parsing of prepared queries with no parameters

lib/buffer-list.js

@@ -1,23 +1,24 @@
 BufferList = function() {
   this.buffers = [];
 };
+var p = BufferList.prototype;
 
-BufferList.prototype.add = function(buffer, front) {
+p.add = function(buffer, front) {
   this.buffers[front ? "unshift" : "push"](buffer);
   return this;
 };
 
-BufferList.prototype.addInt16 = function(val, front) {
+p.addInt16 = function(val, front) {
   return this.add(Buffer([(val >>> 8),(val >>> 0)]),front);
 };
 
-BufferList.prototype.getByteLength = function(initial) {
+p.getByteLength = function(initial) {
   return this.buffers.reduce(function(previous, current){
     return previous + current.length;
   },initial || 0);
 };
 
-BufferList.prototype.addInt32 = function(val, first) {
+p.addInt32 = function(val, first) {
   return this.add(Buffer([
     (val >>> 24 & 0xFF),
     (val >>> 16 & 0xFF),
@@ -26,15 +27,15 @@ BufferList.prototype.addInt32 = function(val, first) {
   ]),first);
 };
 
-BufferList.prototype.addCString = function(val) {
+p.addCString = function(val) {
   return this.add(Buffer(val + '\0','utf8'));
 };
 
-BufferList.prototype.addChar = function(char, first) {
+p.addChar = function(char, first) {
   return this.add(Buffer(char,'utf8'), first);
 };
 
-BufferList.prototype.join = function(appendLength, char) {
+p.join = function(appendLength, char) {
   var length = this.getByteLength();
   if(appendLength) {
     this.addInt32(length+4, true);

lib/client.js

@@ -4,6 +4,7 @@ var crypto = require('crypto');
 var EventEmitter = require('events').EventEmitter;
 
 var utils = require(__dirname + '/utils');
+var BufferList = require(__dirname + '/buffer-list');
 
 var Client = function(config) {
   EventEmitter.call(this);
@@ -28,7 +29,7 @@ sys.inherits(Client, EventEmitter);
 var p = Client.prototype;
 
 p.connect = function() {
-  if(this.stream.readyState == 'closed'){
+  if(this.stream.readyState === 'closed'){
     this.stream.connect(this.port, this.host);
   }
   var self = this;
@@ -109,8 +110,23 @@ p.query = function(text) {
   return this;
 };
 
-p.parse = function(text, types) {
-  
+p.parse = function(query) {
+  //expect something like this:
+  // { name: 'queryName',
+  //   text: 'select * from blah',
+  //   types: ['int8', 'bool'] }
+
+  //normalize missing query names to allow for null
+  query.name = query.name || '';
+  //normalize null type array
+  query.types = query.types || [];
+
+  //append internal type identifier
+  query.type = 'preparedQuery';
+
+  this.queryQueue.push(query);
+  this.pulseQueryQueue();
+  return this;
 };
 
 p.pulseQueryQueue = function(ready) {
@@ -121,10 +137,22 @@ p.pulseQueryQueue = function(ready) {
   if(query) {
     var self = this;
     this.readyForQuery = false;
-    if(query.type !== 'simpleQuery') {
-      throw new Error("do not know how to handle this");
+    if(query.type === 'simpleQuery') {
+      this.send('Q', new Buffer(query.text + '\0', this.encoding));
+      return;
     }
-    this.send('Q', new Buffer(query.text + '\0', this.encoding));
+    if(query.type === 'preparedQuery') {
+      var buffer = new BufferList()
+        .addCString(query.name) //name of query
+        .addCString(query.text) //actual query text
+        .addInt16(0).join();
+      if(query.types.length) {
+        sys.debug("Typed parameters not supported yet!");
+      }
+      this.send('P', buffer);
+      return;
+    }
+    throw new Error("I don't know this query type " + sys.inspect(query));
   }
 };
 //query handling
@@ -242,16 +270,16 @@ p.parseMessage =  function() {
 
 p.parseR = function(msg) {
   var code = 0;
-  if(msg.length == 8) {
+  if(msg.length === 8) {
     code = this.parseInt32();
-    if(code == 3) {
+    if(code === 3) {
       msg.name = 'authenticationCleartextPassword';
     }
     return msg;
   }
-  if(msg.length == 12) {
+  if(msg.length === 12) {
     code = this.parseInt32();
-    if(code == 5) { //md5 required
+    if(code === 5) { //md5 required
       msg.name = 'authenticationMD5Password';
       msg.salt = new Buffer(4);
       this.buffer.copy(msg.salt, 0, this.offset, this.offset + 4);
@@ -302,7 +330,7 @@ p.parseField = function() {
     dataTypeID: this.parseInt32(),
     dataTypeSize: this.parseInt16(),
     dataTypeModifier: this.parseInt32(),
-    format: this.parseInt16() == 0 ? 'text' : 'binary'
+    format: this.parseInt16() === 0 ? 'text' : 'binary'
   };
   return field;
 };
@@ -312,7 +340,7 @@ p.parseD = function(msg) {
   var fields = [];
   for(var i = 0; i < fieldCount; i++) {
     var length = this.parseInt32();
-    fields[i] = (length == -1 ? null : this.readString(length))
+    fields[i] = (length === -1 ? null : this.readString(length))
   };
   msg.fieldCount = fieldCount;
   msg.fields = fields;

test/unit/prepared-query-tests.js

@@ -8,9 +8,31 @@ test('prepared queries', function() {
 
   test("parse messages", function() {
 
-    test('parsing a query with no parameters', function() {
-      client.parse('!');
+    test('parsing a query with no parameters and no name', function() {
+      client.parse({text: '!'});
       assert.length(client.stream.packets, 1);
+      var expected = new BufferList()
+        .addCString("")
+        .addCString("!")
+        .addInt16(0).join(true, 'P');
+      assert.equalBuffers(client.stream.packets.pop(), expected);
+      client.stream.emit('data', buffers.readyForQuery());
+    });
+
+    test('parsing a query with a name', function() {
+      //clear packets
+      client.parse({
+        name: 'boom',
+        text: 'select * from boom',
+        types: []
+      });
+      assert.length(client.stream.packets, 1);
+      var expected = new BufferList()
+        .addCString("boom")
+        .addCString("select * from boom")
+        .addInt16(0).join(true,'P');
+      assert.equalBuffers(client.stream.packets.pop(), expected);
+      client.stream.emit('data', buffers.readyForQuery());
     });
 
   });

test/unit/test-helper.js

@@ -2,7 +2,7 @@ sys = require('sys');
 assert = require('assert');
 Client = require(__dirname+'/../../lib/client');
 EventEmitter = require('events').EventEmitter;
-BufferList = require(__dirname+'/buffer-list');
+BufferList = require(__dirname+'/../../lib/buffer-list');
 buffers = require(__dirname+'/test-buffers');
 
 assert.same = function(actual, expected) {