799 lines
26 KiB
C#
799 lines
26 KiB
C#
// Protocol Buffers - Google's data interchange format
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// Copyright 2008 Google Inc.
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// http://code.google.com/p/protobuf/
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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using System;
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using System.Collections.Generic;
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using System.IO;
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using System.Text;
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using Google.ProtocolBuffers.Descriptors;
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namespace Google.ProtocolBuffers {
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/// <summary>
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/// Readings and decodes protocol message fields.
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/// </summary>
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/// <remarks>
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/// This class contains two kinds of methods: methods that read specific
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/// protocol message constructs and field types (e.g. ReadTag and
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/// ReadInt32) and methods that read low-level values (e.g.
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/// ReadRawVarint32 and ReadRawBytes). If you are reading encoded protocol
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/// messages, you should use the former methods, but if you are reading some
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/// other format of your own design, use the latter. The names of the former
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/// methods are taken from the protocol buffer type names, not .NET types.
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/// (Hence ReadFloat instead of ReadSingle, and ReadBool instead of ReadBoolean.)
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///
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/// TODO(jonskeet): Consider whether recursion and size limits shouldn't be readonly,
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/// set at construction time.
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/// </remarks>
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public sealed class CodedInputStream {
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private readonly byte[] buffer;
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private int bufferSize;
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private int bufferSizeAfterLimit = 0;
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private int bufferPos = 0;
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private readonly Stream input;
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private uint lastTag = 0;
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const int DefaultRecursionLimit = 64;
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const int DefaultSizeLimit = 64 << 20; // 64MB
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const int BufferSize = 4096;
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/// <summary>
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/// The total number of bytes read before the current buffer. The
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/// total bytes read up to the current position can be computed as
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/// totalBytesRetired + bufferPos.
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/// </summary>
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private int totalBytesRetired = 0;
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/// <summary>
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/// The absolute position of the end of the current message.
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/// </summary>
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private int currentLimit = int.MaxValue;
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/// <summary>
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/// <see cref="SetRecursionLimit"/>
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/// </summary>
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private int recursionDepth = 0;
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private int recursionLimit = DefaultRecursionLimit;
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/// <summary>
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/// <see cref="SetSizeLimit"/>
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/// </summary>
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private int sizeLimit = DefaultSizeLimit;
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#region Construction
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/// <summary>
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/// Creates a new CodedInputStream reading data from the given
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/// stream.
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/// </summary>
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public static CodedInputStream CreateInstance(Stream input) {
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return new CodedInputStream(input);
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}
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/// <summary>
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/// Creates a new CodedInputStream reading data from the given
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/// byte array.
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/// </summary>
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public static CodedInputStream CreateInstance(byte[] buf) {
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return new CodedInputStream(buf);
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}
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private CodedInputStream(byte[] buffer) {
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this.buffer = buffer;
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this.bufferSize = buffer.Length;
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this.input = null;
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}
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private CodedInputStream(Stream input) {
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this.buffer = new byte[BufferSize];
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this.bufferSize = 0;
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this.input = input;
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}
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#endregion
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#region Uncategorised (TODO: Fix this!)
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/// <summary>
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/// Verifies that the last call to ReadTag() returned the given tag value.
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/// This is used to verify that a nested group ended with the correct
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/// end tag.
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/// </summary>
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/// <exception cref="InvalidProtocolBufferException">The last
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/// tag read was not the one specified</exception>
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public void CheckLastTagWas(uint value) {
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if (lastTag != value) {
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throw InvalidProtocolBufferException.InvalidEndTag();
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}
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}
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#endregion
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#region Reading of tags etc
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/// <summary>
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/// Attempt to read a field tag, returning 0 if we have reached the end
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/// of the input data. Protocol message parsers use this to read tags,
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/// since a protocol message may legally end wherever a tag occurs, and
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/// zero is not a valid tag number.
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/// </summary>
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public uint ReadTag() {
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if (bufferPos == bufferSize && !RefillBuffer(false)) {
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lastTag = 0;
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return 0;
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}
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lastTag = ReadRawVarint32();
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if (lastTag == 0) {
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// If we actually read zero, that's not a valid tag.
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throw InvalidProtocolBufferException.InvalidTag();
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}
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return lastTag;
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}
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/// <summary>
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/// Read a double field from the stream.
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/// </summary>
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public double ReadDouble() {
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// TODO(jonskeet): Test this on different endiannesses
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return BitConverter.Int64BitsToDouble((long) ReadRawLittleEndian64());
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}
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/// <summary>
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/// Read a float field from the stream.
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/// </summary>
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public float ReadFloat() {
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// TODO(jonskeet): Test this on different endiannesses
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uint raw = ReadRawLittleEndian32();
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byte[] rawBytes = BitConverter.GetBytes(raw);
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return BitConverter.ToSingle(rawBytes, 0);
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}
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/// <summary>
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/// Read a uint64 field from the stream.
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/// </summary>
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public ulong ReadUInt64() {
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return ReadRawVarint64();
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}
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/// <summary>
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/// Read an int64 field from the stream.
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/// </summary>
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public long ReadInt64() {
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return (long) ReadRawVarint64();
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}
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/// <summary>
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/// Read an int32 field from the stream.
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/// </summary>
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public int ReadInt32() {
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return (int) ReadRawVarint32();
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}
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/// <summary>
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/// Read a fixed64 field from the stream.
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/// </summary>
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public ulong ReadFixed64() {
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return ReadRawLittleEndian64();
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}
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/// <summary>
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/// Read a fixed32 field from the stream.
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/// </summary>
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public uint ReadFixed32() {
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return ReadRawLittleEndian32();
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}
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/// <summary>
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/// Read a bool field from the stream.
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/// </summary>
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public bool ReadBool() {
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return ReadRawVarint32() != 0;
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}
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/// <summary>
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/// Reads a string field from the stream.
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/// </summary>
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public String ReadString() {
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int size = (int) ReadRawVarint32();
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if (size < bufferSize - bufferPos && size > 0) {
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// Fast path: We already have the bytes in a contiguous buffer, so
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// just copy directly from it.
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String result = Encoding.UTF8.GetString(buffer, bufferPos, size);
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bufferPos += size;
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return result;
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} else {
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// Slow path: Build a byte array first then copy it.
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return Encoding.UTF8.GetString(ReadRawBytes(size));
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}
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}
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/// <summary>
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/// Reads a group field value from the stream.
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/// </summary>
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public void ReadGroup(int fieldNumber, IBuilder builder,
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ExtensionRegistry extensionRegistry) {
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if (recursionDepth >= recursionLimit) {
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throw InvalidProtocolBufferException.RecursionLimitExceeded();
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}
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++recursionDepth;
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builder.MergeFrom(this, extensionRegistry);
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CheckLastTagWas(WireFormat.MakeTag(fieldNumber, WireFormat.WireType.EndGroup));
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--recursionDepth;
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}
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/// <summary>
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/// Reads a group field value from the stream and merges it into the given
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/// UnknownFieldSet.
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/// </summary>
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public void ReadUnknownGroup(int fieldNumber, UnknownFieldSet.Builder builder) {
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if (recursionDepth >= recursionLimit) {
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throw InvalidProtocolBufferException.RecursionLimitExceeded();
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}
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++recursionDepth;
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builder.MergeFrom(this);
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CheckLastTagWas(WireFormat.MakeTag(fieldNumber, WireFormat.WireType.EndGroup));
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--recursionDepth;
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}
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/// <summary>
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/// Reads an embedded message field value from the stream.
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/// </summary>
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public void ReadMessage(IBuilder builder, ExtensionRegistry extensionRegistry) {
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int length = (int) ReadRawVarint32();
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if (recursionDepth >= recursionLimit) {
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throw InvalidProtocolBufferException.RecursionLimitExceeded();
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}
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int oldLimit = PushLimit(length);
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++recursionDepth;
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builder.MergeFrom(this, extensionRegistry);
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CheckLastTagWas(0);
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--recursionDepth;
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PopLimit(oldLimit);
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}
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/// <summary>
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/// Reads a bytes field value from the stream.
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/// </summary>
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public ByteString ReadBytes() {
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int size = (int) ReadRawVarint32();
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if (size < bufferSize - bufferPos && size > 0) {
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// Fast path: We already have the bytes in a contiguous buffer, so
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// just copy directly from it.
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ByteString result = ByteString.CopyFrom(buffer, bufferPos, size);
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bufferPos += size;
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return result;
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} else {
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// Slow path: Build a byte array first then copy it.
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return ByteString.CopyFrom(ReadRawBytes(size));
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}
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}
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/// <summary>
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/// Reads a uint32 field value from the stream.
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/// </summary>
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public uint ReadUInt32() {
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return ReadRawVarint32();
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}
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/// <summary>
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/// Reads an enum field value from the stream. The caller is responsible
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/// for converting the numeric value to an actual enum.
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/// </summary>
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public int ReadEnum() {
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return (int) ReadRawVarint32();
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}
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/// <summary>
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/// Reads an sfixed32 field value from the stream.
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/// </summary>
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public int ReadSFixed32() {
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return (int) ReadRawLittleEndian32();
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}
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/// <summary>
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/// Reads an sfixed64 field value from the stream.
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/// </summary>
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public long ReadSFixed64() {
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return (long) ReadRawLittleEndian64();
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}
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/// <summary>
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/// Reads an sint32 field value from the stream.
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/// </summary>
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public int ReadSInt32() {
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return DecodeZigZag32(ReadRawVarint32());
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}
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/// <summary>
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/// Reads an sint64 field value from the stream.
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/// </summary>
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public long ReadSInt64() {
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return DecodeZigZag64(ReadRawVarint64());
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}
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/// <summary>
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/// Reads a field of any primitive type. Enums, groups and embedded
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/// messages are not handled by this method.
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/// </summary>
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public object ReadPrimitiveField(FieldType fieldType) {
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switch (fieldType) {
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case FieldType.Double: return ReadDouble();
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case FieldType.Float: return ReadFloat();
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case FieldType.Int64: return ReadInt64();
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case FieldType.UInt64: return ReadUInt64();
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case FieldType.Int32: return ReadInt32();
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case FieldType.Fixed64: return ReadFixed64();
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case FieldType.Fixed32: return ReadFixed32();
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case FieldType.Bool: return ReadBool();
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case FieldType.String: return ReadString();
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case FieldType.Bytes: return ReadBytes();
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case FieldType.UInt32: return ReadUInt32();
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case FieldType.SFixed32: return ReadSFixed32();
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case FieldType.SFixed64: return ReadSFixed64();
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case FieldType.SInt32: return ReadSInt32();
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case FieldType.SInt64: return ReadSInt64();
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case FieldType.Group:
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throw new ArgumentException("ReadPrimitiveField() cannot handle nested groups.");
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case FieldType.Message:
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throw new ArgumentException("ReadPrimitiveField() cannot handle embedded messages.");
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// We don't handle enums because we don't know what to do if the
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// value is not recognized.
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case FieldType.Enum:
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throw new ArgumentException("ReadPrimitiveField() cannot handle enums.");
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default:
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throw new ArgumentOutOfRangeException("Invalid field type " + fieldType);
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}
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}
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#endregion
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#region Underlying reading primitives
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/// <summary>
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/// Read a raw Varint from the stream. If larger than 32 bits, discard the upper bits.
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/// </summary>
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/// <returns></returns>
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public uint ReadRawVarint32() {
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int tmp = ReadRawByte();
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if (tmp < 128) {
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return (uint) tmp;
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}
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int result = tmp & 0x7f;
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if ((tmp = ReadRawByte()) < 128) {
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result |= tmp << 7;
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} else {
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result |= (tmp & 0x7f) << 7;
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if ((tmp = ReadRawByte()) < 128) {
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result |= tmp << 14;
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} else {
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result |= (tmp & 0x7f) << 14;
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if ((tmp = ReadRawByte()) < 128) {
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result |= tmp << 21;
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} else {
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result |= (tmp & 0x7f) << 21;
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result |= (tmp = ReadRawByte()) << 28;
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if (tmp >= 128) {
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// Discard upper 32 bits.
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for (int i = 0; i < 5; i++) {
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if (ReadRawByte() < 128) return (uint) result;
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}
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throw InvalidProtocolBufferException.MalformedVarint();
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}
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}
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}
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}
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return (uint) result;
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}
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/// <summary>
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/// Read a raw varint from the stream.
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/// </summary>
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public ulong ReadRawVarint64() {
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int shift = 0;
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ulong result = 0;
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while (shift < 64) {
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byte b = ReadRawByte();
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result |= (ulong)(b & 0x7F) << shift;
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if ((b & 0x80) == 0) {
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return result;
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}
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shift += 7;
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}
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throw InvalidProtocolBufferException.MalformedVarint();
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}
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/// <summary>
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/// Read a 32-bit little-endian integer from the stream.
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/// </summary>
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public uint ReadRawLittleEndian32() {
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uint b1 = ReadRawByte();
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uint b2 = ReadRawByte();
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uint b3 = ReadRawByte();
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uint b4 = ReadRawByte();
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return b1 | (b2 << 8) | (b3 << 16) | (b4 << 24);
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}
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/// <summary>
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/// Read a 64-bit little-endian integer from the stream.
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/// </summary>
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public ulong ReadRawLittleEndian64() {
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ulong b1 = ReadRawByte();
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ulong b2 = ReadRawByte();
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ulong b3 = ReadRawByte();
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ulong b4 = ReadRawByte();
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ulong b5 = ReadRawByte();
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ulong b6 = ReadRawByte();
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ulong b7 = ReadRawByte();
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ulong b8 = ReadRawByte();
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return b1 | (b2 << 8) | (b3 << 16) | (b4 << 24)
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| (b5 << 32) | (b6 << 40) | (b7 << 48) | (b8 << 56);
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}
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#endregion
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/// <summary>
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/// Decode a 32-bit value with ZigZag encoding.
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/// </summary>
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/// <remarks>
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/// ZigZag encodes signed integers into values that can be efficiently
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/// encoded with varint. (Otherwise, negative values must be
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/// sign-extended to 64 bits to be varint encoded, thus always taking
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/// 10 bytes on the wire.)
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/// </remarks>
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public static int DecodeZigZag32(uint n) {
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return (int)(n >> 1) ^ -(int)(n & 1);
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}
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/// <summary>
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/// Decode a 32-bit value with ZigZag encoding.
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/// </summary>
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/// <remarks>
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/// ZigZag encodes signed integers into values that can be efficiently
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/// encoded with varint. (Otherwise, negative values must be
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/// sign-extended to 64 bits to be varint encoded, thus always taking
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/// 10 bytes on the wire.)
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/// </remarks>
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public static long DecodeZigZag64(ulong n) {
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return (long)(n >> 1) ^ -(long)(n & 1);
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}
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/// <summary>
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/// Set the maximum message recursion depth.
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/// </summary>
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/// <remarks>
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/// In order to prevent malicious
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/// messages from causing stack overflows, CodedInputStream limits
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/// how deeply messages may be nested. The default limit is 64.
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/// </remarks>
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public int SetRecursionLimit(int limit) {
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if (limit < 0) {
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throw new ArgumentOutOfRangeException("Recursion limit cannot be negative: " + limit);
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}
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int oldLimit = recursionLimit;
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recursionLimit = limit;
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return oldLimit;
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}
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/// <summary>
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/// Set the maximum message size.
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/// </summary>
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/// <remarks>
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/// In order to prevent malicious messages from exhausting memory or
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/// causing integer overflows, CodedInputStream limits how large a message may be.
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/// The default limit is 64MB. You should set this limit as small
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/// as you can without harming your app's functionality. Note that
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/// size limits only apply when reading from an InputStream, not
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/// when constructed around a raw byte array (nor with ByteString.NewCodedInput).
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/// </remarks>
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public int SetSizeLimit(int limit) {
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if (limit < 0) {
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throw new ArgumentOutOfRangeException("Size limit cannot be negative: " + limit);
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}
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int oldLimit = sizeLimit;
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sizeLimit = limit;
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return oldLimit;
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}
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#region Internal reading and buffer management
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/// <summary>
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/// Sets currentLimit to (current position) + byteLimit. This is called
|
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/// when descending into a length-delimited embedded message. The previous
|
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/// limit is returned.
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/// </summary>
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/// <returns>The old limit.</returns>
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public int PushLimit(int byteLimit) {
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if (byteLimit < 0) {
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throw InvalidProtocolBufferException.NegativeSize();
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}
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byteLimit += totalBytesRetired + bufferPos;
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int oldLimit = currentLimit;
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if (byteLimit > oldLimit) {
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throw InvalidProtocolBufferException.TruncatedMessage();
|
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}
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currentLimit = byteLimit;
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RecomputeBufferSizeAfterLimit();
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return oldLimit;
|
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}
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|
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private void RecomputeBufferSizeAfterLimit() {
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bufferSize += bufferSizeAfterLimit;
|
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int bufferEnd = totalBytesRetired + bufferSize;
|
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if (bufferEnd > currentLimit) {
|
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// Limit is in current buffer.
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bufferSizeAfterLimit = bufferEnd - currentLimit;
|
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bufferSize -= bufferSizeAfterLimit;
|
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} else {
|
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bufferSizeAfterLimit = 0;
|
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}
|
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}
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|
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/// <summary>
|
|
/// Discards the current limit, returning the previous limit.
|
|
/// </summary>
|
|
public void PopLimit(int oldLimit) {
|
|
currentLimit = oldLimit;
|
|
RecomputeBufferSizeAfterLimit();
|
|
}
|
|
|
|
/// <summary>
|
|
/// Called when buffer is empty to read more bytes from the
|
|
/// input. If <paramref name="mustSucceed"/> is true, RefillBuffer() gurantees that
|
|
/// either there will be at least one byte in the buffer when it returns
|
|
/// or it will throw an exception. If <paramref name="mustSucceed"/> is false,
|
|
/// RefillBuffer() returns false if no more bytes were available.
|
|
/// </summary>
|
|
/// <param name="mustSucceed"></param>
|
|
/// <returns></returns>
|
|
private bool RefillBuffer(bool mustSucceed) {
|
|
if (bufferPos < bufferSize) {
|
|
throw new InvalidOperationException("RefillBuffer() called when buffer wasn't empty.");
|
|
}
|
|
|
|
if (totalBytesRetired + bufferSize == currentLimit) {
|
|
// Oops, we hit a limit.
|
|
if (mustSucceed) {
|
|
throw InvalidProtocolBufferException.TruncatedMessage();
|
|
} else {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
totalBytesRetired += bufferSize;
|
|
|
|
bufferPos = 0;
|
|
bufferSize = (input == null) ? -1 : input.Read(buffer, 0, buffer.Length);
|
|
if (bufferSize == -1) {
|
|
bufferSize = 0;
|
|
if (mustSucceed) {
|
|
throw InvalidProtocolBufferException.TruncatedMessage();
|
|
} else {
|
|
return false;
|
|
}
|
|
} else {
|
|
RecomputeBufferSizeAfterLimit();
|
|
int totalBytesRead =
|
|
totalBytesRetired + bufferSize + bufferSizeAfterLimit;
|
|
if (totalBytesRead > sizeLimit || totalBytesRead < 0) {
|
|
throw InvalidProtocolBufferException.SizeLimitExceeded();
|
|
}
|
|
return true;
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// Read one byte from the input.
|
|
/// </summary>
|
|
/// <exception cref="InvalidProtocolBufferException">
|
|
/// he end of the stream or the current limit was reached
|
|
/// </exception>
|
|
public byte ReadRawByte() {
|
|
if (bufferPos == bufferSize) {
|
|
RefillBuffer(true);
|
|
}
|
|
return buffer[bufferPos++];
|
|
}
|
|
|
|
/// <summary>
|
|
/// Read a fixed size of bytes from the input.
|
|
/// </summary>
|
|
/// <exception cref="InvalidProtocolBufferException">
|
|
/// the end of the stream or the current limit was reached
|
|
/// </exception>
|
|
public byte[] ReadRawBytes(int size) {
|
|
if (size < 0) {
|
|
throw InvalidProtocolBufferException.NegativeSize();
|
|
}
|
|
|
|
if (totalBytesRetired + bufferPos + size > currentLimit) {
|
|
// Read to the end of the stream anyway.
|
|
SkipRawBytes(currentLimit - totalBytesRetired - bufferPos);
|
|
// Then fail.
|
|
throw InvalidProtocolBufferException.TruncatedMessage();
|
|
}
|
|
|
|
if (size <= bufferSize - bufferPos) {
|
|
// We have all the bytes we need already.
|
|
byte[] bytes = new byte[size];
|
|
Array.Copy(buffer, bufferPos, bytes, 0, size);
|
|
bufferPos += size;
|
|
return bytes;
|
|
} else if (size < BufferSize) {
|
|
// Reading more bytes than are in the buffer, but not an excessive number
|
|
// of bytes. We can safely allocate the resulting array ahead of time.
|
|
|
|
// First copy what we have.
|
|
byte[] bytes = new byte[size];
|
|
int pos = bufferSize - bufferPos;
|
|
Array.Copy(buffer, bufferPos, bytes, 0, pos);
|
|
bufferPos = bufferSize;
|
|
|
|
// We want to use RefillBuffer() and then copy from the buffer into our
|
|
// byte array rather than reading directly into our byte array because
|
|
// the input may be unbuffered.
|
|
RefillBuffer(true);
|
|
|
|
while (size - pos > bufferSize) {
|
|
Array.Copy(buffer, 0, bytes, pos, bufferSize);
|
|
pos += bufferSize;
|
|
bufferPos = bufferSize;
|
|
RefillBuffer(true);
|
|
}
|
|
|
|
Array.Copy(buffer, 0, bytes, pos, size - pos);
|
|
bufferPos = size - pos;
|
|
|
|
return bytes;
|
|
} else {
|
|
// The size is very large. For security reasons, we can't allocate the
|
|
// entire byte array yet. The size comes directly from the input, so a
|
|
// maliciously-crafted message could provide a bogus very large size in
|
|
// order to trick the app into allocating a lot of memory. We avoid this
|
|
// by allocating and reading only a small chunk at a time, so that the
|
|
// malicious message must actually *be* extremely large to cause
|
|
// problems. Meanwhile, we limit the allowed size of a message elsewhere.
|
|
|
|
// Remember the buffer markers since we'll have to copy the bytes out of
|
|
// it later.
|
|
int originalBufferPos = bufferPos;
|
|
int originalBufferSize = bufferSize;
|
|
|
|
// Mark the current buffer consumed.
|
|
totalBytesRetired += bufferSize;
|
|
bufferPos = 0;
|
|
bufferSize = 0;
|
|
|
|
// Read all the rest of the bytes we need.
|
|
int sizeLeft = size - (originalBufferSize - originalBufferPos);
|
|
List<byte[]> chunks = new List<byte[]>();
|
|
|
|
while (sizeLeft > 0) {
|
|
byte[] chunk = new byte[Math.Min(sizeLeft, BufferSize)];
|
|
int pos = 0;
|
|
while (pos < chunk.Length) {
|
|
int n = (input == null) ? -1 : input.Read(chunk, pos, chunk.Length - pos);
|
|
if (n <= 0) {
|
|
throw InvalidProtocolBufferException.TruncatedMessage();
|
|
}
|
|
totalBytesRetired += n;
|
|
pos += n;
|
|
}
|
|
sizeLeft -= chunk.Length;
|
|
chunks.Add(chunk);
|
|
}
|
|
|
|
// OK, got everything. Now concatenate it all into one buffer.
|
|
byte[] bytes = new byte[size];
|
|
|
|
// Start by copying the leftover bytes from this.buffer.
|
|
int newPos = originalBufferSize - originalBufferPos;
|
|
Array.Copy(buffer, originalBufferPos, bytes, 0, newPos);
|
|
|
|
// And now all the chunks.
|
|
foreach (byte[] chunk in chunks) {
|
|
Array.Copy(chunk, 0, bytes, newPos, chunk.Length);
|
|
newPos += chunk.Length;
|
|
}
|
|
|
|
// Done.
|
|
return bytes;
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// Reads and discards a single field, given its tag value.
|
|
/// </summary>
|
|
/// <returns>false if the tag is an end-group tag, in which case
|
|
/// nothing is skipped. Otherwise, returns true.</returns>
|
|
public bool SkipField(uint tag) {
|
|
switch (WireFormat.GetTagWireType(tag)) {
|
|
case WireFormat.WireType.Varint:
|
|
ReadInt32();
|
|
return true;
|
|
case WireFormat.WireType.Fixed64:
|
|
ReadRawLittleEndian64();
|
|
return true;
|
|
case WireFormat.WireType.LengthDelimited:
|
|
SkipRawBytes((int) ReadRawVarint32());
|
|
return true;
|
|
case WireFormat.WireType.StartGroup:
|
|
SkipMessage();
|
|
CheckLastTagWas(
|
|
WireFormat.MakeTag(WireFormat.GetTagFieldNumber(tag),
|
|
WireFormat.WireType.EndGroup));
|
|
return true;
|
|
case WireFormat.WireType.EndGroup:
|
|
return false;
|
|
case WireFormat.WireType.Fixed32:
|
|
ReadRawLittleEndian32();
|
|
return true;
|
|
default:
|
|
throw InvalidProtocolBufferException.InvalidWireType();
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// Reads and discards an entire message. This will read either until EOF
|
|
/// or until an endgroup tag, whichever comes first.
|
|
/// </summary>
|
|
public void SkipMessage() {
|
|
while (true) {
|
|
uint tag = ReadTag();
|
|
if (tag == 0 || !SkipField(tag)) {
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
|
|
/// <summary>
|
|
/// Reads and discards <paramref name="size"/> bytes.
|
|
/// </summary>
|
|
/// <exception cref="InvalidProtocolBufferException">the end of the stream
|
|
/// or the current limit was reached</exception>
|
|
public void SkipRawBytes(int size) {
|
|
if (size < 0) {
|
|
throw InvalidProtocolBufferException.NegativeSize();
|
|
}
|
|
|
|
if (totalBytesRetired + bufferPos + size > currentLimit) {
|
|
// Read to the end of the stream anyway.
|
|
SkipRawBytes(currentLimit - totalBytesRetired - bufferPos);
|
|
// Then fail.
|
|
throw InvalidProtocolBufferException.TruncatedMessage();
|
|
}
|
|
|
|
if (size < bufferSize - bufferPos) {
|
|
// We have all the bytes we need already.
|
|
bufferPos += size;
|
|
} else {
|
|
// Skipping more bytes than are in the buffer. First skip what we have.
|
|
int pos = bufferSize - bufferPos;
|
|
totalBytesRetired += pos;
|
|
bufferPos = 0;
|
|
bufferSize = 0;
|
|
|
|
// Then skip directly from the InputStream for the rest.
|
|
if (pos < size) {
|
|
// TODO(jonskeet): Java implementation uses skip(). Not sure whether this is really equivalent...
|
|
if (input == null) {
|
|
throw InvalidProtocolBufferException.TruncatedMessage();
|
|
}
|
|
input.Seek(size - pos, SeekOrigin.Current);
|
|
if (input.Position > input.Length) {
|
|
throw InvalidProtocolBufferException.TruncatedMessage();
|
|
}
|
|
totalBytesRetired += size - pos;
|
|
}
|
|
}
|
|
}
|
|
#endregion
|
|
}
|
|
}
|