasttup;
+ int num_indexes;
+ int validIndex;
+ SnapshotData SnapshotToast;
+
+ if (!VARATT_IS_EXTERNAL_ONDISK(attr))
+ return;
+
+ /* Must copy to access aligned fields */
+ VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);
+
+ /*
+ * Open the toast relation and its indexes
+ */
+ toastrel = table_open(toast_pointer.va_toastrelid, RowExclusiveLock);
+
+ /* Fetch valid relation used for process */
+ validIndex = toast_open_indexes(toastrel,
+ RowExclusiveLock,
+ &toastidxs,
+ &num_indexes);
+
+ /*
+ * Setup a scan key to find chunks with matching va_valueid
+ */
+ ScanKeyInit(&toastkey,
+ (AttrNumber) 1,
+ BTEqualStrategyNumber, F_OIDEQ,
+ ObjectIdGetDatum(toast_pointer.va_valueid));
+
+ /*
+ * Find all the chunks. (We don't actually care whether we see them in
+ * sequence or not, but since we've already locked the index we might as
+ * well use systable_beginscan_ordered.)
+ */
+ init_toast_snapshot(&SnapshotToast);
+ toastscan = systable_beginscan_ordered(toastrel, toastidxs[validIndex],
+ &SnapshotToast, 1, &toastkey);
+ while ((toasttup = systable_getnext_ordered(toastscan, ForwardScanDirection)) != NULL)
+ {
+ /*
+ * Have a chunk, delete it
+ */
+ if (is_speculative)
+ heap_abort_speculative(toastrel, &toasttup->t_self);
+ else
+ simple_heap_delete(toastrel, &toasttup->t_self);
+ }
+
+ /*
+ * End scan and close relations
+ */
+ systable_endscan_ordered(toastscan);
+ toast_close_indexes(toastidxs, num_indexes, RowExclusiveLock);
+ table_close(toastrel, RowExclusiveLock);
+}
+
+/* ----------
+ * toastrel_valueid_exists -
+ *
+ * Test whether a toast value with the given ID exists in the toast relation.
+ * For safety, we consider a value to exist if there are either live or dead
+ * toast rows with that ID; see notes for GetNewOidWithIndex().
+ * ----------
+ */
+static bool
+toastrel_valueid_exists(Relation toastrel, Oid valueid)
+{
+ bool result = false;
+ ScanKeyData toastkey;
+ SysScanDesc toastscan;
+ int num_indexes;
+ int validIndex;
+ Relation *toastidxs;
+
+ /* Fetch a valid index relation */
+ validIndex = toast_open_indexes(toastrel,
+ RowExclusiveLock,
+ &toastidxs,
+ &num_indexes);
+
+ /*
+ * Setup a scan key to find chunks with matching va_valueid
+ */
+ ScanKeyInit(&toastkey,
+ (AttrNumber) 1,
+ BTEqualStrategyNumber, F_OIDEQ,
+ ObjectIdGetDatum(valueid));
+
+ /*
+ * Is there any such chunk?
+ */
+ toastscan = systable_beginscan(toastrel,
+ RelationGetRelid(toastidxs[validIndex]),
+ true, SnapshotAny, 1, &toastkey);
+
+ if (systable_getnext(toastscan) != NULL)
+ result = true;
+
+ systable_endscan(toastscan);
+
+ /* Clean up */
+ toast_close_indexes(toastidxs, num_indexes, RowExclusiveLock);
+
+ return result;
+}
+
+/* ----------
+ * toastid_valueid_exists -
+ *
+ * As above, but work from toast rel's OID not an open relation
+ * ----------
+ */
+static bool
+toastid_valueid_exists(Oid toastrelid, Oid valueid)
+{
+ bool result;
+ Relation toastrel;
+
+ toastrel = table_open(toastrelid, AccessShareLock);
+
+ result = toastrel_valueid_exists(toastrel, valueid);
+
+ table_close(toastrel, AccessShareLock);
+
+ return result;
+}
+
+/* ----------
+ * toast_get_valid_index
+ *
+ * Get OID of valid index associated to given toast relation. A toast
+ * relation can have only one valid index at the same time.
+ */
+Oid
+toast_get_valid_index(Oid toastoid, LOCKMODE lock)
+{
+ int num_indexes;
+ int validIndex;
+ Oid validIndexOid;
+ Relation *toastidxs;
+ Relation toastrel;
+
+ /* Open the toast relation */
+ toastrel = table_open(toastoid, lock);
+
+ /* Look for the valid index of the toast relation */
+ validIndex = toast_open_indexes(toastrel,
+ lock,
+ &toastidxs,
+ &num_indexes);
+ validIndexOid = RelationGetRelid(toastidxs[validIndex]);
+
+ /* Close the toast relation and all its indexes */
+ toast_close_indexes(toastidxs, num_indexes, lock);
+ table_close(toastrel, lock);
+
+ return validIndexOid;
+}
+
+/* ----------
+ * toast_open_indexes
+ *
+ * Get an array of the indexes associated to the given toast relation
+ * and return as well the position of the valid index used by the toast
+ * relation in this array. It is the responsibility of the caller of this
+ * function to close the indexes as well as free them.
+ */
+int
+toast_open_indexes(Relation toastrel,
+ LOCKMODE lock,
+ Relation **toastidxs,
+ int *num_indexes)
+{
+ int i = 0;
+ int res = 0;
+ bool found = false;
+ List *indexlist;
+ ListCell *lc;
+
+ /* Get index list of the toast relation */
+ indexlist = RelationGetIndexList(toastrel);
+ Assert(indexlist != NIL);
+
+ *num_indexes = list_length(indexlist);
+
+ /* Open all the index relations */
+ *toastidxs = (Relation *) palloc(*num_indexes * sizeof(Relation));
+ foreach(lc, indexlist)
+ (*toastidxs)[i++] = index_open(lfirst_oid(lc), lock);
+
+ /* Fetch the first valid index in list */
+ for (i = 0; i < *num_indexes; i++)
+ {
+ Relation toastidx = (*toastidxs)[i];
+
+ if (toastidx->rd_index->indisvalid)
+ {
+ res = i;
+ found = true;
+ break;
+ }
+ }
+
+ /*
+ * Free index list, not necessary anymore as relations are opened and a
+ * valid index has been found.
+ */
+ list_free(indexlist);
+
+ /*
+ * The toast relation should have one valid index, so something is going
+ * wrong if there is nothing.
+ */
+ if (!found)
+ elog(ERROR, "no valid index found for toast relation with Oid %u",
+ RelationGetRelid(toastrel));
+
+ return res;
+}
+
+/* ----------
+ * toast_close_indexes
+ *
+ * Close an array of indexes for a toast relation and free it. This should
+ * be called for a set of indexes opened previously with toast_open_indexes.
+ */
+void
+toast_close_indexes(Relation *toastidxs, int num_indexes, LOCKMODE lock)
+{
+ int i;
+
+ /* Close relations and clean up things */
+ for (i = 0; i < num_indexes; i++)
+ index_close(toastidxs[i], lock);
+ pfree(toastidxs);
+}
+
+/* ----------
+ * init_toast_snapshot
+ *
+ * Initialize an appropriate TOAST snapshot. We must use an MVCC snapshot
+ * to initialize the TOAST snapshot; since we don't know which one to use,
+ * just use the oldest one. This is safe: at worst, we will get a "snapshot
+ * too old" error that might have been avoided otherwise.
+ */
+void
+init_toast_snapshot(Snapshot toast_snapshot)
+{
+ Snapshot snapshot = GetOldestSnapshot();
+
+ if (snapshot == NULL)
+ elog(ERROR, "no known snapshots");
+
+ InitToastSnapshot(*toast_snapshot, snapshot->lsn, snapshot->whenTaken);
+}
include $(top_builddir)/src/Makefile.global
OBJS = heapam.o heapam_handler.o heapam_visibility.o hio.o pruneheap.o rewriteheap.o \
- syncscan.o tuptoaster.o vacuumlazy.o visibilitymap.o
+ syncscan.o heaptoast.o vacuumlazy.o visibilitymap.o
include $(top_srcdir)/src/backend/common.mk
#include "access/genam.h"
#include "access/heapam.h"
#include "access/heapam_xlog.h"
+#include "access/heaptoast.h"
#include "access/hio.h"
#include "access/multixact.h"
#include "access/parallel.h"
#include "access/sysattr.h"
#include "access/tableam.h"
#include "access/transam.h"
-#include "access/tuptoaster.h"
#include "access/valid.h"
#include "access/visibilitymap.h"
#include "access/xact.h"
#include "access/genam.h"
#include "access/heapam.h"
+#include "access/heaptoast.h"
#include "access/multixact.h"
#include "access/rewriteheap.h"
#include "access/tableam.h"
#include "access/tsmapi.h"
-#include "access/tuptoaster.h"
#include "access/xact.h"
#include "catalog/catalog.h"
#include "catalog/index.h"
--- /dev/null
+/*-------------------------------------------------------------------------
+ *
+ * heaptoast.c
+ * Heap-specific definitions for external and compressed storage
+ * of variable size attributes.
+ *
+ * Copyright (c) 2000-2019, PostgreSQL Global Development Group
+ *
+ *
+ * IDENTIFICATION
+ * src/backend/access/heap/heaptoast.c
+ *
+ *
+ * INTERFACE ROUTINES
+ * toast_insert_or_update -
+ * Try to make a given tuple fit into one page by compressing
+ * or moving off attributes
+ *
+ * toast_delete -
+ * Reclaim toast storage when a tuple is deleted
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "postgres.h"
+
+#include "access/detoast.h"
+#include "access/heapam.h"
+#include "access/heaptoast.h"
+#include "access/toast_internals.h"
+
+
+/* ----------
+ * toast_delete -
+ *
+ * Cascaded delete toast-entries on DELETE
+ * ----------
+ */
+void
+toast_delete(Relation rel, HeapTuple oldtup, bool is_speculative)
+{
+ TupleDesc tupleDesc;
+ int numAttrs;
+ int i;
+ Datum toast_values[MaxHeapAttributeNumber];
+ bool toast_isnull[MaxHeapAttributeNumber];
+
+ /*
+ * We should only ever be called for tuples of plain relations or
+ * materialized views --- recursing on a toast rel is bad news.
+ */
+ Assert(rel->rd_rel->relkind == RELKIND_RELATION ||
+ rel->rd_rel->relkind == RELKIND_MATVIEW);
+
+ /*
+ * Get the tuple descriptor and break down the tuple into fields.
+ *
+ * NOTE: it's debatable whether to use heap_deform_tuple() here or just
+ * heap_getattr() only the varlena columns. The latter could win if there
+ * are few varlena columns and many non-varlena ones. However,
+ * heap_deform_tuple costs only O(N) while the heap_getattr way would cost
+ * O(N^2) if there are many varlena columns, so it seems better to err on
+ * the side of linear cost. (We won't even be here unless there's at
+ * least one varlena column, by the way.)
+ */
+ tupleDesc = rel->rd_att;
+ numAttrs = tupleDesc->natts;
+
+ Assert(numAttrs <= MaxHeapAttributeNumber);
+ heap_deform_tuple(oldtup, tupleDesc, toast_values, toast_isnull);
+
+ /*
+ * Check for external stored attributes and delete them from the secondary
+ * relation.
+ */
+ for (i = 0; i < numAttrs; i++)
+ {
+ if (TupleDescAttr(tupleDesc, i)->attlen == -1)
+ {
+ Datum value = toast_values[i];
+
+ if (toast_isnull[i])
+ continue;
+ else if (VARATT_IS_EXTERNAL_ONDISK(PointerGetDatum(value)))
+ toast_delete_datum(rel, value, is_speculative);
+ }
+ }
+}
+
+
+/* ----------
+ * toast_insert_or_update -
+ *
+ * Delete no-longer-used toast-entries and create new ones to
+ * make the new tuple fit on INSERT or UPDATE
+ *
+ * Inputs:
+ * newtup: the candidate new tuple to be inserted
+ * oldtup: the old row version for UPDATE, or NULL for INSERT
+ * options: options to be passed to heap_insert() for toast rows
+ * Result:
+ * either newtup if no toasting is needed, or a palloc'd modified tuple
+ * that is what should actually get stored
+ *
+ * NOTE: neither newtup nor oldtup will be modified. This is a change
+ * from the pre-8.1 API of this routine.
+ * ----------
+ */
+HeapTuple
+toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup,
+ int options)
+{
+ HeapTuple result_tuple;
+ TupleDesc tupleDesc;
+ int numAttrs;
+ int i;
+
+ bool need_change = false;
+ bool need_free = false;
+ bool need_delold = false;
+ bool has_nulls = false;
+
+ Size maxDataLen;
+ Size hoff;
+
+ char toast_action[MaxHeapAttributeNumber];
+ bool toast_isnull[MaxHeapAttributeNumber];
+ bool toast_oldisnull[MaxHeapAttributeNumber];
+ Datum toast_values[MaxHeapAttributeNumber];
+ Datum toast_oldvalues[MaxHeapAttributeNumber];
+ struct varlena *toast_oldexternal[MaxHeapAttributeNumber];
+ int32 toast_sizes[MaxHeapAttributeNumber];
+ bool toast_free[MaxHeapAttributeNumber];
+ bool toast_delold[MaxHeapAttributeNumber];
+
+ /*
+ * Ignore the INSERT_SPECULATIVE option. Speculative insertions/super
+ * deletions just normally insert/delete the toast values. It seems
+ * easiest to deal with that here, instead on, potentially, multiple
+ * callers.
+ */
+ options &= ~HEAP_INSERT_SPECULATIVE;
+
+ /*
+ * We should only ever be called for tuples of plain relations or
+ * materialized views --- recursing on a toast rel is bad news.
+ */
+ Assert(rel->rd_rel->relkind == RELKIND_RELATION ||
+ rel->rd_rel->relkind == RELKIND_MATVIEW);
+
+ /*
+ * Get the tuple descriptor and break down the tuple(s) into fields.
+ */
+ tupleDesc = rel->rd_att;
+ numAttrs = tupleDesc->natts;
+
+ Assert(numAttrs <= MaxHeapAttributeNumber);
+ heap_deform_tuple(newtup, tupleDesc, toast_values, toast_isnull);
+ if (oldtup != NULL)
+ heap_deform_tuple(oldtup, tupleDesc, toast_oldvalues, toast_oldisnull);
+
+ /* ----------
+ * Then collect information about the values given
+ *
+ * NOTE: toast_action[i] can have these values:
+ * ' ' default handling
+ * 'p' already processed --- don't touch it
+ * 'x' incompressible, but OK to move off
+ *
+ * NOTE: toast_sizes[i] is only made valid for varlena attributes with
+ * toast_action[i] different from 'p'.
+ * ----------
+ */
+ memset(toast_action, ' ', numAttrs * sizeof(char));
+ memset(toast_oldexternal, 0, numAttrs * sizeof(struct varlena *));
+ memset(toast_free, 0, numAttrs * sizeof(bool));
+ memset(toast_delold, 0, numAttrs * sizeof(bool));
+
+ for (i = 0; i < numAttrs; i++)
+ {
+ Form_pg_attribute att = TupleDescAttr(tupleDesc, i);
+ struct varlena *old_value;
+ struct varlena *new_value;
+
+ if (oldtup != NULL)
+ {
+ /*
+ * For UPDATE get the old and new values of this attribute
+ */
+ old_value = (struct varlena *) DatumGetPointer(toast_oldvalues[i]);
+ new_value = (struct varlena *) DatumGetPointer(toast_values[i]);
+
+ /*
+ * If the old value is stored on disk, check if it has changed so
+ * we have to delete it later.
+ */
+ if (att->attlen == -1 && !toast_oldisnull[i] &&
+ VARATT_IS_EXTERNAL_ONDISK(old_value))
+ {
+ if (toast_isnull[i] || !VARATT_IS_EXTERNAL_ONDISK(new_value) ||
+ memcmp((char *) old_value, (char *) new_value,
+ VARSIZE_EXTERNAL(old_value)) != 0)
+ {
+ /*
+ * The old external stored value isn't needed any more
+ * after the update
+ */
+ toast_delold[i] = true;
+ need_delold = true;
+ }
+ else
+ {
+ /*
+ * This attribute isn't changed by this update so we reuse
+ * the original reference to the old value in the new
+ * tuple.
+ */
+ toast_action[i] = 'p';
+ continue;
+ }
+ }
+ }
+ else
+ {
+ /*
+ * For INSERT simply get the new value
+ */
+ new_value = (struct varlena *) DatumGetPointer(toast_values[i]);
+ }
+
+ /*
+ * Handle NULL attributes
+ */
+ if (toast_isnull[i])
+ {
+ toast_action[i] = 'p';
+ has_nulls = true;
+ continue;
+ }
+
+ /*
+ * Now look at varlena attributes
+ */
+ if (att->attlen == -1)
+ {
+ /*
+ * If the table's attribute says PLAIN always, force it so.
+ */
+ if (att->attstorage == 'p')
+ toast_action[i] = 'p';
+
+ /*
+ * We took care of UPDATE above, so any external value we find
+ * still in the tuple must be someone else's that we cannot reuse
+ * (this includes the case of an out-of-line in-memory datum).
+ * Fetch it back (without decompression, unless we are forcing
+ * PLAIN storage). If necessary, we'll push it out as a new
+ * external value below.
+ */
+ if (VARATT_IS_EXTERNAL(new_value))
+ {
+ toast_oldexternal[i] = new_value;
+ if (att->attstorage == 'p')
+ new_value = heap_tuple_untoast_attr(new_value);
+ else
+ new_value = heap_tuple_fetch_attr(new_value);
+ toast_values[i] = PointerGetDatum(new_value);
+ toast_free[i] = true;
+ need_change = true;
+ need_free = true;
+ }
+
+ /*
+ * Remember the size of this attribute
+ */
+ toast_sizes[i] = VARSIZE_ANY(new_value);
+ }
+ else
+ {
+ /*
+ * Not a varlena attribute, plain storage always
+ */
+ toast_action[i] = 'p';
+ }
+ }
+
+ /* ----------
+ * Compress and/or save external until data fits into target length
+ *
+ * 1: Inline compress attributes with attstorage 'x', and store very
+ * large attributes with attstorage 'x' or 'e' external immediately
+ * 2: Store attributes with attstorage 'x' or 'e' external
+ * 3: Inline compress attributes with attstorage 'm'
+ * 4: Store attributes with attstorage 'm' external
+ * ----------
+ */
+
+ /* compute header overhead --- this should match heap_form_tuple() */
+ hoff = SizeofHeapTupleHeader;
+ if (has_nulls)
+ hoff += BITMAPLEN(numAttrs);
+ hoff = MAXALIGN(hoff);
+ /* now convert to a limit on the tuple data size */
+ maxDataLen = RelationGetToastTupleTarget(rel, TOAST_TUPLE_TARGET) - hoff;
+
+ /*
+ * Look for attributes with attstorage 'x' to compress. Also find large
+ * attributes with attstorage 'x' or 'e', and store them external.
+ */
+ while (heap_compute_data_size(tupleDesc,
+ toast_values, toast_isnull) > maxDataLen)
+ {
+ int biggest_attno = -1;
+ int32 biggest_size = MAXALIGN(TOAST_POINTER_SIZE);
+ Datum old_value;
+ Datum new_value;
+
+ /*
+ * Search for the biggest yet unprocessed internal attribute
+ */
+ for (i = 0; i < numAttrs; i++)
+ {
+ Form_pg_attribute att = TupleDescAttr(tupleDesc, i);
+
+ if (toast_action[i] != ' ')
+ continue;
+ if (VARATT_IS_EXTERNAL(DatumGetPointer(toast_values[i])))
+ continue; /* can't happen, toast_action would be 'p' */
+ if (VARATT_IS_COMPRESSED(DatumGetPointer(toast_values[i])))
+ continue;
+ if (att->attstorage != 'x' && att->attstorage != 'e')
+ continue;
+ if (toast_sizes[i] > biggest_size)
+ {
+ biggest_attno = i;
+ biggest_size = toast_sizes[i];
+ }
+ }
+
+ if (biggest_attno < 0)
+ break;
+
+ /*
+ * Attempt to compress it inline, if it has attstorage 'x'
+ */
+ i = biggest_attno;
+ if (TupleDescAttr(tupleDesc, i)->attstorage == 'x')
+ {
+ old_value = toast_values[i];
+ new_value = toast_compress_datum(old_value);
+
+ if (DatumGetPointer(new_value) != NULL)
+ {
+ /* successful compression */
+ if (toast_free[i])
+ pfree(DatumGetPointer(old_value));
+ toast_values[i] = new_value;
+ toast_free[i] = true;
+ toast_sizes[i] = VARSIZE(DatumGetPointer(toast_values[i]));
+ need_change = true;
+ need_free = true;
+ }
+ else
+ {
+ /* incompressible, ignore on subsequent compression passes */
+ toast_action[i] = 'x';
+ }
+ }
+ else
+ {
+ /* has attstorage 'e', ignore on subsequent compression passes */
+ toast_action[i] = 'x';
+ }
+
+ /*
+ * If this value is by itself more than maxDataLen (after compression
+ * if any), push it out to the toast table immediately, if possible.
+ * This avoids uselessly compressing other fields in the common case
+ * where we have one long field and several short ones.
+ *
+ * XXX maybe the threshold should be less than maxDataLen?
+ */
+ if (toast_sizes[i] > maxDataLen &&
+ rel->rd_rel->reltoastrelid != InvalidOid)
+ {
+ old_value = toast_values[i];
+ toast_action[i] = 'p';
+ toast_values[i] = toast_save_datum(rel, toast_values[i],
+ toast_oldexternal[i], options);
+ if (toast_free[i])
+ pfree(DatumGetPointer(old_value));
+ toast_free[i] = true;
+ need_change = true;
+ need_free = true;
+ }
+ }
+
+ /*
+ * Second we look for attributes of attstorage 'x' or 'e' that are still
+ * inline. But skip this if there's no toast table to push them to.
+ */
+ while (heap_compute_data_size(tupleDesc,
+ toast_values, toast_isnull) > maxDataLen &&
+ rel->rd_rel->reltoastrelid != InvalidOid)
+ {
+ int biggest_attno = -1;
+ int32 biggest_size = MAXALIGN(TOAST_POINTER_SIZE);
+ Datum old_value;
+
+ /*------
+ * Search for the biggest yet inlined attribute with
+ * attstorage equals 'x' or 'e'
+ *------
+ */
+ for (i = 0; i < numAttrs; i++)
+ {
+ Form_pg_attribute att = TupleDescAttr(tupleDesc, i);
+
+ if (toast_action[i] == 'p')
+ continue;
+ if (VARATT_IS_EXTERNAL(DatumGetPointer(toast_values[i])))
+ continue; /* can't happen, toast_action would be 'p' */
+ if (att->attstorage != 'x' && att->attstorage != 'e')
+ continue;
+ if (toast_sizes[i] > biggest_size)
+ {
+ biggest_attno = i;
+ biggest_size = toast_sizes[i];
+ }
+ }
+
+ if (biggest_attno < 0)
+ break;
+
+ /*
+ * Store this external
+ */
+ i = biggest_attno;
+ old_value = toast_values[i];
+ toast_action[i] = 'p';
+ toast_values[i] = toast_save_datum(rel, toast_values[i],
+ toast_oldexternal[i], options);
+ if (toast_free[i])
+ pfree(DatumGetPointer(old_value));
+ toast_free[i] = true;
+
+ need_change = true;
+ need_free = true;
+ }
+
+ /*
+ * Round 3 - this time we take attributes with storage 'm' into
+ * compression
+ */
+ while (heap_compute_data_size(tupleDesc,
+ toast_values, toast_isnull) > maxDataLen)
+ {
+ int biggest_attno = -1;
+ int32 biggest_size = MAXALIGN(TOAST_POINTER_SIZE);
+ Datum old_value;
+ Datum new_value;
+
+ /*
+ * Search for the biggest yet uncompressed internal attribute
+ */
+ for (i = 0; i < numAttrs; i++)
+ {
+ if (toast_action[i] != ' ')
+ continue;
+ if (VARATT_IS_EXTERNAL(DatumGetPointer(toast_values[i])))
+ continue; /* can't happen, toast_action would be 'p' */
+ if (VARATT_IS_COMPRESSED(DatumGetPointer(toast_values[i])))
+ continue;
+ if (TupleDescAttr(tupleDesc, i)->attstorage != 'm')
+ continue;
+ if (toast_sizes[i] > biggest_size)
+ {
+ biggest_attno = i;
+ biggest_size = toast_sizes[i];
+ }
+ }
+
+ if (biggest_attno < 0)
+ break;
+
+ /*
+ * Attempt to compress it inline
+ */
+ i = biggest_attno;
+ old_value = toast_values[i];
+ new_value = toast_compress_datum(old_value);
+
+ if (DatumGetPointer(new_value) != NULL)
+ {
+ /* successful compression */
+ if (toast_free[i])
+ pfree(DatumGetPointer(old_value));
+ toast_values[i] = new_value;
+ toast_free[i] = true;
+ toast_sizes[i] = VARSIZE(DatumGetPointer(toast_values[i]));
+ need_change = true;
+ need_free = true;
+ }
+ else
+ {
+ /* incompressible, ignore on subsequent compression passes */
+ toast_action[i] = 'x';
+ }
+ }
+
+ /*
+ * Finally we store attributes of type 'm' externally. At this point we
+ * increase the target tuple size, so that 'm' attributes aren't stored
+ * externally unless really necessary.
+ */
+ maxDataLen = TOAST_TUPLE_TARGET_MAIN - hoff;
+
+ while (heap_compute_data_size(tupleDesc,
+ toast_values, toast_isnull) > maxDataLen &&
+ rel->rd_rel->reltoastrelid != InvalidOid)
+ {
+ int biggest_attno = -1;
+ int32 biggest_size = MAXALIGN(TOAST_POINTER_SIZE);
+ Datum old_value;
+
+ /*--------
+ * Search for the biggest yet inlined attribute with
+ * attstorage = 'm'
+ *--------
+ */
+ for (i = 0; i < numAttrs; i++)
+ {
+ if (toast_action[i] == 'p')
+ continue;
+ if (VARATT_IS_EXTERNAL(DatumGetPointer(toast_values[i])))
+ continue; /* can't happen, toast_action would be 'p' */
+ if (TupleDescAttr(tupleDesc, i)->attstorage != 'm')
+ continue;
+ if (toast_sizes[i] > biggest_size)
+ {
+ biggest_attno = i;
+ biggest_size = toast_sizes[i];
+ }
+ }
+
+ if (biggest_attno < 0)
+ break;
+
+ /*
+ * Store this external
+ */
+ i = biggest_attno;
+ old_value = toast_values[i];
+ toast_action[i] = 'p';
+ toast_values[i] = toast_save_datum(rel, toast_values[i],
+ toast_oldexternal[i], options);
+ if (toast_free[i])
+ pfree(DatumGetPointer(old_value));
+ toast_free[i] = true;
+
+ need_change = true;
+ need_free = true;
+ }
+
+ /*
+ * In the case we toasted any values, we need to build a new heap tuple
+ * with the changed values.
+ */
+ if (need_change)
+ {
+ HeapTupleHeader olddata = newtup->t_data;
+ HeapTupleHeader new_data;
+ int32 new_header_len;
+ int32 new_data_len;
+ int32 new_tuple_len;
+
+ /*
+ * Calculate the new size of the tuple.
+ *
+ * Note: we used to assume here that the old tuple's t_hoff must equal
+ * the new_header_len value, but that was incorrect. The old tuple
+ * might have a smaller-than-current natts, if there's been an ALTER
+ * TABLE ADD COLUMN since it was stored; and that would lead to a
+ * different conclusion about the size of the null bitmap, or even
+ * whether there needs to be one at all.
+ */
+ new_header_len = SizeofHeapTupleHeader;
+ if (has_nulls)
+ new_header_len += BITMAPLEN(numAttrs);
+ new_header_len = MAXALIGN(new_header_len);
+ new_data_len = heap_compute_data_size(tupleDesc,
+ toast_values, toast_isnull);
+ new_tuple_len = new_header_len + new_data_len;
+
+ /*
+ * Allocate and zero the space needed, and fill HeapTupleData fields.
+ */
+ result_tuple = (HeapTuple) palloc0(HEAPTUPLESIZE + new_tuple_len);
+ result_tuple->t_len = new_tuple_len;
+ result_tuple->t_self = newtup->t_self;
+ result_tuple->t_tableOid = newtup->t_tableOid;
+ new_data = (HeapTupleHeader) ((char *) result_tuple + HEAPTUPLESIZE);
+ result_tuple->t_data = new_data;
+
+ /*
+ * Copy the existing tuple header, but adjust natts and t_hoff.
+ */
+ memcpy(new_data, olddata, SizeofHeapTupleHeader);
+ HeapTupleHeaderSetNatts(new_data, numAttrs);
+ new_data->t_hoff = new_header_len;
+
+ /* Copy over the data, and fill the null bitmap if needed */
+ heap_fill_tuple(tupleDesc,
+ toast_values,
+ toast_isnull,
+ (char *) new_data + new_header_len,
+ new_data_len,
+ &(new_data->t_infomask),
+ has_nulls ? new_data->t_bits : NULL);
+ }
+ else
+ result_tuple = newtup;
+
+ /*
+ * Free allocated temp values
+ */
+ if (need_free)
+ for (i = 0; i < numAttrs; i++)
+ if (toast_free[i])
+ pfree(DatumGetPointer(toast_values[i]));
+
+ /*
+ * Delete external values from the old tuple
+ */
+ if (need_delold)
+ for (i = 0; i < numAttrs; i++)
+ if (toast_delold[i])
+ toast_delete_datum(rel, toast_oldvalues[i], false);
+
+ return result_tuple;
+}
+
+
+/* ----------
+ * toast_flatten_tuple -
+ *
+ * "Flatten" a tuple to contain no out-of-line toasted fields.
+ * (This does not eliminate compressed or short-header datums.)
+ *
+ * Note: we expect the caller already checked HeapTupleHasExternal(tup),
+ * so there is no need for a short-circuit path.
+ * ----------
+ */
+HeapTuple
+toast_flatten_tuple(HeapTuple tup, TupleDesc tupleDesc)
+{
+ HeapTuple new_tuple;
+ int numAttrs = tupleDesc->natts;
+ int i;
+ Datum toast_values[MaxTupleAttributeNumber];
+ bool toast_isnull[MaxTupleAttributeNumber];
+ bool toast_free[MaxTupleAttributeNumber];
+
+ /*
+ * Break down the tuple into fields.
+ */
+ Assert(numAttrs <= MaxTupleAttributeNumber);
+ heap_deform_tuple(tup, tupleDesc, toast_values, toast_isnull);
+
+ memset(toast_free, 0, numAttrs * sizeof(bool));
+
+ for (i = 0; i < numAttrs; i++)
+ {
+ /*
+ * Look at non-null varlena attributes
+ */
+ if (!toast_isnull[i] && TupleDescAttr(tupleDesc, i)->attlen == -1)
+ {
+ struct varlena *new_value;
+
+ new_value = (struct varlena *) DatumGetPointer(toast_values[i]);
+ if (VARATT_IS_EXTERNAL(new_value))
+ {
+ new_value = heap_tuple_fetch_attr(new_value);
+ toast_values[i] = PointerGetDatum(new_value);
+ toast_free[i] = true;
+ }
+ }
+ }
+
+ /*
+ * Form the reconfigured tuple.
+ */
+ new_tuple = heap_form_tuple(tupleDesc, toast_values, toast_isnull);
+
+ /*
+ * Be sure to copy the tuple's identity fields. We also make a point of
+ * copying visibility info, just in case anybody looks at those fields in
+ * a syscache entry.
+ */
+ new_tuple->t_self = tup->t_self;
+ new_tuple->t_tableOid = tup->t_tableOid;
+
+ new_tuple->t_data->t_choice = tup->t_data->t_choice;
+ new_tuple->t_data->t_ctid = tup->t_data->t_ctid;
+ new_tuple->t_data->t_infomask &= ~HEAP_XACT_MASK;
+ new_tuple->t_data->t_infomask |=
+ tup->t_data->t_infomask & HEAP_XACT_MASK;
+ new_tuple->t_data->t_infomask2 &= ~HEAP2_XACT_MASK;
+ new_tuple->t_data->t_infomask2 |=
+ tup->t_data->t_infomask2 & HEAP2_XACT_MASK;
+
+ /*
+ * Free allocated temp values
+ */
+ for (i = 0; i < numAttrs; i++)
+ if (toast_free[i])
+ pfree(DatumGetPointer(toast_values[i]));
+
+ return new_tuple;
+}
+
+
+/* ----------
+ * toast_flatten_tuple_to_datum -
+ *
+ * "Flatten" a tuple containing out-of-line toasted fields into a Datum.
+ * The result is always palloc'd in the current memory context.
+ *
+ * We have a general rule that Datums of container types (rows, arrays,
+ * ranges, etc) must not contain any external TOAST pointers. Without
+ * this rule, we'd have to look inside each Datum when preparing a tuple
+ * for storage, which would be expensive and would fail to extend cleanly
+ * to new sorts of container types.
+ *
+ * However, we don't want to say that tuples represented as HeapTuples
+ * can't contain toasted fields, so instead this routine should be called
+ * when such a HeapTuple is being converted into a Datum.
+ *
+ * While we're at it, we decompress any compressed fields too. This is not
+ * necessary for correctness, but reflects an expectation that compression
+ * will be more effective if applied to the whole tuple not individual
+ * fields. We are not so concerned about that that we want to deconstruct
+ * and reconstruct tuples just to get rid of compressed fields, however.
+ * So callers typically won't call this unless they see that the tuple has
+ * at least one external field.
+ *
+ * On the other hand, in-line short-header varlena fields are left alone.
+ * If we "untoasted" them here, they'd just get changed back to short-header
+ * format anyway within heap_fill_tuple.
+ * ----------
+ */
+Datum
+toast_flatten_tuple_to_datum(HeapTupleHeader tup,
+ uint32 tup_len,
+ TupleDesc tupleDesc)
+{
+ HeapTupleHeader new_data;
+ int32 new_header_len;
+ int32 new_data_len;
+ int32 new_tuple_len;
+ HeapTupleData tmptup;
+ int numAttrs = tupleDesc->natts;
+ int i;
+ bool has_nulls = false;
+ Datum toast_values[MaxTupleAttributeNumber];
+ bool toast_isnull[MaxTupleAttributeNumber];
+ bool toast_free[MaxTupleAttributeNumber];
+
+ /* Build a temporary HeapTuple control structure */
+ tmptup.t_len = tup_len;
+ ItemPointerSetInvalid(&(tmptup.t_self));
+ tmptup.t_tableOid = InvalidOid;
+ tmptup.t_data = tup;
+
+ /*
+ * Break down the tuple into fields.
+ */
+ Assert(numAttrs <= MaxTupleAttributeNumber);
+ heap_deform_tuple(&tmptup, tupleDesc, toast_values, toast_isnull);
+
+ memset(toast_free, 0, numAttrs * sizeof(bool));
+
+ for (i = 0; i < numAttrs; i++)
+ {
+ /*
+ * Look at non-null varlena attributes
+ */
+ if (toast_isnull[i])
+ has_nulls = true;
+ else if (TupleDescAttr(tupleDesc, i)->attlen == -1)
+ {
+ struct varlena *new_value;
+
+ new_value = (struct varlena *) DatumGetPointer(toast_values[i]);
+ if (VARATT_IS_EXTERNAL(new_value) ||
+ VARATT_IS_COMPRESSED(new_value))
+ {
+ new_value = heap_tuple_untoast_attr(new_value);
+ toast_values[i] = PointerGetDatum(new_value);
+ toast_free[i] = true;
+ }
+ }
+ }
+
+ /*
+ * Calculate the new size of the tuple.
+ *
+ * This should match the reconstruction code in toast_insert_or_update.
+ */
+ new_header_len = SizeofHeapTupleHeader;
+ if (has_nulls)
+ new_header_len += BITMAPLEN(numAttrs);
+ new_header_len = MAXALIGN(new_header_len);
+ new_data_len = heap_compute_data_size(tupleDesc,
+ toast_values, toast_isnull);
+ new_tuple_len = new_header_len + new_data_len;
+
+ new_data = (HeapTupleHeader) palloc0(new_tuple_len);
+
+ /*
+ * Copy the existing tuple header, but adjust natts and t_hoff.
+ */
+ memcpy(new_data, tup, SizeofHeapTupleHeader);
+ HeapTupleHeaderSetNatts(new_data, numAttrs);
+ new_data->t_hoff = new_header_len;
+
+ /* Set the composite-Datum header fields correctly */
+ HeapTupleHeaderSetDatumLength(new_data, new_tuple_len);
+ HeapTupleHeaderSetTypeId(new_data, tupleDesc->tdtypeid);
+ HeapTupleHeaderSetTypMod(new_data, tupleDesc->tdtypmod);
+
+ /* Copy over the data, and fill the null bitmap if needed */
+ heap_fill_tuple(tupleDesc,
+ toast_values,
+ toast_isnull,
+ (char *) new_data + new_header_len,
+ new_data_len,
+ &(new_data->t_infomask),
+ has_nulls ? new_data->t_bits : NULL);
+
+ /*
+ * Free allocated temp values
+ */
+ for (i = 0; i < numAttrs; i++)
+ if (toast_free[i])
+ pfree(DatumGetPointer(toast_values[i]));
+
+ return PointerGetDatum(new_data);
+}
+
+
+/* ----------
+ * toast_build_flattened_tuple -
+ *
+ * Build a tuple containing no out-of-line toasted fields.
+ * (This does not eliminate compressed or short-header datums.)
+ *
+ * This is essentially just like heap_form_tuple, except that it will
+ * expand any external-data pointers beforehand.
+ *
+ * It's not very clear whether it would be preferable to decompress
+ * in-line compressed datums while at it. For now, we don't.
+ * ----------
+ */
+HeapTuple
+toast_build_flattened_tuple(TupleDesc tupleDesc,
+ Datum *values,
+ bool *isnull)
+{
+ HeapTuple new_tuple;
+ int numAttrs = tupleDesc->natts;
+ int num_to_free;
+ int i;
+ Datum new_values[MaxTupleAttributeNumber];
+ Pointer freeable_values[MaxTupleAttributeNumber];
+
+ /*
+ * We can pass the caller's isnull array directly to heap_form_tuple, but
+ * we potentially need to modify the values array.
+ */
+ Assert(numAttrs <= MaxTupleAttributeNumber);
+ memcpy(new_values, values, numAttrs * sizeof(Datum));
+
+ num_to_free = 0;
+ for (i = 0; i < numAttrs; i++)
+ {
+ /*
+ * Look at non-null varlena attributes
+ */
+ if (!isnull[i] && TupleDescAttr(tupleDesc, i)->attlen == -1)
+ {
+ struct varlena *new_value;
+
+ new_value = (struct varlena *) DatumGetPointer(new_values[i]);
+ if (VARATT_IS_EXTERNAL(new_value))
+ {
+ new_value = heap_tuple_fetch_attr(new_value);
+ new_values[i] = PointerGetDatum(new_value);
+ freeable_values[num_to_free++] = (Pointer) new_value;
+ }
+ }
+ }
+
+ /*
+ * Form the reconfigured tuple.
+ */
+ new_tuple = heap_form_tuple(tupleDesc, new_values, isnull);
+
+ /*
+ * Free allocated temp values
+ */
+ for (i = 0; i < num_to_free; i++)
+ pfree(freeable_values[i]);
+
+ return new_tuple;
+}
#include "access/heapam.h"
#include "access/heapam_xlog.h"
+#include "access/heaptoast.h"
#include "access/rewriteheap.h"
#include "access/transam.h"
-#include "access/tuptoaster.h"
#include "access/xact.h"
#include "access/xloginsert.h"
+++ /dev/null
-/*-------------------------------------------------------------------------
- *
- * tuptoaster.c
- * Support routines for external and compressed storage of
- * variable size attributes.
- *
- * Copyright (c) 2000-2019, PostgreSQL Global Development Group
- *
- *
- * IDENTIFICATION
- * src/backend/access/heap/tuptoaster.c
- *
- *
- * INTERFACE ROUTINES
- * toast_insert_or_update -
- * Try to make a given tuple fit into one page by compressing
- * or moving off attributes
- *
- * toast_delete -
- * Reclaim toast storage when a tuple is deleted
- *
- * heap_tuple_untoast_attr -
- * Fetch back a given value from the "secondary" relation
- *
- *-------------------------------------------------------------------------
- */
-
-#include "postgres.h"
-
-#include <unistd.h>
-#include <fcntl.h>
-
-#include "access/genam.h"
-#include "access/heapam.h"
-#include "access/tuptoaster.h"
-#include "access/xact.h"
-#include "catalog/catalog.h"
-#include "common/pg_lzcompress.h"
-#include "miscadmin.h"
-#include "utils/expandeddatum.h"
-#include "utils/fmgroids.h"
-#include "utils/rel.h"
-#include "utils/snapmgr.h"
-#include "utils/typcache.h"
-
-
-/*
- * The information at the start of the compressed toast data.
- */
-typedef struct toast_compress_header
-{
- int32 vl_len_; /* varlena header (do not touch directly!) */
- int32 rawsize;
-} toast_compress_header;
-
-/*
- * Utilities for manipulation of header information for compressed
- * toast entries.
- */
-#define TOAST_COMPRESS_HDRSZ ((int32) sizeof(toast_compress_header))
-#define TOAST_COMPRESS_RAWSIZE(ptr) (((toast_compress_header *) (ptr))->rawsize)
-#define TOAST_COMPRESS_RAWDATA(ptr) \
- (((char *) (ptr)) + TOAST_COMPRESS_HDRSZ)
-#define TOAST_COMPRESS_SET_RAWSIZE(ptr, len) \
- (((toast_compress_header *) (ptr))->rawsize = (len))
-
-static void toast_delete_datum(Relation rel, Datum value, bool is_speculative);
-static Datum toast_save_datum(Relation rel, Datum value,
- struct varlena *oldexternal, int options);
-static bool toastrel_valueid_exists(Relation toastrel, Oid valueid);
-static bool toastid_valueid_exists(Oid toastrelid, Oid valueid);
-static struct varlena *toast_fetch_datum(struct varlena *attr);
-static struct varlena *toast_fetch_datum_slice(struct varlena *attr,
- int32 sliceoffset, int32 length);
-static struct varlena *toast_decompress_datum(struct varlena *attr);
-static struct varlena *toast_decompress_datum_slice(struct varlena *attr, int32 slicelength);
-static int toast_open_indexes(Relation toastrel,
- LOCKMODE lock,
- Relation **toastidxs,
- int *num_indexes);
-static void toast_close_indexes(Relation *toastidxs, int num_indexes,
- LOCKMODE lock);
-static void init_toast_snapshot(Snapshot toast_snapshot);
-
-
-/* ----------
- * heap_tuple_fetch_attr -
- *
- * Public entry point to get back a toasted value from
- * external source (possibly still in compressed format).
- *
- * This will return a datum that contains all the data internally, ie, not
- * relying on external storage or memory, but it can still be compressed or
- * have a short header. Note some callers assume that if the input is an
- * EXTERNAL datum, the result will be a pfree'able chunk.
- * ----------
- */
-struct varlena *
-heap_tuple_fetch_attr(struct varlena *attr)
-{
- struct varlena *result;
-
- if (VARATT_IS_EXTERNAL_ONDISK(attr))
- {
- /*
- * This is an external stored plain value
- */
- result = toast_fetch_datum(attr);
- }
- else if (VARATT_IS_EXTERNAL_INDIRECT(attr))
- {
- /*
- * This is an indirect pointer --- dereference it
- */
- struct varatt_indirect redirect;
-
- VARATT_EXTERNAL_GET_POINTER(redirect, attr);
- attr = (struct varlena *) redirect.pointer;
-
- /* nested indirect Datums aren't allowed */
- Assert(!VARATT_IS_EXTERNAL_INDIRECT(attr));
-
- /* recurse if value is still external in some other way */
- if (VARATT_IS_EXTERNAL(attr))
- return heap_tuple_fetch_attr(attr);
-
- /*
- * Copy into the caller's memory context, in case caller tries to
- * pfree the result.
- */
- result = (struct varlena *) palloc(VARSIZE_ANY(attr));
- memcpy(result, attr, VARSIZE_ANY(attr));
- }
- else if (VARATT_IS_EXTERNAL_EXPANDED(attr))
- {
- /*
- * This is an expanded-object pointer --- get flat format
- */
- ExpandedObjectHeader *eoh;
- Size resultsize;
-
- eoh = DatumGetEOHP(PointerGetDatum(attr));
- resultsize = EOH_get_flat_size(eoh);
- result = (struct varlena *) palloc(resultsize);
- EOH_flatten_into(eoh, (void *) result, resultsize);
- }
- else
- {
- /*
- * This is a plain value inside of the main tuple - why am I called?
- */
- result = attr;
- }
-
- return result;
-}
-
-
-/* ----------
- * heap_tuple_untoast_attr -
- *
- * Public entry point to get back a toasted value from compression
- * or external storage. The result is always non-extended varlena form.
- *
- * Note some callers assume that if the input is an EXTERNAL or COMPRESSED
- * datum, the result will be a pfree'able chunk.
- * ----------
- */
-struct varlena *
-heap_tuple_untoast_attr(struct varlena *attr)
-{
- if (VARATT_IS_EXTERNAL_ONDISK(attr))
- {
- /*
- * This is an externally stored datum --- fetch it back from there
- */
- attr = toast_fetch_datum(attr);
- /* If it's compressed, decompress it */
- if (VARATT_IS_COMPRESSED(attr))
- {
- struct varlena *tmp = attr;
-
- attr = toast_decompress_datum(tmp);
- pfree(tmp);
- }
- }
- else if (VARATT_IS_EXTERNAL_INDIRECT(attr))
- {
- /*
- * This is an indirect pointer --- dereference it
- */
- struct varatt_indirect redirect;
-
- VARATT_EXTERNAL_GET_POINTER(redirect, attr);
- attr = (struct varlena *) redirect.pointer;
-
- /* nested indirect Datums aren't allowed */
- Assert(!VARATT_IS_EXTERNAL_INDIRECT(attr));
-
- /* recurse in case value is still extended in some other way */
- attr = heap_tuple_untoast_attr(attr);
-
- /* if it isn't, we'd better copy it */
- if (attr == (struct varlena *) redirect.pointer)
- {
- struct varlena *result;
-
- result = (struct varlena *) palloc(VARSIZE_ANY(attr));
- memcpy(result, attr, VARSIZE_ANY(attr));
- attr = result;
- }
- }
- else if (VARATT_IS_EXTERNAL_EXPANDED(attr))
- {
- /*
- * This is an expanded-object pointer --- get flat format
- */
- attr = heap_tuple_fetch_attr(attr);
- /* flatteners are not allowed to produce compressed/short output */
- Assert(!VARATT_IS_EXTENDED(attr));
- }
- else if (VARATT_IS_COMPRESSED(attr))
- {
- /*
- * This is a compressed value inside of the main tuple
- */
- attr = toast_decompress_datum(attr);
- }
- else if (VARATT_IS_SHORT(attr))
- {
- /*
- * This is a short-header varlena --- convert to 4-byte header format
- */
- Size data_size = VARSIZE_SHORT(attr) - VARHDRSZ_SHORT;
- Size new_size = data_size + VARHDRSZ;
- struct varlena *new_attr;
-
- new_attr = (struct varlena *) palloc(new_size);
- SET_VARSIZE(new_attr, new_size);
- memcpy(VARDATA(new_attr), VARDATA_SHORT(attr), data_size);
- attr = new_attr;
- }
-
- return attr;
-}
-
-
-/* ----------
- * heap_tuple_untoast_attr_slice -
- *
- * Public entry point to get back part of a toasted value
- * from compression or external storage.
- * ----------
- */
-struct varlena *
-heap_tuple_untoast_attr_slice(struct varlena *attr,
- int32 sliceoffset, int32 slicelength)
-{
- struct varlena *preslice;
- struct varlena *result;
- char *attrdata;
- int32 attrsize;
-
- if (VARATT_IS_EXTERNAL_ONDISK(attr))
- {
- struct varatt_external toast_pointer;
-
- VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);
-
- /* fast path for non-compressed external datums */
- if (!VARATT_EXTERNAL_IS_COMPRESSED(toast_pointer))
- return toast_fetch_datum_slice(attr, sliceoffset, slicelength);
-
- /* fetch it back (compressed marker will get set automatically) */
- preslice = toast_fetch_datum(attr);
- }
- else if (VARATT_IS_EXTERNAL_INDIRECT(attr))
- {
- struct varatt_indirect redirect;
-
- VARATT_EXTERNAL_GET_POINTER(redirect, attr);
-
- /* nested indirect Datums aren't allowed */
- Assert(!VARATT_IS_EXTERNAL_INDIRECT(redirect.pointer));
-
- return heap_tuple_untoast_attr_slice(redirect.pointer,
- sliceoffset, slicelength);
- }
- else if (VARATT_IS_EXTERNAL_EXPANDED(attr))
- {
- /* pass it off to heap_tuple_fetch_attr to flatten */
- preslice = heap_tuple_fetch_attr(attr);
- }
- else
- preslice = attr;
-
- Assert(!VARATT_IS_EXTERNAL(preslice));
-
- if (VARATT_IS_COMPRESSED(preslice))
- {
- struct varlena *tmp = preslice;
-
- /* Decompress enough to encompass the slice and the offset */
- if (slicelength > 0 && sliceoffset >= 0)
- preslice = toast_decompress_datum_slice(tmp, slicelength + sliceoffset);
- else
- preslice = toast_decompress_datum(tmp);
-
- if (tmp != attr)
- pfree(tmp);
- }
-
- if (VARATT_IS_SHORT(preslice))
- {
- attrdata = VARDATA_SHORT(preslice);
- attrsize = VARSIZE_SHORT(preslice) - VARHDRSZ_SHORT;
- }
- else
- {
- attrdata = VARDATA(preslice);
- attrsize = VARSIZE(preslice) - VARHDRSZ;
- }
-
- /* slicing of datum for compressed cases and plain value */
-
- if (sliceoffset >= attrsize)
- {
- sliceoffset = 0;
- slicelength = 0;
- }
-
- if (((sliceoffset + slicelength) > attrsize) || slicelength < 0)
- slicelength = attrsize - sliceoffset;
-
- result = (struct varlena *) palloc(slicelength + VARHDRSZ);
- SET_VARSIZE(result, slicelength + VARHDRSZ);
-
- memcpy(VARDATA(result), attrdata + sliceoffset, slicelength);
-
- if (preslice != attr)
- pfree(preslice);
-
- return result;
-}
-
-
-/* ----------
- * toast_raw_datum_size -
- *
- * Return the raw (detoasted) size of a varlena datum
- * (including the VARHDRSZ header)
- * ----------
- */
-Size
-toast_raw_datum_size(Datum value)
-{
- struct varlena *attr = (struct varlena *) DatumGetPointer(value);
- Size result;
-
- if (VARATT_IS_EXTERNAL_ONDISK(attr))
- {
- /* va_rawsize is the size of the original datum -- including header */
- struct varatt_external toast_pointer;
-
- VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);
- result = toast_pointer.va_rawsize;
- }
- else if (VARATT_IS_EXTERNAL_INDIRECT(attr))
- {
- struct varatt_indirect toast_pointer;
-
- VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);
-
- /* nested indirect Datums aren't allowed */
- Assert(!VARATT_IS_EXTERNAL_INDIRECT(toast_pointer.pointer));
-
- return toast_raw_datum_size(PointerGetDatum(toast_pointer.pointer));
- }
- else if (VARATT_IS_EXTERNAL_EXPANDED(attr))
- {
- result = EOH_get_flat_size(DatumGetEOHP(value));
- }
- else if (VARATT_IS_COMPRESSED(attr))
- {
- /* here, va_rawsize is just the payload size */
- result = VARRAWSIZE_4B_C(attr) + VARHDRSZ;
- }
- else if (VARATT_IS_SHORT(attr))
- {
- /*
- * we have to normalize the header length to VARHDRSZ or else the
- * callers of this function will be confused.
- */
- result = VARSIZE_SHORT(attr) - VARHDRSZ_SHORT + VARHDRSZ;
- }
- else
- {
- /* plain untoasted datum */
- result = VARSIZE(attr);
- }
- return result;
-}
-
-/* ----------
- * toast_datum_size
- *
- * Return the physical storage size (possibly compressed) of a varlena datum
- * ----------
- */
-Size
-toast_datum_size(Datum value)
-{
- struct varlena *attr = (struct varlena *) DatumGetPointer(value);
- Size result;
-
- if (VARATT_IS_EXTERNAL_ONDISK(attr))
- {
- /*
- * Attribute is stored externally - return the extsize whether
- * compressed or not. We do not count the size of the toast pointer
- * ... should we?
- */
- struct varatt_external toast_pointer;
-
- VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);
- result = toast_pointer.va_extsize;
- }
- else if (VARATT_IS_EXTERNAL_INDIRECT(attr))
- {
- struct varatt_indirect toast_pointer;
-
- VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);
-
- /* nested indirect Datums aren't allowed */
- Assert(!VARATT_IS_EXTERNAL_INDIRECT(attr));
-
- return toast_datum_size(PointerGetDatum(toast_pointer.pointer));
- }
- else if (VARATT_IS_EXTERNAL_EXPANDED(attr))
- {
- result = EOH_get_flat_size(DatumGetEOHP(value));
- }
- else if (VARATT_IS_SHORT(attr))
- {
- result = VARSIZE_SHORT(attr);
- }
- else
- {
- /*
- * Attribute is stored inline either compressed or not, just calculate
- * the size of the datum in either case.
- */
- result = VARSIZE(attr);
- }
- return result;
-}
-
-
-/* ----------
- * toast_delete -
- *
- * Cascaded delete toast-entries on DELETE
- * ----------
- */
-void
-toast_delete(Relation rel, HeapTuple oldtup, bool is_speculative)
-{
- TupleDesc tupleDesc;
- int numAttrs;
- int i;
- Datum toast_values[MaxHeapAttributeNumber];
- bool toast_isnull[MaxHeapAttributeNumber];
-
- /*
- * We should only ever be called for tuples of plain relations or
- * materialized views --- recursing on a toast rel is bad news.
- */
- Assert(rel->rd_rel->relkind == RELKIND_RELATION ||
- rel->rd_rel->relkind == RELKIND_MATVIEW);
-
- /*
- * Get the tuple descriptor and break down the tuple into fields.
- *
- * NOTE: it's debatable whether to use heap_deform_tuple() here or just
- * heap_getattr() only the varlena columns. The latter could win if there
- * are few varlena columns and many non-varlena ones. However,
- * heap_deform_tuple costs only O(N) while the heap_getattr way would cost
- * O(N^2) if there are many varlena columns, so it seems better to err on
- * the side of linear cost. (We won't even be here unless there's at
- * least one varlena column, by the way.)
- */
- tupleDesc = rel->rd_att;
- numAttrs = tupleDesc->natts;
-
- Assert(numAttrs <= MaxHeapAttributeNumber);
- heap_deform_tuple(oldtup, tupleDesc, toast_values, toast_isnull);
-
- /*
- * Check for external stored attributes and delete them from the secondary
- * relation.
- */
- for (i = 0; i < numAttrs; i++)
- {
- if (TupleDescAttr(tupleDesc, i)->attlen == -1)
- {
- Datum value = toast_values[i];
-
- if (toast_isnull[i])
- continue;
- else if (VARATT_IS_EXTERNAL_ONDISK(PointerGetDatum(value)))
- toast_delete_datum(rel, value, is_speculative);
- }
- }
-}
-
-
-/* ----------
- * toast_insert_or_update -
- *
- * Delete no-longer-used toast-entries and create new ones to
- * make the new tuple fit on INSERT or UPDATE
- *
- * Inputs:
- * newtup: the candidate new tuple to be inserted
- * oldtup: the old row version for UPDATE, or NULL for INSERT
- * options: options to be passed to heap_insert() for toast rows
- * Result:
- * either newtup if no toasting is needed, or a palloc'd modified tuple
- * that is what should actually get stored
- *
- * NOTE: neither newtup nor oldtup will be modified. This is a change
- * from the pre-8.1 API of this routine.
- * ----------
- */
-HeapTuple
-toast_insert_or_update(Relation rel, HeapTuple newtup, HeapTuple oldtup,
- int options)
-{
- HeapTuple result_tuple;
- TupleDesc tupleDesc;
- int numAttrs;
- int i;
-
- bool need_change = false;
- bool need_free = false;
- bool need_delold = false;
- bool has_nulls = false;
-
- Size maxDataLen;
- Size hoff;
-
- char toast_action[MaxHeapAttributeNumber];
- bool toast_isnull[MaxHeapAttributeNumber];
- bool toast_oldisnull[MaxHeapAttributeNumber];
- Datum toast_values[MaxHeapAttributeNumber];
- Datum toast_oldvalues[MaxHeapAttributeNumber];
- struct varlena *toast_oldexternal[MaxHeapAttributeNumber];
- int32 toast_sizes[MaxHeapAttributeNumber];
- bool toast_free[MaxHeapAttributeNumber];
- bool toast_delold[MaxHeapAttributeNumber];
-
- /*
- * Ignore the INSERT_SPECULATIVE option. Speculative insertions/super
- * deletions just normally insert/delete the toast values. It seems
- * easiest to deal with that here, instead on, potentially, multiple
- * callers.
- */
- options &= ~HEAP_INSERT_SPECULATIVE;
-
- /*
- * We should only ever be called for tuples of plain relations or
- * materialized views --- recursing on a toast rel is bad news.
- */
- Assert(rel->rd_rel->relkind == RELKIND_RELATION ||
- rel->rd_rel->relkind == RELKIND_MATVIEW);
-
- /*
- * Get the tuple descriptor and break down the tuple(s) into fields.
- */
- tupleDesc = rel->rd_att;
- numAttrs = tupleDesc->natts;
-
- Assert(numAttrs <= MaxHeapAttributeNumber);
- heap_deform_tuple(newtup, tupleDesc, toast_values, toast_isnull);
- if (oldtup != NULL)
- heap_deform_tuple(oldtup, tupleDesc, toast_oldvalues, toast_oldisnull);
-
- /* ----------
- * Then collect information about the values given
- *
- * NOTE: toast_action[i] can have these values:
- * ' ' default handling
- * 'p' already processed --- don't touch it
- * 'x' incompressible, but OK to move off
- *
- * NOTE: toast_sizes[i] is only made valid for varlena attributes with
- * toast_action[i] different from 'p'.
- * ----------
- */
- memset(toast_action, ' ', numAttrs * sizeof(char));
- memset(toast_oldexternal, 0, numAttrs * sizeof(struct varlena *));
- memset(toast_free, 0, numAttrs * sizeof(bool));
- memset(toast_delold, 0, numAttrs * sizeof(bool));
-
- for (i = 0; i < numAttrs; i++)
- {
- Form_pg_attribute att = TupleDescAttr(tupleDesc, i);
- struct varlena *old_value;
- struct varlena *new_value;
-
- if (oldtup != NULL)
- {
- /*
- * For UPDATE get the old and new values of this attribute
- */
- old_value = (struct varlena *) DatumGetPointer(toast_oldvalues[i]);
- new_value = (struct varlena *) DatumGetPointer(toast_values[i]);
-
- /*
- * If the old value is stored on disk, check if it has changed so
- * we have to delete it later.
- */
- if (att->attlen == -1 && !toast_oldisnull[i] &&
- VARATT_IS_EXTERNAL_ONDISK(old_value))
- {
- if (toast_isnull[i] || !VARATT_IS_EXTERNAL_ONDISK(new_value) ||
- memcmp((char *) old_value, (char *) new_value,
- VARSIZE_EXTERNAL(old_value)) != 0)
- {
- /*
- * The old external stored value isn't needed any more
- * after the update
- */
- toast_delold[i] = true;
- need_delold = true;
- }
- else
- {
- /*
- * This attribute isn't changed by this update so we reuse
- * the original reference to the old value in the new
- * tuple.
- */
- toast_action[i] = 'p';
- continue;
- }
- }
- }
- else
- {
- /*
- * For INSERT simply get the new value
- */
- new_value = (struct varlena *) DatumGetPointer(toast_values[i]);
- }
-
- /*
- * Handle NULL attributes
- */
- if (toast_isnull[i])
- {
- toast_action[i] = 'p';
- has_nulls = true;
- continue;
- }
-
- /*
- * Now look at varlena attributes
- */
- if (att->attlen == -1)
- {
- /*
- * If the table's attribute says PLAIN always, force it so.
- */
- if (att->attstorage == 'p')
- toast_action[i] = 'p';
-
- /*
- * We took care of UPDATE above, so any external value we find
- * still in the tuple must be someone else's that we cannot reuse
- * (this includes the case of an out-of-line in-memory datum).
- * Fetch it back (without decompression, unless we are forcing
- * PLAIN storage). If necessary, we'll push it out as a new
- * external value below.
- */
- if (VARATT_IS_EXTERNAL(new_value))
- {
- toast_oldexternal[i] = new_value;
- if (att->attstorage == 'p')
- new_value = heap_tuple_untoast_attr(new_value);
- else
- new_value = heap_tuple_fetch_attr(new_value);
- toast_values[i] = PointerGetDatum(new_value);
- toast_free[i] = true;
- need_change = true;
- need_free = true;
- }
-
- /*
- * Remember the size of this attribute
- */
- toast_sizes[i] = VARSIZE_ANY(new_value);
- }
- else
- {
- /*
- * Not a varlena attribute, plain storage always
- */
- toast_action[i] = 'p';
- }
- }
-
- /* ----------
- * Compress and/or save external until data fits into target length
- *
- * 1: Inline compress attributes with attstorage 'x', and store very
- * large attributes with attstorage 'x' or 'e' external immediately
- * 2: Store attributes with attstorage 'x' or 'e' external
- * 3: Inline compress attributes with attstorage 'm'
- * 4: Store attributes with attstorage 'm' external
- * ----------
- */
-
- /* compute header overhead --- this should match heap_form_tuple() */
- hoff = SizeofHeapTupleHeader;
- if (has_nulls)
- hoff += BITMAPLEN(numAttrs);
- hoff = MAXALIGN(hoff);
- /* now convert to a limit on the tuple data size */
- maxDataLen = RelationGetToastTupleTarget(rel, TOAST_TUPLE_TARGET) - hoff;
-
- /*
- * Look for attributes with attstorage 'x' to compress. Also find large
- * attributes with attstorage 'x' or 'e', and store them external.
- */
- while (heap_compute_data_size(tupleDesc,
- toast_values, toast_isnull) > maxDataLen)
- {
- int biggest_attno = -1;
- int32 biggest_size = MAXALIGN(TOAST_POINTER_SIZE);
- Datum old_value;
- Datum new_value;
-
- /*
- * Search for the biggest yet unprocessed internal attribute
- */
- for (i = 0; i < numAttrs; i++)
- {
- Form_pg_attribute att = TupleDescAttr(tupleDesc, i);
-
- if (toast_action[i] != ' ')
- continue;
- if (VARATT_IS_EXTERNAL(DatumGetPointer(toast_values[i])))
- continue; /* can't happen, toast_action would be 'p' */
- if (VARATT_IS_COMPRESSED(DatumGetPointer(toast_values[i])))
- continue;
- if (att->attstorage != 'x' && att->attstorage != 'e')
- continue;
- if (toast_sizes[i] > biggest_size)
- {
- biggest_attno = i;
- biggest_size = toast_sizes[i];
- }
- }
-
- if (biggest_attno < 0)
- break;
-
- /*
- * Attempt to compress it inline, if it has attstorage 'x'
- */
- i = biggest_attno;
- if (TupleDescAttr(tupleDesc, i)->attstorage == 'x')
- {
- old_value = toast_values[i];
- new_value = toast_compress_datum(old_value);
-
- if (DatumGetPointer(new_value) != NULL)
- {
- /* successful compression */
- if (toast_free[i])
- pfree(DatumGetPointer(old_value));
- toast_values[i] = new_value;
- toast_free[i] = true;
- toast_sizes[i] = VARSIZE(DatumGetPointer(toast_values[i]));
- need_change = true;
- need_free = true;
- }
- else
- {
- /* incompressible, ignore on subsequent compression passes */
- toast_action[i] = 'x';
- }
- }
- else
- {
- /* has attstorage 'e', ignore on subsequent compression passes */
- toast_action[i] = 'x';
- }
-
- /*
- * If this value is by itself more than maxDataLen (after compression
- * if any), push it out to the toast table immediately, if possible.
- * This avoids uselessly compressing other fields in the common case
- * where we have one long field and several short ones.
- *
- * XXX maybe the threshold should be less than maxDataLen?
- */
- if (toast_sizes[i] > maxDataLen &&
- rel->rd_rel->reltoastrelid != InvalidOid)
- {
- old_value = toast_values[i];
- toast_action[i] = 'p';
- toast_values[i] = toast_save_datum(rel, toast_values[i],
- toast_oldexternal[i], options);
- if (toast_free[i])
- pfree(DatumGetPointer(old_value));
- toast_free[i] = true;
- need_change = true;
- need_free = true;
- }
- }
-
- /*
- * Second we look for attributes of attstorage 'x' or 'e' that are still
- * inline. But skip this if there's no toast table to push them to.
- */
- while (heap_compute_data_size(tupleDesc,
- toast_values, toast_isnull) > maxDataLen &&
- rel->rd_rel->reltoastrelid != InvalidOid)
- {
- int biggest_attno = -1;
- int32 biggest_size = MAXALIGN(TOAST_POINTER_SIZE);
- Datum old_value;
-
- /*------
- * Search for the biggest yet inlined attribute with
- * attstorage equals 'x' or 'e'
- *------
- */
- for (i = 0; i < numAttrs; i++)
- {
- Form_pg_attribute att = TupleDescAttr(tupleDesc, i);
-
- if (toast_action[i] == 'p')
- continue;
- if (VARATT_IS_EXTERNAL(DatumGetPointer(toast_values[i])))
- continue; /* can't happen, toast_action would be 'p' */
- if (att->attstorage != 'x' && att->attstorage != 'e')
- continue;
- if (toast_sizes[i] > biggest_size)
- {
- biggest_attno = i;
- biggest_size = toast_sizes[i];
- }
- }
-
- if (biggest_attno < 0)
- break;
-
- /*
- * Store this external
- */
- i = biggest_attno;
- old_value = toast_values[i];
- toast_action[i] = 'p';
- toast_values[i] = toast_save_datum(rel, toast_values[i],
- toast_oldexternal[i], options);
- if (toast_free[i])
- pfree(DatumGetPointer(old_value));
- toast_free[i] = true;
-
- need_change = true;
- need_free = true;
- }
-
- /*
- * Round 3 - this time we take attributes with storage 'm' into
- * compression
- */
- while (heap_compute_data_size(tupleDesc,
- toast_values, toast_isnull) > maxDataLen)
- {
- int biggest_attno = -1;
- int32 biggest_size = MAXALIGN(TOAST_POINTER_SIZE);
- Datum old_value;
- Datum new_value;
-
- /*
- * Search for the biggest yet uncompressed internal attribute
- */
- for (i = 0; i < numAttrs; i++)
- {
- if (toast_action[i] != ' ')
- continue;
- if (VARATT_IS_EXTERNAL(DatumGetPointer(toast_values[i])))
- continue; /* can't happen, toast_action would be 'p' */
- if (VARATT_IS_COMPRESSED(DatumGetPointer(toast_values[i])))
- continue;
- if (TupleDescAttr(tupleDesc, i)->attstorage != 'm')
- continue;
- if (toast_sizes[i] > biggest_size)
- {
- biggest_attno = i;
- biggest_size = toast_sizes[i];
- }
- }
-
- if (biggest_attno < 0)
- break;
-
- /*
- * Attempt to compress it inline
- */
- i = biggest_attno;
- old_value = toast_values[i];
- new_value = toast_compress_datum(old_value);
-
- if (DatumGetPointer(new_value) != NULL)
- {
- /* successful compression */
- if (toast_free[i])
- pfree(DatumGetPointer(old_value));
- toast_values[i] = new_value;
- toast_free[i] = true;
- toast_sizes[i] = VARSIZE(DatumGetPointer(toast_values[i]));
- need_change = true;
- need_free = true;
- }
- else
- {
- /* incompressible, ignore on subsequent compression passes */
- toast_action[i] = 'x';
- }
- }
-
- /*
- * Finally we store attributes of type 'm' externally. At this point we
- * increase the target tuple size, so that 'm' attributes aren't stored
- * externally unless really necessary.
- */
- maxDataLen = TOAST_TUPLE_TARGET_MAIN - hoff;
-
- while (heap_compute_data_size(tupleDesc,
- toast_values, toast_isnull) > maxDataLen &&
- rel->rd_rel->reltoastrelid != InvalidOid)
- {
- int biggest_attno = -1;
- int32 biggest_size = MAXALIGN(TOAST_POINTER_SIZE);
- Datum old_value;
-
- /*--------
- * Search for the biggest yet inlined attribute with
- * attstorage = 'm'
- *--------
- */
- for (i = 0; i < numAttrs; i++)
- {
- if (toast_action[i] == 'p')
- continue;
- if (VARATT_IS_EXTERNAL(DatumGetPointer(toast_values[i])))
- continue; /* can't happen, toast_action would be 'p' */
- if (TupleDescAttr(tupleDesc, i)->attstorage != 'm')
- continue;
- if (toast_sizes[i] > biggest_size)
- {
- biggest_attno = i;
- biggest_size = toast_sizes[i];
- }
- }
-
- if (biggest_attno < 0)
- break;
-
- /*
- * Store this external
- */
- i = biggest_attno;
- old_value = toast_values[i];
- toast_action[i] = 'p';
- toast_values[i] = toast_save_datum(rel, toast_values[i],
- toast_oldexternal[i], options);
- if (toast_free[i])
- pfree(DatumGetPointer(old_value));
- toast_free[i] = true;
-
- need_change = true;
- need_free = true;
- }
-
- /*
- * In the case we toasted any values, we need to build a new heap tuple
- * with the changed values.
- */
- if (need_change)
- {
- HeapTupleHeader olddata = newtup->t_data;
- HeapTupleHeader new_data;
- int32 new_header_len;
- int32 new_data_len;
- int32 new_tuple_len;
-
- /*
- * Calculate the new size of the tuple.
- *
- * Note: we used to assume here that the old tuple's t_hoff must equal
- * the new_header_len value, but that was incorrect. The old tuple
- * might have a smaller-than-current natts, if there's been an ALTER
- * TABLE ADD COLUMN since it was stored; and that would lead to a
- * different conclusion about the size of the null bitmap, or even
- * whether there needs to be one at all.
- */
- new_header_len = SizeofHeapTupleHeader;
- if (has_nulls)
- new_header_len += BITMAPLEN(numAttrs);
- new_header_len = MAXALIGN(new_header_len);
- new_data_len = heap_compute_data_size(tupleDesc,
- toast_values, toast_isnull);
- new_tuple_len = new_header_len + new_data_len;
-
- /*
- * Allocate and zero the space needed, and fill HeapTupleData fields.
- */
- result_tuple = (HeapTuple) palloc0(HEAPTUPLESIZE + new_tuple_len);
- result_tuple->t_len = new_tuple_len;
- result_tuple->t_self = newtup->t_self;
- result_tuple->t_tableOid = newtup->t_tableOid;
- new_data = (HeapTupleHeader) ((char *) result_tuple + HEAPTUPLESIZE);
- result_tuple->t_data = new_data;
-
- /*
- * Copy the existing tuple header, but adjust natts and t_hoff.
- */
- memcpy(new_data, olddata, SizeofHeapTupleHeader);
- HeapTupleHeaderSetNatts(new_data, numAttrs);
- new_data->t_hoff = new_header_len;
-
- /* Copy over the data, and fill the null bitmap if needed */
- heap_fill_tuple(tupleDesc,
- toast_values,
- toast_isnull,
- (char *) new_data + new_header_len,
- new_data_len,
- &(new_data->t_infomask),
- has_nulls ? new_data->t_bits : NULL);
- }
- else
- result_tuple = newtup;
-
- /*
- * Free allocated temp values
- */
- if (need_free)
- for (i = 0; i < numAttrs; i++)
- if (toast_free[i])
- pfree(DatumGetPointer(toast_values[i]));
-
- /*
- * Delete external values from the old tuple
- */
- if (need_delold)
- for (i = 0; i < numAttrs; i++)
- if (toast_delold[i])
- toast_delete_datum(rel, toast_oldvalues[i], false);
-
- return result_tuple;
-}
-
-
-/* ----------
- * toast_flatten_tuple -
- *
- * "Flatten" a tuple to contain no out-of-line toasted fields.
- * (This does not eliminate compressed or short-header datums.)
- *
- * Note: we expect the caller already checked HeapTupleHasExternal(tup),
- * so there is no need for a short-circuit path.
- * ----------
- */
-HeapTuple
-toast_flatten_tuple(HeapTuple tup, TupleDesc tupleDesc)
-{
- HeapTuple new_tuple;
- int numAttrs = tupleDesc->natts;
- int i;
- Datum toast_values[MaxTupleAttributeNumber];
- bool toast_isnull[MaxTupleAttributeNumber];
- bool toast_free[MaxTupleAttributeNumber];
-
- /*
- * Break down the tuple into fields.
- */
- Assert(numAttrs <= MaxTupleAttributeNumber);
- heap_deform_tuple(tup, tupleDesc, toast_values, toast_isnull);
-
- memset(toast_free, 0, numAttrs * sizeof(bool));
-
- for (i = 0; i < numAttrs; i++)
- {
- /*
- * Look at non-null varlena attributes
- */
- if (!toast_isnull[i] && TupleDescAttr(tupleDesc, i)->attlen == -1)
- {
- struct varlena *new_value;
-
- new_value = (struct varlena *) DatumGetPointer(toast_values[i]);
- if (VARATT_IS_EXTERNAL(new_value))
- {
- new_value = heap_tuple_fetch_attr(new_value);
- toast_values[i] = PointerGetDatum(new_value);
- toast_free[i] = true;
- }
- }
- }
-
- /*
- * Form the reconfigured tuple.
- */
- new_tuple = heap_form_tuple(tupleDesc, toast_values, toast_isnull);
-
- /*
- * Be sure to copy the tuple's identity fields. We also make a point of
- * copying visibility info, just in case anybody looks at those fields in
- * a syscache entry.
- */
- new_tuple->t_self = tup->t_self;
- new_tuple->t_tableOid = tup->t_tableOid;
-
- new_tuple->t_data->t_choice = tup->t_data->t_choice;
- new_tuple->t_data->t_ctid = tup->t_data->t_ctid;
- new_tuple->t_data->t_infomask &= ~HEAP_XACT_MASK;
- new_tuple->t_data->t_infomask |=
- tup->t_data->t_infomask & HEAP_XACT_MASK;
- new_tuple->t_data->t_infomask2 &= ~HEAP2_XACT_MASK;
- new_tuple->t_data->t_infomask2 |=
- tup->t_data->t_infomask2 & HEAP2_XACT_MASK;
-
- /*
- * Free allocated temp values
- */
- for (i = 0; i < numAttrs; i++)
- if (toast_free[i])
- pfree(DatumGetPointer(toast_values[i]));
-
- return new_tuple;
-}
-
-
-/* ----------
- * toast_flatten_tuple_to_datum -
- *
- * "Flatten" a tuple containing out-of-line toasted fields into a Datum.
- * The result is always palloc'd in the current memory context.
- *
- * We have a general rule that Datums of container types (rows, arrays,
- * ranges, etc) must not contain any external TOAST pointers. Without
- * this rule, we'd have to look inside each Datum when preparing a tuple
- * for storage, which would be expensive and would fail to extend cleanly
- * to new sorts of container types.
- *
- * However, we don't want to say that tuples represented as HeapTuples
- * can't contain toasted fields, so instead this routine should be called
- * when such a HeapTuple is being converted into a Datum.
- *
- * While we're at it, we decompress any compressed fields too. This is not
- * necessary for correctness, but reflects an expectation that compression
- * will be more effective if applied to the whole tuple not individual
- * fields. We are not so concerned about that that we want to deconstruct
- * and reconstruct tuples just to get rid of compressed fields, however.
- * So callers typically won't call this unless they see that the tuple has
- * at least one external field.
- *
- * On the other hand, in-line short-header varlena fields are left alone.
- * If we "untoasted" them here, they'd just get changed back to short-header
- * format anyway within heap_fill_tuple.
- * ----------
- */
-Datum
-toast_flatten_tuple_to_datum(HeapTupleHeader tup,
- uint32 tup_len,
- TupleDesc tupleDesc)
-{
- HeapTupleHeader new_data;
- int32 new_header_len;
- int32 new_data_len;
- int32 new_tuple_len;
- HeapTupleData tmptup;
- int numAttrs = tupleDesc->natts;
- int i;
- bool has_nulls = false;
- Datum toast_values[MaxTupleAttributeNumber];
- bool toast_isnull[MaxTupleAttributeNumber];
- bool toast_free[MaxTupleAttributeNumber];
-
- /* Build a temporary HeapTuple control structure */
- tmptup.t_len = tup_len;
- ItemPointerSetInvalid(&(tmptup.t_self));
- tmptup.t_tableOid = InvalidOid;
- tmptup.t_data = tup;
-
- /*
- * Break down the tuple into fields.
- */
- Assert(numAttrs <= MaxTupleAttributeNumber);
- heap_deform_tuple(&tmptup, tupleDesc, toast_values, toast_isnull);
-
- memset(toast_free, 0, numAttrs * sizeof(bool));
-
- for (i = 0; i < numAttrs; i++)
- {
- /*
- * Look at non-null varlena attributes
- */
- if (toast_isnull[i])
- has_nulls = true;
- else if (TupleDescAttr(tupleDesc, i)->attlen == -1)
- {
- struct varlena *new_value;
-
- new_value = (struct varlena *) DatumGetPointer(toast_values[i]);
- if (VARATT_IS_EXTERNAL(new_value) ||
- VARATT_IS_COMPRESSED(new_value))
- {
- new_value = heap_tuple_untoast_attr(new_value);
- toast_values[i] = PointerGetDatum(new_value);
- toast_free[i] = true;
- }
- }
- }
-
- /*
- * Calculate the new size of the tuple.
- *
- * This should match the reconstruction code in toast_insert_or_update.
- */
- new_header_len = SizeofHeapTupleHeader;
- if (has_nulls)
- new_header_len += BITMAPLEN(numAttrs);
- new_header_len = MAXALIGN(new_header_len);
- new_data_len = heap_compute_data_size(tupleDesc,
- toast_values, toast_isnull);
- new_tuple_len = new_header_len + new_data_len;
-
- new_data = (HeapTupleHeader) palloc0(new_tuple_len);
-
- /*
- * Copy the existing tuple header, but adjust natts and t_hoff.
- */
- memcpy(new_data, tup, SizeofHeapTupleHeader);
- HeapTupleHeaderSetNatts(new_data, numAttrs);
- new_data->t_hoff = new_header_len;
-
- /* Set the composite-Datum header fields correctly */
- HeapTupleHeaderSetDatumLength(new_data, new_tuple_len);
- HeapTupleHeaderSetTypeId(new_data, tupleDesc->tdtypeid);
- HeapTupleHeaderSetTypMod(new_data, tupleDesc->tdtypmod);
-
- /* Copy over the data, and fill the null bitmap if needed */
- heap_fill_tuple(tupleDesc,
- toast_values,
- toast_isnull,
- (char *) new_data + new_header_len,
- new_data_len,
- &(new_data->t_infomask),
- has_nulls ? new_data->t_bits : NULL);
-
- /*
- * Free allocated temp values
- */
- for (i = 0; i < numAttrs; i++)
- if (toast_free[i])
- pfree(DatumGetPointer(toast_values[i]));
-
- return PointerGetDatum(new_data);
-}
-
-
-/* ----------
- * toast_build_flattened_tuple -
- *
- * Build a tuple containing no out-of-line toasted fields.
- * (This does not eliminate compressed or short-header datums.)
- *
- * This is essentially just like heap_form_tuple, except that it will
- * expand any external-data pointers beforehand.
- *
- * It's not very clear whether it would be preferable to decompress
- * in-line compressed datums while at it. For now, we don't.
- * ----------
- */
-HeapTuple
-toast_build_flattened_tuple(TupleDesc tupleDesc,
- Datum *values,
- bool *isnull)
-{
- HeapTuple new_tuple;
- int numAttrs = tupleDesc->natts;
- int num_to_free;
- int i;
- Datum new_values[MaxTupleAttributeNumber];
- Pointer freeable_values[MaxTupleAttributeNumber];
-
- /*
- * We can pass the caller's isnull array directly to heap_form_tuple, but
- * we potentially need to modify the values array.
- */
- Assert(numAttrs <= MaxTupleAttributeNumber);
- memcpy(new_values, values, numAttrs * sizeof(Datum));
-
- num_to_free = 0;
- for (i = 0; i < numAttrs; i++)
- {
- /*
- * Look at non-null varlena attributes
- */
- if (!isnull[i] && TupleDescAttr(tupleDesc, i)->attlen == -1)
- {
- struct varlena *new_value;
-
- new_value = (struct varlena *) DatumGetPointer(new_values[i]);
- if (VARATT_IS_EXTERNAL(new_value))
- {
- new_value = heap_tuple_fetch_attr(new_value);
- new_values[i] = PointerGetDatum(new_value);
- freeable_values[num_to_free++] = (Pointer) new_value;
- }
- }
- }
-
- /*
- * Form the reconfigured tuple.
- */
- new_tuple = heap_form_tuple(tupleDesc, new_values, isnull);
-
- /*
- * Free allocated temp values
- */
- for (i = 0; i < num_to_free; i++)
- pfree(freeable_values[i]);
-
- return new_tuple;
-}
-
-
-/* ----------
- * toast_compress_datum -
- *
- * Create a compressed version of a varlena datum
- *
- * If we fail (ie, compressed result is actually bigger than original)
- * then return NULL. We must not use compressed data if it'd expand
- * the tuple!
- *
- * We use VAR{SIZE,DATA}_ANY so we can handle short varlenas here without
- * copying them. But we can't handle external or compressed datums.
- * ----------
- */
-Datum
-toast_compress_datum(Datum value)
-{
- struct varlena *tmp;
- int32 valsize = VARSIZE_ANY_EXHDR(DatumGetPointer(value));
- int32 len;
-
- Assert(!VARATT_IS_EXTERNAL(DatumGetPointer(value)));
- Assert(!VARATT_IS_COMPRESSED(DatumGetPointer(value)));
-
- /*
- * No point in wasting a palloc cycle if value size is out of the allowed
- * range for compression
- */
- if (valsize < PGLZ_strategy_default->min_input_size ||
- valsize > PGLZ_strategy_default->max_input_size)
- return PointerGetDatum(NULL);
-
- tmp = (struct varlena *) palloc(PGLZ_MAX_OUTPUT(valsize) +
- TOAST_COMPRESS_HDRSZ);
-
- /*
- * We recheck the actual size even if pglz_compress() reports success,
- * because it might be satisfied with having saved as little as one byte
- * in the compressed data --- which could turn into a net loss once you
- * consider header and alignment padding. Worst case, the compressed
- * format might require three padding bytes (plus header, which is
- * included in VARSIZE(tmp)), whereas the uncompressed format would take
- * only one header byte and no padding if the value is short enough. So
- * we insist on a savings of more than 2 bytes to ensure we have a gain.
- */
- len = pglz_compress(VARDATA_ANY(DatumGetPointer(value)),
- valsize,
- TOAST_COMPRESS_RAWDATA(tmp),
- PGLZ_strategy_default);
- if (len >= 0 &&
- len + TOAST_COMPRESS_HDRSZ < valsize - 2)
- {
- TOAST_COMPRESS_SET_RAWSIZE(tmp, valsize);
- SET_VARSIZE_COMPRESSED(tmp, len + TOAST_COMPRESS_HDRSZ);
- /* successful compression */
- return PointerGetDatum(tmp);
- }
- else
- {
- /* incompressible data */
- pfree(tmp);
- return PointerGetDatum(NULL);
- }
-}
-
-
-/* ----------
- * toast_get_valid_index
- *
- * Get OID of valid index associated to given toast relation. A toast
- * relation can have only one valid index at the same time.
- */
-Oid
-toast_get_valid_index(Oid toastoid, LOCKMODE lock)
-{
- int num_indexes;
- int validIndex;
- Oid validIndexOid;
- Relation *toastidxs;
- Relation toastrel;
-
- /* Open the toast relation */
- toastrel = table_open(toastoid, lock);
-
- /* Look for the valid index of the toast relation */
- validIndex = toast_open_indexes(toastrel,
- lock,
- &toastidxs,
- &num_indexes);
- validIndexOid = RelationGetRelid(toastidxs[validIndex]);
-
- /* Close the toast relation and all its indexes */
- toast_close_indexes(toastidxs, num_indexes, lock);
- table_close(toastrel, lock);
-
- return validIndexOid;
-}
-
-
-/* ----------
- * toast_save_datum -
- *
- * Save one single datum into the secondary relation and return
- * a Datum reference for it.
- *
- * rel: the main relation we're working with (not the toast rel!)
- * value: datum to be pushed to toast storage
- * oldexternal: if not NULL, toast pointer previously representing the datum
- * options: options to be passed to heap_insert() for toast rows
- * ----------
- */
-static Datum
-toast_save_datum(Relation rel, Datum value,
- struct varlena *oldexternal, int options)
-{
- Relation toastrel;
- Relation *toastidxs;
- HeapTuple toasttup;
- TupleDesc toasttupDesc;
- Datum t_values[3];
- bool t_isnull[3];
- CommandId mycid = GetCurrentCommandId(true);
- struct varlena *result;
- struct varatt_external toast_pointer;
- union
- {
- struct varlena hdr;
- /* this is to make the union big enough for a chunk: */
- char data[TOAST_MAX_CHUNK_SIZE + VARHDRSZ];
- /* ensure union is aligned well enough: */
- int32 align_it;
- } chunk_data;
- int32 chunk_size;
- int32 chunk_seq = 0;
- char *data_p;
- int32 data_todo;
- Pointer dval = DatumGetPointer(value);
- int num_indexes;
- int validIndex;
-
- Assert(!VARATT_IS_EXTERNAL(value));
-
- /*
- * Open the toast relation and its indexes. We can use the index to check
- * uniqueness of the OID we assign to the toasted item, even though it has
- * additional columns besides OID.
- */
- toastrel = table_open(rel->rd_rel->reltoastrelid, RowExclusiveLock);
- toasttupDesc = toastrel->rd_att;
-
- /* Open all the toast indexes and look for the valid one */
- validIndex = toast_open_indexes(toastrel,
- RowExclusiveLock,
- &toastidxs,
- &num_indexes);
-
- /*
- * Get the data pointer and length, and compute va_rawsize and va_extsize.
- *
- * va_rawsize is the size of the equivalent fully uncompressed datum, so
- * we have to adjust for short headers.
- *
- * va_extsize is the actual size of the data payload in the toast records.
- */
- if (VARATT_IS_SHORT(dval))
- {
- data_p = VARDATA_SHORT(dval);
- data_todo = VARSIZE_SHORT(dval) - VARHDRSZ_SHORT;
- toast_pointer.va_rawsize = data_todo + VARHDRSZ; /* as if not short */
- toast_pointer.va_extsize = data_todo;
- }
- else if (VARATT_IS_COMPRESSED(dval))
- {
- data_p = VARDATA(dval);
- data_todo = VARSIZE(dval) - VARHDRSZ;
- /* rawsize in a compressed datum is just the size of the payload */
- toast_pointer.va_rawsize = VARRAWSIZE_4B_C(dval) + VARHDRSZ;
- toast_pointer.va_extsize = data_todo;
- /* Assert that the numbers look like it's compressed */
- Assert(VARATT_EXTERNAL_IS_COMPRESSED(toast_pointer));
- }
- else
- {
- data_p = VARDATA(dval);
- data_todo = VARSIZE(dval) - VARHDRSZ;
- toast_pointer.va_rawsize = VARSIZE(dval);
- toast_pointer.va_extsize = data_todo;
- }
-
- /*
- * Insert the correct table OID into the result TOAST pointer.
- *
- * Normally this is the actual OID of the target toast table, but during
- * table-rewriting operations such as CLUSTER, we have to insert the OID
- * of the table's real permanent toast table instead. rd_toastoid is set
- * if we have to substitute such an OID.
- */
- if (OidIsValid(rel->rd_toastoid))
- toast_pointer.va_toastrelid = rel->rd_toastoid;
- else
- toast_pointer.va_toastrelid = RelationGetRelid(toastrel);
-
- /*
- * Choose an OID to use as the value ID for this toast value.
- *
- * Normally we just choose an unused OID within the toast table. But
- * during table-rewriting operations where we are preserving an existing
- * toast table OID, we want to preserve toast value OIDs too. So, if
- * rd_toastoid is set and we had a prior external value from that same
- * toast table, re-use its value ID. If we didn't have a prior external
- * value (which is a corner case, but possible if the table's attstorage
- * options have been changed), we have to pick a value ID that doesn't
- * conflict with either new or existing toast value OIDs.
- */
- if (!OidIsValid(rel->rd_toastoid))
- {
- /* normal case: just choose an unused OID */
- toast_pointer.va_valueid =
- GetNewOidWithIndex(toastrel,
- RelationGetRelid(toastidxs[validIndex]),
- (AttrNumber) 1);
- }
- else
- {
- /* rewrite case: check to see if value was in old toast table */
- toast_pointer.va_valueid = InvalidOid;
- if (oldexternal != NULL)
- {
- struct varatt_external old_toast_pointer;
-
- Assert(VARATT_IS_EXTERNAL_ONDISK(oldexternal));
- /* Must copy to access aligned fields */
- VARATT_EXTERNAL_GET_POINTER(old_toast_pointer, oldexternal);
- if (old_toast_pointer.va_toastrelid == rel->rd_toastoid)
- {
- /* This value came from the old toast table; reuse its OID */
- toast_pointer.va_valueid = old_toast_pointer.va_valueid;
-
- /*
- * There is a corner case here: the table rewrite might have
- * to copy both live and recently-dead versions of a row, and
- * those versions could easily reference the same toast value.
- * When we copy the second or later version of such a row,
- * reusing the OID will mean we select an OID that's already
- * in the new toast table. Check for that, and if so, just
- * fall through without writing the data again.
- *
- * While annoying and ugly-looking, this is a good thing
- * because it ensures that we wind up with only one copy of
- * the toast value when there is only one copy in the old
- * toast table. Before we detected this case, we'd have made
- * multiple copies, wasting space; and what's worse, the
- * copies belonging to already-deleted heap tuples would not
- * be reclaimed by VACUUM.
- */
- if (toastrel_valueid_exists(toastrel,
- toast_pointer.va_valueid))
- {
- /* Match, so short-circuit the data storage loop below */
- data_todo = 0;
- }
- }
- }
- if (toast_pointer.va_valueid == InvalidOid)
- {
- /*
- * new value; must choose an OID that doesn't conflict in either
- * old or new toast table
- */
- do
- {
- toast_pointer.va_valueid =
- GetNewOidWithIndex(toastrel,
- RelationGetRelid(toastidxs[validIndex]),
- (AttrNumber) 1);
- } while (toastid_valueid_exists(rel->rd_toastoid,
- toast_pointer.va_valueid));
- }
- }
-
- /*
- * Initialize constant parts of the tuple data
- */
- t_values[0] = ObjectIdGetDatum(toast_pointer.va_valueid);
- t_values[2] = PointerGetDatum(&chunk_data);
- t_isnull[0] = false;
- t_isnull[1] = false;
- t_isnull[2] = false;
-
- /*
- * Split up the item into chunks
- */
- while (data_todo > 0)
- {
- int i;
-
- CHECK_FOR_INTERRUPTS();
-
- /*
- * Calculate the size of this chunk
- */
- chunk_size = Min(TOAST_MAX_CHUNK_SIZE, data_todo);
-
- /*
- * Build a tuple and store it
- */
- t_values[1] = Int32GetDatum(chunk_seq++);
- SET_VARSIZE(&chunk_data, chunk_size + VARHDRSZ);
- memcpy(VARDATA(&chunk_data), data_p, chunk_size);
- toasttup = heap_form_tuple(toasttupDesc, t_values, t_isnull);
-
- heap_insert(toastrel, toasttup, mycid, options, NULL);
-
- /*
- * Create the index entry. We cheat a little here by not using
- * FormIndexDatum: this relies on the knowledge that the index columns
- * are the same as the initial columns of the table for all the
- * indexes. We also cheat by not providing an IndexInfo: this is okay
- * for now because btree doesn't need one, but we might have to be
- * more honest someday.
- *
- * Note also that there had better not be any user-created index on
- * the TOAST table, since we don't bother to update anything else.
- */
- for (i = 0; i < num_indexes; i++)
- {
- /* Only index relations marked as ready can be updated */
- if (toastidxs[i]->rd_index->indisready)
- index_insert(toastidxs[i], t_values, t_isnull,
- &(toasttup->t_self),
- toastrel,
- toastidxs[i]->rd_index->indisunique ?
- UNIQUE_CHECK_YES : UNIQUE_CHECK_NO,
- NULL);
- }
-
- /*
- * Free memory
- */
- heap_freetuple(toasttup);
-
- /*
- * Move on to next chunk
- */
- data_todo -= chunk_size;
- data_p += chunk_size;
- }
-
- /*
- * Done - close toast relation and its indexes
- */
- toast_close_indexes(toastidxs, num_indexes, RowExclusiveLock);
- table_close(toastrel, RowExclusiveLock);
-
- /*
- * Create the TOAST pointer value that we'll return
- */
- result = (struct varlena *) palloc(TOAST_POINTER_SIZE);
- SET_VARTAG_EXTERNAL(result, VARTAG_ONDISK);
- memcpy(VARDATA_EXTERNAL(result), &toast_pointer, sizeof(toast_pointer));
-
- return PointerGetDatum(result);
-}
-
-
-/* ----------
- * toast_delete_datum -
- *
- * Delete a single external stored value.
- * ----------
- */
-static void
-toast_delete_datum(Relation rel, Datum value, bool is_speculative)
-{
- struct varlena *attr = (struct varlena *) DatumGetPointer(value);
- struct varatt_external toast_pointer;
- Relation toastrel;
- Relation *toastidxs;
- ScanKeyData toastkey;
- SysScanDesc toastscan;
- HeapTuple toasttup;
- int num_indexes;
- int validIndex;
- SnapshotData SnapshotToast;
-
- if (!VARATT_IS_EXTERNAL_ONDISK(attr))
- return;
-
- /* Must copy to access aligned fields */
- VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);
-
- /*
- * Open the toast relation and its indexes
- */
- toastrel = table_open(toast_pointer.va_toastrelid, RowExclusiveLock);
-
- /* Fetch valid relation used for process */
- validIndex = toast_open_indexes(toastrel,
- RowExclusiveLock,
- &toastidxs,
- &num_indexes);
-
- /*
- * Setup a scan key to find chunks with matching va_valueid
- */
- ScanKeyInit(&toastkey,
- (AttrNumber) 1,
- BTEqualStrategyNumber, F_OIDEQ,
- ObjectIdGetDatum(toast_pointer.va_valueid));
-
- /*
- * Find all the chunks. (We don't actually care whether we see them in
- * sequence or not, but since we've already locked the index we might as
- * well use systable_beginscan_ordered.)
- */
- init_toast_snapshot(&SnapshotToast);
- toastscan = systable_beginscan_ordered(toastrel, toastidxs[validIndex],
- &SnapshotToast, 1, &toastkey);
- while ((toasttup = systable_getnext_ordered(toastscan, ForwardScanDirection)) != NULL)
- {
- /*
- * Have a chunk, delete it
- */
- if (is_speculative)
- heap_abort_speculative(toastrel, &toasttup->t_self);
- else
- simple_heap_delete(toastrel, &toasttup->t_self);
- }
-
- /*
- * End scan and close relations
- */
- systable_endscan_ordered(toastscan);
- toast_close_indexes(toastidxs, num_indexes, RowExclusiveLock);
- table_close(toastrel, RowExclusiveLock);
-}
-
-
-/* ----------
- * toastrel_valueid_exists -
- *
- * Test whether a toast value with the given ID exists in the toast relation.
- * For safety, we consider a value to exist if there are either live or dead
- * toast rows with that ID; see notes for GetNewOidWithIndex().
- * ----------
- */
-static bool
-toastrel_valueid_exists(Relation toastrel, Oid valueid)
-{
- bool result = false;
- ScanKeyData toastkey;
- SysScanDesc toastscan;
- int num_indexes;
- int validIndex;
- Relation *toastidxs;
-
- /* Fetch a valid index relation */
- validIndex = toast_open_indexes(toastrel,
- RowExclusiveLock,
- &toastidxs,
- &num_indexes);
-
- /*
- * Setup a scan key to find chunks with matching va_valueid
- */
- ScanKeyInit(&toastkey,
- (AttrNumber) 1,
- BTEqualStrategyNumber, F_OIDEQ,
- ObjectIdGetDatum(valueid));
-
- /*
- * Is there any such chunk?
- */
- toastscan = systable_beginscan(toastrel,
- RelationGetRelid(toastidxs[validIndex]),
- true, SnapshotAny, 1, &toastkey);
-
- if (systable_getnext(toastscan) != NULL)
- result = true;
-
- systable_endscan(toastscan);
-
- /* Clean up */
- toast_close_indexes(toastidxs, num_indexes, RowExclusiveLock);
-
- return result;
-}
-
-/* ----------
- * toastid_valueid_exists -
- *
- * As above, but work from toast rel's OID not an open relation
- * ----------
- */
-static bool
-toastid_valueid_exists(Oid toastrelid, Oid valueid)
-{
- bool result;
- Relation toastrel;
-
- toastrel = table_open(toastrelid, AccessShareLock);
-
- result = toastrel_valueid_exists(toastrel, valueid);
-
- table_close(toastrel, AccessShareLock);
-
- return result;
-}
-
-
-/* ----------
- * toast_fetch_datum -
- *
- * Reconstruct an in memory Datum from the chunks saved
- * in the toast relation
- * ----------
- */
-static struct varlena *
-toast_fetch_datum(struct varlena *attr)
-{
- Relation toastrel;
- Relation *toastidxs;
- ScanKeyData toastkey;
- SysScanDesc toastscan;
- HeapTuple ttup;
- TupleDesc toasttupDesc;
- struct varlena *result;
- struct varatt_external toast_pointer;
- int32 ressize;
- int32 residx,
- nextidx;
- int32 numchunks;
- Pointer chunk;
- bool isnull;
- char *chunkdata;
- int32 chunksize;
- int num_indexes;
- int validIndex;
- SnapshotData SnapshotToast;
-
- if (!VARATT_IS_EXTERNAL_ONDISK(attr))
- elog(ERROR, "toast_fetch_datum shouldn't be called for non-ondisk datums");
-
- /* Must copy to access aligned fields */
- VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);
-
- ressize = toast_pointer.va_extsize;
- numchunks = ((ressize - 1) / TOAST_MAX_CHUNK_SIZE) + 1;
-
- result = (struct varlena *) palloc(ressize + VARHDRSZ);
-
- if (VARATT_EXTERNAL_IS_COMPRESSED(toast_pointer))
- SET_VARSIZE_COMPRESSED(result, ressize + VARHDRSZ);
- else
- SET_VARSIZE(result, ressize + VARHDRSZ);
-
- /*
- * Open the toast relation and its indexes
- */
- toastrel = table_open(toast_pointer.va_toastrelid, AccessShareLock);
- toasttupDesc = toastrel->rd_att;
-
- /* Look for the valid index of the toast relation */
- validIndex = toast_open_indexes(toastrel,
- AccessShareLock,
- &toastidxs,
- &num_indexes);
-
- /*
- * Setup a scan key to fetch from the index by va_valueid
- */
- ScanKeyInit(&toastkey,
- (AttrNumber) 1,
- BTEqualStrategyNumber, F_OIDEQ,
- ObjectIdGetDatum(toast_pointer.va_valueid));
-
- /*
- * Read the chunks by index
- *
- * Note that because the index is actually on (valueid, chunkidx) we will
- * see the chunks in chunkidx order, even though we didn't explicitly ask
- * for it.
- */
- nextidx = 0;
-
- init_toast_snapshot(&SnapshotToast);
- toastscan = systable_beginscan_ordered(toastrel, toastidxs[validIndex],
- &SnapshotToast, 1, &toastkey);
- while ((ttup = systable_getnext_ordered(toastscan, ForwardScanDirection)) != NULL)
- {
- /*
- * Have a chunk, extract the sequence number and the data
- */
- residx = DatumGetInt32(fastgetattr(ttup, 2, toasttupDesc, &isnull));
- Assert(!isnull);
- chunk = DatumGetPointer(fastgetattr(ttup, 3, toasttupDesc, &isnull));
- Assert(!isnull);
- if (!VARATT_IS_EXTENDED(chunk))
- {
- chunksize = VARSIZE(chunk) - VARHDRSZ;
- chunkdata = VARDATA(chunk);
- }
- else if (VARATT_IS_SHORT(chunk))
- {
- /* could happen due to heap_form_tuple doing its thing */
- chunksize = VARSIZE_SHORT(chunk) - VARHDRSZ_SHORT;
- chunkdata = VARDATA_SHORT(chunk);
- }
- else
- {
- /* should never happen */
- elog(ERROR, "found toasted toast chunk for toast value %u in %s",
- toast_pointer.va_valueid,
- RelationGetRelationName(toastrel));
- chunksize = 0; /* keep compiler quiet */
- chunkdata = NULL;
- }
-
- /*
- * Some checks on the data we've found
- */
- if (residx != nextidx)
- ereport(ERROR,
- (errcode(ERRCODE_DATA_CORRUPTED),
- errmsg_internal("unexpected chunk number %d (expected %d) for toast value %u in %s",
- residx, nextidx,
- toast_pointer.va_valueid,
- RelationGetRelationName(toastrel))));
- if (residx < numchunks - 1)
- {
- if (chunksize != TOAST_MAX_CHUNK_SIZE)
- ereport(ERROR,
- (errcode(ERRCODE_DATA_CORRUPTED),
- errmsg_internal("unexpected chunk size %d (expected %d) in chunk %d of %d for toast value %u in %s",
- chunksize, (int) TOAST_MAX_CHUNK_SIZE,
- residx, numchunks,
- toast_pointer.va_valueid,
- RelationGetRelationName(toastrel))));
- }
- else if (residx == numchunks - 1)
- {
- if ((residx * TOAST_MAX_CHUNK_SIZE + chunksize) != ressize)
- ereport(ERROR,
- (errcode(ERRCODE_DATA_CORRUPTED),
- errmsg_internal("unexpected chunk size %d (expected %d) in final chunk %d for toast value %u in %s",
- chunksize,
- (int) (ressize - residx * TOAST_MAX_CHUNK_SIZE),
- residx,
- toast_pointer.va_valueid,
- RelationGetRelationName(toastrel))));
- }
- else
- ereport(ERROR,
- (errcode(ERRCODE_DATA_CORRUPTED),
- errmsg_internal("unexpected chunk number %d (out of range %d..%d) for toast value %u in %s",
- residx,
- 0, numchunks - 1,
- toast_pointer.va_valueid,
- RelationGetRelationName(toastrel))));
-
- /*
- * Copy the data into proper place in our result
- */
- memcpy(VARDATA(result) + residx * TOAST_MAX_CHUNK_SIZE,
- chunkdata,
- chunksize);
-
- nextidx++;
- }
-
- /*
- * Final checks that we successfully fetched the datum
- */
- if (nextidx != numchunks)
- ereport(ERROR,
- (errcode(ERRCODE_DATA_CORRUPTED),
- errmsg_internal("missing chunk number %d for toast value %u in %s",
- nextidx,
- toast_pointer.va_valueid,
- RelationGetRelationName(toastrel))));
-
- /*
- * End scan and close relations
- */
- systable_endscan_ordered(toastscan);
- toast_close_indexes(toastidxs, num_indexes, AccessShareLock);
- table_close(toastrel, AccessShareLock);
-
- return result;
-}
-
-/* ----------
- * toast_fetch_datum_slice -
- *
- * Reconstruct a segment of a Datum from the chunks saved
- * in the toast relation
- *
- * Note that this function only supports non-compressed external datums.
- * ----------
- */
-static struct varlena *
-toast_fetch_datum_slice(struct varlena *attr, int32 sliceoffset, int32 length)
-{
- Relation toastrel;
- Relation *toastidxs;
- ScanKeyData toastkey[3];
- int nscankeys;
- SysScanDesc toastscan;
- HeapTuple ttup;
- TupleDesc toasttupDesc;
- struct varlena *result;
- struct varatt_external toast_pointer;
- int32 attrsize;
- int32 residx;
- int32 nextidx;
- int numchunks;
- int startchunk;
- int endchunk;
- int32 startoffset;
- int32 endoffset;
- int totalchunks;
- Pointer chunk;
- bool isnull;
- char *chunkdata;
- int32 chunksize;
- int32 chcpystrt;
- int32 chcpyend;
- int num_indexes;
- int validIndex;
- SnapshotData SnapshotToast;
-
- if (!VARATT_IS_EXTERNAL_ONDISK(attr))
- elog(ERROR, "toast_fetch_datum_slice shouldn't be called for non-ondisk datums");
-
- /* Must copy to access aligned fields */
- VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr);
-
- /*
- * It's nonsense to fetch slices of a compressed datum -- this isn't lo_*
- * we can't return a compressed datum which is meaningful to toast later
- */
- Assert(!VARATT_EXTERNAL_IS_COMPRESSED(toast_pointer));
-
- attrsize = toast_pointer.va_extsize;
- totalchunks = ((attrsize - 1) / TOAST_MAX_CHUNK_SIZE) + 1;
-
- if (sliceoffset >= attrsize)
- {
- sliceoffset = 0;
- length = 0;
- }
-
- if (((sliceoffset + length) > attrsize) || length < 0)
- length = attrsize - sliceoffset;
-
- result = (struct varlena *) palloc(length + VARHDRSZ);
-
- SET_VARSIZE(result, length + VARHDRSZ);
-
- if (length == 0)
- return result; /* Can save a lot of work at this point! */
-
- startchunk = sliceoffset / TOAST_MAX_CHUNK_SIZE;
- endchunk = (sliceoffset + length - 1) / TOAST_MAX_CHUNK_SIZE;
- numchunks = (endchunk - startchunk) + 1;
-
- startoffset = sliceoffset % TOAST_MAX_CHUNK_SIZE;
- endoffset = (sliceoffset + length - 1) % TOAST_MAX_CHUNK_SIZE;
-
- /*
- * Open the toast relation and its indexes
- */
- toastrel = table_open(toast_pointer.va_toastrelid, AccessShareLock);
- toasttupDesc = toastrel->rd_att;
-
- /* Look for the valid index of toast relation */
- validIndex = toast_open_indexes(toastrel,
- AccessShareLock,
- &toastidxs,
- &num_indexes);
-
- /*
- * Setup a scan key to fetch from the index. This is either two keys or
- * three depending on the number of chunks.
- */
- ScanKeyInit(&toastkey[0],
- (AttrNumber) 1,
- BTEqualStrategyNumber, F_OIDEQ,
- ObjectIdGetDatum(toast_pointer.va_valueid));
-
- /*
- * Use equality condition for one chunk, a range condition otherwise:
- */
- if (numchunks == 1)
- {
- ScanKeyInit(&toastkey[1],
- (AttrNumber) 2,
- BTEqualStrategyNumber, F_INT4EQ,
- Int32GetDatum(startchunk));
- nscankeys = 2;
- }
- else
- {
- ScanKeyInit(&toastkey[1],
- (AttrNumber) 2,
- BTGreaterEqualStrategyNumber, F_INT4GE,
- Int32GetDatum(startchunk));
- ScanKeyInit(&toastkey[2],
- (AttrNumber) 2,
- BTLessEqualStrategyNumber, F_INT4LE,
- Int32GetDatum(endchunk));
- nscankeys = 3;
- }
-
- /*
- * Read the chunks by index
- *
- * The index is on (valueid, chunkidx) so they will come in order
- */
- init_toast_snapshot(&SnapshotToast);
- nextidx = startchunk;
- toastscan = systable_beginscan_ordered(toastrel, toastidxs[validIndex],
- &SnapshotToast, nscankeys, toastkey);
- while ((ttup = systable_getnext_ordered(toastscan, ForwardScanDirection)) != NULL)
- {
- /*
- * Have a chunk, extract the sequence number and the data
- */
- residx = DatumGetInt32(fastgetattr(ttup, 2, toasttupDesc, &isnull));
- Assert(!isnull);
- chunk = DatumGetPointer(fastgetattr(ttup, 3, toasttupDesc, &isnull));
- Assert(!isnull);
- if (!VARATT_IS_EXTENDED(chunk))
- {
- chunksize = VARSIZE(chunk) - VARHDRSZ;
- chunkdata = VARDATA(chunk);
- }
- else if (VARATT_IS_SHORT(chunk))
- {
- /* could happen due to heap_form_tuple doing its thing */
- chunksize = VARSIZE_SHORT(chunk) - VARHDRSZ_SHORT;
- chunkdata = VARDATA_SHORT(chunk);
- }
- else
- {
- /* should never happen */
- elog(ERROR, "found toasted toast chunk for toast value %u in %s",
- toast_pointer.va_valueid,
- RelationGetRelationName(toastrel));
- chunksize = 0; /* keep compiler quiet */
- chunkdata = NULL;
- }
-
- /*
- * Some checks on the data we've found
- */
- if ((residx != nextidx) || (residx > endchunk) || (residx < startchunk))
- elog(ERROR, "unexpected chunk number %d (expected %d) for toast value %u in %s",
- residx, nextidx,
- toast_pointer.va_valueid,
- RelationGetRelationName(toastrel));
- if (residx < totalchunks - 1)
- {
- if (chunksize != TOAST_MAX_CHUNK_SIZE)
- elog(ERROR, "unexpected chunk size %d (expected %d) in chunk %d of %d for toast value %u in %s when fetching slice",
- chunksize, (int) TOAST_MAX_CHUNK_SIZE,
- residx, totalchunks,
- toast_pointer.va_valueid,
- RelationGetRelationName(toastrel));
- }
- else if (residx == totalchunks - 1)
- {
- if ((residx * TOAST_MAX_CHUNK_SIZE + chunksize) != attrsize)
- elog(ERROR, "unexpected chunk size %d (expected %d) in final chunk %d for toast value %u in %s when fetching slice",
- chunksize,
- (int) (attrsize - residx * TOAST_MAX_CHUNK_SIZE),
- residx,
- toast_pointer.va_valueid,
- RelationGetRelationName(toastrel));
- }
- else
- elog(ERROR, "unexpected chunk number %d (out of range %d..%d) for toast value %u in %s",
- residx,
- 0, totalchunks - 1,
- toast_pointer.va_valueid,
- RelationGetRelationName(toastrel));
-
- /*
- * Copy the data into proper place in our result
- */
- chcpystrt = 0;
- chcpyend = chunksize - 1;
- if (residx == startchunk)
- chcpystrt = startoffset;
- if (residx == endchunk)
- chcpyend = endoffset;
-
- memcpy(VARDATA(result) +
- (residx * TOAST_MAX_CHUNK_SIZE - sliceoffset) + chcpystrt,
- chunkdata + chcpystrt,
- (chcpyend - chcpystrt) + 1);
-
- nextidx++;
- }
-
- /*
- * Final checks that we successfully fetched the datum
- */
- if (nextidx != (endchunk + 1))
- elog(ERROR, "missing chunk number %d for toast value %u in %s",
- nextidx,
- toast_pointer.va_valueid,
- RelationGetRelationName(toastrel));
-
- /*
- * End scan and close relations
- */
- systable_endscan_ordered(toastscan);
- toast_close_indexes(toastidxs, num_indexes, AccessShareLock);
- table_close(toastrel, AccessShareLock);
-
- return result;
-}
-
-/* ----------
- * toast_decompress_datum -
- *
- * Decompress a compressed version of a varlena datum
- */
-static struct varlena *
-toast_decompress_datum(struct varlena *attr)
-{
- struct varlena *result;
-
- Assert(VARATT_IS_COMPRESSED(attr));
-
- result = (struct varlena *)
- palloc(TOAST_COMPRESS_RAWSIZE(attr) + VARHDRSZ);
- SET_VARSIZE(result, TOAST_COMPRESS_RAWSIZE(attr) + VARHDRSZ);
-
- if (pglz_decompress(TOAST_COMPRESS_RAWDATA(attr),
- VARSIZE(attr) - TOAST_COMPRESS_HDRSZ,
- VARDATA(result),
- TOAST_COMPRESS_RAWSIZE(attr), true) < 0)
- elog(ERROR, "compressed data is corrupted");
-
- return result;
-}
-
-
-/* ----------
- * toast_decompress_datum_slice -
- *
- * Decompress the front of a compressed version of a varlena datum.
- * offset handling happens in heap_tuple_untoast_attr_slice.
- * Here we just decompress a slice from the front.
- */
-static struct varlena *
-toast_decompress_datum_slice(struct varlena *attr, int32 slicelength)
-{
- struct varlena *result;
- int32 rawsize;
-
- Assert(VARATT_IS_COMPRESSED(attr));
-
- result = (struct varlena *) palloc(slicelength + VARHDRSZ);
-
- rawsize = pglz_decompress(TOAST_COMPRESS_RAWDATA(attr),
- VARSIZE(attr) - TOAST_COMPRESS_HDRSZ,
- VARDATA(result),
- slicelength, false);
- if (rawsize < 0)
- elog(ERROR, "compressed data is corrupted");
-
- SET_VARSIZE(result, rawsize + VARHDRSZ);
- return result;
-}
-
-
-/* ----------
- * toast_open_indexes
- *
- * Get an array of the indexes associated to the given toast relation
- * and return as well the position of the valid index used by the toast
- * relation in this array. It is the responsibility of the caller of this
- * function to close the indexes as well as free them.
- */
-static int
-toast_open_indexes(Relation toastrel,
- LOCKMODE lock,
- Relation **toastidxs,
- int *num_indexes)
-{
- int i = 0;
- int res = 0;
- bool found = false;
- List *indexlist;
- ListCell *lc;
-
- /* Get index list of the toast relation */
- indexlist = RelationGetIndexList(toastrel);
- Assert(indexlist != NIL);
-
- *num_indexes = list_length(indexlist);
-
- /* Open all the index relations */
- *toastidxs = (Relation *) palloc(*num_indexes * sizeof(Relation));
- foreach(lc, indexlist)
- (*toastidxs)[i++] = index_open(lfirst_oid(lc), lock);
-
- /* Fetch the first valid index in list */
- for (i = 0; i < *num_indexes; i++)
- {
- Relation toastidx = (*toastidxs)[i];
-
- if (toastidx->rd_index->indisvalid)
- {
- res = i;
- found = true;
- break;
- }
- }
-
- /*
- * Free index list, not necessary anymore as relations are opened and a
- * valid index has been found.
- */
- list_free(indexlist);
-
- /*
- * The toast relation should have one valid index, so something is going
- * wrong if there is nothing.
- */
- if (!found)
- elog(ERROR, "no valid index found for toast relation with Oid %u",
- RelationGetRelid(toastrel));
-
- return res;
-}
-
-/* ----------
- * toast_close_indexes
- *
- * Close an array of indexes for a toast relation and free it. This should
- * be called for a set of indexes opened previously with toast_open_indexes.
- */
-static void
-toast_close_indexes(Relation *toastidxs, int num_indexes, LOCKMODE lock)
-{
- int i;
-
- /* Close relations and clean up things */
- for (i = 0; i < num_indexes; i++)
- index_close(toastidxs[i], lock);
- pfree(toastidxs);
-}
-
-/* ----------
- * init_toast_snapshot
- *
- * Initialize an appropriate TOAST snapshot. We must use an MVCC snapshot
- * to initialize the TOAST snapshot; since we don't know which one to use,
- * just use the oldest one. This is safe: at worst, we will get a "snapshot
- * too old" error that might have been avoided otherwise.
- */
-static void
-init_toast_snapshot(Snapshot toast_snapshot)
-{
- Snapshot snapshot = GetOldestSnapshot();
-
- if (snapshot == NULL)
- elog(ERROR, "no known snapshots");
-
- InitToastSnapshot(*toast_snapshot, snapshot->lsn, snapshot->whenTaken);
-}
#include "access/clog.h"
#include "access/commit_ts.h"
+#include "access/heaptoast.h"
#include "access/multixact.h"
#include "access/rewriteheap.h"
#include "access/subtrans.h"
#include "access/timeline.h"
#include "access/transam.h"
-#include "access/tuptoaster.h"
#include "access/twophase.h"
#include "access/xact.h"
#include "access/xlog_internal.h"
#include <math.h>
+#include "access/detoast.h"
#include "access/genam.h"
#include "access/multixact.h"
#include "access/relation.h"
#include "access/tableam.h"
#include "access/transam.h"
#include "access/tupconvert.h"
-#include "access/tuptoaster.h"
#include "access/visibilitymap.h"
#include "access/xact.h"
#include "catalog/catalog.h"
#include "access/relscan.h"
#include "access/tableam.h"
#include "access/transam.h"
-#include "access/tuptoaster.h"
+#include "access/toast_internals.h"
#include "access/xact.h"
#include "access/xlog.h"
#include "catalog/pg_am.h"
*/
#include "postgres.h"
-#include "access/tuptoaster.h"
+#include "access/heaptoast.h"
#include "catalog/pg_type.h"
#include "commands/sequence.h"
#include "executor/execExpr.h"
*/
#include "postgres.h"
+#include "access/heaptoast.h"
#include "access/htup_details.h"
#include "access/tupdesc_details.h"
-#include "access/tuptoaster.h"
#include "funcapi.h"
#include "catalog/pg_type.h"
#include "nodes/nodeFuncs.h"
#include "postgres.h"
-#include "access/tuptoaster.h"
+#include "access/detoast.h"
#include "executor/tstoreReceiver.h"
#include <unistd.h>
#include <sys/stat.h>
+#include "access/detoast.h"
#include "access/heapam.h"
#include "access/rewriteheap.h"
#include "access/transam.h"
-#include "access/tuptoaster.h"
#include "access/xact.h"
#include "access/xlog_internal.h"
#include "catalog/catalog.h"
*/
#include "postgres.h"
+#include "access/detoast.h"
#include "access/genam.h"
#include "access/htup_details.h"
#include "access/table.h"
-#include "access/tuptoaster.h"
#include "catalog/indexing.h"
#include "catalog/pg_collation.h"
#include "catalog/pg_statistic_ext.h"
#include <limits.h>
+#include "access/detoast.h"
#include "access/genam.h"
+#include "access/htup_details.h"
#include "access/sysattr.h"
#include "access/table.h"
-#include "access/tuptoaster.h"
#include "access/xact.h"
#include "catalog/dependency.h"
#include "catalog/indexing.h"
*/
#include "postgres.h"
-#include "access/tuptoaster.h"
+#include "access/detoast.h"
#include "commands/vacuum.h"
#include "utils/array.h"
#include "utils/builtins.h"
#include "postgres.h"
-#include "access/tuptoaster.h"
+#include "access/detoast.h"
#include "fmgr.h"
#include "utils/datum.h"
#include "utils/expandeddatum.h"
*/
#include "postgres.h"
+#include "access/detoast.h"
+#include "access/heaptoast.h"
#include "access/htup_details.h"
-#include "access/tuptoaster.h"
#include "catalog/heap.h"
#include "catalog/pg_type.h"
#include "utils/builtins.h"
#include <ctype.h>
+#include "access/detoast.h"
#include "access/htup_details.h"
-#include "access/tuptoaster.h"
#include "catalog/pg_type.h"
#include "funcapi.h"
#include "libpq/pqformat.h"
#include "postgres.h"
#include "access/gist.h"
-#include "access/tuptoaster.h"
+#include "access/heaptoast.h"
#include "port/pg_bitutils.h"
#include "tsearch/ts_utils.h"
#include "utils/builtins.h"
*/
#include "postgres.h"
-#include "access/tuptoaster.h"
+#include "access/detoast.h"
#include "catalog/pg_collation.h"
#include "catalog/pg_type.h"
#include "libpq/pqformat.h"
#include <ctype.h>
#include <limits.h>
-#include "access/tuptoaster.h"
+#include "access/detoast.h"
#include "catalog/pg_collation.h"
#include "catalog/pg_type.h"
#include "common/int.h"
#include "postgres.h"
#include "access/genam.h"
+#include "access/heaptoast.h"
#include "access/relscan.h"
#include "access/sysattr.h"
#include "access/table.h"
-#include "access/tuptoaster.h"
#include "access/valid.h"
#include "access/xact.h"
#include "catalog/pg_collation.h"
#include "postgres.h"
-#include "access/tuptoaster.h"
+#include "access/detoast.h"
#include "catalog/pg_language.h"
#include "catalog/pg_proc.h"
#include "executor/functions.h"
#include <unistd.h>
#include "access/transam.h"
-#include "access/tuptoaster.h"
+#include "access/heaptoast.h"
#include "access/multixact.h"
#include "access/xlog.h"
#include "access/xlog_internal.h"
--- /dev/null
+/*-------------------------------------------------------------------------
+ *
+ * detoast.h
+ * Access to compressed and external varlena values.
+ *
+ * Copyright (c) 2000-2019, PostgreSQL Global Development Group
+ *
+ * src/include/access/detoast.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef DETOAST_H
+#define DETOAST_H
+
+/*
+ * Testing whether an externally-stored value is compressed now requires
+ * comparing extsize (the actual length of the external data) to rawsize
+ * (the original uncompressed datum's size). The latter includes VARHDRSZ
+ * overhead, the former doesn't. We never use compression unless it actually
+ * saves space, so we expect either equality or less-than.
+ */
+#define VARATT_EXTERNAL_IS_COMPRESSED(toast_pointer) \
+ ((toast_pointer).va_extsize < (toast_pointer).va_rawsize - VARHDRSZ)
+
+/*
+ * Macro to fetch the possibly-unaligned contents of an EXTERNAL datum
+ * into a local "struct varatt_external" toast pointer. This should be
+ * just a memcpy, but some versions of gcc seem to produce broken code
+ * that assumes the datum contents are aligned. Introducing an explicit
+ * intermediate "varattrib_1b_e *" variable seems to fix it.
+ */
+#define VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr) \
+do { \
+ varattrib_1b_e *attre = (varattrib_1b_e *) (attr); \
+ Assert(VARATT_IS_EXTERNAL(attre)); \
+ Assert(VARSIZE_EXTERNAL(attre) == sizeof(toast_pointer) + VARHDRSZ_EXTERNAL); \
+ memcpy(&(toast_pointer), VARDATA_EXTERNAL(attre), sizeof(toast_pointer)); \
+} while (0)
+
+/* Size of an EXTERNAL datum that contains a standard TOAST pointer */
+#define TOAST_POINTER_SIZE (VARHDRSZ_EXTERNAL + sizeof(varatt_external))
+
+/* Size of an EXTERNAL datum that contains an indirection pointer */
+#define INDIRECT_POINTER_SIZE (VARHDRSZ_EXTERNAL + sizeof(varatt_indirect))
+
+/* ----------
+ * heap_tuple_fetch_attr() -
+ *
+ * Fetches an external stored attribute from the toast
+ * relation. Does NOT decompress it, if stored external
+ * in compressed format.
+ * ----------
+ */
+extern struct varlena *heap_tuple_fetch_attr(struct varlena *attr);
+
+/* ----------
+ * heap_tuple_untoast_attr() -
+ *
+ * Fully detoasts one attribute, fetching and/or decompressing
+ * it as needed.
+ * ----------
+ */
+extern struct varlena *heap_tuple_untoast_attr(struct varlena *attr);
+
+/* ----------
+ * heap_tuple_untoast_attr_slice() -
+ *
+ * Fetches only the specified portion of an attribute.
+ * (Handles all cases for attribute storage)
+ * ----------
+ */
+extern struct varlena *heap_tuple_untoast_attr_slice(struct varlena *attr,
+ int32 sliceoffset,
+ int32 slicelength);
+
+/* ----------
+ * toast_raw_datum_size -
+ *
+ * Return the raw (detoasted) size of a varlena datum
+ * ----------
+ */
+extern Size toast_raw_datum_size(Datum value);
+
+/* ----------
+ * toast_datum_size -
+ *
+ * Return the storage size of a varlena datum
+ * ----------
+ */
+extern Size toast_datum_size(Datum value);
+
+#endif /* DETOAST_H */
/*-------------------------------------------------------------------------
*
- * tuptoaster.h
- * POSTGRES definitions for external and compressed storage
+ * heaptoast.h
+ * Heap-specific definitions for external and compressed storage
* of variable size attributes.
*
* Copyright (c) 2000-2019, PostgreSQL Global Development Group
*
- * src/include/access/tuptoaster.h
+ * src/include/access/heaptoast.h
*
*-------------------------------------------------------------------------
*/
-#ifndef TUPTOASTER_H
-#define TUPTOASTER_H
+#ifndef HEAPTOAST_H
+#define HEAPTOAST_H
#include "access/htup_details.h"
#include "storage/lockdefs.h"
#include "utils/relcache.h"
-/*
- * This enables de-toasting of index entries. Needed until VACUUM is
- * smart enough to rebuild indexes from scratch.
- */
-#define TOAST_INDEX_HACK
-
-
/*
* Find the maximum size of a tuple if there are to be N tuples per page.
*/
sizeof(int32) - \
VARHDRSZ)
-/* Size of an EXTERNAL datum that contains a standard TOAST pointer */
-#define TOAST_POINTER_SIZE (VARHDRSZ_EXTERNAL + sizeof(varatt_external))
-
-/* Size of an EXTERNAL datum that contains an indirection pointer */
-#define INDIRECT_POINTER_SIZE (VARHDRSZ_EXTERNAL + sizeof(varatt_indirect))
-
-/*
- * Testing whether an externally-stored value is compressed now requires
- * comparing extsize (the actual length of the external data) to rawsize
- * (the original uncompressed datum's size). The latter includes VARHDRSZ
- * overhead, the former doesn't. We never use compression unless it actually
- * saves space, so we expect either equality or less-than.
- */
-#define VARATT_EXTERNAL_IS_COMPRESSED(toast_pointer) \
- ((toast_pointer).va_extsize < (toast_pointer).va_rawsize - VARHDRSZ)
-
-/*
- * Macro to fetch the possibly-unaligned contents of an EXTERNAL datum
- * into a local "struct varatt_external" toast pointer. This should be
- * just a memcpy, but some versions of gcc seem to produce broken code
- * that assumes the datum contents are aligned. Introducing an explicit
- * intermediate "varattrib_1b_e *" variable seems to fix it.
- */
-#define VARATT_EXTERNAL_GET_POINTER(toast_pointer, attr) \
-do { \
- varattrib_1b_e *attre = (varattrib_1b_e *) (attr); \
- Assert(VARATT_IS_EXTERNAL(attre)); \
- Assert(VARSIZE_EXTERNAL(attre) == sizeof(toast_pointer) + VARHDRSZ_EXTERNAL); \
- memcpy(&(toast_pointer), VARDATA_EXTERNAL(attre), sizeof(toast_pointer)); \
-} while (0)
-
/* ----------
* toast_insert_or_update -
*
*/
extern void toast_delete(Relation rel, HeapTuple oldtup, bool is_speculative);
-/* ----------
- * heap_tuple_fetch_attr() -
- *
- * Fetches an external stored attribute from the toast
- * relation. Does NOT decompress it, if stored external
- * in compressed format.
- * ----------
- */
-extern struct varlena *heap_tuple_fetch_attr(struct varlena *attr);
-
-/* ----------
- * heap_tuple_untoast_attr() -
- *
- * Fully detoasts one attribute, fetching and/or decompressing
- * it as needed.
- * ----------
- */
-extern struct varlena *heap_tuple_untoast_attr(struct varlena *attr);
-
-/* ----------
- * heap_tuple_untoast_attr_slice() -
- *
- * Fetches only the specified portion of an attribute.
- * (Handles all cases for attribute storage)
- * ----------
- */
-extern struct varlena *heap_tuple_untoast_attr_slice(struct varlena *attr,
- int32 sliceoffset,
- int32 slicelength);
-
/* ----------
* toast_flatten_tuple -
*
Datum *values,
bool *isnull);
-/* ----------
- * toast_compress_datum -
- *
- * Create a compressed version of a varlena datum, if possible
- * ----------
- */
-extern Datum toast_compress_datum(Datum value);
-
-/* ----------
- * toast_raw_datum_size -
- *
- * Return the raw (detoasted) size of a varlena datum
- * ----------
- */
-extern Size toast_raw_datum_size(Datum value);
-
-/* ----------
- * toast_datum_size -
- *
- * Return the storage size of a varlena datum
- * ----------
- */
-extern Size toast_datum_size(Datum value);
-
-/* ----------
- * toast_get_valid_index -
- *
- * Return OID of valid index associated to a toast relation
- * ----------
- */
-extern Oid toast_get_valid_index(Oid toastoid, LOCKMODE lock);
-
-#endif /* TUPTOASTER_H */
+#endif /* HEAPTOAST_H */
--- /dev/null
+/*-------------------------------------------------------------------------
+ *
+ * toast_internals.h
+ * Internal definitions for the TOAST system.
+ *
+ * Copyright (c) 2000-2019, PostgreSQL Global Development Group
+ *
+ * src/include/access/toast_internals.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef TOAST_INTERNALS_H
+#define TOAST_INTERNALS_H
+
+#include "storage/lockdefs.h"
+#include "utils/relcache.h"
+#include "utils/snapshot.h"
+
+/*
+ * The information at the start of the compressed toast data.
+ */
+typedef struct toast_compress_header
+{
+ int32 vl_len_; /* varlena header (do not touch directly!) */
+ int32 rawsize;
+} toast_compress_header;
+
+/*
+ * Utilities for manipulation of header information for compressed
+ * toast entries.
+ */
+#define TOAST_COMPRESS_HDRSZ ((int32) sizeof(toast_compress_header))
+#define TOAST_COMPRESS_RAWSIZE(ptr) (((toast_compress_header *) (ptr))->rawsize)
+#define TOAST_COMPRESS_RAWDATA(ptr) \
+ (((char *) (ptr)) + TOAST_COMPRESS_HDRSZ)
+#define TOAST_COMPRESS_SET_RAWSIZE(ptr, len) \
+ (((toast_compress_header *) (ptr))->rawsize = (len))
+
+extern Datum toast_compress_datum(Datum value);
+extern Oid toast_get_valid_index(Oid toastoid, LOCKMODE lock);
+
+extern void toast_delete_datum(Relation rel, Datum value, bool is_speculative);
+extern Datum toast_save_datum(Relation rel, Datum value,
+ struct varlena *oldexternal, int options);
+
+extern int toast_open_indexes(Relation toastrel,
+ LOCKMODE lock,
+ Relation **toastidxs,
+ int *num_indexes);
+extern void toast_close_indexes(Relation *toastidxs, int num_indexes,
+ LOCKMODE lock);
+extern void init_toast_snapshot(Snapshot toast_snapshot);
+
+#endif /* TOAST_INTERNALS_H */
#include <ctype.h>
+#include "access/detoast.h"
#include "access/htup_details.h"
#include "access/transam.h"
#include "access/tupconvert.h"
-#include "access/tuptoaster.h"
#include "catalog/pg_proc.h"
#include "catalog/pg_type.h"
#include "commands/defrem.h"
#include <math.h>
#include <signal.h>
+#include "access/detoast.h"
#include "access/htup_details.h"
#include "access/transam.h"
-#include "access/tuptoaster.h"
#include "access/xact.h"
#include "catalog/pg_operator.h"
#include "catalog/pg_type.h"
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