From 8cb44e3cf37667f4f1d93bd8a68205ed3a43f5ed Mon Sep 17 00:00:00 2001
From: brianc <brian.m.carlson@gmail.com>
Date: Fri, 15 Oct 2010 00:24:58 -0500
Subject: [PATCH] substantial refactoring of the parser

---
 lib/parser.js            | 111 +++++++++++++++++----------------------
 test/unit/test-helper.js |   1 +
 2 files changed, 48 insertions(+), 64 deletions(-)

diff --git a/lib/parser.js b/lib/parser.js
index 8fc57e7d..b7f0fba1 100644
--- a/lib/parser.js
+++ b/lib/parser.js
@@ -8,94 +8,81 @@ p.setBuffer = function(buffer) {
     var remaining = this.lastBuffer.length - this.lastOffset;
     var combinedBuffer = new Buffer(buffer.length + remaining);
     this.lastBuffer.copy(combinedBuffer, 0, this.lastOffset);
-    this.lastBuffer = false;
     buffer.copy(combinedBuffer, remaining, 0);
-    this.buffer = combinedBuffer;
-    this.offset = 0;
-    return;
+    buffer = combinedBuffer;
   }
   this.buffer = buffer;
   this.offset = 0;
 };
 
+var messageNames = {
+  R: 'authenticationOk',
+  S: 'parameterStatus',
+  K: 'backendKeyData',
+  C: 'commandComplete',
+  Z: 'readyForQuery',
+  T: 'rowDescription',
+  D: 'dataRow',
+  E: 'error'
+};
+
 p.parseMessage =  function() {
-  if(this.buffer.length == this.offset) {
-    //clean packet - nothing left for next buffer
-    return false;
-  }
   var remaining = this.buffer.length - this.offset - 1;
-  var messageID = this.buffer[this.offset];
-  var length = this.peekInt32(this.offset + 1);
-  if(remaining < 5 || remaining < length) {
+  if(remaining < 5) {
+    //cannot read id + length without at least 5 bytes
+    //just abort the read now
     this.lastBuffer = this.buffer;
     this.lastOffset = this.offset;
+    return;
+  }
+  var id = this.readChar();
+  var message = {
+    id: id,
+    name: messageNames[id],
+    length: this.parseInt32()
+  };
+
+  if(remaining < message.length) {
+    this.lastBuffer = this.buffer;
+    //rewind the last 5 bytes we read
+    this.lastOffset = this.offset-5;
     return false;
   }
 
-  return this["parse"+messageID]();
+  return this["parse"+message.id](message);
 };
 
-//parse 'R' message
-p.parse82 = function() {
-  var type = this.buffer[this.offset++];
-  var length = this.parseLength();
-  if(length == 8) {
+p.parseR = function(msg) {
+  if(msg.length == 8) {
     this.offset += 4;
-    return {
-      name: 'authenticationOk',
-      id: 'R',
-      length: length
-    }
+    return msg;
   }
-  throw new Error("Unknown AuthenticatinOk message type");
+  throw new Error("Unknown authenticatinOk message type");
 };
 
-//parse 'S' message
-p.parse83 = function(buffer) {
-  var msg = this.parseStart('parameterStatus');
+p.parseS = function(msg) {
   msg.parameterName = this.parseCString();
   msg.parameterValue = this.parseCString();
   return msg;
 };
 
-//parse 'K' message
-p.parse75 = function() {
-  var msg = this.parseStart('backendKeyData');
+p.parseK = function(msg) {
   msg.processID = this.parseInt32();
   msg.secretKey = this.parseInt32();
   return msg;
 };
 
-//parse 'C' message
-p.parse67 = function() {
-  var msg = this.parseStart('commandComplete');
+p.parseC = function(msg) {
   msg.text = this.parseCString();
   return msg;
 };
 
-//parses common start of message packets
-p.parseStart = function(name) {
-  return {
-    name: name,
-    id: this.readChar(),
-    length: this.parseInt32()
-  }
-};
-
-p.readChar = function() {
-  return Buffer([this.buffer[this.offset++]]).toString('utf8');
-};
-
-//parse 'Z' message
-p.parse90 = function() {
-  var msg = this.parseStart('readyForQuery');
+p.parseZ = function(msg) {
   msg.status = this.readChar();
   return msg;
 };
 
-//parse 'T' message
-p.parse84 = function() {
-  var msg = this.parseStart('rowDescription');
+p.parseT = function(msg) {
   msg.fieldCount = this.parseInt16();
   var fields = [];
   for(var i = 0; i < msg.fieldCount; i++){
@@ -106,7 +93,7 @@ p.parse84 = function() {
 };
 
 p.parseField = function() {
-  var row = {
+  var field = {
     name: this.parseCString(),
     tableID: this.parseInt32(),
     columnID: this.parseInt16(),
@@ -115,12 +102,10 @@ p.parseField = function() {
     dataTypeModifier: this.parseInt32(),
     format: this.parseInt16() == 0 ? 'text' : 'binary'
   };
-  return row;
+  return field;
 };
 
-//parse 'D' message
-p.parse68 = function() {
-  var msg = this.parseStart('dataRow');
+p.parseD = function(msg) {
   var fieldCount = this.parseInt16();
   var fields = [];
   for(var i = 0; i < fieldCount; i++) {
@@ -132,9 +117,7 @@ p.parse68 = function() {
   return msg;
 };
 
-//parse 'E' message
-p.parse69 = function() {
-  var msg = this.parseStart('error');
+p.parseE = function(msg) {
   var fields = {};
   var fieldType = this.readString(1);
   while(fieldType != '\0') {
@@ -156,6 +139,9 @@ p.parse69 = function() {
   return msg;
 };
 
+p.readChar = function() {
+  return Buffer([this.buffer[this.offset++]]).toString('utf8');
+};
 
 p.parseInt32 = function() {
   var value = this.peekInt32();
@@ -174,11 +160,8 @@ p.peekInt32 = function(offset) {
 
 
 p.parseInt16 = function() {
-  return ((this.buffer[this.offset++] << 8) + (this.buffer[this.offset++] << 0));
-};
-
-p.parseLength =  function() {
-  return this.parseInt32();
+  return ((this.buffer[this.offset++] << 8) +
+          (this.buffer[this.offset++] << 0));
 };
 
 p.readString = function(length) {
diff --git a/test/unit/test-helper.js b/test/unit/test-helper.js
index 36ecfd19..8674ac4c 100644
--- a/test/unit/test-helper.js
+++ b/test/unit/test-helper.js
@@ -53,6 +53,7 @@ test = function(name, action) {
     global.TEST_RESULTS.testCount++;
     action();
   }catch(e) {
+    console.log('');
     console.log(name);
     throw e;
   }