Make the HttpParser and HttpUtil classes private

runtime/bin/http_parser.dart

+// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+// Global constants.
+class _Const {
+  // Bytes for "HTTP/1.0".
+  static final HTTP10 = const [72, 84, 84, 80, 47, 49, 46, 48];
+  // Bytes for "HTTP/1.1".
+  static final HTTP11 = const [72, 84, 84, 80, 47, 49, 46, 49];
+
+  static final END_CHUNKED = const [0x30, 13, 10, 13, 10];
+}
+
+
+// Frequently used character codes.
+class _CharCode {
+  static final int HT = 9;
+  static final int LF = 10;
+  static final int CR = 13;
+  static final int SP = 32;
+  static final int COLON = 58;
+}
+
+
+// States of the HTTP parser state machine.
+class _State {
+  static final int START = 0;
+  static final int METHOD_OR_HTTP_VERSION = 1;
+  static final int REQUEST_LINE_METHOD = 2;
+  static final int REQUEST_LINE_URI = 3;
+  static final int REQUEST_LINE_HTTP_VERSION = 4;
+  static final int REQUEST_LINE_ENDING = 5;
+  static final int RESPONSE_LINE_STATUS_CODE = 6;
+  static final int RESPONSE_LINE_REASON_PHRASE = 7;
+  static final int RESPONSE_LINE_ENDING = 8;
+  static final int HEADER_START = 9;
+  static final int HEADER_FIELD = 10;
+  static final int HEADER_VALUE_START = 11;
+  static final int HEADER_VALUE = 12;
+  static final int HEADER_VALUE_FOLDING_OR_ENDING = 13;
+  static final int HEADER_VALUE_FOLD_OR_END = 14;
+  static final int HEADER_ENDING = 15;
+  static final int CHUNK_SIZE_STARTING_CR = 16;
+  static final int CHUNK_SIZE_STARTING_LF = 17;
+  static final int CHUNK_SIZE = 18;
+  static final int CHUNK_SIZE_ENDING = 19;
+  static final int CHUNKED_BODY_DONE_CR = 20;
+  static final int CHUNKED_BODY_DONE_LF = 21;
+  static final int BODY = 22;
+}
+
+
+/**
+ * HTTP parser which parses the HTTP stream as data is supplied
+ * through the writeList method. As the data is parsed the events
+ *   RequestStart
+ *   UriReceived
+ *   HeaderReceived
+ *   HeadersComplete
+ *   DataReceived
+ *   DataEnd
+ * are generated.
+ * Currently only HTTP requests with Content-Length header are supported.
+ */
+class _HttpParser {
+  _HttpParser()
+      : _state = _State.START,
+        _failure = false,
+        _headerField = new StringBuffer(),
+        _headerValue = new StringBuffer(),
+        _method_or_status_code = new StringBuffer(),
+        _uri_or_reason_phrase = new StringBuffer();
+
+  // From RFC 2616.
+  // generic-message = start-line
+  //                   *(message-header CRLF)
+  //                   CRLF
+  //                   [ message-body ]
+  // start-line      = Request-Line | Status-Line
+  // Request-Line    = Method SP Request-URI SP HTTP-Version CRLF
+  // Status-Line     = HTTP-Version SP Status-Code SP Reason-Phrase CRLF
+  // message-header  = field-name ":" [ field-value ]
+  int writeList(List<int> buffer, int offset, int count) {
+    int index = offset;
+    int lastIndex = offset + count;
+    while ((index < lastIndex) && !_failure) {
+      int byte = buffer[index];
+      switch (_state) {
+        case _State.START:
+          _contentLength = 0;
+          _keepAlive = false;
+          _chunked = false;
+
+          if (byte == _Const.HTTP11[0]) {
+            // Start parsing HTTP method.
+            _httpVersionIndex = 1;
+            _state = _State.METHOD_OR_HTTP_VERSION;
+          } else {
+            // Start parsing method.
+            _method_or_status_code.addCharCode(byte);
+            _state = _State.REQUEST_LINE_METHOD;
+          }
+          break;
+
+        case _State.METHOD_OR_HTTP_VERSION:
+          if (_httpVersionIndex < _Const.HTTP11.length &&
+              byte == _Const.HTTP11[_httpVersionIndex]) {
+            // Continue parsing HTTP version.
+            _httpVersionIndex++;
+          } else if (_httpVersionIndex == _Const.HTTP11.length &&
+                     byte == _CharCode.SP) {
+            // HTTP version parsed.
+            _state = _State.RESPONSE_LINE_STATUS_CODE;
+          } else {
+            // Did not parse HTTP version. Expect method instead.
+            for (int i = 0; i < _httpVersionIndex; i++) {
+              _method_or_status_code.addCharCode(_Const.HTTP11[i]);
+            }
+            _state = _State.REQUEST_LINE_URI;
+          }
+          break;
+
+        case _State.REQUEST_LINE_METHOD:
+          if (byte == _CharCode.SP) {
+            _state = _State.REQUEST_LINE_URI;
+          } else {
+            _method_or_status_code.addCharCode(byte);
+          }
+          break;
+
+        case _State.REQUEST_LINE_URI:
+          if (byte == _CharCode.SP) {
+            _state = _State.REQUEST_LINE_HTTP_VERSION;
+            _httpVersionIndex = 0;
+          } else {
+            _uri_or_reason_phrase.addCharCode(byte);
+          }
+          break;
+
+        case _State.REQUEST_LINE_HTTP_VERSION:
+          if (_httpVersionIndex < _Const.HTTP11.length) {
+            _expect(byte, _Const.HTTP11[_httpVersionIndex]);
+            _httpVersionIndex++;
+          } else {
+            _expect(byte, _CharCode.CR);
+            _state = _State.REQUEST_LINE_ENDING;
+          }
+          break;
+
+        case _State.REQUEST_LINE_ENDING:
+          _expect(byte, _CharCode.LF);
+          if (requestStart != null) {
+            requestStart(_method_or_status_code.toString(),
+                         _uri_or_reason_phrase.toString());
+          }
+          _method_or_status_code.clear();
+          _uri_or_reason_phrase.clear();
+          _state = _State.HEADER_START;
+          break;
+
+        case _State.RESPONSE_LINE_STATUS_CODE:
+          if (byte == _CharCode.SP) {
+            _state = _State.RESPONSE_LINE_REASON_PHRASE;
+          } else {
+            if (byte < 0x30 && 0x39 < byte) {
+              _failure = true;
+            } else {
+              _method_or_status_code.addCharCode(byte);
+            }
+          }
+          break;
+
+        case _State.RESPONSE_LINE_REASON_PHRASE:
+          if (byte == _CharCode.CR) {
+            _state = _State.RESPONSE_LINE_ENDING;
+          } else {
+            _uri_or_reason_phrase.addCharCode(byte);
+          }
+          break;
+
+        case _State.RESPONSE_LINE_ENDING:
+          _expect(byte, _CharCode.LF);
+          // TODO(sgjesse): Check for valid status code.
+          if (responseStart != null) {
+            responseStart(Math.parseInt(_method_or_status_code.toString()),
+                          _uri_or_reason_phrase.toString());
+          }
+          _method_or_status_code.clear();
+          _uri_or_reason_phrase.clear();
+          _state = _State.HEADER_START;
+          break;
+
+        case _State.HEADER_START:
+          if (byte == _CharCode.CR) {
+            _state = _State.HEADER_ENDING;
+          } else {
+            // Start of new header field.
+            _headerField.addCharCode(_toLowerCase(byte));
+            _state = _State.HEADER_FIELD;
+          }
+          break;
+
+        case _State.HEADER_FIELD:
+          if (byte == _CharCode.COLON) {
+            _state = _State.HEADER_VALUE_START;
+          } else {
+            _headerField.addCharCode(_toLowerCase(byte));
+          }
+          break;
+
+        case _State.HEADER_VALUE_START:
+          if (byte != _CharCode.SP && byte != _CharCode.HT) {
+            // Start of new header value.
+            _headerValue.addCharCode(byte);
+            _state = _State.HEADER_VALUE;
+          }
+          break;
+
+        case _State.HEADER_VALUE:
+          if (byte == _CharCode.CR) {
+            _state = _State.HEADER_VALUE_FOLDING_OR_ENDING;
+          } else {
+            _headerValue.addCharCode(byte);
+          }
+          break;
+
+        case _State.HEADER_VALUE_FOLDING_OR_ENDING:
+          _expect(byte, _CharCode.LF);
+          _state = _State.HEADER_VALUE_FOLD_OR_END;
+          break;
+
+        case _State.HEADER_VALUE_FOLD_OR_END:
+          if (byte == _CharCode.SP || byte == _CharCode.HT) {
+            _state = _State.HEADER_VALUE_START;
+          } else {
+            String headerField = _headerField.toString();
+            String headerValue =_headerValue.toString();
+            // Ignore the Content-Length header if Transfer-Encoding
+            // is chunked (RFC 2616 section 4.4)
+            if (headerField == "content-length" && !_chunked) {
+              _contentLength = Math.parseInt(headerValue);
+            } else if (headerField == "connection" &&
+                       headerValue == "keep-alive") {
+              _keepAlive = true;
+            } else if (headerField == "transfer-encoding" &&
+                       headerValue == "chunked") {
+              _chunked = true;
+              _contentLength = -1;
+            }
+            if (headerReceived != null) {
+              headerReceived(headerField, headerValue);
+            }
+            _headerField.clear();
+            _headerValue.clear();
+
+            if (byte == _CharCode.CR) {
+              _state = _State.HEADER_ENDING;
+            } else {
+              // Start of new header field.
+              _headerField.addCharCode(_toLowerCase(byte));
+              _state = _State.HEADER_FIELD;
+            }
+          }
+          break;
+
+        case _State.HEADER_ENDING:
+          _expect(byte, _CharCode.LF);
+          if (headersComplete != null) headersComplete();
+
+          // If there is no data get ready to process the next request.
+          if (_chunked) {
+            _state = _State.CHUNK_SIZE;
+            _remainingContent = 0;
+          } else if (_contentLength == 0) {
+            if (dataEnd != null) dataEnd();
+            _state = _State.START;
+          } else if (_contentLength > 0) {
+            _remainingContent = _contentLength;
+            _state = _State.BODY;
+          } else {
+            // TODO(sgjesse): Error handling.
+          }
+          break;
+
+        case _State.CHUNK_SIZE_STARTING_CR:
+          _expect(byte, _CharCode.CR);
+          _state = _State.CHUNK_SIZE_STARTING_LF;
+          break;
+
+        case _State.CHUNK_SIZE_STARTING_LF:
+          _expect(byte, _CharCode.LF);
+          _state = _State.CHUNK_SIZE;
+          break;
+
+        case _State.CHUNK_SIZE:
+          if (byte == _CharCode.CR) {
+            _state = _State.CHUNK_SIZE_ENDING;
+          } else {
+            int value = _expectHexDigit(byte);
+            _remainingContent = _remainingContent * 16 + value;
+          }
+          break;
+
+        case _State.CHUNK_SIZE_ENDING:
+          _expect(byte, _CharCode.LF);
+          if (_remainingContent > 0) {
+            _state = _State.BODY;
+          } else {
+            _state = _State.CHUNKED_BODY_DONE_CR;
+          }
+          break;
+
+        case _State.CHUNKED_BODY_DONE_CR:
+          _expect(byte, _CharCode.CR);
+          _state = _State.CHUNKED_BODY_DONE_LF;
+          break;
+
+        case _State.CHUNKED_BODY_DONE_LF:
+          _expect(byte, _CharCode.LF);
+          if (dataEnd != null) dataEnd();
+          _state = _State.START;
+          break;
+
+        case _State.BODY:
+          // The body is not handled one byte at the time but in blocks.
+          int dataAvailable = lastIndex - index;
+          ByteArray data;
+          if (dataAvailable <= _remainingContent) {
+            data = new ByteArray(dataAvailable);
+            data.setRange(0, dataAvailable, buffer, index);
+          } else {
+            data = new ByteArray(_remainingContent);
+            data.setRange(0, _remainingContent, buffer, index);
+          }
+
+          if (dataReceived != null) dataReceived(data);
+          _remainingContent -= data.length;
+          index += data.length;
+          if (_remainingContent == 0) {
+            if (!_chunked) {
+              if (dataEnd != null) dataEnd();
+              _state = _State.START;
+            } else {
+              _state = _State.CHUNK_SIZE_STARTING_CR;
+            }
+          }
+
+          // Hack - as we always do index++ below.
+          index--;
+          break;
+
+        default:
+          // Should be unreachable.
+          assert(false);
+      }
+
+      // Move to the next byte.
+      index++;
+    }
+
+    // Return the number of bytes parsed.
+    return index - offset;
+  }
+
+  int get contentLength() => _contentLength;
+  bool get keepAlive() => _keepAlive;
+
+  int _toLowerCase(int byte) {
+    final int aCode = "A".charCodeAt(0);
+    final int zCode = "Z".charCodeAt(0);
+    final int delta = "a".charCodeAt(0) - aCode;
+    return (aCode <= byte && byte <= zCode) ? byte + delta : byte;
+  }
+
+  int _expect(int val1, int val2) {
+    if (val1 != val2) {
+      _failure = true;
+    }
+  }
+
+  int _expectHexDigit(int byte) {
+    if (0x30 <= byte && byte <= 0x39) {
+      return byte - 0x30;  // 0 - 9
+    } else if (0x41 <= byte && byte <= 0x46) {
+      return byte - 0x41 + 10;  // A - F
+    } else if (0x61 <= byte && byte <= 0x66) {
+      return byte - 0x61 + 10;  // a - f
+    } else {
+      _failure = true;
+      return 0;
+    }
+  }
+
+  int _state;
+  bool _failure;
+  int _httpVersionIndex;
+  StringBuffer _method_or_status_code;
+  StringBuffer _uri_or_reason_phrase;
+  StringBuffer _headerField;
+  StringBuffer _headerValue;
+
+  int _contentLength;
+  bool _keepAlive;
+  bool _chunked;
+
+  int _remainingContent;
+
+  // Callbacks.
+  Function requestStart;
+  Function responseStart;
+  Function headerReceived;
+  Function headersComplete;
+  Function dataReceived;
+  Function dataEnd;
+}