50x performance increase on javascript client prepared statement execution on linux!

lib/connection.js

@@ -78,8 +78,12 @@ p.password = function(password) {
   this._send(0x70, this.writer.addCString(password));
 };
 
-p._send = function(code, writer) {
-  return this.stream.write(writer.flush(code));
+p._send = function(code, more) {
+  if(more === true) {
+    this.writer.addHeader(code);
+  } else {
+    return this.stream.write(this.writer.flush(code));
+  }
 }
 
 var termBuffer = new Buffer([0x58, 0, 0, 0, 4]);
@@ -92,7 +96,9 @@ p.query = function(text) {
   this.stream.write(this.writer.addCString(text).flush(0x51));
 };
 
-p.parse = function(query) {
+//send parse message
+//"more" === true to buffer the message until flush() is called
+p.parse = function(query, more) {
   //expect something like this:
   // { name: 'queryName',
   //   text: 'select * from blah',
@@ -111,13 +117,13 @@ p.parse = function(query) {
     buffer.addInt32(query.types[i]);
   }
 
-  //0x50 = 'P'
-  this._send(0x50, buffer);
-
-  return this;
+  var code = 0x50;
+  this._send(code, more);
 };
 
-p.bind = function(config) {
+//send bind message
+//"more" === true to buffer the message until flush() is called
+p.bind = function(config, more) {
   //normalize config
   config = config || {};
   config.portal = config.portal || '';
@@ -141,11 +147,12 @@ p.bind = function(config) {
   }
   buffer.addInt16(0); //no format codes, use text
   //0x42 = 'B'
-
-  this._send(0x42, buffer);
+  this._send(0x42, more);
 };
 
-p.execute = function(config) {
+//send execute message
+//"more" === true to buffer the message until flush() is called
+p.execute = function(config, more) {
   config = config || {};
   config.portal = config.portal || '';
   config.rows = config.rows || '';
@@ -154,28 +161,34 @@ p.execute = function(config) {
     .addInt32(config.rows);
 
   //0x45 = 'E'
-  this._send(0x45, buffer);
+  this._send(0x45, more);
 };
 
 var emptyBuffer = Buffer(0);
 
 p.flush = function() {
   //0x48 = 'H'
-  this._send(0x48,this.writer.add(emptyBuffer));
+  this.writer.add(emptyBuffer)
+  this._send(0x48);
 }
 
 p.sync = function() {
-  //0x53 = 'S'
-  this._send(0x53, this.writer.add(emptyBuffer));
+  //clear out any pending data in the writer
+  this.writer.flush(0)
+  
+  this.writer.add(emptyBuffer);
+  this._send(0x53);
 };
 
 p.end = function() {
   //0x58 = 'X'
-  this._send(0x58, this.writer.add(emptyBuffer));
+  this.writer.add(emptyBuffer);
+  this._send(0x58);
 };
 
-p.describe = function(msg) {
-  this._send(0x44, this.writer.addCString(msg.type + (msg.name || '')));
+p.describe = function(msg, more) {
+  this.writer.addCString(msg.type + (msg.name || ''));
+  this._send(0x44, more);
 };
 
 //parsing methods

lib/query.js

@@ -106,7 +106,7 @@ p.getRows = function(connection) {
   connection.execute({
     portal: this.name,
     rows: this.rows
-  });
+  }, true);
   connection.flush();
 };
 
@@ -121,7 +121,7 @@ p.prepare = function(connection) {
       text: self.text,
       name: self.name,
       types: self.types
-    });
+    }, true);
     connection.parsedStatements[this.name] = true;
   }
 
@@ -137,12 +137,12 @@ p.prepare = function(connection) {
     portal: self.name,
     statement: self.name,
     values: self.values
-  });
+  }, true);
 
   connection.describe({
     type: 'P',
     name: self.name || ""
-  });
+  }, true);
 
   this.getRows(connection);
 };

lib/writer.js

@@ -2,6 +2,7 @@ var Writer = function(size) {
   this.size = size || 1024;
   this.buffer = new Buffer(this.size + 5);
   this.offset = 5;
+  this.headerPosition = 0;
 };
 
 var p = Writer.prototype;
@@ -70,18 +71,32 @@ p.add = function(otherBuffer) {
 }
 
 p.clear = function() {
-  this.offset=5;
+  this.offset = 5;
+  this.headerPosition = 0;
+  this.lastEnd = 0;
+}
+
+//appends a header block to all the written data since the last
+//subsequent header or to the beginning if there is only one data block
+p.addHeader = function(code, last) {
+  var origOffset = this.offset;
+  this.offset = this.headerPosition;
+  this.buffer[this.offset++] = code;
+  //length is everything in this packet minus the code
+  this.addInt32(origOffset - (this.headerPosition+1))
+  //set next header position
+  this.headerPosition = origOffset;
+  //make space for next header
+  this.offset = origOffset;
+  if(!last) {
+    this._ensure(5);
+    this.offset += 5;
+  }
 }
 
 p.join = function(code) {
   if(code) {
-    var end = this.offset;
-    this.offset = 0;
-    this.buffer[this.offset++] = code;
-    //write the length which is length of entire packet not including
-    //message type code byte
-    this.addInt32(end - 1);
-    this.offset = end;
+    this.addHeader(code, true);
   }
   return this.buffer.slice(code ? 0 : 5, this.offset);
 }

test/unit/writer-tests.js

@@ -156,7 +156,7 @@ test("resizing to much larger", function() {
   assert.equalBuffers(result, [33, 33, 33, 33, 33, 33, 33, 33, 0])
 })
 
-test("header", function() {
+test("flush", function() {
   test('added as a hex code to a full writer', function() {
     var subject = new Writer(2);
     var result = subject.addCString("!").flush(0x50)
@@ -175,3 +175,15 @@ test("header", function() {
     assert.equalBuffers(result, [0x50, 0, 0, 0, 0x0D, 33, 33, 33, 33, 33, 33, 33, 33, 0]);
   })
 })
+
+test("header", function() {
+  test('adding two packets with headers', function() {
+    var subject = new Writer(10).addCString("!");
+    subject.addHeader(0x50);
+    subject.addCString("!!");
+    subject.addHeader(0x40);
+    subject.addCString("!");
+    var result = subject.flush(0x10);
+    assert.equalBuffers(result, [0x50, 0, 0, 0, 6, 33, 0, 0x40, 0, 0, 0, 7, 33, 33, 0, 0x10, 0, 0, 0, 6, 33, 0 ]);
+  })
+})