diff options
Diffstat (limited to 'csharp/src/ProtocolBuffers/CodedInputStream.cs')
| -rw-r--r-- | csharp/src/ProtocolBuffers/CodedInputStream.cs | 302 |
1 files changed, 145 insertions, 157 deletions
diff --git a/csharp/src/ProtocolBuffers/CodedInputStream.cs b/csharp/src/ProtocolBuffers/CodedInputStream.cs index 75178d14..5c64fd97 100644 --- a/csharp/src/ProtocolBuffers/CodedInputStream.cs +++ b/csharp/src/ProtocolBuffers/CodedInputStream.cs @@ -37,7 +37,6 @@ using System;
using System.Collections.Generic;
using System.IO;
-using Google.Protobuf.Collections;
namespace Google.Protobuf
{
@@ -178,8 +177,61 @@ namespace Google.Protobuf /// </summary>
internal uint LastTag { get { return lastTag; } }
- #region Validation
+ #region Limits for recursion and length
+ /// <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;
+ }
+
+ /// <summary>
+ /// Resets the current size counter to zero (see <see cref="SetSizeLimit"/>).
+ /// </summary>
+ public void ResetSizeCounter()
+ {
+ totalBytesRetired = 0;
+ }
+ #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
@@ -194,13 +246,12 @@ namespace Google.Protobuf throw InvalidProtocolBufferException.InvalidEndTag();
}
}
-
#endregion
#region Reading of tags etc
/// <summary>
- /// Attempt to peek at the next field tag.
+ /// Attempts to peek at the next field tag.
/// </summary>
public bool PeekNextTag(out uint fieldTag)
{
@@ -218,7 +269,7 @@ namespace Google.Protobuf }
/// <summary>
- /// Attempt to read a field tag, returning false if we have reached the end
+ /// Attempts to read a field tag, returning false if we have reached the end
/// of the input data.
/// </summary>
/// <param name="fieldTag">The 'tag' of the field (id * 8 + wire-format)</param>
@@ -233,14 +284,42 @@ namespace Google.Protobuf return true;
}
- if (IsAtEnd)
+ // Optimize for the incredibly common case of having at least two bytes left in the buffer,
+ // and those two bytes being enough to get the tag. This will be true for fields up to 4095.
+ if (bufferPos + 2 <= bufferSize)
{
- fieldTag = 0;
- lastTag = fieldTag;
- return false;
+ int tmp = buffer[bufferPos++];
+ if (tmp < 128)
+ {
+ fieldTag = (uint)tmp;
+ }
+ else
+ {
+ int result = tmp & 0x7f;
+ if ((tmp = buffer[bufferPos++]) < 128)
+ {
+ result |= tmp << 7;
+ fieldTag = (uint) result;
+ }
+ else
+ {
+ // Nope, rewind and go the potentially slow route.
+ bufferPos -= 2;
+ fieldTag = ReadRawVarint32();
+ }
+ }
}
+ else
+ {
+ if (IsAtEnd)
+ {
+ fieldTag = 0;
+ lastTag = fieldTag;
+ return false;
+ }
- fieldTag = ReadRawVarint32();
+ fieldTag = ReadRawVarint32();
+ }
lastTag = fieldTag;
if (lastTag == 0)
{
@@ -251,7 +330,7 @@ namespace Google.Protobuf }
/// <summary>
- /// Read a double field from the stream.
+ /// Reads a double field from the stream.
/// </summary>
public double ReadDouble()
{
@@ -259,7 +338,7 @@ namespace Google.Protobuf }
/// <summary>
- /// Read a float field from the stream.
+ /// Reads a float field from the stream.
/// </summary>
public float ReadFloat()
{
@@ -281,7 +360,7 @@ namespace Google.Protobuf }
/// <summary>
- /// Read a uint64 field from the stream.
+ /// Reads a uint64 field from the stream.
/// </summary>
public ulong ReadUInt64()
{
@@ -289,7 +368,7 @@ namespace Google.Protobuf }
/// <summary>
- /// Read an int64 field from the stream.
+ /// Reads an int64 field from the stream.
/// </summary>
public long ReadInt64()
{
@@ -297,7 +376,7 @@ namespace Google.Protobuf }
/// <summary>
- /// Read an int32 field from the stream.
+ /// Reads an int32 field from the stream.
/// </summary>
public int ReadInt32()
{
@@ -305,7 +384,7 @@ namespace Google.Protobuf }
/// <summary>
- /// Read a fixed64 field from the stream.
+ /// Reads a fixed64 field from the stream.
/// </summary>
public ulong ReadFixed64()
{
@@ -313,7 +392,7 @@ namespace Google.Protobuf }
/// <summary>
- /// Read a fixed32 field from the stream.
+ /// Reads a fixed32 field from the stream.
/// </summary>
public uint ReadFixed32()
{
@@ -321,7 +400,7 @@ namespace Google.Protobuf }
/// <summary>
- /// Read a bool field from the stream.
+ /// Reads a bool field from the stream.
/// </summary>
public bool ReadBool()
{
@@ -333,22 +412,22 @@ namespace Google.Protobuf /// </summary>
public string ReadString()
{
- int size = (int) ReadRawVarint32();
+ int length = ReadLength();
// No need to read any data for an empty string.
- if (size == 0)
+ if (length == 0)
{
return "";
}
- if (size <= bufferSize - bufferPos)
+ if (length <= bufferSize - bufferPos)
{
// Fast path: We already have the bytes in a contiguous buffer, so
// just copy directly from it.
- String result = CodedOutputStream.Utf8Encoding.GetString(buffer, bufferPos, size);
- bufferPos += size;
+ String result = CodedOutputStream.Utf8Encoding.GetString(buffer, bufferPos, length);
+ bufferPos += length;
return result;
}
// Slow path: Build a byte array first then copy it.
- return CodedOutputStream.Utf8Encoding.GetString(ReadRawBytes(size), 0, size);
+ return CodedOutputStream.Utf8Encoding.GetString(ReadRawBytes(length), 0, length);
}
/// <summary>
@@ -356,7 +435,7 @@ namespace Google.Protobuf /// </summary>
public void ReadMessage(IMessage builder)
{
- int length = (int) ReadRawVarint32();
+ int length = ReadLength();
if (recursionDepth >= recursionLimit)
{
throw InvalidProtocolBufferException.RecursionLimitExceeded();
@@ -374,19 +453,19 @@ namespace Google.Protobuf /// </summary>
public ByteString ReadBytes()
{
- int size = (int) ReadRawVarint32();
- if (size <= bufferSize - bufferPos && size > 0)
+ int length = ReadLength();
+ if (length <= bufferSize - bufferPos && length > 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;
+ ByteString result = ByteString.CopyFrom(buffer, bufferPos, length);
+ bufferPos += length;
return result;
}
else
{
// Slow path: Build a byte array and attach it to a new ByteString.
- return ByteString.AttachBytes(ReadRawBytes(size));
+ return ByteString.AttachBytes(ReadRawBytes(length));
}
}
@@ -442,6 +521,18 @@ namespace Google.Protobuf }
/// <summary>
+ /// Reads a length for length-delimited data.
+ /// </summary>
+ /// <remarks>
+ /// This is internally just reading a varint, but this method exists
+ /// to make the calling code clearer.
+ /// </remarks>
+ public int ReadLength()
+ {
+ return (int) ReadRawVarint32();
+ }
+
+ /// <summary>
/// Peeks at the next tag in the stream. If it matches <paramref name="tag"/>,
/// the tag is consumed and the method returns <c>true</c>; otherwise, the
/// stream is left in the original position and the method returns <c>false</c>.
@@ -517,12 +608,12 @@ namespace Google.Protobuf }
/// <summary>
- /// Read a raw Varint from the stream. If larger than 32 bits, discard the upper bits.
+ /// Reads 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>
- public uint ReadRawVarint32()
+ internal uint ReadRawVarint32()
{
if (bufferPos + 5 > bufferSize)
{
@@ -581,13 +672,13 @@ namespace Google.Protobuf /// <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)}
+ /// 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>
- public static uint ReadRawVarint32(Stream input)
+ internal static uint ReadRawVarint32(Stream input)
{
int result = 0;
int offset = 0;
@@ -621,9 +712,9 @@ namespace Google.Protobuf }
/// <summary>
- /// Read a raw varint from the stream.
+ /// Reads a raw varint from the stream.
/// </summary>
- public ulong ReadRawVarint64()
+ internal ulong ReadRawVarint64()
{
int shift = 0;
ulong result = 0;
@@ -641,9 +732,9 @@ namespace Google.Protobuf }
/// <summary>
- /// Read a 32-bit little-endian integer from the stream.
+ /// Reads a 32-bit little-endian integer from the stream.
/// </summary>
- public uint ReadRawLittleEndian32()
+ internal uint ReadRawLittleEndian32()
{
uint b1 = ReadRawByte();
uint b2 = ReadRawByte();
@@ -653,9 +744,9 @@ namespace Google.Protobuf }
/// <summary>
- /// Read a 64-bit little-endian integer from the stream.
+ /// Reads a 64-bit little-endian integer from the stream.
/// </summary>
- public ulong ReadRawLittleEndian64()
+ internal ulong ReadRawLittleEndian64()
{
ulong b1 = ReadRawByte();
ulong b2 = ReadRawByte();
@@ -669,8 +760,6 @@ namespace Google.Protobuf | (b5 << 32) | (b6 << 40) | (b7 << 48) | (b8 << 56);
}
- #endregion
-
/// <summary>
/// Decode a 32-bit value with ZigZag encoding.
/// </summary>
@@ -680,9 +769,9 @@ namespace Google.Protobuf /// sign-extended to 64 bits to be varint encoded, thus always taking
/// 10 bytes on the wire.)
/// </remarks>
- public static int DecodeZigZag32(uint n)
+ internal static int DecodeZigZag32(uint n)
{
- return (int) (n >> 1) ^ -(int) (n & 1);
+ return (int)(n >> 1) ^ -(int)(n & 1);
}
/// <summary>
@@ -694,72 +783,21 @@ namespace Google.Protobuf /// sign-extended to 64 bits to be varint encoded, thus always taking
/// 10 bytes on the wire.)
/// </remarks>
- 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)
+ internal static long DecodeZigZag64(ulong n)
{
- if (limit < 0)
- {
- throw new ArgumentOutOfRangeException("Size limit cannot be negative: " + limit);
- }
- int oldLimit = sizeLimit;
- sizeLimit = limit;
- return oldLimit;
+ return (long)(n >> 1) ^ -(long)(n & 1);
}
+ #endregion
#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)
+ internal int PushLimit(int byteLimit)
{
if (byteLimit < 0)
{
@@ -797,7 +835,7 @@ namespace Google.Protobuf /// <summary>
/// Discards the current limit, returning the previous limit.
/// </summary>
- public void PopLimit(int oldLimit)
+ internal void PopLimit(int oldLimit)
{
currentLimit = oldLimit;
RecomputeBufferSizeAfterLimit();
@@ -807,7 +845,7 @@ namespace Google.Protobuf /// Returns whether or not all the data before the limit has been read.
/// </summary>
/// <returns></returns>
- public bool ReachedLimit
+ internal bool ReachedLimit
{
get
{
@@ -897,7 +935,7 @@ namespace Google.Protobuf /// <exception cref="InvalidProtocolBufferException">
/// the end of the stream or the current limit was reached
/// </exception>
- public byte ReadRawByte()
+ internal byte ReadRawByte()
{
if (bufferPos == bufferSize)
{
@@ -907,12 +945,12 @@ namespace Google.Protobuf }
/// <summary>
- /// Read a fixed size of bytes from the input.
+ /// Reads 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)
+ internal byte[] ReadRawBytes(int size)
{
if (size < 0)
{
@@ -921,7 +959,8 @@ namespace Google.Protobuf if (totalBytesRetired + bufferPos + size > currentLimit)
{
- // Read to the end of the stream anyway.
+ // Read to the end of the stream (up to the current limit) anyway.
+ // TODO(jonskeet): This is the only usage of SkipRawBytes. Do we really need to do it?
SkipRawBytes(currentLimit - totalBytesRetired - bufferPos);
// Then fail.
throw InvalidProtocolBufferException.TruncatedMessage();
@@ -1026,62 +1065,11 @@ namespace Google.Protobuf }
/// <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 = lastTag;
- switch (WireFormat.GetTagWireType(tag))
- {
- case WireFormat.WireType.Varint:
- ReadRawVarint64();
- 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()
- {
- uint tag;
- while (ReadTag(out tag))
- {
- if (!SkipField())
- {
- 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)
+ private void SkipRawBytes(int size)
{
if (size < 0)
{
|