Merge remote branch 'upstream/master'

Author: AlexanderS

README.md

@@ -118,6 +118,8 @@ Many thanks to the following:
 * [homme](https://github.com/homme)
 * [bdunavant](https://github.com/bdunavant)
 * [tokumine](https://github.com/tokumine)
+* [shtylman](https://github.com/shtylman)
+* [cricri](https://github.com/cricri)
 
 ## Documentation
 

lib/client.js

@@ -21,6 +21,8 @@ var Client = function(config) {
   this.queryQueue = [];
   this.password = config.password || defaults.password;
   this.encoding = 'utf8';
+  this.processID = null;
+  this.secretKey = null;
   var self = this;
 };
 
@@ -59,6 +61,11 @@ p.connect = function(callback) {
     con.password(md5password);
   });
 
+  con.once('backendKeyData', function(msg) {
+  	self.processID = msg.processID;
+  	self.secretKey = msg.secretKey;
+	});
+
   //hook up query handling events to connection
   //after the connection initially becomes ready for queries
   con.once('readyForQuery', function() {
@@ -130,6 +137,25 @@ p.connect = function(callback) {
 
 };
 
+p.cancel = function(client, query) {
+	if (client.activeQuery == query) {
+		var con = this.connection;
+
+		if(this.host && this.host.indexOf('/') === 0) {
+			con.connect(this.host + '/.s.PGSQL.' + this.port);
+		} else {
+			con.connect(this.port, this.host);
+		}
+
+		//once connection is established send cancel message
+		con.on('connect', function() {
+			con.cancel(client.processID, client.secretKey);
+		});
+	}
+	else if (client.queryQueue.indexOf(query) != -1)
+		client.queryQueue.splice(client.queryQueue.indexOf(query), 1);
+};
+
 p._pulseQueryQueue = function() {
   if(this.readyForQuery===true) {
     this.activeQuery = this.queryQueue.shift();

lib/connection.js

@@ -73,6 +73,23 @@ p.startup = function(config) {
   this.stream.write(buffer);
 };
 
+p.cancel = function(processID, secretKey) {
+  var bodyBuffer = this.writer
+    .addInt16(1234)
+    .addInt16(5678)
+    .addInt32(processID)
+    .addInt32(secretKey)
+    .addCString('').flush();
+
+  var length = bodyBuffer.length + 4;
+
+  var buffer = new Writer()
+    .addInt32(length)
+    .add(bodyBuffer)
+    .join();
+  this.stream.write(buffer);
+};
+
 p.password = function(password) {
   //0x70 = 'p'
   this._send(0x70, this.writer.addCString(password));

lib/index.js

@@ -81,6 +81,16 @@ PG.prototype.connect = function(config, callback) {
   return pool.acquire(cb);
 }
 
+// cancel the query runned by the given client
+PG.prototype.cancel = function(config, client, query) {
+  var c = config;
+  //allow for no config to be passed
+  if(typeof c === 'function')
+    c = defaults;
+  var cancellingClient = new this.Client(c);
+  cancellingClient.cancel(client, query);
+}
+
 module.exports = new PG(Client);
 
 //lazy require native module...the native module may not have installed 

lib/native/index.js

@@ -56,6 +56,15 @@ p.query = function(config, values, callback) {
   return q;
 }
 
+var nativeCancel = p.cancel;
+
+p.cancel = function(client, query) {
+	if (client._activeQuery == query)
+		this.connect(nativeCancel.bind(client));
+	else if (client._queryQueue.indexOf(query) != -1)
+		client._queryQueue.splice(client._queryQueue.indexOf(query), 1);
+};
+
 p._pulseQueryQueue = function(initialConnection) {
   if(!this._connected) {
     return;
@@ -94,8 +103,8 @@ p.pauseDrain = function() {
 };
 
 p.resumeDrain = function() {
-  if(this._drainPaused > 1) { 
-    this.emit('drain') 
+  if(this._drainPaused > 1) {
+    this.emit('drain')
   };
   this._drainPaused = 0;
 };

lib/writer.js

@@ -3,7 +3,7 @@
 //same buffer to avoid memcpy and limit memory allocations
 var Writer = function(size) {
   this.size = size || 1024;
-  this.buffer = new Buffer(this.size + 5);
+  this.buffer = Buffer(this.size + 5);
   this.offset = 5;
   this.headerPosition = 0;
 };
@@ -15,7 +15,7 @@ p._ensure = function(size) {
   var remaining = this.buffer.length - this.offset;
   if(remaining < size) {
     var oldBuffer = this.buffer;
-    this.buffer = Buffer(oldBuffer.length + size);
+    this.buffer = new Buffer(oldBuffer.length + size);
     oldBuffer.copy(this.buffer);
   }
 }
@@ -36,24 +36,36 @@ p.addInt16 = function(num) {
   return this;
 }
 
+//for versions of node requiring 'length' as 3rd argument to buffer.write
+var writeString = function(buffer, string, offset, len) {
+  buffer.write(string, offset, len);
+}
+
+//overwrite function for older versions of node
+if(Buffer.prototype.write.length === 3) {
+  writeString = function(buffer, string, offset, len) {
+    buffer.write(string, offset);
+  }
+}
+
 p.addCString = function(string) {
   //just write a 0 for empty or null strings
   if(!string) {
     this._ensure(1);
-    this.buffer[this.offset++] = 0;
-    return this;
+  } else {
+    var len = Buffer.byteLength(string);
+    this._ensure(len + 1); //+1 for null terminator
+    writeString(this.buffer, string, this.offset, len);
+    this.offset += len;
   }
-  var len = Buffer.byteLength(string) + 1;
-  this._ensure(len);
-  this.buffer.write(string, this.offset);
-  this.offset += len;
-  this.buffer[this.offset] = 0; //add null terminator
+
+  this.buffer[this.offset++] = 0; // null terminator
   return this;
 }
 
 p.addChar = function(char) {
   this._ensure(1);
-  this.buffer.write(char, this.offset);
+  writeString(this.buffer, char, this.offset, 1);
   this.offset++;
   return this;
 }

package.json

@@ -1,5 +1,5 @@
 { "name": "pg",
-  "version": "0.6.3",
+  "version": "0.6.6",
   "description": "PostgreSQL client - pure javascript & libpq with the same API",
   "keywords" : ["postgres", "pg", "libpq", "postgre", "database", "rdbms"],
   "homepage": "http://github.com/brianc/node-postgres",

script/create-test-tables.js

@@ -1,4 +1,3 @@
-var sys = require('utils');
 var args = require(__dirname + '/../test/cli');
 var pg = require(__dirname + '/../lib');
 

src/binding.cc

@@ -69,6 +69,7 @@ class Connection : public ObjectWrap {
     NODE_SET_PROTOTYPE_METHOD(t, "_sendQueryWithParams", SendQueryWithParams);
     NODE_SET_PROTOTYPE_METHOD(t, "_sendPrepare", SendPrepare);
     NODE_SET_PROTOTYPE_METHOD(t, "_sendQueryPrepared", SendQueryPrepared);
+    NODE_SET_PROTOTYPE_METHOD(t, "cancel", Cancel);
     NODE_SET_PROTOTYPE_METHOD(t, "end", End);
 
     target->Set(String::NewSymbol("Connection"), t->GetFunction());
@@ -104,6 +105,22 @@ class Connection : public ObjectWrap {
     return Undefined();
   }
 
+  //v8 entry point into Connection#cancel
+  static Handle<Value>
+  Cancel(const Arguments& args)
+  {
+    HandleScope scope;
+    Connection *self = ObjectWrap::Unwrap<Connection>(args.This());
+
+    bool success = self->Cancel();
+    if(!success) {
+      self -> EmitLastError();
+      self -> DestroyConnection();
+    }
+
+    return Undefined();
+  }
+
   //v8 entry point into Connection#_sendQuery
   static Handle<Value>
   SendQuery(const Arguments& args)
@@ -267,6 +284,15 @@ class Connection : public ObjectWrap {
     return PQsendQueryPrepared(connection_, name, nParams, paramValues, NULL, NULL, 0);
   }
 
+  int Cancel()
+  {
+  	PGcancel* pgCancel = PQgetCancel(connection_);
+  	char errbuf[256];
+		int result = PQcancel(pgCancel, errbuf, 256);
+		PQfreeCancel(pgCancel);
+		return result;
+  }
+
   //flushes socket
   void Flush()
   {

test/integration/client/cancel-query-tests.js

@@ -0,0 +1,46 @@
+var helper = require(__dirname+"/test-helper");
+
+//before running this test make sure you run the script create-test-tables
+test("cancellation of a query", function() {
+
+  var client = helper.client();
+
+  var qry = client.query("select name from person order by name");
+
+  client.on('drain', client.end.bind(client));
+
+	var rows1 = 0, rows2 = 0, rows3 = 0, rows4 = 0;
+
+	var query1 = client.query(qry);
+	query1.on('row', function(row) {
+		rows1++;
+	});
+	var query2 = client.query(qry);
+	query2.on('row', function(row) {
+		rows2++;
+	});
+	var query3 = client.query(qry);
+	query3.on('row', function(row) {
+		rows3++;
+	});
+	var query4 = client.query(qry);
+	query4.on('row', function(row) {
+		rows4++;
+	});
+
+	helper.pg.cancel(helper.connectionString, client, query1);
+	helper.pg.cancel(helper.connectionString, client, query2);
+	helper.pg.cancel(helper.connectionString, client, query4);
+
+	setTimeout(function() {
+		assert.equal(rows1, 0);
+		assert.equal(rows2, 0);
+		assert.equal(rows4, 0);
+	}, 2000);
+
+  assert.emits(query3, 'end', function() {
+		test("returned right number of rows", function() {
+			assert.equal(rows3, 26);
+		});
+	});
+});