Refactoring of the HTTP library

sdk/lib/io/http_parser.dart

Index: sdk/lib/io/http_parser.dart
diff --git a/sdk/lib/io/http_parser.dart b/sdk/lib/io/http_parser.dart
index 61e0a64a588e34fc9111455ccda531969c1bc8bb..45a2d4f0a43296c949e0922c9af2775b1f9a33b3 100644
--- a/sdk/lib/io/http_parser.dart
+++ b/sdk/lib/io/http_parser.dart
@@ -103,6 +103,7 @@ class _MessageType {
  *   [:headersComplete:]
  *   [:dataReceived:]
  *   [:dataEnd:]
+ *   [:closed:]
  *   [:error:]
  *
  * If an HTTP parser error occours it is possible to get an exception
@@ -124,7 +125,12 @@ class _MessageType {
  * upgraded to.
  */
 class _HttpParser {
-  _HttpParser() {
+  _HttpParser.requestParser() {
+    _requestParser = true;
+    _reset();
+  }
+  _HttpParser.responseParser() {
+    _requestParser = false;
     _reset();
   }
 
@@ -165,6 +171,9 @@ class _HttpParser {
                 throw new HttpParserException("Invalid request method");
               }
               _method_or_status_code.addCharCode(byte);
+              if (!_requestParser) {
+                throw new HttpParserException("Invalid response line");
+              }
               _state = _State.REQUEST_LINE_METHOD;
             }
             break;
@@ -179,6 +188,9 @@ class _HttpParser {
               // HTTP/ parsed. As method is a token this cannot be a
               // method anymore.
               _httpVersionIndex++;
+              if (_requestParser) {
+                throw new HttpParserException("Invalid request line");
+              }
               _state = _State.RESPONSE_HTTP_VERSION;
             } else {
               // Did not parse HTTP version. Expect method instead.
@@ -190,6 +202,9 @@ class _HttpParser {
               } else {
                 _method_or_status_code.addCharCode(byte);
                 _httpVersion = _HttpVersion.UNDETERMINED;
+                if (!_requestParser) {
+                  throw new HttpParserException("Invalid response line");
+                }
                 _state = _State.REQUEST_LINE_METHOD;
               }
             }
@@ -274,11 +289,9 @@ class _HttpParser {
           case _State.REQUEST_LINE_ENDING:
             _expect(byte, _CharCode.LF);
             _messageType = _MessageType.REQUEST;
-            if (requestStart != null) {
-              requestStart(_method_or_status_code.toString(),
-                           _uri_or_reason_phrase.toString(),
-                           version);
-            }
+            requestStart(_method_or_status_code.toString(),
+                         _uri_or_reason_phrase.toString(),
+                         version);
             _method_or_status_code.clear();
             _uri_or_reason_phrase.clear();
             _state = _State.HEADER_START;
@@ -324,11 +337,9 @@ class _HttpParser {
               _noMessageBody =
                   statusCode <= 199 || statusCode == 204 || statusCode == 304;
             }
-            if (responseStart != null) {
-              responseStart(statusCode,
-                            _uri_or_reason_phrase.toString(),
-                            version);
-            }
+            responseStart(statusCode,
+                          _uri_or_reason_phrase.toString(),
+                          version);
             _method_or_status_code.clear();
             _uri_or_reason_phrase.clear();
             _state = _State.HEADER_START;
@@ -400,9 +411,7 @@ class _HttpParser {
                   } else if (token == "upgrade") {
                     _connectionUpgrade = true;
                   }
-                  if (headerReceived != null) {
-                    headerReceived(headerField, token);
-                  }
+                  headerReceived(headerField, token);
                 }
                 reportHeader = false;
               } else if (headerField == "transfer-encoding" &&
@@ -412,7 +421,7 @@ class _HttpParser {
                 _chunked = true;
                 _contentLength = -1;
               }
-              if (reportHeader && headerReceived != null) {
+              if (reportHeader) {
                 headerReceived(headerField, headerValue);
               }
               _headerField.clear();
@@ -440,9 +449,9 @@ class _HttpParser {
             }
             if (_connectionUpgrade) {
               _state = _State.UPGRADED;
-              if (headersComplete != null) headersComplete();
+              headersComplete();
             } else {
-              if (headersComplete != null) headersComplete();
+              headersComplete();
               if (_chunked) {
                 _state = _State.CHUNK_SIZE;
                 _remainingContent = 0;
@@ -525,7 +534,7 @@ class _HttpParser {
               data.setRange(0, _remainingContent, _buffer, _index);
             }
 
-            if (dataReceived != null) dataReceived(data);
+            dataReceived(data);
             if (_remainingContent != null) {
               _remainingContent -= data.length;
             }
@@ -552,14 +561,8 @@ class _HttpParser {
         }
       }
     } catch (e) {
-      // Report the error through the error callback if any. Otherwise
-      // throw the error.
-      if (error != null) {
-        error(e);
-        _state = _State.FAILURE;
-      } else {
-        throw e;
-      }
+      _state = _State.FAILURE;
+      error(e);
     }
 
     // If all data is parsed or not needed due to failure there is no
@@ -567,45 +570,60 @@ class _HttpParser {
     if (_state != _State.UPGRADED) _releaseBuffer();
   }
 
-  void writeList(List<int> buffer, int offset, int count) {
+  void streamData(List<int> buffer) {
     assert(_buffer == null);
     _buffer = buffer;
-    _index = offset;
-    _lastIndex = offset + count;
+    _index = 0;
+    _lastIndex = buffer.length;
     _parse();
   }
 
-  void connectionClosed() {
+  void streamDone() {
+    // If the connection is idle the HTTP stream is closed.
+    if (_state == _State.START) {
+      if (_requestParser) {
+        closed();
+      } else {
+        error(
+            new HttpParserException(
+                "Connection closed before full header was received"));
+      }
+      return;
+    }
+
     if (_state < _State.FIRST_BODY_STATE) {
       _state = _State.FAILURE;
       // Report the error through the error callback if any. Otherwise
       // throw the error.
-      var e = new HttpParserException(
-          "Connection closed before full header was received");
-      if (error != null) {
-        error(e);
-        return;
-      }
-      throw e;
+      error(
+          new HttpParserException(
+              "Connection closed before full header was received"));
+      return;
     }
 
     if (!_chunked && _contentLength == -1) {
-      if (_state != _State.START) {
-        if (dataEnd != null) dataEnd(true);
-      }
+      dataEnd(true);
       _state = _State.CLOSED;
+      closed();
     } else {
       _state = _State.FAILURE;
       // Report the error through the error callback if any. Otherwise
       // throw the error.
-      var e = new HttpParserException(
-          "Connection closed before full body was received");
-      if (error != null) {
-        error(e);
-        return;
-      }
-      throw e;
+      error(
+          new HttpParserException(
+              "Connection closed before full body was received"));
+    }
+  }
+
+  void streamError(e) {
+    // Don't report errors when HTTP parser is in idle state. Clients
+    // can close the connection and cause a connection reset by peer
+    // error which is OK.
+    if (_state == _State.START) {
+      closed();
+      return;
     }
+    error(e);
   }
 
   String get version {
@@ -625,8 +643,6 @@ class _HttpParser {
 
   void set responseToMethod(String method) { _responseToMethod = method; }
 
-  bool get isIdle => _state == _State.START;
-
   List<int> readUnparsedData() {
     if (_buffer == null) return [];
     if (_index == _lastIndex) return [];
@@ -636,9 +652,7 @@ class _HttpParser {
   }
 
   void _bodyEnd() {
-    if (dataEnd != null) {
-      dataEnd(_messageType == _MessageType.RESPONSE && !_persistentConnection);
-    }
+    dataEnd(_messageType == _MessageType.RESPONSE && !_persistentConnection);
   }
 
   _reset() {
@@ -717,6 +731,7 @@ class _HttpParser {
   int _index;
   int _lastIndex;
 
+  bool _requestParser;
   int _state;
   int _httpVersionIndex;
   int _messageType;
@@ -743,6 +758,7 @@ class _HttpParser {
   Function dataReceived;
   Function dataEnd;
   Function error;
+  Function closed;
 }