http: Clean up parser usage

Move parsers.free(parser) to a single function, which also
nulls all of the various references we hang on them.

Also, move the parser.on* methods out of the closure, so that
there's one shared definition of each, instead of re-defining
for each parser in a spot where they can close over references
to other request-specific objects.

lib/http.js

@@ -35,29 +35,18 @@ if (process.env.NODE_DEBUG && /http/.test(process.env.NODE_DEBUG)) {
   debug = function() { };
 }
 
+function parserOnHeaders(headers, url) {
+  this._headers = this._headers.concat(headers);
+  this._url += url;
+}
 
-var parsers = new FreeList('parsers', 1000, function() {
+// info.headers and info.url are set only if .onHeaders()
-  var parser = new HTTPParser(HTTPParser.REQUEST);
+// has not been called for this request.
-
+//
-  parser._headers = [];
+// info.url is not set for response parsers but that's not
-  parser._url = '';
+// applicable here since all our parsers are request parsers.
-
+function parserOnHeadersComplete(info) {
-  // Only called in the slow case where slow means
+  var parser = this;
-  // that the request headers were either fragmented
-  // across multiple TCP packets or too large to be
-  // processed in a single run. This method is also
-  // called to process trailing HTTP headers.
-  parser.onHeaders = function(headers, url) {
-    parser._headers = parser._headers.concat(headers);
-    parser._url += url;
-  };
-
-  // info.headers and info.url are set only if .onHeaders()
-  // has not been called for this request.
-  //
-  // info.url is not set for response parsers but that's not
-  // applicable here since all our parsers are request parsers.
-  parser.onHeadersComplete = function(info) {
   var headers = info.headers;
   var url = info.url;
 
@@ -103,9 +92,10 @@ var parsers = new FreeList('parsers', 1000, function() {
   }
 
   return isHeadResponse;
-  };
+}
 
-  parser.onBody = function(b, start, len) {
+function parserOnBody(b, start, len) {
+  var parser = this;
   // TODO body encoding?
   var slice = b.slice(start, start + len);
   if (parser.incoming._decoder) {
@@ -114,9 +104,9 @@ var parsers = new FreeList('parsers', 1000, function() {
   } else {
     parser.incoming.emit('data', slice);
   }
-  };
+}
-
+function parserOnMessageComplete() {
-  parser.onMessageComplete = function() {
+  var parser = this;
   parser.incoming.complete = true;
 
   // Emit any trailing headers.
@@ -141,7 +131,24 @@ var parsers = new FreeList('parsers', 1000, function() {
     // force to read the next incoming message
     parser.socket.resume();
   }
-  };
+}
+
+
+var parsers = new FreeList('parsers', 1000, function() {
+  var parser = new HTTPParser(HTTPParser.REQUEST);
+
+  parser._headers = [];
+  parser._url = '';
+
+  // Only called in the slow case where slow means
+  // that the request headers were either fragmented
+  // across multiple TCP packets or too large to be
+  // processed in a single run. This method is also
+  // called to process trailing HTTP headers.
+  parser.onHeaders = parserOnHeaders;
+  parser.onHeadersComplete = parserOnHeadersComplete;
+  parser.onBody = parserOnBody;
+  parser.onMessageComplete = parserOnMessageComplete;
 
   return parser;
 });
@@ -1110,6 +1117,31 @@ function createHangUpError() {
   return error;
 }
 
+// Free the parser and also break any links that it
+// might have to any other things.
+// TODO: All parser data should be attached to a
+// single object, so that it can be easily cleaned
+// up by doing `parser.data = {}`, which should
+// be done in FreeList.free.  `parsers.free(parser)`
+// should be all that is needed.
+function freeParser(parser, req) {
+  if (parser) {
+    parser._headers = [];
+    parser.onIncoming = null;
+    if (parser.socket) {
+      parser.socket.onend = null;
+      parser.socket.ondata = null;
+    }
+    parser.socket = null;
+    parser.incoming = null;
+    parsers.free(parser);
+    parser = null;
+  }
+  if (req) {
+    req.parser = null;
+  }
+};
+
 
 ClientRequest.prototype.onSocket = function(socket) {
   var req = this;
@@ -1126,21 +1158,6 @@ ClientRequest.prototype.onSocket = function(socket) {
     // Setup "drain" propogation.
     httpSocketSetup(socket);
 
-    var freeParser = function() {
-      if (parser) {
-        parser.onIncoming = null;
-        parser.socket.onend = null;
-        parser.socket.ondata = null;
-        parser.socket = null;
-        parser.incoming = null;
-        parsers.free(parser);
-        parser = null;
-      }
-      if (req) {
-        req.parser = null;
-      }
-    };
-
     var errorListener = function(err) {
       debug('HTTP SOCKET ERROR: ' + err.message + '\n' + err.stack);
       req.emit('error', err);
@@ -1149,7 +1166,7 @@ ClientRequest.prototype.onSocket = function(socket) {
       req._hadError = true;
       if (parser) {
         parser.finish();
-        freeParser();
+        freeParser(parser, req);
       }
       socket.destroy();
     }
@@ -1159,7 +1176,7 @@ ClientRequest.prototype.onSocket = function(socket) {
       var ret = parser.execute(d, start, end - start);
       if (ret instanceof Error) {
         debug('parse error');
-        freeParser();
+        freeParser(parser, req);
         socket.destroy(ret);
       } else if (parser.incoming && parser.incoming.upgrade) {
         var bytesParsed = ret;
@@ -1180,13 +1197,13 @@ ClientRequest.prototype.onSocket = function(socket) {
           // Got upgrade header, but have no handler.
           socket.destroy();
         }
-        freeParser();
+        freeParser(parser, req);
       } else if (parser.incoming && parser.incoming.complete &&
                  // When the status code is 100 (Continue), the server will
                  // send a final response after this client sends a request
                  // body. So, we must not free the parser.
                  parser.incoming.statusCode !== 100) {
-        freeParser();
+        freeParser(parser, req);
       }
     };
 
@@ -1199,7 +1216,7 @@ ClientRequest.prototype.onSocket = function(socket) {
       }
       if (parser) {
         parser.finish();
-        freeParser();
+        freeParser(parser, req);
       }
       socket.destroy();
     };
@@ -1494,8 +1511,8 @@ function connectionListener(socket) {
 
   socket.addListener('close', function() {
     debug('server socket close');
-    // unref the parser for easy gc
+    // mark this parser as reusable
-    parsers.free(parser);
+    freeParser(parser);
 
     abortIncoming();
   });