PG_FUNCTION_INFO_V1(bt_page_items_bytea);
PG_FUNCTION_INFO_V1(bt_page_stats_1_9);
PG_FUNCTION_INFO_V1(bt_page_stats);
+PG_FUNCTION_INFO_V1(bt_multi_page_stats);
#define IS_INDEX(r) ((r)->rd_rel->relkind == RELKIND_INDEX)
#define IS_BTREE(r) ((r)->rd_rel->relam == BTREE_AM_OID)
#define DatumGetItemPointer(X) ((ItemPointer) DatumGetPointer(X))
#define ItemPointerGetDatum(X) PointerGetDatum(X)
-/* note: BlockNumber is unsigned, hence can't be negative */
-#define CHECK_RELATION_BLOCK_RANGE(rel, blkno) { \
- if ( RelationGetNumberOfBlocks(rel) <= (BlockNumber) (blkno) ) \
- elog(ERROR, "block number out of range"); }
-
/* ------------------------------------------------
* structure for single btree page statistics
* ------------------------------------------------
BTCycleId btpo_cycleid;
} BTPageStat;
+/*
+ * cross-call data structure for SRF for page stats
+ */
+typedef struct ua_page_stats
+{
+ Oid relid;
+ int64 blkno;
+ int64 blk_count;
+ bool allpages;
+} ua_page_stats;
+
+/*
+ * cross-call data structure for SRF for page items
+ */
+typedef struct ua_page_items
+{
+ Page page;
+ OffsetNumber offset;
+ bool leafpage;
+ bool rightmost;
+ TupleDesc tupd;
+} ua_page_items;
+
/* -------------------------------------------------
* GetBTPageStatistics()
}
/* -----------------------------------------------
- * bt_page_stats()
+ * check_relation_block_range()
*
- * Usage: SELECT * FROM bt_page_stats('t1_pkey', 1);
+ * Verify that a block number (given as int64) is valid for the relation.
* -----------------------------------------------
*/
-static Datum
-bt_page_stats_internal(PG_FUNCTION_ARGS, enum pageinspect_version ext_version)
+static void
+check_relation_block_range(Relation rel, int64 blkno)
{
- text *relname = PG_GETARG_TEXT_PP(0);
- int64 blkno = (ext_version == PAGEINSPECT_V1_8 ? PG_GETARG_UINT32(1) : PG_GETARG_INT64(1));
- Buffer buffer;
- Relation rel;
- RangeVar *relrv;
- Datum result;
- HeapTuple tuple;
- TupleDesc tupleDesc;
- int j;
- char *values[11];
- BTPageStat stat;
-
- if (!superuser())
+ /* Ensure we can cast to BlockNumber */
+ if (blkno < 0 || blkno > MaxBlockNumber)
ereport(ERROR,
- (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
- errmsg("must be superuser to use pageinspect functions")));
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("invalid block number %lld",
+ (long long) blkno)));
- relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
- rel = relation_openrv(relrv, AccessShareLock);
+ if ((BlockNumber) (blkno) >= RelationGetNumberOfBlocks(rel))
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+ errmsg("block number %lld is out of range",
+ (long long) blkno)));
+}
+/* -----------------------------------------------
+ * bt_index_block_validate()
+ *
+ * Validate index type is btree and block number
+ * is valid (and not the metapage).
+ * -----------------------------------------------
+ */
+static void
+bt_index_block_validate(Relation rel, int64 blkno)
+{
if (!IS_INDEX(rel) || !IS_BTREE(rel))
ereport(ERROR,
(errcode(ERRCODE_WRONG_OBJECT_TYPE),
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("cannot access temporary tables of other sessions")));
- if (blkno < 0 || blkno > MaxBlockNumber)
- ereport(ERROR,
- (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
- errmsg("invalid block number")));
-
if (blkno == 0)
ereport(ERROR,
(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
errmsg("block 0 is a meta page")));
- CHECK_RELATION_BLOCK_RANGE(rel, blkno);
+ check_relation_block_range(rel, blkno);
+}
+
+/* -----------------------------------------------
+ * bt_page_stats()
+ *
+ * Usage: SELECT * FROM bt_page_stats('t1_pkey', 1);
+ * Arguments are index relation name and block number
+ * -----------------------------------------------
+ */
+static Datum
+bt_page_stats_internal(PG_FUNCTION_ARGS, enum pageinspect_version ext_version)
+{
+ text *relname = PG_GETARG_TEXT_PP(0);
+ int64 blkno = (ext_version == PAGEINSPECT_V1_8 ? PG_GETARG_UINT32(1) : PG_GETARG_INT64(1));
+ Buffer buffer;
+ Relation rel;
+ RangeVar *relrv;
+ Datum result;
+ HeapTuple tuple;
+ TupleDesc tupleDesc;
+ int j;
+ char *values[11];
+ BTPageStat stat;
+
+ if (!superuser())
+ ereport(ERROR,
+ (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+ errmsg("must be superuser to use pageinspect functions")));
+
+ relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
+ rel = relation_openrv(relrv, AccessShareLock);
+
+ bt_index_block_validate(rel, blkno);
buffer = ReadBuffer(rel, blkno);
LockBuffer(buffer, BUFFER_LOCK_SHARE);
}
-/*
- * cross-call data structure for SRF
+/* -----------------------------------------------
+ * bt_multi_page_stats()
+ *
+ * Usage: SELECT * FROM bt_page_stats('t1_pkey', 1, 2);
+ * Arguments are index relation name, first block number, number of blocks
+ * (but number of blocks can be negative to mean "read all the rest")
+ * -----------------------------------------------
*/
-struct user_args
+Datum
+bt_multi_page_stats(PG_FUNCTION_ARGS)
{
- Page page;
- OffsetNumber offset;
- bool leafpage;
- bool rightmost;
- TupleDesc tupd;
-};
+ Relation rel;
+ ua_page_stats *uargs;
+ FuncCallContext *fctx;
+ MemoryContext mctx;
+
+ if (!superuser())
+ ereport(ERROR,
+ (errcode(ERRCODE_INSUFFICIENT_PRIVILEGE),
+ errmsg("must be superuser to use pageinspect functions")));
+
+ if (SRF_IS_FIRSTCALL())
+ {
+ text *relname = PG_GETARG_TEXT_PP(0);
+ int64 blkno = PG_GETARG_INT64(1);
+ int64 blk_count = PG_GETARG_INT64(2);
+ RangeVar *relrv;
+
+ fctx = SRF_FIRSTCALL_INIT();
+
+ relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
+ rel = relation_openrv(relrv, AccessShareLock);
+
+ /* Check that rel is a valid btree index and 1st block number is OK */
+ bt_index_block_validate(rel, blkno);
+
+ /*
+ * Check if upper bound of the specified range is valid. If only one
+ * page is requested, skip as we've already validated the page. (Also,
+ * it's important to skip this if blk_count is negative.)
+ */
+ if (blk_count > 1)
+ check_relation_block_range(rel, blkno + blk_count - 1);
+
+ /* Save arguments for reuse */
+ mctx = MemoryContextSwitchTo(fctx->multi_call_memory_ctx);
+
+ uargs = palloc(sizeof(ua_page_stats));
+
+ uargs->relid = RelationGetRelid(rel);
+ uargs->blkno = blkno;
+ uargs->blk_count = blk_count;
+ uargs->allpages = (blk_count < 0);
+
+ fctx->user_fctx = uargs;
+
+ MemoryContextSwitchTo(mctx);
+
+ /*
+ * To avoid possibly leaking a relcache reference if the SRF isn't run
+ * to completion, we close and re-open the index rel each time
+ * through, using the index's OID for re-opens to ensure we get the
+ * same rel. Keep the AccessShareLock though, to ensure it doesn't go
+ * away underneath us.
+ */
+ relation_close(rel, NoLock);
+ }
+
+ fctx = SRF_PERCALL_SETUP();
+ uargs = fctx->user_fctx;
+
+ /* We should have lock already */
+ rel = relation_open(uargs->relid, NoLock);
+
+ /* In all-pages mode, recheck the index length each time */
+ if (uargs->allpages)
+ uargs->blk_count = RelationGetNumberOfBlocks(rel) - uargs->blkno;
+
+ if (uargs->blk_count > 0)
+ {
+ /* We need to fetch next block statistics */
+ Buffer buffer;
+ Datum result;
+ HeapTuple tuple;
+ int j;
+ char *values[11];
+ BTPageStat stat;
+ TupleDesc tupleDesc;
+
+ buffer = ReadBuffer(rel, uargs->blkno);
+ LockBuffer(buffer, BUFFER_LOCK_SHARE);
+
+ /* keep compiler quiet */
+ stat.btpo_prev = stat.btpo_next = InvalidBlockNumber;
+ stat.btpo_flags = stat.free_size = stat.avg_item_size = 0;
+
+ GetBTPageStatistics(uargs->blkno, buffer, &stat);
+
+ UnlockReleaseBuffer(buffer);
+ relation_close(rel, NoLock);
+
+ /* Build a tuple descriptor for our result type */
+ if (get_call_result_type(fcinfo, NULL, &tupleDesc) != TYPEFUNC_COMPOSITE)
+ elog(ERROR, "return type must be a row type");
+
+ j = 0;
+ values[j++] = psprintf("%u", stat.blkno);
+ values[j++] = psprintf("%c", stat.type);
+ values[j++] = psprintf("%u", stat.live_items);
+ values[j++] = psprintf("%u", stat.dead_items);
+ values[j++] = psprintf("%u", stat.avg_item_size);
+ values[j++] = psprintf("%u", stat.page_size);
+ values[j++] = psprintf("%u", stat.free_size);
+ values[j++] = psprintf("%u", stat.btpo_prev);
+ values[j++] = psprintf("%u", stat.btpo_next);
+ values[j++] = psprintf("%u", stat.btpo_level);
+ values[j++] = psprintf("%d", stat.btpo_flags);
+
+ /* Construct tuple to be returned */
+ tuple = BuildTupleFromCStrings(TupleDescGetAttInMetadata(tupleDesc),
+ values);
+
+ result = HeapTupleGetDatum(tuple);
+
+ /*
+ * Move to the next block number and decrement the number of blocks
+ * still to be fetched
+ */
+ uargs->blkno++;
+ uargs->blk_count--;
+
+ SRF_RETURN_NEXT(fctx, result);
+ }
+
+ /* Done, so finally we can release the index lock */
+ relation_close(rel, AccessShareLock);
+ SRF_RETURN_DONE(fctx);
+}
/*-------------------------------------------------------
* bt_page_print_tuples()
* ------------------------------------------------------
*/
static Datum
-bt_page_print_tuples(struct user_args *uargs)
+bt_page_print_tuples(ua_page_items *uargs)
{
Page page = uargs->page;
OffsetNumber offset = uargs->offset;
Datum result;
FuncCallContext *fctx;
MemoryContext mctx;
- struct user_args *uargs;
+ ua_page_items *uargs;
if (!superuser())
ereport(ERROR,
relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
rel = relation_openrv(relrv, AccessShareLock);
- if (!IS_INDEX(rel) || !IS_BTREE(rel))
- ereport(ERROR,
- (errcode(ERRCODE_WRONG_OBJECT_TYPE),
- errmsg("\"%s\" is not a %s index",
- RelationGetRelationName(rel), "btree")));
-
- /*
- * Reject attempts to read non-local temporary relations; we would be
- * likely to get wrong data since we have no visibility into the
- * owning session's local buffers.
- */
- if (RELATION_IS_OTHER_TEMP(rel))
- ereport(ERROR,
- (errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
- errmsg("cannot access temporary tables of other sessions")));
-
- if (blkno < 0 || blkno > MaxBlockNumber)
- ereport(ERROR,
- (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
- errmsg("invalid block number")));
-
- if (blkno == 0)
- ereport(ERROR,
- (errcode(ERRCODE_INVALID_PARAMETER_VALUE),
- errmsg("block 0 is a meta page")));
-
- CHECK_RELATION_BLOCK_RANGE(rel, blkno);
+ bt_index_block_validate(rel, blkno);
buffer = ReadBuffer(rel, blkno);
LockBuffer(buffer, BUFFER_LOCK_SHARE);
*/
mctx = MemoryContextSwitchTo(fctx->multi_call_memory_ctx);
- uargs = palloc(sizeof(struct user_args));
+ uargs = palloc(sizeof(ua_page_items));
uargs->page = palloc(BLCKSZ);
memcpy(uargs->page, BufferGetPage(buffer), BLCKSZ);
bytea *raw_page = PG_GETARG_BYTEA_P(0);
Datum result;
FuncCallContext *fctx;
- struct user_args *uargs;
+ ua_page_items *uargs;
if (!superuser())
ereport(ERROR,
fctx = SRF_FIRSTCALL_INIT();
mctx = MemoryContextSwitchTo(fctx->multi_call_memory_ctx);
- uargs = palloc(sizeof(struct user_args));
+ uargs = palloc(sizeof(ua_page_items));
uargs->page = get_page_from_raw(raw_page);
projects / users / gsingh / postgres.git / commitdiff