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Diffstat (limited to 'src/ProtocolBuffers/CodedInputStream.cs')
-rw-r--r-- | src/ProtocolBuffers/CodedInputStream.cs | 2140 |
1 files changed, 1155 insertions, 985 deletions
diff --git a/src/ProtocolBuffers/CodedInputStream.cs b/src/ProtocolBuffers/CodedInputStream.cs index 8b4c860b..225cf4da 100644 --- a/src/ProtocolBuffers/CodedInputStream.cs +++ b/src/ProtocolBuffers/CodedInputStream.cs @@ -1,985 +1,1155 @@ -#region Copyright notice and license -// Protocol Buffers - Google's data interchange format -// Copyright 2008 Google Inc. All rights reserved. -// http://github.com/jskeet/dotnet-protobufs/ -// Original C++/Java/Python code: -// http://code.google.com/p/protobuf/ -// -// Redistribution and use in source and binary forms, with or without -// modification, are permitted provided that the following conditions are -// met: -// -// * Redistributions of source code must retain the above copyright -// notice, this list of conditions and the following disclaimer. -// * Redistributions in binary form must reproduce the above -// copyright notice, this list of conditions and the following disclaimer -// in the documentation and/or other materials provided with the -// distribution. -// * Neither the name of Google Inc. nor the names of its -// contributors may be used to endorse or promote products derived from -// this software without specific prior written permission. -// -// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS -// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT -// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR -// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT -// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, -// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT -// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, -// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY -// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT -// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE -// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. -#endregion - -using System; -using System.Collections.Generic; -using System.IO; -using System.Text; -using Google.ProtocolBuffers.Descriptors; - -namespace Google.ProtocolBuffers { - - /// <summary> - /// Readings and decodes protocol message fields. - /// </summary> - /// <remarks> - /// This class contains two kinds of methods: methods that read specific - /// protocol message constructs and field types (e.g. ReadTag and - /// ReadInt32) and methods that read low-level values (e.g. - /// ReadRawVarint32 and ReadRawBytes). If you are reading encoded protocol - /// messages, you should use the former methods, but if you are reading some - /// other format of your own design, use the latter. The names of the former - /// methods are taken from the protocol buffer type names, not .NET types. - /// (Hence ReadFloat instead of ReadSingle, and ReadBool instead of ReadBoolean.) - /// - /// TODO(jonskeet): Consider whether recursion and size limits shouldn't be readonly, - /// set at construction time. - /// </remarks> - public sealed class CodedInputStream { - private readonly byte[] buffer; - private int bufferSize; - private int bufferSizeAfterLimit = 0; - private int bufferPos = 0; - private readonly Stream input; - private uint lastTag = 0; - - internal const int DefaultRecursionLimit = 64; - internal const int DefaultSizeLimit = 64 << 20; // 64MB - public const int BufferSize = 4096; - - /// <summary> - /// The total number of bytes read before the current buffer. The - /// total bytes read up to the current position can be computed as - /// totalBytesRetired + bufferPos. - /// </summary> - private int totalBytesRetired = 0; - - /// <summary> - /// The absolute position of the end of the current message. - /// </summary> - private int currentLimit = int.MaxValue; - - /// <summary> - /// <see cref="SetRecursionLimit"/> - /// </summary> - private int recursionDepth = 0; - private int recursionLimit = DefaultRecursionLimit; - - /// <summary> - /// <see cref="SetSizeLimit"/> - /// </summary> - private int sizeLimit = DefaultSizeLimit; - - #region Construction - /// <summary> - /// Creates a new CodedInputStream reading data from the given - /// stream. - /// </summary> - public static CodedInputStream CreateInstance(Stream input) { - return new CodedInputStream(input); - } - - /// <summary> - /// Creates a new CodedInputStream reading data from the given - /// byte array. - /// </summary> - public static CodedInputStream CreateInstance(byte[] buf) { - return new CodedInputStream(buf, 0, buf.Length); - } - - /// <summary> - /// Creates a new CodedInputStream that reads from the given - /// byte array slice. - /// </summary> - public static CodedInputStream CreateInstance(byte[] buf, int offset, int length) { - return new CodedInputStream(buf, offset, length); - } - - private CodedInputStream(byte[] buffer, int offset, int length) { - this.buffer = buffer; - this.bufferPos = offset; - this.bufferSize = offset + length; - this.input = null; - } - - private CodedInputStream(Stream input) { - this.buffer = new byte[BufferSize]; - this.bufferSize = 0; - this.input = input; - } - #endregion - - #region Validation - /// <summary> - /// Verifies that the last call to ReadTag() returned the given tag value. - /// This is used to verify that a nested group ended with the correct - /// end tag. - /// </summary> - /// <exception cref="InvalidProtocolBufferException">The last - /// tag read was not the one specified</exception> - [CLSCompliant(false)] - public void CheckLastTagWas(uint value) { - if (lastTag != value) { - throw InvalidProtocolBufferException.InvalidEndTag(); - } - } - #endregion - - #region Reading of tags etc - /// <summary> - /// Attempt to read a field tag, returning 0 if we have reached the end - /// of the input data. Protocol message parsers use this to read tags, - /// since a protocol message may legally end wherever a tag occurs, and - /// zero is not a valid tag number. - /// </summary> - [CLSCompliant(false)] - public uint ReadTag() { - if (IsAtEnd) { - lastTag = 0; - return 0; - } - - lastTag = ReadRawVarint32(); - if (lastTag == 0) { - // If we actually read zero, that's not a valid tag. - throw InvalidProtocolBufferException.InvalidTag(); - } - return lastTag; - } - - /// <summary> - /// Read a double field from the stream. - /// </summary> - public double ReadDouble() { -#if SILVERLIGHT2 || COMPACT_FRAMEWORK_35 - byte[] bytes = ReadRawBytes(8); - return BitConverter.ToDouble(bytes, 0); -#else - return BitConverter.Int64BitsToDouble((long) ReadRawLittleEndian64()); -#endif - } - - /// <summary> - /// Read a float field from the stream. - /// </summary> - public float ReadFloat() { - // TODO(jonskeet): Test this on different endiannesses - uint raw = ReadRawLittleEndian32(); - byte[] rawBytes = BitConverter.GetBytes(raw); - return BitConverter.ToSingle(rawBytes, 0); - } - - /// <summary> - /// Read a uint64 field from the stream. - /// </summary> - [CLSCompliant(false)] - public ulong ReadUInt64() { - return ReadRawVarint64(); - } - - /// <summary> - /// Read an int64 field from the stream. - /// </summary> - public long ReadInt64() { - return (long) ReadRawVarint64(); - } - - /// <summary> - /// Read an int32 field from the stream. - /// </summary> - public int ReadInt32() { - return (int) ReadRawVarint32(); - } - - /// <summary> - /// Read a fixed64 field from the stream. - /// </summary> - [CLSCompliant(false)] - public ulong ReadFixed64() { - return ReadRawLittleEndian64(); - } - - /// <summary> - /// Read a fixed32 field from the stream. - /// </summary> - [CLSCompliant(false)] - public uint ReadFixed32() { - return ReadRawLittleEndian32(); - } - - /// <summary> - /// Read a bool field from the stream. - /// </summary> - public bool ReadBool() { - return ReadRawVarint32() != 0; - } - - /// <summary> - /// Reads a string field from the stream. - /// </summary> - public String ReadString() { - int size = (int) ReadRawVarint32(); - // No need to read any data for an empty string. - if (size == 0) { - return ""; - } - if (size <= bufferSize - bufferPos) { - // Fast path: We already have the bytes in a contiguous buffer, so - // just copy directly from it. - String result = Encoding.UTF8.GetString(buffer, bufferPos, size); - bufferPos += size; - return result; - } - // Slow path: Build a byte array first then copy it. - return Encoding.UTF8.GetString(ReadRawBytes(size), 0, size); - } - - /// <summary> - /// Reads a group field value from the stream. - /// </summary> - public void ReadGroup(int fieldNumber, IBuilderLite builder, - ExtensionRegistry extensionRegistry) { - if (recursionDepth >= recursionLimit) { - throw InvalidProtocolBufferException.RecursionLimitExceeded(); - } - ++recursionDepth; - builder.WeakMergeFrom(this, extensionRegistry); - CheckLastTagWas(WireFormat.MakeTag(fieldNumber, WireFormat.WireType.EndGroup)); - --recursionDepth; - } - - /// <summary> - /// Reads a group field value from the stream and merges it into the given - /// UnknownFieldSet. - /// </summary> - [Obsolete] - public void ReadUnknownGroup(int fieldNumber, IBuilderLite builder) - { - if (recursionDepth >= recursionLimit) { - throw InvalidProtocolBufferException.RecursionLimitExceeded(); - } - ++recursionDepth; - builder.WeakMergeFrom(this); - CheckLastTagWas(WireFormat.MakeTag(fieldNumber, WireFormat.WireType.EndGroup)); - --recursionDepth; - } - - /// <summary> - /// Reads an embedded message field value from the stream. - /// </summary> - public void ReadMessage(IBuilderLite builder, ExtensionRegistry extensionRegistry) { - int length = (int) ReadRawVarint32(); - if (recursionDepth >= recursionLimit) { - throw InvalidProtocolBufferException.RecursionLimitExceeded(); - } - int oldLimit = PushLimit(length); - ++recursionDepth; - builder.WeakMergeFrom(this, extensionRegistry); - CheckLastTagWas(0); - --recursionDepth; - PopLimit(oldLimit); - } - - /// <summary> - /// Reads a bytes field value from the stream. - /// </summary> - public ByteString ReadBytes() { - int size = (int) ReadRawVarint32(); - if (size < bufferSize - bufferPos && size > 0) { - // Fast path: We already have the bytes in a contiguous buffer, so - // just copy directly from it. - ByteString result = ByteString.CopyFrom(buffer, bufferPos, size); - bufferPos += size; - return result; - } else { - // Slow path: Build a byte array first then copy it. - return ByteString.CopyFrom(ReadRawBytes(size)); - } - } - - /// <summary> - /// Reads a uint32 field value from the stream. - /// </summary> - [CLSCompliant(false)] - public uint ReadUInt32() { - return ReadRawVarint32(); - } - - /// <summary> - /// Reads an enum field value from the stream. The caller is responsible - /// for converting the numeric value to an actual enum. - /// </summary> - public int ReadEnum() { - return (int) ReadRawVarint32(); - } - - /// <summary> - /// Reads an sfixed32 field value from the stream. - /// </summary> - public int ReadSFixed32() { - return (int) ReadRawLittleEndian32(); - } - - /// <summary> - /// Reads an sfixed64 field value from the stream. - /// </summary> - public long ReadSFixed64() { - return (long) ReadRawLittleEndian64(); - } - - /// <summary> - /// Reads an sint32 field value from the stream. - /// </summary> - public int ReadSInt32() { - return DecodeZigZag32(ReadRawVarint32()); - } - - /// <summary> - /// Reads an sint64 field value from the stream. - /// </summary> - public long ReadSInt64() { - return DecodeZigZag64(ReadRawVarint64()); - } - - /// <summary> - /// Reads a field of any primitive type. Enums, groups and embedded - /// messages are not handled by this method. - /// </summary> - public object ReadPrimitiveField(FieldType fieldType) { - switch (fieldType) { - case FieldType.Double: return ReadDouble(); - case FieldType.Float: return ReadFloat(); - case FieldType.Int64: return ReadInt64(); - case FieldType.UInt64: return ReadUInt64(); - case FieldType.Int32: return ReadInt32(); - case FieldType.Fixed64: return ReadFixed64(); - case FieldType.Fixed32: return ReadFixed32(); - case FieldType.Bool: return ReadBool(); - case FieldType.String: return ReadString(); - case FieldType.Bytes: return ReadBytes(); - case FieldType.UInt32: return ReadUInt32(); - case FieldType.SFixed32: return ReadSFixed32(); - case FieldType.SFixed64: return ReadSFixed64(); - case FieldType.SInt32: return ReadSInt32(); - case FieldType.SInt64: return ReadSInt64(); - case FieldType.Group: - throw new ArgumentException("ReadPrimitiveField() cannot handle nested groups."); - case FieldType.Message: - throw new ArgumentException("ReadPrimitiveField() cannot handle embedded messages."); - // We don't handle enums because we don't know what to do if the - // value is not recognized. - case FieldType.Enum: - throw new ArgumentException("ReadPrimitiveField() cannot handle enums."); - default: - throw new ArgumentOutOfRangeException("Invalid field type " + fieldType); - } - } - #endregion - - #region Underlying reading primitives - - /// <summary> - /// Same code as ReadRawVarint32, but read each byte individually, checking for - /// buffer overflow. - /// </summary> - private uint SlowReadRawVarint32() { - int tmp = ReadRawByte(); - if (tmp < 128) { - return (uint)tmp; - } - int result = tmp & 0x7f; - if ((tmp = ReadRawByte()) < 128) { - result |= tmp << 7; - } else { - result |= (tmp & 0x7f) << 7; - if ((tmp = ReadRawByte()) < 128) { - result |= tmp << 14; - } else { - result |= (tmp & 0x7f) << 14; - if ((tmp = ReadRawByte()) < 128) { - result |= tmp << 21; - } else { - result |= (tmp & 0x7f) << 21; - result |= (tmp = ReadRawByte()) << 28; - if (tmp >= 128) { - // Discard upper 32 bits. - for (int i = 0; i < 5; i++) { - if (ReadRawByte() < 128) return (uint)result; - } - throw InvalidProtocolBufferException.MalformedVarint(); - } - } - } - } - return (uint)result; - } - - /// <summary> - /// Read a raw Varint from the stream. If larger than 32 bits, discard the upper bits. - /// This method is optimised for the case where we've got lots of data in the buffer. - /// That means we can check the size just once, then just read directly from the buffer - /// without constant rechecking of the buffer length. - /// </summary> - [CLSCompliant(false)] - public uint ReadRawVarint32() { - if (bufferPos + 5 > bufferSize) { - return SlowReadRawVarint32(); - } - - int tmp = buffer[bufferPos++]; - if (tmp < 128) { - return (uint)tmp; - } - int result = tmp & 0x7f; - if ((tmp = buffer[bufferPos++]) < 128) { - result |= tmp << 7; - } else { - result |= (tmp & 0x7f) << 7; - if ((tmp = buffer[bufferPos++]) < 128) { - result |= tmp << 14; - } else { - result |= (tmp & 0x7f) << 14; - if ((tmp = buffer[bufferPos++]) < 128) { - result |= tmp << 21; - } else { - result |= (tmp & 0x7f) << 21; - result |= (tmp = buffer[bufferPos++]) << 28; - if (tmp >= 128) { - // Discard upper 32 bits. - // Note that this has to use ReadRawByte() as we only ensure we've - // got at least 5 bytes at the start of the method. This lets us - // use the fast path in more cases, and we rarely hit this section of code. - for (int i = 0; i < 5; i++) { - if (ReadRawByte() < 128) return (uint)result; - } - throw InvalidProtocolBufferException.MalformedVarint(); - } - } - } - } - return (uint)result; - } - - /// <summary> - /// Reads a varint from the input one byte at a time, so that it does not - /// read any bytes after the end of the varint. If you simply wrapped the - /// stream in a CodedInputStream and used ReadRawVarint32(Stream)} - /// then you would probably end up reading past the end of the varint since - /// CodedInputStream buffers its input. - /// </summary> - /// <param name="input"></param> - /// <returns></returns>
- [CLSCompliant(false)]
- public static uint ReadRawVarint32(Stream input)
- { - int result = 0; - int offset = 0; - for (; offset < 32; offset += 7) { - int b = input.ReadByte(); - if (b == -1) { - throw InvalidProtocolBufferException.TruncatedMessage(); - } - result |= (b & 0x7f) << offset; - if ((b & 0x80) == 0) { - return (uint) result; - } - } - // Keep reading up to 64 bits. - for (; offset < 64; offset += 7) { - int b = input.ReadByte(); - if (b == -1) { - throw InvalidProtocolBufferException.TruncatedMessage(); - } - if ((b & 0x80) == 0) { - return (uint) result; - } - } - throw InvalidProtocolBufferException.MalformedVarint(); - } - - /// <summary> - /// Read a raw varint from the stream. - /// </summary> - [CLSCompliant(false)] - public ulong ReadRawVarint64() { - int shift = 0; - ulong result = 0; - while (shift < 64) { - byte b = ReadRawByte(); - result |= (ulong)(b & 0x7F) << shift; - if ((b & 0x80) == 0) { - return result; - } - shift += 7; - } - throw InvalidProtocolBufferException.MalformedVarint(); - } - - /// <summary> - /// Read a 32-bit little-endian integer from the stream. - /// </summary> - [CLSCompliant(false)] - public uint ReadRawLittleEndian32() { - uint b1 = ReadRawByte(); - uint b2 = ReadRawByte(); - uint b3 = ReadRawByte(); - uint b4 = ReadRawByte(); - return b1 | (b2 << 8) | (b3 << 16) | (b4 << 24); - } - - /// <summary> - /// Read a 64-bit little-endian integer from the stream. - /// </summary> - [CLSCompliant(false)] - public ulong ReadRawLittleEndian64() { - ulong b1 = ReadRawByte(); - ulong b2 = ReadRawByte(); - ulong b3 = ReadRawByte(); - ulong b4 = ReadRawByte(); - ulong b5 = ReadRawByte(); - ulong b6 = ReadRawByte(); - ulong b7 = ReadRawByte(); - ulong b8 = ReadRawByte(); - return b1 | (b2 << 8) | (b3 << 16) | (b4 << 24) - | (b5 << 32) | (b6 << 40) | (b7 << 48) | (b8 << 56); - } - #endregion - - /// <summary> - /// Decode a 32-bit value with ZigZag encoding. - /// </summary> - /// <remarks> - /// ZigZag encodes signed integers into values that can be efficiently - /// encoded with varint. (Otherwise, negative values must be - /// sign-extended to 64 bits to be varint encoded, thus always taking - /// 10 bytes on the wire.) - /// </remarks> - [CLSCompliant(false)] - public static int DecodeZigZag32(uint n) { - return (int)(n >> 1) ^ -(int)(n & 1); - } - - /// <summary> - /// Decode a 32-bit value with ZigZag encoding. - /// </summary> - /// <remarks> - /// ZigZag encodes signed integers into values that can be efficiently - /// encoded with varint. (Otherwise, negative values must be - /// sign-extended to 64 bits to be varint encoded, thus always taking - /// 10 bytes on the wire.) - /// </remarks> - [CLSCompliant(false)] - public static long DecodeZigZag64(ulong n) { - return (long)(n >> 1) ^ -(long)(n & 1); - } - - /// <summary> - /// Set the maximum message recursion depth. - /// </summary> - /// <remarks> - /// In order to prevent malicious - /// messages from causing stack overflows, CodedInputStream limits - /// how deeply messages may be nested. The default limit is 64. - /// </remarks> - public int SetRecursionLimit(int limit) { - if (limit < 0) { - throw new ArgumentOutOfRangeException("Recursion limit cannot be negative: " + limit); - } - int oldLimit = recursionLimit; - recursionLimit = limit; - return oldLimit; - } - - /// <summary> - /// Set the maximum message size. - /// </summary> - /// <remarks> - /// In order to prevent malicious messages from exhausting memory or - /// causing integer overflows, CodedInputStream limits how large a message may be. - /// The default limit is 64MB. You should set this limit as small - /// as you can without harming your app's functionality. Note that - /// size limits only apply when reading from an InputStream, not - /// when constructed around a raw byte array (nor with ByteString.NewCodedInput). - /// If you want to read several messages from a single CodedInputStream, you - /// can call ResetSizeCounter() after each message to avoid hitting the - /// size limit. - /// </remarks> - public int SetSizeLimit(int limit) { - if (limit < 0) { - throw new ArgumentOutOfRangeException("Size limit cannot be negative: " + limit); - } - int oldLimit = sizeLimit; - sizeLimit = limit; - return oldLimit; - } - - #region Internal reading and buffer management - /// <summary> - /// Resets the current size counter to zero (see SetSizeLimit). - /// </summary> - public void ResetSizeCounter() { - totalBytesRetired = 0; - } - - /// <summary> - /// Sets currentLimit to (current position) + byteLimit. This is called - /// when descending into a length-delimited embedded message. The previous - /// limit is returned. - /// </summary> - /// <returns>The old limit.</returns> - public int PushLimit(int byteLimit) { - if (byteLimit < 0) { - throw InvalidProtocolBufferException.NegativeSize(); - } - byteLimit += totalBytesRetired + bufferPos; - int oldLimit = currentLimit; - if (byteLimit > oldLimit) { - throw InvalidProtocolBufferException.TruncatedMessage(); - } - currentLimit = byteLimit; - - RecomputeBufferSizeAfterLimit(); - - return oldLimit; - } - - private void RecomputeBufferSizeAfterLimit() { - bufferSize += bufferSizeAfterLimit; - int bufferEnd = totalBytesRetired + bufferSize; - if (bufferEnd > currentLimit) { - // Limit is in current buffer. - bufferSizeAfterLimit = bufferEnd - currentLimit; - bufferSize -= bufferSizeAfterLimit; - } else { - bufferSizeAfterLimit = 0; - } - } - - /// <summary> - /// Discards the current limit, returning the previous limit. - /// </summary> - public void PopLimit(int oldLimit) { - currentLimit = oldLimit; - RecomputeBufferSizeAfterLimit(); - } - - /// <summary> - /// Returns whether or not all the data before the limit has been read. - /// </summary> - /// <returns></returns> - public bool ReachedLimit { - get { - if (currentLimit == int.MaxValue) { - return false; - } - int currentAbsolutePosition = totalBytesRetired + bufferPos; - return currentAbsolutePosition >= currentLimit; - } - } - - /// <summary> - /// Returns true if the stream has reached the end of the input. This is the - /// case if either the end of the underlying input source has been reached or - /// the stream has reached a limit created using PushLimit. - /// </summary> - public bool IsAtEnd { - get { - return bufferPos == bufferSize && !RefillBuffer(false); - } - } - - /// <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) ? 0 : input.Read(buffer, 0, buffer.Length); - if (bufferSize < 0) { - throw new InvalidOperationException("Stream.Read returned a negative count"); - } - if (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"> - /// the 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> - [CLSCompliant(false)] - 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) { - if (input == null) { - throw InvalidProtocolBufferException.TruncatedMessage(); - } - SkipImpl(size - pos); - totalBytesRetired += size - pos; - } - } - } - - /// <summary> - /// Abstraction of skipping to cope with streams which can't really skip. - /// </summary> - private void SkipImpl(int amountToSkip) { - if (input.CanSeek) { - long previousPosition = input.Position; - input.Position += amountToSkip; - if (input.Position != previousPosition + amountToSkip) { - throw InvalidProtocolBufferException.TruncatedMessage(); - } - } else { - byte[] skipBuffer = new byte[1024]; - while (amountToSkip > 0) { - int bytesRead = input.Read(skipBuffer, 0, skipBuffer.Length); - if (bytesRead <= 0) { - throw InvalidProtocolBufferException.TruncatedMessage(); - } - amountToSkip -= bytesRead; - } - } - } - #endregion - } -} +#region Copyright notice and license
+
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc. All rights reserved.
+// http://github.com/jskeet/dotnet-protobufs/
+// Original C++/Java/Python code:
+// http://code.google.com/p/protobuf/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+// * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+// * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+// * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#endregion
+
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Text;
+using Google.ProtocolBuffers.Descriptors;
+
+namespace Google.ProtocolBuffers
+{
+ /// <summary>
+ /// Readings and decodes protocol message fields.
+ /// </summary>
+ /// <remarks>
+ /// This class contains two kinds of methods: methods that read specific
+ /// protocol message constructs and field types (e.g. ReadTag and
+ /// ReadInt32) and methods that read low-level values (e.g.
+ /// ReadRawVarint32 and ReadRawBytes). If you are reading encoded protocol
+ /// messages, you should use the former methods, but if you are reading some
+ /// other format of your own design, use the latter. The names of the former
+ /// methods are taken from the protocol buffer type names, not .NET types.
+ /// (Hence ReadFloat instead of ReadSingle, and ReadBool instead of ReadBoolean.)
+ ///
+ /// TODO(jonskeet): Consider whether recursion and size limits shouldn't be readonly,
+ /// set at construction time.
+ /// </remarks>
+ public sealed class CodedInputStream
+ {
+ private readonly byte[] buffer;
+ private int bufferSize;
+ private int bufferSizeAfterLimit = 0;
+ private int bufferPos = 0;
+ private readonly Stream input;
+ private uint lastTag = 0;
+
+ internal const int DefaultRecursionLimit = 64;
+ internal const int DefaultSizeLimit = 64 << 20; // 64MB
+ public const int BufferSize = 4096;
+
+ /// <summary>
+ /// The total number of bytes read before the current buffer. The
+ /// total bytes read up to the current position can be computed as
+ /// totalBytesRetired + bufferPos.
+ /// </summary>
+ private int totalBytesRetired = 0;
+
+ /// <summary>
+ /// The absolute position of the end of the current message.
+ /// </summary>
+ private int currentLimit = int.MaxValue;
+
+ /// <summary>
+ /// <see cref="SetRecursionLimit"/>
+ /// </summary>
+ private int recursionDepth = 0;
+
+ private int recursionLimit = DefaultRecursionLimit;
+
+ /// <summary>
+ /// <see cref="SetSizeLimit"/>
+ /// </summary>
+ private int sizeLimit = DefaultSizeLimit;
+
+ #region Construction
+
+ /// <summary>
+ /// Creates a new CodedInputStream reading data from the given
+ /// stream.
+ /// </summary>
+ public static CodedInputStream CreateInstance(Stream input)
+ {
+ return new CodedInputStream(input);
+ }
+
+ /// <summary>
+ /// Creates a new CodedInputStream reading data from the given
+ /// byte array.
+ /// </summary>
+ public static CodedInputStream CreateInstance(byte[] buf)
+ {
+ return new CodedInputStream(buf, 0, buf.Length);
+ }
+
+ /// <summary>
+ /// Creates a new CodedInputStream that reads from the given
+ /// byte array slice.
+ /// </summary>
+ public static CodedInputStream CreateInstance(byte[] buf, int offset, int length)
+ {
+ return new CodedInputStream(buf, offset, length);
+ }
+
+ private CodedInputStream(byte[] buffer, int offset, int length)
+ {
+ this.buffer = buffer;
+ this.bufferPos = offset;
+ this.bufferSize = offset + length;
+ this.input = null;
+ }
+
+ private CodedInputStream(Stream input)
+ {
+ this.buffer = new byte[BufferSize];
+ this.bufferSize = 0;
+ this.input = input;
+ }
+
+ #endregion
+
+ #region Validation
+
+ /// <summary>
+ /// Verifies that the last call to ReadTag() returned the given tag value.
+ /// This is used to verify that a nested group ended with the correct
+ /// end tag.
+ /// </summary>
+ /// <exception cref="InvalidProtocolBufferException">The last
+ /// tag read was not the one specified</exception>
+ [CLSCompliant(false)]
+ public void CheckLastTagWas(uint value)
+ {
+ if (lastTag != value)
+ {
+ throw InvalidProtocolBufferException.InvalidEndTag();
+ }
+ }
+
+ #endregion
+
+ #region Reading of tags etc
+
+ /// <summary>
+ /// Attempt to read a field tag, returning 0 if we have reached the end
+ /// of the input data. Protocol message parsers use this to read tags,
+ /// since a protocol message may legally end wherever a tag occurs, and
+ /// zero is not a valid tag number.
+ /// </summary>
+ [CLSCompliant(false)]
+ public uint ReadTag()
+ {
+ if (IsAtEnd)
+ {
+ lastTag = 0;
+ return 0;
+ }
+
+ lastTag = ReadRawVarint32();
+ if (lastTag == 0)
+ {
+ // If we actually read zero, that's not a valid tag.
+ throw InvalidProtocolBufferException.InvalidTag();
+ }
+ return lastTag;
+ }
+
+ /// <summary>
+ /// Read a double field from the stream.
+ /// </summary>
+ public double ReadDouble()
+ {
+#if SILVERLIGHT2 || COMPACT_FRAMEWORK_35
+ byte[] bytes = ReadRawBytes(8);
+ return BitConverter.ToDouble(bytes, 0);
+#else
+ return BitConverter.Int64BitsToDouble((long) ReadRawLittleEndian64());
+#endif
+ }
+
+ /// <summary>
+ /// Read a float field from the stream.
+ /// </summary>
+ public float ReadFloat()
+ {
+ // TODO(jonskeet): Test this on different endiannesses
+ uint raw = ReadRawLittleEndian32();
+ byte[] rawBytes = BitConverter.GetBytes(raw);
+ return BitConverter.ToSingle(rawBytes, 0);
+ }
+
+ /// <summary>
+ /// Read a uint64 field from the stream.
+ /// </summary>
+ [CLSCompliant(false)]
+ public ulong ReadUInt64()
+ {
+ return ReadRawVarint64();
+ }
+
+ /// <summary>
+ /// Read an int64 field from the stream.
+ /// </summary>
+ public long ReadInt64()
+ {
+ return (long) ReadRawVarint64();
+ }
+
+ /// <summary>
+ /// Read an int32 field from the stream.
+ /// </summary>
+ public int ReadInt32()
+ {
+ return (int) ReadRawVarint32();
+ }
+
+ /// <summary>
+ /// Read a fixed64 field from the stream.
+ /// </summary>
+ [CLSCompliant(false)]
+ public ulong ReadFixed64()
+ {
+ return ReadRawLittleEndian64();
+ }
+
+ /// <summary>
+ /// Read a fixed32 field from the stream.
+ /// </summary>
+ [CLSCompliant(false)]
+ public uint ReadFixed32()
+ {
+ return ReadRawLittleEndian32();
+ }
+
+ /// <summary>
+ /// Read a bool field from the stream.
+ /// </summary>
+ public bool ReadBool()
+ {
+ return ReadRawVarint32() != 0;
+ }
+
+ /// <summary>
+ /// Reads a string field from the stream.
+ /// </summary>
+ public String ReadString()
+ {
+ int size = (int) ReadRawVarint32();
+ // No need to read any data for an empty string.
+ if (size == 0)
+ {
+ return "";
+ }
+ if (size <= bufferSize - bufferPos)
+ {
+ // Fast path: We already have the bytes in a contiguous buffer, so
+ // just copy directly from it.
+ String result = Encoding.UTF8.GetString(buffer, bufferPos, size);
+ bufferPos += size;
+ return result;
+ }
+ // Slow path: Build a byte array first then copy it.
+ return Encoding.UTF8.GetString(ReadRawBytes(size), 0, size);
+ }
+
+ /// <summary>
+ /// Reads a group field value from the stream.
+ /// </summary>
+ public void ReadGroup(int fieldNumber, IBuilderLite builder,
+ ExtensionRegistry extensionRegistry)
+ {
+ if (recursionDepth >= recursionLimit)
+ {
+ throw InvalidProtocolBufferException.RecursionLimitExceeded();
+ }
+ ++recursionDepth;
+ builder.WeakMergeFrom(this, extensionRegistry);
+ CheckLastTagWas(WireFormat.MakeTag(fieldNumber, WireFormat.WireType.EndGroup));
+ --recursionDepth;
+ }
+
+ /// <summary>
+ /// Reads a group field value from the stream and merges it into the given
+ /// UnknownFieldSet.
+ /// </summary>
+ [Obsolete]
+ public void ReadUnknownGroup(int fieldNumber, IBuilderLite builder)
+ {
+ if (recursionDepth >= recursionLimit)
+ {
+ throw InvalidProtocolBufferException.RecursionLimitExceeded();
+ }
+ ++recursionDepth;
+ builder.WeakMergeFrom(this);
+ CheckLastTagWas(WireFormat.MakeTag(fieldNumber, WireFormat.WireType.EndGroup));
+ --recursionDepth;
+ }
+
+ /// <summary>
+ /// Reads an embedded message field value from the stream.
+ /// </summary>
+ public void ReadMessage(IBuilderLite builder, ExtensionRegistry extensionRegistry)
+ {
+ int length = (int) ReadRawVarint32();
+ if (recursionDepth >= recursionLimit)
+ {
+ throw InvalidProtocolBufferException.RecursionLimitExceeded();
+ }
+ int oldLimit = PushLimit(length);
+ ++recursionDepth;
+ builder.WeakMergeFrom(this, extensionRegistry);
+ CheckLastTagWas(0);
+ --recursionDepth;
+ PopLimit(oldLimit);
+ }
+
+ /// <summary>
+ /// Reads a bytes field value from the stream.
+ /// </summary>
+ public ByteString ReadBytes()
+ {
+ int size = (int) ReadRawVarint32();
+ if (size < bufferSize - bufferPos && size > 0)
+ {
+ // Fast path: We already have the bytes in a contiguous buffer, so
+ // just copy directly from it.
+ ByteString result = ByteString.CopyFrom(buffer, bufferPos, size);
+ bufferPos += size;
+ return result;
+ }
+ else
+ {
+ // Slow path: Build a byte array first then copy it.
+ return ByteString.CopyFrom(ReadRawBytes(size));
+ }
+ }
+
+ /// <summary>
+ /// Reads a uint32 field value from the stream.
+ /// </summary>
+ [CLSCompliant(false)]
+ public uint ReadUInt32()
+ {
+ return ReadRawVarint32();
+ }
+
+ /// <summary>
+ /// Reads an enum field value from the stream. The caller is responsible
+ /// for converting the numeric value to an actual enum.
+ /// </summary>
+ public int ReadEnum()
+ {
+ return (int) ReadRawVarint32();
+ }
+
+ /// <summary>
+ /// Reads an sfixed32 field value from the stream.
+ /// </summary>
+ public int ReadSFixed32()
+ {
+ return (int) ReadRawLittleEndian32();
+ }
+
+ /// <summary>
+ /// Reads an sfixed64 field value from the stream.
+ /// </summary>
+ public long ReadSFixed64()
+ {
+ return (long) ReadRawLittleEndian64();
+ }
+
+ /// <summary>
+ /// Reads an sint32 field value from the stream.
+ /// </summary>
+ public int ReadSInt32()
+ {
+ return DecodeZigZag32(ReadRawVarint32());
+ }
+
+ /// <summary>
+ /// Reads an sint64 field value from the stream.
+ /// </summary>
+ public long ReadSInt64()
+ {
+ return DecodeZigZag64(ReadRawVarint64());
+ }
+
+ /// <summary>
+ /// Reads a field of any primitive type. Enums, groups and embedded
+ /// messages are not handled by this method.
+ /// </summary>
+ public object ReadPrimitiveField(FieldType fieldType)
+ {
+ switch (fieldType)
+ {
+ case FieldType.Double:
+ return ReadDouble();
+ case FieldType.Float:
+ return ReadFloat();
+ case FieldType.Int64:
+ return ReadInt64();
+ case FieldType.UInt64:
+ return ReadUInt64();
+ case FieldType.Int32:
+ return ReadInt32();
+ case FieldType.Fixed64:
+ return ReadFixed64();
+ case FieldType.Fixed32:
+ return ReadFixed32();
+ case FieldType.Bool:
+ return ReadBool();
+ case FieldType.String:
+ return ReadString();
+ case FieldType.Bytes:
+ return ReadBytes();
+ case FieldType.UInt32:
+ return ReadUInt32();
+ case FieldType.SFixed32:
+ return ReadSFixed32();
+ case FieldType.SFixed64:
+ return ReadSFixed64();
+ case FieldType.SInt32:
+ return ReadSInt32();
+ case FieldType.SInt64:
+ return ReadSInt64();
+ case FieldType.Group:
+ throw new ArgumentException("ReadPrimitiveField() cannot handle nested groups.");
+ case FieldType.Message:
+ throw new ArgumentException("ReadPrimitiveField() cannot handle embedded messages.");
+ // We don't handle enums because we don't know what to do if the
+ // value is not recognized.
+ case FieldType.Enum:
+ throw new ArgumentException("ReadPrimitiveField() cannot handle enums.");
+ default:
+ throw new ArgumentOutOfRangeException("Invalid field type " + fieldType);
+ }
+ }
+
+ #endregion
+
+ #region Underlying reading primitives
+
+ /// <summary>
+ /// Same code as ReadRawVarint32, but read each byte individually, checking for
+ /// buffer overflow.
+ /// </summary>
+ private uint SlowReadRawVarint32()
+ {
+ int tmp = ReadRawByte();
+ if (tmp < 128)
+ {
+ return (uint) tmp;
+ }
+ int result = tmp & 0x7f;
+ if ((tmp = ReadRawByte()) < 128)
+ {
+ result |= tmp << 7;
+ }
+ else
+ {
+ result |= (tmp & 0x7f) << 7;
+ if ((tmp = ReadRawByte()) < 128)
+ {
+ result |= tmp << 14;
+ }
+ else
+ {
+ result |= (tmp & 0x7f) << 14;
+ if ((tmp = ReadRawByte()) < 128)
+ {
+ result |= tmp << 21;
+ }
+ else
+ {
+ result |= (tmp & 0x7f) << 21;
+ result |= (tmp = ReadRawByte()) << 28;
+ if (tmp >= 128)
+ {
+ // Discard upper 32 bits.
+ for (int i = 0; i < 5; i++)
+ {
+ if (ReadRawByte() < 128) return (uint) result;
+ }
+ throw InvalidProtocolBufferException.MalformedVarint();
+ }
+ }
+ }
+ }
+ return (uint) result;
+ }
+
+ /// <summary>
+ /// Read a raw Varint from the stream. If larger than 32 bits, discard the upper bits.
+ /// This method is optimised for the case where we've got lots of data in the buffer.
+ /// That means we can check the size just once, then just read directly from the buffer
+ /// without constant rechecking of the buffer length.
+ /// </summary>
+ [CLSCompliant(false)]
+ public uint ReadRawVarint32()
+ {
+ if (bufferPos + 5 > bufferSize)
+ {
+ return SlowReadRawVarint32();
+ }
+
+ int tmp = buffer[bufferPos++];
+ if (tmp < 128)
+ {
+ return (uint) tmp;
+ }
+ int result = tmp & 0x7f;
+ if ((tmp = buffer[bufferPos++]) < 128)
+ {
+ result |= tmp << 7;
+ }
+ else
+ {
+ result |= (tmp & 0x7f) << 7;
+ if ((tmp = buffer[bufferPos++]) < 128)
+ {
+ result |= tmp << 14;
+ }
+ else
+ {
+ result |= (tmp & 0x7f) << 14;
+ if ((tmp = buffer[bufferPos++]) < 128)
+ {
+ result |= tmp << 21;
+ }
+ else
+ {
+ result |= (tmp & 0x7f) << 21;
+ result |= (tmp = buffer[bufferPos++]) << 28;
+ if (tmp >= 128)
+ {
+ // Discard upper 32 bits.
+ // Note that this has to use ReadRawByte() as we only ensure we've
+ // got at least 5 bytes at the start of the method. This lets us
+ // use the fast path in more cases, and we rarely hit this section of code.
+ for (int i = 0; i < 5; i++)
+ {
+ if (ReadRawByte() < 128) return (uint) result;
+ }
+ throw InvalidProtocolBufferException.MalformedVarint();
+ }
+ }
+ }
+ }
+ return (uint) result;
+ }
+
+ /// <summary>
+ /// Reads a varint from the input one byte at a time, so that it does not
+ /// read any bytes after the end of the varint. If you simply wrapped the
+ /// stream in a CodedInputStream and used ReadRawVarint32(Stream)}
+ /// then you would probably end up reading past the end of the varint since
+ /// CodedInputStream buffers its input.
+ /// </summary>
+ /// <param name="input"></param>
+ /// <returns></returns>
+ [CLSCompliant(false)]
+ public static uint ReadRawVarint32(Stream input)
+ {
+ int result = 0;
+ int offset = 0;
+ for (; offset < 32; offset += 7)
+ {
+ int b = input.ReadByte();
+ if (b == -1)
+ {
+ throw InvalidProtocolBufferException.TruncatedMessage();
+ }
+ result |= (b & 0x7f) << offset;
+ if ((b & 0x80) == 0)
+ {
+ return (uint) result;
+ }
+ }
+ // Keep reading up to 64 bits.
+ for (; offset < 64; offset += 7)
+ {
+ int b = input.ReadByte();
+ if (b == -1)
+ {
+ throw InvalidProtocolBufferException.TruncatedMessage();
+ }
+ if ((b & 0x80) == 0)
+ {
+ return (uint) result;
+ }
+ }
+ throw InvalidProtocolBufferException.MalformedVarint();
+ }
+
+ /// <summary>
+ /// Read a raw varint from the stream.
+ /// </summary>
+ [CLSCompliant(false)]
+ public ulong ReadRawVarint64()
+ {
+ int shift = 0;
+ ulong result = 0;
+ while (shift < 64)
+ {
+ byte b = ReadRawByte();
+ result |= (ulong) (b & 0x7F) << shift;
+ if ((b & 0x80) == 0)
+ {
+ return result;
+ }
+ shift += 7;
+ }
+ throw InvalidProtocolBufferException.MalformedVarint();
+ }
+
+ /// <summary>
+ /// Read a 32-bit little-endian integer from the stream.
+ /// </summary>
+ [CLSCompliant(false)]
+ public uint ReadRawLittleEndian32()
+ {
+ uint b1 = ReadRawByte();
+ uint b2 = ReadRawByte();
+ uint b3 = ReadRawByte();
+ uint b4 = ReadRawByte();
+ return b1 | (b2 << 8) | (b3 << 16) | (b4 << 24);
+ }
+
+ /// <summary>
+ /// Read a 64-bit little-endian integer from the stream.
+ /// </summary>
+ [CLSCompliant(false)]
+ public ulong ReadRawLittleEndian64()
+ {
+ ulong b1 = ReadRawByte();
+ ulong b2 = ReadRawByte();
+ ulong b3 = ReadRawByte();
+ ulong b4 = ReadRawByte();
+ ulong b5 = ReadRawByte();
+ ulong b6 = ReadRawByte();
+ ulong b7 = ReadRawByte();
+ ulong b8 = ReadRawByte();
+ return b1 | (b2 << 8) | (b3 << 16) | (b4 << 24)
+ | (b5 << 32) | (b6 << 40) | (b7 << 48) | (b8 << 56);
+ }
+
+ #endregion
+
+ /// <summary>
+ /// Decode a 32-bit value with ZigZag encoding.
+ /// </summary>
+ /// <remarks>
+ /// ZigZag encodes signed integers into values that can be efficiently
+ /// encoded with varint. (Otherwise, negative values must be
+ /// sign-extended to 64 bits to be varint encoded, thus always taking
+ /// 10 bytes on the wire.)
+ /// </remarks>
+ [CLSCompliant(false)]
+ public static int DecodeZigZag32(uint n)
+ {
+ return (int) (n >> 1) ^ -(int) (n & 1);
+ }
+
+ /// <summary>
+ /// Decode a 32-bit value with ZigZag encoding.
+ /// </summary>
+ /// <remarks>
+ /// ZigZag encodes signed integers into values that can be efficiently
+ /// encoded with varint. (Otherwise, negative values must be
+ /// sign-extended to 64 bits to be varint encoded, thus always taking
+ /// 10 bytes on the wire.)
+ /// </remarks>
+ [CLSCompliant(false)]
+ public static long DecodeZigZag64(ulong n)
+ {
+ return (long) (n >> 1) ^ -(long) (n & 1);
+ }
+
+ /// <summary>
+ /// Set the maximum message recursion depth.
+ /// </summary>
+ /// <remarks>
+ /// In order to prevent malicious
+ /// messages from causing stack overflows, CodedInputStream limits
+ /// how deeply messages may be nested. The default limit is 64.
+ /// </remarks>
+ public int SetRecursionLimit(int limit)
+ {
+ if (limit < 0)
+ {
+ throw new ArgumentOutOfRangeException("Recursion limit cannot be negative: " + limit);
+ }
+ int oldLimit = recursionLimit;
+ recursionLimit = limit;
+ return oldLimit;
+ }
+
+ /// <summary>
+ /// Set the maximum message size.
+ /// </summary>
+ /// <remarks>
+ /// In order to prevent malicious messages from exhausting memory or
+ /// causing integer overflows, CodedInputStream limits how large a message may be.
+ /// The default limit is 64MB. You should set this limit as small
+ /// as you can without harming your app's functionality. Note that
+ /// size limits only apply when reading from an InputStream, not
+ /// when constructed around a raw byte array (nor with ByteString.NewCodedInput).
+ /// If you want to read several messages from a single CodedInputStream, you
+ /// can call ResetSizeCounter() after each message to avoid hitting the
+ /// size limit.
+ /// </remarks>
+ public int SetSizeLimit(int limit)
+ {
+ if (limit < 0)
+ {
+ throw new ArgumentOutOfRangeException("Size limit cannot be negative: " + limit);
+ }
+ int oldLimit = sizeLimit;
+ sizeLimit = limit;
+ return oldLimit;
+ }
+
+ #region Internal reading and buffer management
+
+ /// <summary>
+ /// Resets the current size counter to zero (see SetSizeLimit).
+ /// </summary>
+ public void ResetSizeCounter()
+ {
+ totalBytesRetired = 0;
+ }
+
+ /// <summary>
+ /// Sets currentLimit to (current position) + byteLimit. This is called
+ /// when descending into a length-delimited embedded message. The previous
+ /// limit is returned.
+ /// </summary>
+ /// <returns>The old limit.</returns>
+ public int PushLimit(int byteLimit)
+ {
+ if (byteLimit < 0)
+ {
+ throw InvalidProtocolBufferException.NegativeSize();
+ }
+ byteLimit += totalBytesRetired + bufferPos;
+ int oldLimit = currentLimit;
+ if (byteLimit > oldLimit)
+ {
+ throw InvalidProtocolBufferException.TruncatedMessage();
+ }
+ currentLimit = byteLimit;
+
+ RecomputeBufferSizeAfterLimit();
+
+ return oldLimit;
+ }
+
+ private void RecomputeBufferSizeAfterLimit()
+ {
+ bufferSize += bufferSizeAfterLimit;
+ int bufferEnd = totalBytesRetired + bufferSize;
+ if (bufferEnd > currentLimit)
+ {
+ // Limit is in current buffer.
+ bufferSizeAfterLimit = bufferEnd - currentLimit;
+ bufferSize -= bufferSizeAfterLimit;
+ }
+ else
+ {
+ bufferSizeAfterLimit = 0;
+ }
+ }
+
+ /// <summary>
+ /// Discards the current limit, returning the previous limit.
+ /// </summary>
+ public void PopLimit(int oldLimit)
+ {
+ currentLimit = oldLimit;
+ RecomputeBufferSizeAfterLimit();
+ }
+
+ /// <summary>
+ /// Returns whether or not all the data before the limit has been read.
+ /// </summary>
+ /// <returns></returns>
+ public bool ReachedLimit
+ {
+ get
+ {
+ if (currentLimit == int.MaxValue)
+ {
+ return false;
+ }
+ int currentAbsolutePosition = totalBytesRetired + bufferPos;
+ return currentAbsolutePosition >= currentLimit;
+ }
+ }
+
+ /// <summary>
+ /// Returns true if the stream has reached the end of the input. This is the
+ /// case if either the end of the underlying input source has been reached or
+ /// the stream has reached a limit created using PushLimit.
+ /// </summary>
+ public bool IsAtEnd
+ {
+ get { return bufferPos == bufferSize && !RefillBuffer(false); }
+ }
+
+ /// <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) ? 0 : input.Read(buffer, 0, buffer.Length);
+ if (bufferSize < 0)
+ {
+ throw new InvalidOperationException("Stream.Read returned a negative count");
+ }
+ if (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">
+ /// the 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>
+ [CLSCompliant(false)]
+ 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)
+ {
+ if (input == null)
+ {
+ throw InvalidProtocolBufferException.TruncatedMessage();
+ }
+ SkipImpl(size - pos);
+ totalBytesRetired += size - pos;
+ }
+ }
+ }
+
+ /// <summary>
+ /// Abstraction of skipping to cope with streams which can't really skip.
+ /// </summary>
+ private void SkipImpl(int amountToSkip)
+ {
+ if (input.CanSeek)
+ {
+ long previousPosition = input.Position;
+ input.Position += amountToSkip;
+ if (input.Position != previousPosition + amountToSkip)
+ {
+ throw InvalidProtocolBufferException.TruncatedMessage();
+ }
+ }
+ else
+ {
+ byte[] skipBuffer = new byte[1024];
+ while (amountToSkip > 0)
+ {
+ int bytesRead = input.Read(skipBuffer, 0, skipBuffer.Length);
+ if (bytesRead <= 0)
+ {
+ throw InvalidProtocolBufferException.TruncatedMessage();
+ }
+ amountToSkip -= bytesRead;
+ }
+ }
+ }
+
+ #endregion
+ }
+}
\ No newline at end of file |