Protocol Buffer runtime library and 'protoc' plugin

lib/protobuf/runtime/CodedStreamReader.dart

+// Copyright (c) 2011, 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.
+
+class CodedStreamReader extends CodedReader {
+  PbInputStreamReader _input;
+
+  CodedStreamReader(InputStream input, [
+      int recursionLimit = CodedReader.DEFAULT_RECURSION_LIMIT,
+      int sizeLimit = CodedReader.DEFAULT_SIZE_LIMIT]) :
+      super(recursionLimit, sizeLimit),
+      _input = new PbInputStreamReader(input);
+
+  bool isAtEnd() => (_currentLimit != -1 &&_bufferPos >= _currentLimit) ||
+      _input.closed;
+
+  Future readGroup(int fieldNumber, Builder builder,
+      ExtensionRegistry extensionRegistry) {
+    if (_recursionDepth >= _recursionLimit) {
+      throw InvalidProtocolBufferException.recursionLimitExceeded();
+    }
+    ++_recursionDepth;
+    return builder.mergeFromCodedStreamReader(this).transform((_) {
+      checkLastTagWas(WireFormat.makeTag(fieldNumber,
+          WireFormat.WIRETYPE_END_GROUP));
+      --_recursionDepth;
+    });
+  }
+
+  Future readUnknownFieldSetGroup(int fieldNumber,
+      UnknownFieldSet_Builder builder, ExtensionRegistry extensionRegistry) {
+    if (_recursionDepth >= _recursionLimit) {
+      throw InvalidProtocolBufferException.recursionLimitExceeded();
+    }
+    ++_recursionDepth;
+    return builder.mergeFromCodedStreamReader(this).transform((_) {
+      checkLastTagWas(WireFormat.makeTag(fieldNumber,
+          WireFormat.WIRETYPE_END_GROUP));
+      --_recursionDepth;
+    });
+  }
+
+  Future readMessage(Builder builder, ExtensionRegistry extensionRegistry) {
+    int oldLimit;
+    return readInt32().chain((int length) {
+      if(_recursionDepth >= _recursionLimit) {
+        throw InvalidProtocolBufferException.recursionLimitExceeded();
+      }
+      oldLimit = _pushLimit(length);
+      ++_recursionDepth;
+      return builder.mergeFromCodedStreamReader(this);
+    }).transform((_){
+      checkLastTagWas(0);
+      --_recursionDepth;
+      _popLimit(oldLimit);
+      return null;
+    });
+  }
+
+  Future<int> readEnum() => readInt32();
+
+  Future<int> readInt32() =>
+      readRawVarint().transform((v) => PbCodec.toInt32(v));
+
+  Future<int> readInt64() =>
+      readRawVarint().transform((v) => PbCodec.toInt64(v));
+
+  Future<int> readUint32() =>
+      readRawVarint().transform((v) => PbCodec.toUint32(v));
+
+  Future<int> readUint64() =>
+      readRawVarint().transform((v) => PbCodec.toUint64(v));
+
+  Future<int> readSint32() =>
+      readRawVarint().transform((v) => PbCodec.toSint32(v));
+
+  Future<int> readSint64() =>
+      readRawVarint().transform((v) => PbCodec.toSint64(v));
+
+  Future<int> readFixed32() =>
+      readRaw32().transform((v) => PbCodec.toFixed32(v));
+
+  Future<int> readFixed64() =>
+      readRaw64().transform((v) => PbCodec.toFixed64(v));
+
+  Future<int> readSfixed32() =>
+      readRaw32().transform((v) => PbCodec.toSfixed32(v));
+
+  Future<int> readSfixed64() =>
+      readRaw64().transform((v) => PbCodec.toSfixed64(v));
+
+  Future<bool> readBool() =>
+      readRawVarint().transform((v) => PbCodec.toBool(v));
+
+  Future<List<int>> readBytes() => readRawLengthDelimited();
+
+  Future<String> readString() =>
+      readRawLengthDelimited().transform((v) => decodeUtf8(v));
+
+  Future<double> readFloat() =>
+      readRaw32().transform((v) => PbCodec.toFloat(v));
+
+  Future<double> readDouble() =>
+      readRaw64().transform((v) => PbCodec.toDouble(v));
+
+
+  Future<int> readTag() {
+    if (isAtEnd()) {
+      _lastTag = 0;
+      return new Future<int>.immediate(0);
+    }
+    return readInt32().transform((int value) {
+      _lastTag = value;
+      if (WireFormat.getTagFieldNumber(_lastTag) == 0) {
+        throw InvalidProtocolBufferException.invalidTag();
+      } else {
+        return _lastTag;
+      }
+    });
+  }
+
+  Future<List<int>> readRawVarint() {
+    List<int> rawBytes = [];
+    Future completeVarint() {
+      return _readRawByte().chain((int value) {
+        if (value == null) {
+          throw InvalidProtocolBufferException.truncatedMessage();
+        }
+        rawBytes.add(value);
+        if (rawBytes.length < 10 && (value & 0x80) != 0) {
+          return completeVarint();
+        } else {
+          return new Future.immediate(0);
+        }
+      });
+    }
+    return completeVarint().transform((_) => rawBytes);
+  }
+
+  Future<List<int>> readRaw32() => _readRawBytes(4);
+  Future<List<int>> readRaw64() => _readRawBytes(8);
+
+  Future<List<int>> readRawLengthDelimited() =>
+      readInt32().chain((int length) => _readRawBytes(length));
+
+  Future<int> _readRawByte() {
+    try {
+      _bufferPos++;
+      _checkLimit();
+    } catch (InvalidProtocolBufferException e) {
+      // add a Future.immediateException() construct...
+      Completer<int> c = new Completer<int>();
+      c.completeException(e);
+      return c.future;
+    }
+    return _input.readByte().transform((int byte) {
+      if (byte == null) {
+        throw InvalidProtocolBufferException.truncatedMessage();
+      }
+      return byte;
+    });
+  }
+
+  Future<List<int>> _readRawBytes(int size) {
+    try {
+      _bufferPos += size;
+      _checkLimit();
+    } catch (InvalidProtocolBufferException e) {
+      // add a Future.immediateException() construct...
+      Completer<int> c = new Completer<int>();
+      c.completeException(e);
+      return c.future;
+    }
+    return _input.readBytes(size);
+  }
+
+  Future skipField(int tag) {
+    int number = tag >> 3;
+    int wireType = tag & 0x7;
+    switch (wireType) {
+      case WireFormat.WIRETYPE_VARINT:
+        return readRawVarint().transform((_) => null);
+      case WireFormat.WIRETYPE_FIXED64:
+        return readRaw64().transform((_) => null);
+      case WireFormat.WIRETYPE_LENGTH_DELIMITED:
+        return readRawLengthDelimited().transform((_) => null);
+      case WireFormat.WIRETYPE_START_GROUP:
+        UnknownFieldSet_Builder subBuilder =
+            new UnknownFieldSet_Builder();
+        return readUnknownFieldSetGroup(number, subBuilder,
+            ExtensionRegistry.EMPTY_REGISTRY).transform((_) => null);
+      case WireFormat.WIRETYPE_END_GROUP: // should not happen, but ignore?
+        return new Future.immediate(null);
+      case WireFormat.WIRETYPE_FIXED32:
+        return readRaw32().transform((_) => null);
+    }
+  }
+
+  Future skipRawBytes(int number) {
+    return _readRawBytes(number).transform((_) => null);
+  }
+
+  void _enableReadAhead(int numberOfBytes) {
+    _input.setReadAhead(numberOfBytes);
+  }
+}