http: Separate out the storeHeader closure

lib/http.js

@@ -511,47 +511,20 @@ OutgoingMessage.prototype._buffer = function(data, encoding) {
 
 
 OutgoingMessage.prototype._storeHeader = function(firstLine, headers) {
-  var sentConnectionHeader = false;
-  var sentContentLengthHeader = false;
-  var sentTransferEncodingHeader = false;
-  var sentDateHeader = false;
-  var sentExpect = false;
-
   // firstLine in the case of request is: 'GET /index.html HTTP/1.1\r\n'
   // in the case of response it is: 'HTTP/1.1 200 OK\r\n'
-  var messageHeader = firstLine;
+  var state = {
+    sentConnectionHeader: false,
+    sentContentLengthHeader: false,
+    sentTransferEncodingHeader: false,
+    sentDateHeader: false,
+    sentExpect: false,
+    messageHeader: firstLine
+  };
+
   var field, value;
   var self = this;
 
-  function store(field, value) {
-    // Protect against response splitting. The if statement is there to
-    // minimize the performance impact in the common case.
-    if (/[\r\n]/.test(value))
-      value = value.replace(/[\r\n]+[ \t]*/g, '');
-
-    messageHeader += field + ': ' + value + CRLF;
-
-    if (connectionExpression.test(field)) {
-      sentConnectionHeader = true;
-      if (closeExpression.test(value)) {
-        self._last = true;
-      } else {
-        self.shouldKeepAlive = true;
-      }
-
-    } else if (transferEncodingExpression.test(field)) {
-      sentTransferEncodingHeader = true;
-      if (chunkExpression.test(value)) self.chunkedEncoding = true;
-
-    } else if (contentLengthExpression.test(field)) {
-      sentContentLengthHeader = true;
-    } else if (dateExpression.test(field)) {
-      sentDateHeader = true;
-    } else if (expectExpression.test(field)) {
-      sentExpect = true;
-    }
-  }
-
   if (headers) {
     var keys = Object.keys(headers);
     var isArray = (Array.isArray(headers));
@@ -569,37 +542,38 @@ OutgoingMessage.prototype._storeHeader = function(firstLine, headers) {
 
       if (Array.isArray(value)) {
         for (var j = 0; j < value.length; j++) {
-          store(field, value[j]);
+          storeHeader(this, state, field, value[j]);
         }
       } else {
-        store(field, value);
+        storeHeader(this, state, field, value);
       }
     }
   }
 
   // Date header
-  if (this.sendDate == true && sentDateHeader == false) {
-    messageHeader += 'Date: ' + utcDate() + CRLF;
+  if (this.sendDate == true && state.sentDateHeader == false) {
+    state.messageHeader += 'Date: ' + utcDate() + CRLF;
   }
 
   // keep-alive logic
-  if (sentConnectionHeader === false) {
+  if (state.sentConnectionHeader === false) {
     var shouldSendKeepAlive = this.shouldKeepAlive &&
-        (sentContentLengthHeader ||
+        (state.sentContentLengthHeader ||
          this.useChunkedEncodingByDefault ||
          this.agent);
     if (shouldSendKeepAlive) {
-      messageHeader += 'Connection: keep-alive\r\n';
+      state.messageHeader += 'Connection: keep-alive\r\n';
     } else {
       this._last = true;
-      messageHeader += 'Connection: close\r\n';
+      state.messageHeader += 'Connection: close\r\n';
     }
   }
 
-  if (sentContentLengthHeader == false && sentTransferEncodingHeader == false) {
+  if (state.sentContentLengthHeader == false &&
+      state.sentTransferEncodingHeader == false) {
     if (this._hasBody) {
       if (this.useChunkedEncodingByDefault) {
-        messageHeader += 'Transfer-Encoding: chunked\r\n';
+        state.messageHeader += 'Transfer-Encoding: chunked\r\n';
         this.chunkedEncoding = true;
       } else {
         this._last = true;
@@ -610,14 +584,43 @@ OutgoingMessage.prototype._storeHeader = function(firstLine, headers) {
     }
   }
 
-  this._header = messageHeader + CRLF;
+  this._header = state.messageHeader + CRLF;
   this._headerSent = false;
 
   // wait until the first body chunk, or close(), is sent to flush,
   // UNLESS we're sending Expect: 100-continue.
-  if (sentExpect) this._send('');
+  if (state.sentExpect) this._send('');
 };
 
+function storeHeader(self, state, field, value) {
+  // Protect against response splitting. The if statement is there to
+  // minimize the performance impact in the common case.
+  if (/[\r\n]/.test(value))
+    value = value.replace(/[\r\n]+[ \t]*/g, '');
+
+  state.messageHeader += field + ': ' + value + CRLF;
+
+  if (connectionExpression.test(field)) {
+    state.sentConnectionHeader = true;
+    if (closeExpression.test(value)) {
+      self._last = true;
+    } else {
+      self.shouldKeepAlive = true;
+    }
+
+  } else if (transferEncodingExpression.test(field)) {
+    state.sentTransferEncodingHeader = true;
+    if (chunkExpression.test(value)) self.chunkedEncoding = true;
+
+  } else if (contentLengthExpression.test(field)) {
+    state.sentContentLengthHeader = true;
+  } else if (dateExpression.test(field)) {
+    state.sentDateHeader = true;
+  } else if (expectExpression.test(field)) {
+    state.sentExpect = true;
+  }
+}
+
 
 OutgoingMessage.prototype.setHeader = function(name, value) {
   if (arguments.length < 2) {