nulib2/nufxlib-0/Deflate.c

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/*
* NuFX archive manipulation library
* Copyright (C) 2000 by Andy McFadden, All Rights Reserved.
* This is free software; you can redistribute it and/or modify it under the
* terms of the GNU Library General Public License, see the file COPYING.LIB.
*
* Support for the "deflate" algorithm, via the "zlib" library.
*
* This compression format is totally unsupported on the Apple II. This
* is provided primarily for the benefit of Apple II emulators that want
2002-10-08 23:56:38 +00:00
* a better storage format for disk images than SHK+LZW or a ZIP file.
*
* This code was developed and tested with ZLIB_VERSION "1.1.3". It is
* expected to work with any version >= 1.1.3 and < 2.x. Please visit
* http://www.zlib.org/ for more information.
*/
#include "NufxLibPriv.h"
#ifdef ENABLE_DEFLATE
#include "zlib.h"
#define kNuDeflateLevel 9 /* use maximum compression */
/*
* Alloc and free functions provided to zlib.
*/
static voidpf
Nu_zalloc(voidpf opaque, uInt items, uInt size)
{
return Nu_Malloc(opaque, items * size);
}
static void
Nu_zfree(voidpf opaque, voidpf address)
{
return Nu_Free(opaque, address);
}
/*
* ===========================================================================
* Compression
* ===========================================================================
*/
/*
* Compress "srcLen" bytes from "pStraw" to "fp".
*/
NuError
Nu_CompressDeflate(NuArchive* pArchive, NuStraw* pStraw, FILE* fp,
ulong srcLen, ulong* pDstLen, ushort* pCrc)
{
NuError err = kNuErrNone;
z_stream zstream;
int zerr;
Bytef* outbuf = nil;
Assert(pArchive != nil);
Assert(pStraw != nil);
Assert(fp != nil);
Assert(srcLen > 0);
Assert(pDstLen != nil);
Assert(pCrc != nil);
err = Nu_AllocCompressionBufferIFN(pArchive);
if (err != kNuErrNone)
return err;
/* allocate a similarly-sized buffer for the output */
outbuf = Nu_Malloc(pArchive, kNuGenCompBufSize);
BailAlloc(outbuf);
/*
* Initialize the zlib stream.
*/
zstream.zalloc = Nu_zalloc;
zstream.zfree = Nu_zfree;
zstream.opaque = pArchive;
zstream.next_in = nil;
zstream.avail_in = 0;
zstream.next_out = outbuf;
zstream.avail_out = kNuGenCompBufSize;
zstream.data_type = Z_UNKNOWN;
zerr = deflateInit(&zstream, kNuDeflateLevel);
if (zerr != Z_OK) {
err = kNuErrInternal;
if (zerr == Z_VERSION_ERROR) {
Nu_ReportError(NU_BLOB, err,
"installed zlib is not compatible with linked version (%s)",
ZLIB_VERSION);
} else {
Nu_ReportError(NU_BLOB, err,
"call to deflateInit failed (zerr=%d)", zerr);
}
goto bail;
}
/*
* Loop while we have data.
*/
do {
ulong getSize;
int flush;
/* should be able to read a full buffer every time */
if (zstream.avail_in == 0 && srcLen) {
getSize = (srcLen > kNuGenCompBufSize) ? kNuGenCompBufSize : srcLen;
DBUG(("+++ reading %ld bytes\n", getSize));
err = Nu_StrawRead(pArchive, pStraw, pArchive->compBuf, getSize);
if (err != kNuErrNone) {
Nu_ReportError(NU_BLOB, err, "deflate read failed");
goto z_bail;
}
srcLen -= getSize;
*pCrc = Nu_CalcCRC16(*pCrc, pArchive->compBuf, getSize);
zstream.next_in = pArchive->compBuf;
zstream.avail_in = getSize;
}
if (srcLen == 0)
flush = Z_FINISH; /* tell zlib that we're done */
else
flush = Z_NO_FLUSH; /* more to come! */
zerr = deflate(&zstream, flush);
if (zerr != Z_OK && zerr != Z_STREAM_END) {
err = kNuErrInternal;
Nu_ReportError(NU_BLOB, err, "zlib deflate call failed (zerr=%d)",
zerr);
goto z_bail;
}
/* write when we're full or when we're done */
if (zstream.avail_out == 0 ||
(zerr == Z_STREAM_END && zstream.avail_out != kNuGenCompBufSize))
{
DBUG(("+++ writing %d bytes\n", zstream.next_out - outbuf));
err = Nu_FWrite(fp, outbuf, zstream.next_out - outbuf);
if (err != kNuErrNone) {
Nu_ReportError(NU_BLOB, err, "fwrite failed in deflate");
goto z_bail;
}
zstream.next_out = outbuf;
zstream.avail_out = kNuGenCompBufSize;
}
} while (zerr == Z_OK);
Assert(zerr == Z_STREAM_END); /* other errors should've been caught */
*pDstLen = zstream.total_out;
z_bail:
deflateEnd(&zstream); /* free up any allocated structures */
bail:
if (outbuf != nil)
free(outbuf);
return err;
}
/*
* ===========================================================================
* Expansion
* ===========================================================================
*/
/*
* Expand from "infp" to "pFunnel".
*/
NuError
Nu_ExpandDeflate(NuArchive* pArchive, const NuRecord* pRecord,
const NuThread* pThread, FILE* infp, NuFunnel* pFunnel, ushort* pCrc)
{
NuError err = kNuErrNone;
z_stream zstream;
int zerr;
ulong compRemaining;
Bytef* outbuf;
Assert(pArchive != nil);
Assert(pThread != nil);
Assert(infp != nil);
Assert(pFunnel != nil);
err = Nu_AllocCompressionBufferIFN(pArchive);
if (err != kNuErrNone)
return err;
/* allocate a similarly-sized buffer for the output */
outbuf = Nu_Malloc(pArchive, kNuGenCompBufSize);
BailAlloc(outbuf);
compRemaining = pThread->thCompThreadEOF;
/*
* Initialize the zlib stream.
*/
zstream.zalloc = Nu_zalloc;
zstream.zfree = Nu_zfree;
zstream.opaque = pArchive;
zstream.next_in = nil;
zstream.avail_in = 0;
zstream.next_out = outbuf;
zstream.avail_out = kNuGenCompBufSize;
zstream.data_type = Z_UNKNOWN;
zerr = inflateInit(&zstream);
if (zerr != Z_OK) {
err = kNuErrInternal;
if (zerr == Z_VERSION_ERROR) {
Nu_ReportError(NU_BLOB, err,
"installed zlib is not compatible with linked version (%s)",
ZLIB_VERSION);
} else {
Nu_ReportError(NU_BLOB, err,
"call to inflateInit failed (zerr=%d)", zerr);
}
goto bail;
}
/*
* Loop while we have data.
*/
do {
ulong getSize;
/* read as much as we can */
if (zstream.avail_in == 0) {
getSize = (compRemaining > kNuGenCompBufSize) ?
kNuGenCompBufSize : compRemaining;
DBUG(("+++ reading %ld bytes (%ld left)\n", getSize,
compRemaining));
err = Nu_FRead(infp, pArchive->compBuf, getSize);
if (err != kNuErrNone) {
Nu_ReportError(NU_BLOB, err, "inflate read failed");
goto z_bail;
}
compRemaining -= getSize;
zstream.next_in = pArchive->compBuf;
zstream.avail_in = getSize;
}
/* uncompress the data */
zerr = inflate(&zstream, Z_NO_FLUSH);
if (zerr != Z_OK && zerr != Z_STREAM_END) {
err = kNuErrInternal;
Nu_ReportError(NU_BLOB, err, "zlib inflate call failed (zerr=%d)",
zerr);
goto z_bail;
}
/* write every time there's anything (buffer will usually be full) */
if (zstream.avail_out != kNuGenCompBufSize) {
DBUG(("+++ writing %d bytes\n", zstream.next_out - outbuf));
err = Nu_FunnelWrite(pArchive, pFunnel, outbuf,
zstream.next_out - outbuf);
if (err != kNuErrNone) {
Nu_ReportError(NU_BLOB, err, "write failed in inflate");
goto z_bail;
}
if (pCrc != nil)
*pCrc = Nu_CalcCRC16(*pCrc, outbuf, zstream.next_out - outbuf);
zstream.next_out = outbuf;
zstream.avail_out = kNuGenCompBufSize;
}
} while (zerr == Z_OK);
Assert(zerr == Z_STREAM_END); /* other errors should've been caught */
if (zstream.total_out != pThread->actualThreadEOF) {
err = kNuErrBadData;
Nu_ReportError(NU_BLOB, err,
"size mismatch on inflated file (%ld vs %ld)",
zstream.total_out, pThread->actualThreadEOF);
goto z_bail;
}
z_bail:
inflateEnd(&zstream); /* free up any allocated structures */
bail:
if (outbuf != nil)
free(outbuf);
return err;
}
#endif /*ENABLE_DEFLATE*/