FreeRDP/libfreerdp/codec/xcrush.c
2016-05-12 14:24:53 -04:00

1070 lines
26 KiB
C

/**
* FreeRDP: A Remote Desktop Protocol Implementation
* XCrush (RDP6.1) Bulk Data Compression
*
* Copyright 2014 Marc-Andre Moreau <marcandre.moreau@gmail.com>
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <winpr/crt.h>
#include <winpr/print.h>
#include <winpr/bitstream.h>
#include <freerdp/log.h>
#include <freerdp/codec/xcrush.h>
#define TAG FREERDP_TAG("codec")
const char* xcrush_get_level_2_compression_flags_string(UINT32 flags)
{
flags &= 0xE0;
if (flags == 0)
return "PACKET_UNCOMPRESSED";
else if (flags == PACKET_COMPRESSED)
return "PACKET_COMPRESSED";
else if (flags == PACKET_AT_FRONT)
return "PACKET_AT_FRONT";
else if (flags == PACKET_FLUSHED)
return "PACKET_FLUSHED";
else if (flags == (PACKET_COMPRESSED | PACKET_AT_FRONT))
return "PACKET_COMPRESSED | PACKET_AT_FRONT";
else if (flags == (PACKET_COMPRESSED | PACKET_FLUSHED))
return "PACKET_COMPRESSED | PACKET_FLUSHED";
else if (flags == (PACKET_AT_FRONT | PACKET_FLUSHED))
return "PACKET_AT_FRONT | PACKET_FLUSHED";
else if (flags == (PACKET_COMPRESSED | PACKET_AT_FRONT | PACKET_FLUSHED))
return "PACKET_COMPRESSED | PACKET_AT_FRONT | PACKET_FLUSHED";
return "PACKET_UNKNOWN";
}
const char* xcrush_get_level_1_compression_flags_string(UINT32 flags)
{
flags &= 0x17;
if (flags == 0)
return "L1_UNKNOWN";
else if (flags == L1_PACKET_AT_FRONT)
return "L1_PACKET_AT_FRONT";
else if (flags == L1_NO_COMPRESSION)
return "L1_NO_COMPRESSION";
else if (flags == L1_COMPRESSED)
return "L1_COMPRESSED";
else if (flags == L1_INNER_COMPRESSION)
return "L1_INNER_COMPRESSION";
else if (flags == (L1_PACKET_AT_FRONT | L1_NO_COMPRESSION))
return "L1_PACKET_AT_FRONT | L1_NO_COMPRESSION";
else if (flags == (L1_PACKET_AT_FRONT | L1_COMPRESSED))
return "L1_PACKET_AT_FRONT | L1_COMPRESSED";
else if (flags == (L1_PACKET_AT_FRONT | L1_INNER_COMPRESSION))
return "L1_PACKET_AT_FRONT | L1_INNER_COMPRESSION";
else if (flags == (L1_NO_COMPRESSION | L1_COMPRESSED))
return "L1_NO_COMPRESSION | L1_COMPRESSED";
else if (flags == (L1_NO_COMPRESSION | L1_INNER_COMPRESSION))
return "L1_NO_COMPRESSION | L1_INNER_COMPRESSION";
else if (flags == (L1_COMPRESSED | L1_INNER_COMPRESSION))
return "L1_COMPRESSED | L1_INNER_COMPRESSION";
else if (flags == (L1_NO_COMPRESSION | L1_COMPRESSED | L1_INNER_COMPRESSION))
return "L1_NO_COMPRESSION | L1_COMPRESSED | L1_INNER_COMPRESSION";
else if (flags == (L1_PACKET_AT_FRONT | L1_COMPRESSED | L1_INNER_COMPRESSION))
return "L1_PACKET_AT_FRONT | L1_COMPRESSED | L1_INNER_COMPRESSION";
else if (flags == (L1_PACKET_AT_FRONT | L1_NO_COMPRESSION | L1_INNER_COMPRESSION))
return "L1_PACKET_AT_FRONT | L1_NO_COMPRESSION | L1_INNER_COMPRESSION";
else if (flags == (L1_PACKET_AT_FRONT | L1_NO_COMPRESSION | L1_COMPRESSED))
return "L1_PACKET_AT_FRONT | L1_NO_COMPRESSION | L1_COMPRESSED";
else if (flags == (L1_PACKET_AT_FRONT | L1_NO_COMPRESSION | L1_COMPRESSED | L1_INNER_COMPRESSION))
return "L1_PACKET_AT_FRONT | L1_NO_COMPRESSION | L1_COMPRESSED | L1_INNER_COMPRESSION";
return "L1_UNKNOWN";
}
UINT32 xcrush_update_hash(BYTE* data, UINT32 size)
{
BYTE* end;
UINT32 seed = 5381; /* same value as in djb2 */
if (size > 32)
{
size = 32;
seed = 5413;
}
end = &data[size - 4];
while (data < end)
{
seed += (data[3] ^ data[0]) + (data[1] << 8);
data += 4;
}
return (UINT16) seed;
}
int xcrush_append_chunk(XCRUSH_CONTEXT* xcrush, BYTE* data, UINT32* beg, UINT32 end)
{
UINT16 seed;
UINT32 size;
if (xcrush->SignatureIndex >= xcrush->SignatureCount)
return 0;
size = end - *beg;
if (size > 65535)
return 0;
if (size >= 15)
{
seed = xcrush_update_hash(&data[*beg], (UINT16) size);
xcrush->Signatures[xcrush->SignatureIndex].size = size;
xcrush->Signatures[xcrush->SignatureIndex].seed = seed;
xcrush->SignatureIndex++;
*beg = end;
}
return 1;
}
int xcrush_compute_chunks(XCRUSH_CONTEXT* xcrush, BYTE* data, UINT32 size, UINT32* pIndex)
{
UINT32 i = 0;
UINT32 offset = 0;
UINT32 rotation = 0;
UINT32 accumulator = 0;
*pIndex = 0;
xcrush->SignatureIndex = 0;
if (size < 128)
return 0;
for (i = 0; i < 32; i++)
{
rotation = _rotl(accumulator, 1);
accumulator = data[i] ^ rotation;
}
for (i = 0; i < size - 64; i++)
{
rotation = _rotl(accumulator, 1);
accumulator = data[i + 32] ^ data[i] ^ rotation;
if (!(accumulator & 0x7F))
{
if (!xcrush_append_chunk(xcrush, data, &offset, i + 32))
return 0;
}
i++;
rotation = _rotl(accumulator, 1);
accumulator = data[i + 32] ^ data[i] ^ rotation;
if (!(accumulator & 0x7F))
{
if (!xcrush_append_chunk(xcrush, data, &offset, i + 32))
return 0;
}
i++;
rotation = _rotl(accumulator, 1);
accumulator = data[i + 32] ^ data[i] ^ rotation;
if (!(accumulator & 0x7F))
{
if (!xcrush_append_chunk(xcrush, data, &offset, i + 32))
return 0;
}
i++;
rotation = _rotl(accumulator, 1);
accumulator = data[i + 32] ^ data[i] ^ rotation;
if (!(accumulator & 0x7F))
{
if (!xcrush_append_chunk(xcrush, data, &offset, i + 32))
return 0;
}
}
if ((size == offset) || xcrush_append_chunk(xcrush, data, &offset, size))
{
*pIndex = xcrush->SignatureIndex;
return 1;
}
return 0;
}
UINT32 xcrush_compute_signatures(XCRUSH_CONTEXT* xcrush, BYTE* data, UINT32 size)
{
UINT32 index = 0;
if (xcrush_compute_chunks(xcrush, data, size, &index))
return index;
return 0;
}
void xcrush_clear_hash_table_range(XCRUSH_CONTEXT* xcrush, UINT32 beg, UINT32 end)
{
UINT32 index;
for (index = 0; index < 65536; index++)
{
if (xcrush->NextChunks[index] >= beg)
{
if (xcrush->NextChunks[index] <= end)
{
xcrush->NextChunks[index] = 0;
}
}
}
for (index = 0; index < 65534; index++)
{
if (xcrush->Chunks[index].next >= beg )
{
if (xcrush->Chunks[index].next <= end)
{
xcrush->Chunks[index].next = 0;
}
}
}
}
int xcrush_find_next_matching_chunk(XCRUSH_CONTEXT* xcrush, XCRUSH_CHUNK* chunk, XCRUSH_CHUNK** pNextChunk)
{
UINT32 index;
XCRUSH_CHUNK* next = NULL;
if (!chunk)
return -4001; /* error */
if (chunk->next)
{
index = (chunk - xcrush->Chunks) / sizeof(XCRUSH_CHUNK);
if (index >= 65534)
return -4002; /* error */
if ((index < xcrush->ChunkHead) || (chunk->next >= xcrush->ChunkHead))
{
if (chunk->next >= 65534)
return -4003; /* error */
next = &xcrush->Chunks[chunk->next];
}
}
*pNextChunk = next;
return 1;
}
int xcrush_insert_chunk(XCRUSH_CONTEXT* xcrush, XCRUSH_SIGNATURE* signature, UINT32 offset, XCRUSH_CHUNK** pPrevChunk)
{
UINT32 seed;
UINT32 index;
if (xcrush->ChunkHead >= 65530)
{
xcrush->ChunkHead = 1;
xcrush->ChunkTail = 1;
}
if (xcrush->ChunkHead >= xcrush->ChunkTail)
{
xcrush_clear_hash_table_range(xcrush, xcrush->ChunkTail, xcrush->ChunkTail + 10000);
xcrush->ChunkTail += 10000;
}
index = xcrush->ChunkHead++;
if (xcrush->ChunkHead >= 65534)
return -3001; /* error */
xcrush->Chunks[index].offset = offset;
seed = signature->seed;
if (seed >= 65536)
return -3002; /* error */
if (xcrush->NextChunks[seed])
{
if (xcrush->NextChunks[seed] >= 65534)
return -3003; /* error */
*pPrevChunk = &xcrush->Chunks[xcrush->NextChunks[seed]];
}
xcrush->Chunks[index].next = xcrush->NextChunks[seed] & 0xFFFF;
xcrush->NextChunks[seed] = index;
return 1;
}
int xcrush_find_match_length(XCRUSH_CONTEXT* xcrush, UINT32 MatchOffset, UINT32 ChunkOffset, UINT32 HistoryOffset, UINT32 SrcSize, UINT32 MaxMatchLength, XCRUSH_MATCH_INFO* MatchInfo)
{
UINT32 MatchSymbol;
UINT32 ChunkSymbol;
BYTE* ChunkBuffer;
BYTE* MatchBuffer;
BYTE* MatchStartPtr;
BYTE* ForwardChunkPtr;
BYTE* ReverseChunkPtr;
BYTE* ForwardMatchPtr;
BYTE* ReverseMatchPtr;
BYTE* HistoryBufferEnd;
UINT32 ReverseMatchLength;
UINT32 ForwardMatchLength;
UINT32 TotalMatchLength;
BYTE* HistoryBuffer;
UINT32 HistoryBufferSize;
ForwardMatchLength = 0;
ReverseMatchLength = 0;
HistoryBuffer = xcrush->HistoryBuffer;
HistoryBufferSize = xcrush->HistoryBufferSize;
HistoryBufferEnd = &HistoryBuffer[HistoryOffset + SrcSize];
if (MatchOffset > HistoryBufferSize)
return -2001; /* error */
MatchBuffer = &HistoryBuffer[MatchOffset];
if (ChunkOffset > HistoryBufferSize)
return -2002; /* error */
ChunkBuffer = &HistoryBuffer[ChunkOffset];
if (MatchOffset == ChunkOffset)
return -2003; /* error */
if (MatchBuffer < HistoryBuffer)
return -2004; /* error */
if (ChunkBuffer < HistoryBuffer)
return -2005; /* error */
ForwardMatchPtr = &HistoryBuffer[MatchOffset];
ForwardChunkPtr = &HistoryBuffer[ChunkOffset];
if ((&MatchBuffer[MaxMatchLength + 1] < HistoryBufferEnd)
&& (MatchBuffer[MaxMatchLength + 1] != ChunkBuffer[MaxMatchLength + 1]))
{
return 0;
}
while (1)
{
MatchSymbol = *ForwardMatchPtr++;
ChunkSymbol = *ForwardChunkPtr++;
if (MatchSymbol != ChunkSymbol)
break;
if (ForwardMatchPtr > HistoryBufferEnd)
break;
ForwardMatchLength++;
}
ReverseMatchPtr = MatchBuffer - 1;
ReverseChunkPtr = ChunkBuffer - 1;
while((ReverseMatchPtr > &HistoryBuffer[HistoryOffset])
&& (ReverseChunkPtr > HistoryBuffer)
&& (*ReverseMatchPtr == *ReverseChunkPtr))
{
ReverseMatchLength++;
ReverseMatchPtr--;
ReverseChunkPtr--;
}
MatchStartPtr = MatchBuffer - ReverseMatchLength;
TotalMatchLength = ReverseMatchLength + ForwardMatchLength;
if (TotalMatchLength < 11)
return 0;
if (MatchStartPtr < HistoryBuffer)
return -2006; /* error */
MatchInfo->MatchOffset = MatchStartPtr - HistoryBuffer;
MatchInfo->ChunkOffset = ChunkBuffer - ReverseMatchLength - HistoryBuffer;
MatchInfo->MatchLength = TotalMatchLength;
return (int) TotalMatchLength;
}
int xcrush_find_all_matches(XCRUSH_CONTEXT* xcrush, UINT32 SignatureIndex, UINT32 HistoryOffset, UINT32 SrcOffset, UINT32 SrcSize)
{
UINT32 i = 0;
UINT32 j = 0;
int status = 0;
UINT32 offset = 0;
UINT32 ChunkIndex = 0;
UINT32 ChunkCount = 0;
XCRUSH_CHUNK* chunk = NULL;
UINT32 MatchLength = 0;
UINT32 MaxMatchLength = 0;
UINT32 PrevMatchEnd = 0;
XCRUSH_MATCH_INFO MatchInfo = { 0 };
XCRUSH_MATCH_INFO MaxMatchInfo = { 0 };
XCRUSH_SIGNATURE* Signatures = NULL;
Signatures = xcrush->Signatures;
for (i = 0; i < SignatureIndex; i++)
{
offset = SrcOffset + HistoryOffset;
if (!Signatures[i].size)
return -1001; /* error */
status = xcrush_insert_chunk(xcrush, &Signatures[i], offset, &chunk);
if (status < 0)
return status;
if (chunk && (SrcOffset + HistoryOffset + Signatures[i].size >= PrevMatchEnd))
{
ChunkCount = 0;
MaxMatchLength = 0;
ZeroMemory(&MaxMatchInfo, sizeof(XCRUSH_MATCH_INFO));
while (chunk)
{
if ((chunk->offset < HistoryOffset) || (chunk->offset < offset)
|| (chunk->offset > SrcSize + HistoryOffset))
{
status = xcrush_find_match_length(xcrush, offset, chunk->offset,
HistoryOffset, SrcSize, MaxMatchLength, &MatchInfo);
if (status < 0)
return status; /* error */
MatchLength = (UINT32) status;
if (MatchLength > MaxMatchLength)
{
MaxMatchLength = MatchLength;
MaxMatchInfo.MatchOffset = MatchInfo.MatchOffset;
MaxMatchInfo.ChunkOffset = MatchInfo.ChunkOffset;
MaxMatchInfo.MatchLength = MatchInfo.MatchLength;
if (MatchLength > 256)
break;
}
}
ChunkIndex = ChunkCount++;
if (ChunkIndex > 4)
break;
status = xcrush_find_next_matching_chunk(xcrush, chunk, &chunk);
if (status < 0)
return status; /* error */
}
if (MaxMatchLength)
{
xcrush->OriginalMatches[j].MatchOffset = MaxMatchInfo.MatchOffset;
xcrush->OriginalMatches[j].ChunkOffset = MaxMatchInfo.ChunkOffset;
xcrush->OriginalMatches[j].MatchLength = MaxMatchInfo.MatchLength;
if (xcrush->OriginalMatches[j].MatchOffset < HistoryOffset)
return -1002; /* error */
PrevMatchEnd = xcrush->OriginalMatches[j].MatchLength + xcrush->OriginalMatches[j].MatchOffset;
j++;
if (j >= 1000)
return -1003; /* error */
}
}
SrcOffset += Signatures[i].size;
if (SrcOffset > SrcSize)
return -1004; /* error */
}
if (SrcOffset > SrcSize)
return -1005; /* error */
return (int) j;
}
int xcrush_optimize_matches(XCRUSH_CONTEXT* xcrush)
{
UINT32 i, j;
UINT32 MatchDiff;
UINT32 PrevMatchEnd;
UINT32 TotalMatchLength;
UINT32 OriginalMatchCount;
UINT32 OptimizedMatchCount;
XCRUSH_MATCH_INFO* OriginalMatch;
XCRUSH_MATCH_INFO* OptimizedMatch;
XCRUSH_MATCH_INFO* OriginalMatches;
XCRUSH_MATCH_INFO* OptimizedMatches;
i = j = 0;
PrevMatchEnd = 0;
TotalMatchLength = 0;
OriginalMatches = xcrush->OriginalMatches;
OriginalMatchCount = xcrush->OriginalMatchCount;
OptimizedMatches = xcrush->OptimizedMatches;
OptimizedMatchCount = xcrush->OptimizedMatchCount;
for (i = 0; i < OriginalMatchCount; i++)
{
if (OriginalMatches[i].MatchOffset <= PrevMatchEnd)
{
if ((OriginalMatches[i].MatchOffset < PrevMatchEnd)
&& (OriginalMatches[i].MatchLength + OriginalMatches[i].MatchOffset > PrevMatchEnd + 6))
{
MatchDiff = PrevMatchEnd - OriginalMatches[i].MatchOffset;
OriginalMatch = &OriginalMatches[i];
OptimizedMatch = &OptimizedMatches[j];
OptimizedMatch->MatchOffset = OriginalMatch->MatchOffset;
OptimizedMatch->ChunkOffset = OriginalMatch->ChunkOffset;
OptimizedMatch->MatchLength = OriginalMatch->MatchLength;
if (OptimizedMatches[j].MatchLength <= MatchDiff)
return -5001; /* error */
if (MatchDiff >= 20000)
return -5002; /* error */
OptimizedMatches[j].MatchLength -= MatchDiff;
OptimizedMatches[j].MatchOffset += MatchDiff;
OptimizedMatches[j].ChunkOffset += MatchDiff;
PrevMatchEnd = OptimizedMatches[j].MatchLength + OptimizedMatches[j].MatchOffset;
TotalMatchLength += OptimizedMatches[j].MatchLength;
j++;
}
}
else
{
OriginalMatch = &OriginalMatches[i];
OptimizedMatch = &OptimizedMatches[j];
OptimizedMatch->MatchOffset = OriginalMatch->MatchOffset;
OptimizedMatch->ChunkOffset = OriginalMatch->ChunkOffset;
OptimizedMatch->MatchLength = OriginalMatch->MatchLength;
PrevMatchEnd = OptimizedMatches[j].MatchLength + OptimizedMatches[j].MatchOffset;
TotalMatchLength += OptimizedMatches[j].MatchLength;
j++;
}
}
OptimizedMatchCount = j;
xcrush->OptimizedMatchCount = OptimizedMatchCount;
return (int) TotalMatchLength;
}
int xcrush_generate_output(XCRUSH_CONTEXT* xcrush, BYTE* OutputBuffer, UINT32 OutputSize, UINT32 HistoryOffset, UINT32* pDstSize)
{
BYTE* Literals;
BYTE* OutputEnd;
UINT32 MatchIndex;
UINT32 MatchOffset;
UINT16 MatchLength;
UINT32 MatchCount;
UINT32 CurrentOffset;
UINT32 MatchOffsetDiff;
UINT32 HistoryOffsetDiff;
RDP61_MATCH_DETAILS* MatchDetails;
MatchCount = xcrush->OptimizedMatchCount;
OutputEnd = &OutputBuffer[OutputSize];
if (&OutputBuffer[2] >= &OutputBuffer[OutputSize])
return -6001; /* error */
*((UINT16*) OutputBuffer) = MatchCount;
MatchDetails = (RDP61_MATCH_DETAILS*) &OutputBuffer[2];
Literals = (BYTE*) &MatchDetails[MatchCount];
if (Literals > OutputEnd)
return -6002; /* error */
for (MatchIndex = 0; MatchIndex < MatchCount; MatchIndex++)
{
MatchDetails[MatchIndex].MatchLength = (UINT16) (xcrush->OptimizedMatches[MatchIndex].MatchLength);
MatchDetails[MatchIndex].MatchOutputOffset = (UINT16) (xcrush->OptimizedMatches[MatchIndex].MatchOffset - HistoryOffset);
MatchDetails[MatchIndex].MatchHistoryOffset = xcrush->OptimizedMatches[MatchIndex].ChunkOffset;
}
CurrentOffset = HistoryOffset;
for (MatchIndex = 0; MatchIndex < MatchCount; MatchIndex++)
{
MatchLength = (UINT16) (xcrush->OptimizedMatches[MatchIndex].MatchLength);
MatchOffset = xcrush->OptimizedMatches[MatchIndex].MatchOffset;
if (MatchOffset <= CurrentOffset)
{
if (MatchOffset != CurrentOffset)
return -6003; /* error */
CurrentOffset = MatchOffset + MatchLength;
}
else
{
MatchOffsetDiff = MatchOffset - CurrentOffset;
if (Literals + MatchOffset - CurrentOffset >= OutputEnd)
return -6004; /* error */
CopyMemory(Literals, &xcrush->HistoryBuffer[CurrentOffset], MatchOffsetDiff);
if (Literals >= OutputEnd)
return -6005; /* error */
Literals += MatchOffsetDiff;
CurrentOffset = MatchOffset + MatchLength;
}
}
HistoryOffsetDiff = xcrush->HistoryOffset - CurrentOffset;
if (Literals + HistoryOffsetDiff >= OutputEnd)
return -6006; /* error */
CopyMemory(Literals, &xcrush->HistoryBuffer[CurrentOffset], HistoryOffsetDiff);
*pDstSize = Literals + HistoryOffsetDiff - OutputBuffer;
return 1;
}
int xcrush_copy_bytes(BYTE* dst, BYTE* src, int num)
{
int index;
for (index = 0; index < num; index++)
{
dst[index] = src[index];
}
return num;
}
int xcrush_decompress_l1(XCRUSH_CONTEXT* xcrush, BYTE* pSrcData, UINT32 SrcSize, BYTE** ppDstData, UINT32* pDstSize, UINT32 flags)
{
BYTE* pSrcEnd = NULL;
BYTE* Literals = NULL;
UINT16 MatchCount = 0;
UINT16 MatchIndex = 0;
BYTE* OutputPtr = NULL;
int OutputLength = 0;
UINT32 OutputOffset = 0;
BYTE* HistoryPtr = NULL;
BYTE* HistoryBuffer = NULL;
BYTE* HistoryBufferEnd = NULL;
UINT32 HistoryBufferSize = 0;
UINT16 MatchLength = 0;
UINT16 MatchOutputOffset = 0;
UINT32 MatchHistoryOffset = 0;
RDP61_MATCH_DETAILS* MatchDetails = NULL;
if (SrcSize < 1)
return -1001;
if (flags & L1_PACKET_AT_FRONT)
xcrush->HistoryOffset = 0;
pSrcEnd = &pSrcData[SrcSize];
HistoryBuffer = xcrush->HistoryBuffer;
HistoryBufferSize = xcrush->HistoryBufferSize;
HistoryBufferEnd = &(HistoryBuffer[HistoryBufferSize]);
xcrush->HistoryPtr = HistoryPtr = &(HistoryBuffer[xcrush->HistoryOffset]);
if (flags & L1_NO_COMPRESSION)
{
Literals = pSrcData;
}
else
{
if (!(flags & L1_COMPRESSED))
return -1002;
if ((pSrcData + 2) > pSrcEnd)
return -1003;
MatchCount = *((UINT16*) pSrcData);
MatchDetails = (RDP61_MATCH_DETAILS*) &pSrcData[2];
Literals = (BYTE*) &MatchDetails[MatchCount];
OutputOffset = 0;
if (Literals > pSrcEnd)
return -1004;
for (MatchIndex = 0; MatchIndex < MatchCount; MatchIndex++)
{
MatchLength = MatchDetails[MatchIndex].MatchLength;
MatchOutputOffset = MatchDetails[MatchIndex].MatchOutputOffset;
MatchHistoryOffset = MatchDetails[MatchIndex].MatchHistoryOffset;
if (MatchOutputOffset < OutputOffset)
return -1005;
if (MatchLength > HistoryBufferSize)
return -1006;
if (MatchHistoryOffset > HistoryBufferSize)
return -1007;
OutputLength = MatchOutputOffset - OutputOffset;
if ((MatchOutputOffset - OutputOffset) > HistoryBufferSize)
return -1008;
if (OutputLength > 0)
{
if ((&HistoryPtr[OutputLength] >= HistoryBufferEnd) || (Literals >= pSrcEnd) || (&Literals[OutputLength] > pSrcEnd))
return -1009;
xcrush_copy_bytes(HistoryPtr, Literals, OutputLength);
HistoryPtr += OutputLength;
Literals += OutputLength;
OutputOffset += OutputLength;
if (Literals > pSrcEnd)
return -1010;
}
OutputPtr = &xcrush->HistoryBuffer[MatchHistoryOffset];
if ((&HistoryPtr[MatchLength] >= HistoryBufferEnd) || (&OutputPtr[MatchLength] >= HistoryBufferEnd))
return -1011;
xcrush_copy_bytes(HistoryPtr, OutputPtr, MatchLength);
OutputOffset += MatchLength;
HistoryPtr += MatchLength;
}
}
if (Literals < pSrcEnd)
{
OutputLength = pSrcEnd - Literals;
if ((&HistoryPtr[OutputLength] >= HistoryBufferEnd) || (&Literals[OutputLength] > pSrcEnd))
return -1012;
xcrush_copy_bytes(HistoryPtr, Literals, OutputLength);
HistoryPtr += OutputLength;
}
xcrush->HistoryOffset = HistoryPtr - HistoryBuffer;
*pDstSize = HistoryPtr - xcrush->HistoryPtr;
*ppDstData = xcrush->HistoryPtr;
return 1;
}
int xcrush_decompress(XCRUSH_CONTEXT* xcrush, BYTE* pSrcData, UINT32 SrcSize, BYTE** ppDstData, UINT32* pDstSize, UINT32 flags)
{
int status = 0;
UINT32 DstSize = 0;
BYTE* pDstData = NULL;
BYTE Level1ComprFlags;
BYTE Level2ComprFlags;
if (SrcSize < 2)
return -1;
Level1ComprFlags = pSrcData[0];
Level2ComprFlags = pSrcData[1];
pSrcData += 2;
SrcSize -= 2;
if (flags & PACKET_FLUSHED)
{
ZeroMemory(xcrush->HistoryBuffer, xcrush->HistoryBufferSize);
xcrush->HistoryOffset = 0;
}
if (!(Level2ComprFlags & PACKET_COMPRESSED))
{
pDstData = pSrcData;
DstSize = SrcSize;
status = xcrush_decompress_l1(xcrush, pDstData, DstSize, ppDstData, pDstSize, Level1ComprFlags);
return status;
}
status = mppc_decompress(xcrush->mppc, pSrcData, SrcSize, &pDstData, &DstSize, Level2ComprFlags);
if (status < 0)
return status;
status = xcrush_decompress_l1(xcrush, pDstData, DstSize, ppDstData, pDstSize, Level1ComprFlags);
return status;
}
int xcrush_compress_l1(XCRUSH_CONTEXT* xcrush, BYTE* pSrcData, UINT32 SrcSize, BYTE** ppDstData, UINT32* pDstSize, UINT32* pFlags)
{
int status = 0;
UINT32 Flags = 0;
UINT32 HistoryOffset = 0;
BYTE* HistoryPtr = NULL;
BYTE* HistoryBuffer = NULL;
UINT32 SignatureIndex = 0;
if (xcrush->HistoryOffset + SrcSize + 8 > xcrush->HistoryBufferSize)
{
xcrush->HistoryOffset = 0;
Flags |= L1_PACKET_AT_FRONT;
}
HistoryOffset = xcrush->HistoryOffset;
HistoryBuffer = xcrush->HistoryBuffer;
HistoryPtr = &HistoryBuffer[HistoryOffset];
MoveMemory(HistoryPtr, pSrcData, SrcSize);
xcrush->HistoryOffset += SrcSize;
if (SrcSize > 50)
{
SignatureIndex = xcrush_compute_signatures(xcrush, pSrcData, SrcSize);
if (SignatureIndex)
{
status = xcrush_find_all_matches(xcrush,
SignatureIndex, HistoryOffset, 0, SrcSize);
if (status < 0)
return status;
xcrush->OriginalMatchCount = (UINT32) status;
xcrush->OptimizedMatchCount = 0;
if (xcrush->OriginalMatchCount)
{
status = xcrush_optimize_matches(xcrush);
if (status < 0)
return status;
}
if (xcrush->OptimizedMatchCount)
{
status = xcrush_generate_output(xcrush, *ppDstData, SrcSize, HistoryOffset, pDstSize);
if (status < 0)
return status;
if (status > 0)
Flags |= L1_COMPRESSED;
}
}
}
if (!(Flags & L1_COMPRESSED))
{
Flags |= L1_NO_COMPRESSION;
*pDstSize = SrcSize;
}
*pFlags = Flags;
return 1;
}
int xcrush_compress(XCRUSH_CONTEXT* xcrush, BYTE* pSrcData, UINT32 SrcSize, BYTE** ppDstData, UINT32* pDstSize, UINT32* pFlags)
{
int status = 0;
UINT32 DstSize = 0;
BYTE* pDstData = NULL;
BYTE* CompressedData = NULL;
UINT32 CompressedDataSize = 0;
BYTE* OriginalData = NULL;
UINT32 OriginalDataSize = 0;
UINT32 Level1ComprFlags = 0;
UINT32 Level2ComprFlags = 0;
UINT32 CompressionLevel = 3;
if (SrcSize > 16384)
return -1001;
if ((SrcSize + 2) > *pDstSize)
return -1002;
OriginalData = *ppDstData;
OriginalDataSize = SrcSize;
pDstData = xcrush->BlockBuffer;
CompressedDataSize = SrcSize;
status = xcrush_compress_l1(xcrush, pSrcData, SrcSize, &pDstData, &CompressedDataSize, &Level1ComprFlags);
if (status < 0)
return status;
if (Level1ComprFlags & L1_COMPRESSED)
{
CompressedData = pDstData;
if (CompressedDataSize > SrcSize)
return -1003;
}
else
{
CompressedData = pSrcData;
if (CompressedDataSize != SrcSize)
return -1004;
}
status = 0;
pDstData = &OriginalData[2];
DstSize = OriginalDataSize - 2;
if (CompressedDataSize > 50)
{
status = mppc_compress(xcrush->mppc, CompressedData, CompressedDataSize, &pDstData, &DstSize, &Level2ComprFlags);
}
if (status < 0)
return status;
if (!status || (Level2ComprFlags & PACKET_FLUSHED))
{
if (CompressedDataSize > DstSize)
{
xcrush_context_reset(xcrush, TRUE);
*ppDstData = pSrcData;
*pDstSize = SrcSize;
*pFlags = 0;
return 1;
}
DstSize = CompressedDataSize;
CopyMemory(&OriginalData[2], CompressedData, CompressedDataSize);
}
if (Level2ComprFlags & PACKET_COMPRESSED)
{
Level2ComprFlags |= xcrush->CompressionFlags;
xcrush->CompressionFlags = 0;
}
else if (Level2ComprFlags & PACKET_FLUSHED)
{
xcrush->CompressionFlags = PACKET_FLUSHED;
}
Level1ComprFlags |= L1_INNER_COMPRESSION;
OriginalData[0] = (BYTE) Level1ComprFlags;
OriginalData[1] = (BYTE) Level2ComprFlags;
#if 0
WLog_DBG(TAG, "XCrushCompress: Level1ComprFlags: %s Level2ComprFlags: %s",
xcrush_get_level_1_compression_flags_string(Level1ComprFlags),
xcrush_get_level_2_compression_flags_string(Level2ComprFlags));
#endif
if (*pDstSize < (DstSize + 2))
return -1006;
*pDstSize = DstSize + 2;
*pFlags = PACKET_COMPRESSED | CompressionLevel;
return 1;
}
void xcrush_context_reset(XCRUSH_CONTEXT* xcrush, BOOL flush)
{
xcrush->SignatureIndex = 0;
xcrush->SignatureCount = 1000;
ZeroMemory(&(xcrush->Signatures), sizeof(XCRUSH_SIGNATURE) * xcrush->SignatureCount);
xcrush->CompressionFlags = 0;
xcrush->ChunkHead = xcrush->ChunkTail = 1;
ZeroMemory(&(xcrush->Chunks), sizeof(xcrush->Chunks));
ZeroMemory(&(xcrush->NextChunks), sizeof(xcrush->NextChunks));
ZeroMemory(&(xcrush->OriginalMatches), sizeof(xcrush->OriginalMatches));
ZeroMemory(&(xcrush->OptimizedMatches), sizeof(xcrush->OptimizedMatches));
if (flush)
xcrush->HistoryOffset = xcrush->HistoryBufferSize + 1;
else
xcrush->HistoryOffset = 0;
mppc_context_reset(xcrush->mppc, flush);
}
XCRUSH_CONTEXT* xcrush_context_new(BOOL Compressor)
{
XCRUSH_CONTEXT* xcrush;
xcrush = (XCRUSH_CONTEXT*) calloc(1, sizeof(XCRUSH_CONTEXT));
if (xcrush)
{
xcrush->Compressor = Compressor;
xcrush->mppc = mppc_context_new(1, Compressor);
xcrush->HistoryOffset = 0;
xcrush->HistoryBufferSize = 2000000;
xcrush_context_reset(xcrush, FALSE);
}
return xcrush;
}
void xcrush_context_free(XCRUSH_CONTEXT* xcrush)
{
if (xcrush)
{
mppc_context_free(xcrush->mppc);
free(xcrush);
}
}