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/*==LICENSE==*
CyanWorlds.com Engine - MMOG client, server and tools
Copyright (C) 2011 Cyan Worlds, Inc.
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
You can contact Cyan Worlds, Inc. by email legal@cyan.com
or by snail mail at:
Cyan Worlds, Inc.
14617 N Newport Hwy
Mead, WA 99021
*==LICENSE==*/
#include "plZlibStream.h"
#include <zlib.h>
voidpf ZlibAlloc(voidpf opaque, uInt items, uInt size)
{
return ALLOC(items*size);
}
void ZlibFree(voidpf opaque, voidpf address)
{
FREE(address);
}
plZlibStream::plZlibStream() : fOutput(nil), fZStream(nil), fHeader(kNeedMoreData), fDecompressedOk(false)
{
}
plZlibStream::~plZlibStream()
{
hsAssert(!fOutput && !fZStream, "plZlibStream not closed");
}
hsBool plZlibStream::Open(const char* filename, const char* mode)
{
wchar* wFilename = hsStringToWString(filename);
wchar* wMode = hsStringToWString(mode);
hsBool ret = Open(wFilename, wMode);
delete [] wFilename;
delete [] wMode;
return ret;
}
hsBool plZlibStream::Open(const wchar* filename, const wchar* mode)
{
fFilename = filename;
fMode = mode;
fOutput = NEW(hsUNIXStream);
return fOutput->Open(filename, L"wb");
}
hsBool plZlibStream::Close()
{
if (fOutput)
{
fOutput->Close();
DEL(fOutput);
fOutput = nil;
}
if (fZStream)
{
z_streamp zstream = (z_streamp)fZStream;
inflateEnd(zstream);
DEL(zstream);
fZStream = nil;
}
return true;
}
UInt32 plZlibStream::Write(UInt32 byteCount, const void* buffer)
{
UInt8* byteBuf = (UInt8*)buffer;
// Check if we've read in the full gzip header yet
if (fHeader == kNeedMoreData)
{
int cutAmt = IValidateGzHeader(byteCount, buffer);
// Once we've read in the whole header, cut out whatever part of it is
// in this buffer, leaving raw compressed data
if (cutAmt != 0)
{
byteCount -= cutAmt;
byteBuf += cutAmt;
}
}
if (fHeader == kInvalidHeader)
return 0;
if (fHeader == kValidHeader)
{
ASSERT(fOutput);
ASSERT(fZStream);
z_streamp zstream = (z_streamp)fZStream;
zstream->avail_in = byteCount;
zstream->next_in = byteBuf;
char outBuf[2048];
while (zstream->avail_in != 0)
{
zstream->avail_out = sizeof(outBuf);
zstream->next_out = (UInt8*)outBuf;
UInt32 amtWritten = zstream->total_out;
int ret = inflate(zstream, Z_NO_FLUSH);
bool inflateErr = (ret == Z_NEED_DICT || ret == Z_DATA_ERROR ||
ret == Z_STREAM_ERROR || ret == Z_MEM_ERROR || ret == Z_BUF_ERROR);
// If we have a decompression error, just fail
if (inflateErr)
{
hsAssert(!inflateErr, "Error in inflate");
fHeader = kInvalidHeader;
break;
}
amtWritten = zstream->total_out - amtWritten;
fOutput->Write(amtWritten, outBuf);
// If zlib says we hit the end of the stream, ignore avail_in
if (ret == Z_STREAM_END)
{
fDecompressedOk = true;
break;
}
}
}
return byteCount;
}
int plZlibStream::IValidateGzHeader(UInt32 byteCount, const void* buffer)
{
// Ripped from gzio.cpp
#define HEAD_CRC 0x02
#define EXTRA_FIELD 0x04
#define ORIG_NAME 0x08
#define COMMENT 0x10
#define RESERVED 0xE0
static int gz_magic[2] = {0x1f, 0x8b}; // gzip magic header
#define CheckForEnd() if (s.AtEnd()) { fHeader = kNeedMoreData; return 0; }
int i;
int initCacheSize = fHeaderCache.size();
for (i = 0; i < byteCount; i++)
fHeaderCache.push_back(((UInt8*)buffer)[i]);
hsReadOnlyStream s(fHeaderCache.size(), &fHeaderCache[0]);
// Check the gzip magic header
for (i = 0; i < 2; i++)
{
UInt8 c = s.ReadByte();
if (c != gz_magic[i])
{
CheckForEnd();
fHeader = kInvalidHeader;
return 0;
}
}
int method = s.ReadByte();
int flags = s.ReadByte();
if (method != Z_DEFLATED || (flags & RESERVED) != 0)
{
CheckForEnd();
fHeader = kInvalidHeader;
return 0;
}
// Discard time, xflags and OS code:
for (i = 0; i < 6; i++)
s.ReadByte();
CheckForEnd();
if ((flags & EXTRA_FIELD) != 0)
{
// skip the extra field
UInt16 len = s.ReadSwap16();
while (len-- != 0 && s.ReadByte())
{
CheckForEnd();
}
}
int c;
// skip the original file name
if ((flags & ORIG_NAME) != 0)
{
while ((c = s.ReadByte()) != 0)
{
CheckForEnd();
}
}
// skip the .gz file comment
if ((flags & COMMENT) != 0)
{
while ((c = s.ReadByte()) != 0)
{
CheckForEnd();
}
}
// skip the header crc
if ((flags & HEAD_CRC) != 0)
{
s.ReadSwap16();
CheckForEnd();
}
CheckForEnd();
UInt32 headerSize = s.GetPosition();
UInt32 clipBuffer = headerSize - initCacheSize;
// Initialize the zlib stream
z_streamp zstream = NEW(z_stream_s);
memset(zstream, 0, sizeof(z_stream_s));
zstream->zalloc = ZlibAlloc;
zstream->zfree = ZlibFree;
zstream->opaque = nil;
zstream->avail_in = byteCount - clipBuffer;
zstream->next_in = (UInt8*)&fHeaderCache[clipBuffer];
// Gotta use inflateInit2, because there's no header for zlib to look at.
// The -15 tells it to not try and find a header
bool initOk = (inflateInit2(zstream, -15) == Z_OK);
fZStream = zstream;
fHeaderCache.clear();
if (!initOk)
{
hsAssert(0, "Zip init failed");
fHeader = kInvalidHeader;
return 0;
}
ASSERT(fZStream);
fHeader = kValidHeader;
return clipBuffer;
}
hsBool plZlibStream::AtEnd()
{
hsAssert(0, "AtEnd not supported");
return true;
}
UInt32 plZlibStream::Read(UInt32 byteCount, void* buffer)
{
hsAssert(0, "Read not supported");
return 0;
}
void plZlibStream::Skip(UInt32 deltaByteCount)
{
hsAssert(0, "Skip not supported");
}
void plZlibStream::Rewind()
{
// hack so rewind will work (someone thought it would be funny to not implement base class functions)
Close();
Open(fFilename.c_str(), fMode.c_str());
fHeader = kNeedMoreData;
fDecompressedOk = false;
}
void plZlibStream::FastFwd()
{
hsAssert(0, "FastFwd not supported");
}
UInt32 plZlibStream::GetEOF()
{
hsAssert(0, "GetEOF not supported");
return 0;
}