Minor speed improvements

Author: brianc

lib/connection.js

@@ -472,8 +472,9 @@ Connection.prototype.parseZ = function(buffer, length) {
   return msg;
 };
 
+ROW_DESCRIPTION = 'rowDescription';
 Connection.prototype.parseT = function(buffer, length) {
-  var msg = new Message('rowDescription', length);
+  var msg = new Message(ROW_DESCRIPTION, length);
   msg.fieldCount = this.parseInt16(buffer);
   var fields = [];
   for(var i = 0; i < msg.fieldCount; i++){
@@ -483,44 +484,56 @@ Connection.prototype.parseT = function(buffer, length) {
   return msg;
 };
 
+var Field = function() {
+  this.name = null;
+  this.tableID = null;
+  this.columnID = null;
+  this.dataTypeID = null;
+  this.dataTypeSize = null;
+  this.dataTypeModifier = null;
+  this.format = null;
+};
+
+FORMAT_TEXT = 'text';
+FORMAT_BINARY = 'binary';
 Connection.prototype.parseField = function(buffer) {
-  var field = {
-    name: this.parseCString(buffer),
-    tableID: this.parseInt32(buffer),
-    columnID: this.parseInt16(buffer),
-    dataTypeID: this.parseInt32(buffer),
-    dataTypeSize: this.parseInt16(buffer),
-    dataTypeModifier: this.parseInt32(buffer),
-    format: undefined
-  };
+  var field = new Field();
+  field.name = this.parseCString(buffer);
+  field.tableID = this.parseInt32(buffer);
+  field.columnID = this.parseInt16(buffer);
+  field.dataTypeID = this.parseInt32(buffer);
+  field.dataTypeSize = this.parseInt16(buffer);
+  field.dataTypeModifier = this.parseInt32(buffer);
   if(this.parseInt16(buffer) === TEXT_MODE) {
     this._mode = TEXT_MODE;
-    field.format = 'text';
+    field.format = FORMAT_TEXT;
   } else {
     this._mode = BINARY_MODE;
-    this.readField = this.readBytes;
-    field.format = 'binary';
+    field.format = FORMAT_BINARY;
   }
   return field;
 };
 
+DATA_ROW = 'dataRow';
 var DataRowMessage = function(name, length, fieldCount) {
-  this.name = name;
+  this.name = DATA_ROW;
   this.length = length;
   this.fieldCount = fieldCount;
   this.fields = [];
-}
+};
+
 
-Connection.prototype.parseD = function(buffer, length) {
+//extremely hot-path code
+Connection.prototype[0x44] = Connection.prototype.parseD = function(buffer, length) {
   var fieldCount = this.parseInt16(buffer);
-  var msg = new DataRowMessage('dataRow', length, fieldCount);
+  var msg = new DataRowMessage(length, fieldCount);
   for(var i = 0; i < fieldCount; i++) {
-    var value = this._readValue(buffer);
-    msg.fields.push(value);
+    msg.fields.push(this._readValue(buffer));
   }
   return msg;
 };
 
+//extremely hot-path code
 Connection.prototype._readValue = function(buffer) {
   var length = this.parseInt32(buffer);
   if(length === -1) return null;