* Copyright (c) Meta Platforms, Inc. and affiliates.

/*
* Copyright (c) Meta Platforms, Inc. and affiliates.
* All rights reserved.
*
* This source code is licensed under both the BSD-style license (found in the
* LICENSE file in the root directory of this source tree) and the GPLv2 (found
* in the COPYING file in the root directory of this source tree).
* You may select, at your option, one of the above-listed licenses.
*/

/* === Tuning parameters === */
#ifndef ZWRAP_USE_ZSTD
#define ZWRAP_USE_ZSTD 0
#endif

/* === Dependencies === */
#include <stdlib.h>
#include <stdio.h> /* vsprintf */
#include <stdarg.h> /* va_list, for z_gzprintf */
#include <string.h>
#define NO_DUMMY_DECL
#define ZLIB_CONST
#include <zlib.h> /* without #define Z_PREFIX */
#include "zstd_zlibwrapper.h"
#define ZSTD_STATIC_LINKING_ONLY /* ZSTD_isFrame, ZSTD_MAGICNUMBER, ZSTD_customMem */
#include "zstd.h"

/* === Constants === */
#define Z_INFLATE_SYNC 8
#define ZLIB_HEADERSIZE 4
#define ZSTD_HEADERSIZE ZSTD_FRAMEHEADERSIZE_MIN(ZSTD_f_zstd1)
#define ZWRAP_DEFAULT_CLEVEL 3 /* Z_DEFAULT_COMPRESSION is translated to ZWRAP_DEFAULT_CLEVEL for zstd */

/* === Debug === */
#define LOG_WRAPPERC(...) /* fprintf(stderr, __VA_ARGS__) */
#define LOG_WRAPPERD(...) /* fprintf(stderr, __VA_ARGS__) */

#define FINISH_WITH_GZ_ERR(msg) { (void)msg; return Z_STREAM_ERROR; }
#define FINISH_WITH_NULL_ERR(msg) { (void)msg; return NULL; }

/* === Utility === */

#define MIN(x,y) ((x) < (y) ? (x) : (y))

static unsigned ZWRAP_isLittleEndian(void)
{
const union { unsigned u; char c[4]; } one = { 1 }; /* don't use static : performance detrimental */
return one.c[0];
}

#ifndef __has_builtin
# define __has_builtin(x) 0
#endif

static unsigned ZWRAP_swap32(unsigned in)
{
#if defined(_MSC_VER) /* Visual Studio */
return _byteswap_ulong(in);
#elif (defined (__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 403)) \
|| (defined(__clang__) && __has_builtin(__builtin_bswap32))
return __builtin_bswap32(in);
#else
return ((in << 24) & 0xff000000 ) |
((in << 8) & 0x00ff0000 ) |
((in >> 8) & 0x0000ff00 ) |
((in >> 24) & 0x000000ff );
#endif
}

static unsigned ZWRAP_readLE32(const void* ptr)
{
unsigned value;
memcpy(&value, ptr, sizeof(value));
if (ZWRAP_isLittleEndian())
return value;
else
return ZWRAP_swap32(value);
}

/* === Wrapper === */
static int g_ZWRAP_useZSTDcompression = ZWRAP_USE_ZSTD; /* 0 = don't use ZSTD */

void ZWRAP_useZSTDcompression(int turn_on) { g_ZWRAP_useZSTDcompression = turn_on; }

int ZWRAP_isUsingZSTDcompression(void) { return g_ZWRAP_useZSTDcompression; }

static ZWRAP_decompress_type g_ZWRAPdecompressionType = ZWRAP_AUTO;

void ZWRAP_setDecompressionType(ZWRAP_decompress_type type) { g_ZWRAPdecompressionType = type; }

ZWRAP_decompress_type ZWRAP_getDecompressionType(void) { return g_ZWRAPdecompressionType; }

const char * zstdVersion(void) { return ZSTD_VERSION_STRING; }

ZEXTERN const char * ZEXPORT z_zlibVersion _Z_OF((void)) { return zlibVersion(); }

static void* ZWRAP_allocFunction(void* opaque, size_t size)
{
z_streamp strm = (z_streamp) opaque;
void* address = strm->zalloc(strm->opaque, 1, (uInt)size);
/* LOG_WRAPPERC("ZWRAP alloc %p, %d \n", address, (int)size); */
return address;
}

static void ZWRAP_freeFunction(void* opaque, void* address)
{
z_streamp strm = (z_streamp) opaque;
strm->zfree(strm->opaque, address);
/* if (address) LOG_WRAPPERC("ZWRAP free %p \n", address); */
}

static void* ZWRAP_customMalloc(size_t size, ZSTD_customMem customMem)
{
if (customMem.customAlloc)
return customMem.customAlloc(customMem.opaque, size);
return malloc(size);
}

static void* ZWRAP_customCalloc(size_t size, ZSTD_customMem customMem)
{
if (customMem.customAlloc) {
/* calloc implemented as malloc+memset;
* not as efficient as calloc, but next best guess for custom malloc */
void* const ptr = customMem.customAlloc(customMem.opaque, size);
memset(ptr, 0, size);
return ptr;
}
return calloc(1, size);
}

static void ZWRAP_customFree(void* ptr, ZSTD_customMem customMem)
{
if (ptr!=NULL) {
if (customMem.customFree)
customMem.customFree(customMem.opaque, ptr);
else
free(ptr);
}
}

/* === Compression === */
typedef enum { ZWRAP_useInit, ZWRAP_useReset, ZWRAP_streamEnd } ZWRAP_state_t;

typedef struct {
ZSTD_CStream* zbc;
int compressionLevel;
int streamEnd; /* a flag to signal the end of a stream */
unsigned long long totalInBytes; /* we need it as strm->total_in can be reset by user */
ZSTD_customMem customMem;
z_stream allocFunc; /* copy of zalloc, zfree, opaque */
ZSTD_inBuffer inBuffer;
ZSTD_outBuffer outBuffer;
ZWRAP_state_t comprState;
unsigned long long pledgedSrcSize;
} ZWRAP_CCtx;

/* typedef ZWRAP_CCtx internal_state; */

static size_t ZWRAP_freeCCtx(ZWRAP_CCtx* zwc)
{
if (zwc==NULL) return 0; /* support free on NULL */
ZSTD_freeCStream(zwc->zbc);
ZWRAP_customFree(zwc, zwc->customMem);
return 0;
}

static ZWRAP_CCtx* ZWRAP_createCCtx(z_streamp strm)
{
ZWRAP_CCtx* zwc;
ZSTD_customMem customMem = { NULL, NULL, NULL };

if (strm->zalloc && strm->zfree) {
customMem.customAlloc = ZWRAP_allocFunction;
customMem.customFree = ZWRAP_freeFunction;
}
customMem.opaque = strm;

zwc = (ZWRAP_CCtx*)ZWRAP_customCalloc(sizeof(ZWRAP_CCtx), customMem);
if (zwc == NULL) return NULL;
zwc->allocFunc = *strm;
customMem.opaque = &zwc->allocFunc;
zwc->customMem = customMem;

return zwc;
}

static int ZWRAP_initializeCStream(ZWRAP_CCtx* zwc, const void* dict, size_t dictSize, unsigned long long pledgedSrcSize)
{
LOG_WRAPPERC("- ZWRAP_initializeCStream=%p\n", zwc);
if (zwc == NULL || zwc->zbc == NULL) return Z_STREAM_ERROR;

if (!pledgedSrcSize) pledgedSrcSize = zwc->pledgedSrcSize;
{ unsigned initErr = 0;
ZSTD_parameters const params = ZSTD_getParams(zwc->compressionLevel, pledgedSrcSize, dictSize);
ZSTD_CCtx_params* cctxParams = ZSTD_createCCtxParams();
if (!cctxParams) return Z_STREAM_ERROR;
LOG_WRAPPERC("pledgedSrcSize=%d windowLog=%d chainLog=%d hashLog=%d searchLog=%d minMatch=%d strategy=%d\n",
(int)pledgedSrcSize, params.cParams.windowLog, params.cParams.chainLog, params.cParams.hashLog, params.cParams.searchLog, params.cParams.minMatch, params.cParams.strategy);

initErr |= ZSTD_isError(ZSTD_CCtx_reset(zwc->zbc, ZSTD_reset_session_only));
initErr |= ZSTD_isError(ZSTD_CCtxParams_init_advanced(cctxParams, params));
initErr |= ZSTD_isError(ZSTD_CCtx_setParametersUsingCCtxParams(zwc->zbc, cctxParams));
initErr |= ZSTD_isError(ZSTD_CCtx_setPledgedSrcSize(zwc->zbc, pledgedSrcSize));
initErr |= ZSTD_isError(ZSTD_CCtx_loadDictionary(zwc->zbc, dict, dictSize));

ZSTD_freeCCtxParams(cctxParams);
if (initErr) return Z_STREAM_ERROR;
}

return Z_OK;
}

static int ZWRAPC_finishWithError(ZWRAP_CCtx* zwc, z_streamp strm, int error)
{
LOG_WRAPPERC("- ZWRAPC_finishWithError=%d\n", error);
if (zwc) ZWRAP_freeCCtx(zwc);
if (strm) strm->state = NULL;
return (error) ? error : Z_STREAM_ERROR;
}

static int ZWRAPC_finishWithErrorMsg(z_streamp strm, char* message)
{
ZWRAP_CCtx* zwc = (ZWRAP_CCtx*) strm->state;
strm->msg = message;
if (zwc == NULL) return Z_STREAM_ERROR;

return ZWRAPC_finishWithError(zwc, strm, 0);
}

int ZWRAP_setPledgedSrcSize(z_streamp strm, unsigned long long pledgedSrcSize)
{
ZWRAP_CCtx* zwc = (ZWRAP_CCtx*) strm->state;
if (zwc == NULL) return Z_STREAM_ERROR;

zwc->pledgedSrcSize = pledgedSrcSize;
zwc->comprState = ZWRAP_useInit;
return Z_OK;
}

static struct internal_state* convert_into_sis(void* ptr)
{
return (struct internal_state*) ptr;
}

ZEXTERN int ZEXPORT z_deflateInit_ _Z_OF((z_streamp strm, int level,
const char *version, int stream_size))
{
ZWRAP_CCtx* zwc;

LOG_WRAPPERC("- deflateInit level=%d\n", level);
if (!g_ZWRAP_useZSTDcompression) {
return deflateInit_((strm), (level), version, stream_size);
}

zwc = ZWRAP_createCCtx(strm);
if (zwc == NULL) return Z_MEM_ERROR;

if (level == Z_DEFAULT_COMPRESSION)
level = ZWRAP_DEFAULT_CLEVEL;

zwc->streamEnd = 0;
zwc->totalInBytes = 0;
zwc->compressionLevel = level;
strm->state = convert_into_sis(zwc); /* use state which in not used by user */
strm->total_in = 0;
strm->total_out = 0;
strm->adler = 0;
return Z_OK;
}

ZEXTERN int ZEXPORT z_deflateInit2_ _Z_OF((z_streamp strm, int level, int method,
int windowBits, int memLevel,
int strategy, const char *version,
int stream_size))
{
if (!g_ZWRAP_useZSTDcompression)
return deflateInit2_(strm, level, method, windowBits, memLevel, strategy, version, stream_size);

return z_deflateInit_ (strm, level, version, stream_size);
}

int ZWRAP_deflateReset_keepDict(z_streamp strm)
{
LOG_WRAPPERC("- ZWRAP_deflateReset_keepDict\n");
if (!g_ZWRAP_useZSTDcompression)
return deflateReset(strm);

{ ZWRAP_CCtx* zwc = (ZWRAP_CCtx*) strm->state;
if (zwc) {
zwc->streamEnd = 0;
zwc->totalInBytes = 0;
}
}

strm->total_in = 0;
strm->total_out = 0;
strm->adler = 0;
return Z_OK;
}

ZEXTERN int ZEXPORT z_deflateReset _Z_OF((z_streamp strm))
{
LOG_WRAPPERC("- deflateReset\n");
if (!g_ZWRAP_useZSTDcompression)
return deflateReset(strm);

ZWRAP_deflateReset_keepDict(strm);

{ ZWRAP_CCtx* zwc = (ZWRAP_CCtx*) strm->state;
if (zwc) zwc->comprState = ZWRAP_useInit;
}
return Z_OK;
}

ZEXTERN int ZEXPORT z_deflateSetDictionary _Z_OF((z_streamp strm,
const Bytef *dictionary,
uInt dictLength))
{
if (!g_ZWRAP_useZSTDcompression) {
LOG_WRAPPERC("- deflateSetDictionary\n");
return deflateSetDictionary(strm, dictionary, dictLength);
}

{ ZWRAP_CCtx* zwc = (ZWRAP_CCtx*) strm->state;
LOG_WRAPPERC("- deflateSetDictionary level=%d\n", (int)zwc->compressionLevel);
if (!zwc) return Z_STREAM_ERROR;
if (zwc->zbc == NULL) {
zwc->zbc = ZSTD_createCStream_advanced(zwc->customMem);
if (zwc->zbc == NULL) return ZWRAPC_finishWithError(zwc, strm, 0);
}
{ int res = ZWRAP_initializeCStream(zwc, dictionary, dictLength, ZSTD_CONTENTSIZE_UNKNOWN);
if (res != Z_OK) return ZWRAPC_finishWithError(zwc, strm, res); }
zwc->comprState = ZWRAP_useReset;
}

return Z_OK;
}

ZEXTERN int ZEXPORT z_deflate _Z_OF((z_streamp strm, int flush))
{
ZWRAP_CCtx* zwc;

if (!g_ZWRAP_useZSTDcompression) {
LOG_WRAPPERC("- deflate1 flush=%d avail_in=%d avail_out=%d total_in=%d total_out=%d\n",
(int)flush, (int)strm->avail_in, (int)strm->avail_out, (int)strm->total_in, (int)strm->total_out);
return deflate(strm, flush);
}

zwc = (ZWRAP_CCtx*) strm->state;
if (zwc == NULL) { LOG_WRAPPERC("zwc == NULL\n"); return Z_STREAM_ERROR; }

if (zwc->zbc == NULL) {
zwc->zbc = ZSTD_createCStream_advanced(zwc->customMem);
if (zwc->zbc == NULL) return ZWRAPC_finishWithError(zwc, strm, 0);
{ int const initErr = ZWRAP_initializeCStream(zwc, NULL, 0, (flush == Z_FINISH) ? strm->avail_in : ZSTD_CONTENTSIZE_UNKNOWN);
if (initErr != Z_OK) return ZWRAPC_finishWithError(zwc, strm, initErr); }
if (flush != Z_FINISH) zwc->comprState = ZWRAP_useReset;
} else {
if (zwc->totalInBytes == 0) {
if (zwc->comprState == ZWRAP_useReset) {
size_t resetErr = ZSTD_CCtx_reset(zwc->zbc, ZSTD_reset_session_only);
if (ZSTD_isError(resetErr)) {
LOG_WRAPPERC("ERROR: ZSTD_CCtx_reset errorCode=%s\n",
ZSTD_getErrorName(resetErr));
return ZWRAPC_finishWithError(zwc, strm, 0);
}
resetErr = ZSTD_CCtx_setPledgedSrcSize(zwc->zbc, (flush == Z_FINISH) ? strm->avail_in : zwc->pledgedSrcSize);
if (ZSTD_isError(resetErr)) {
LOG_WRAPPERC("ERROR: ZSTD_CCtx_setPledgedSrcSize errorCode=%s\n",
ZSTD_getErrorName(resetErr));
return ZWRAPC_finishWithError(zwc, strm, 0);
}
} else {
int const res = ZWRAP_initializeCStream(zwc, NULL, 0, (flush == Z_FINISH) ? strm->avail_in : ZSTD_CONTENTSIZE_UNKNOWN);
if (res != Z_OK) return ZWRAPC_finishWithError(zwc, strm, res);
if (flush != Z_FINISH) zwc->comprState = ZWRAP_useReset;
}
} /* (zwc->totalInBytes == 0) */
} /* ! (zwc->zbc == NULL) */

LOG_WRAPPERC("- deflate2 flush=%d avail_in=%d avail_out=%d total_in=%d total_out=%d\n", (int)flush, (int)strm->avail_in, (int)strm->avail_out, (int)strm->total_in, (int)strm->total_out);
if (strm->avail_in > 0) {
zwc->inBuffer.src = strm->next_in;
zwc->inBuffer.size = strm->avail_in;
zwc->inBuffer.pos = 0;
zwc->outBuffer.dst = strm->next_out;
zwc->outBuffer.size = strm->avail_out;
zwc->outBuffer.pos = 0;
{ size_t const cErr = ZSTD_compressStream(zwc->zbc, &zwc->outBuffer, &zwc->inBuffer);
LOG_WRAPPERC("deflate ZSTD_compressStream srcSize=%d dstCapacity=%d\n", (int)zwc->inBuffer.size, (int)zwc->outBuffer.size);
if (ZSTD_isError(cErr)) return ZWRAPC_finishWithError(zwc, strm, 0);
}
strm->next_out += zwc->outBuffer.pos;
strm->total_out += zwc->outBuffer.pos;
strm->avail_out -= zwc->outBuffer.pos;
strm->total_in += zwc->inBuffer.pos;
zwc->totalInBytes += zwc->inBuffer.pos;
strm->next_in += zwc->inBuffer.pos;
strm->avail_in -= zwc->inBuffer.pos;
}

if (flush == Z_FULL_FLUSH
#if ZLIB_VERNUM >= 0x1240
|| flush == Z_TREES
#endif
|| flush == Z_BLOCK)
return ZWRAPC_finishWithErrorMsg(strm, "Z_FULL_FLUSH, Z_BLOCK and Z_TREES are not supported!");

if (flush == Z_FINISH) {
size_t bytesLeft;
if (zwc->streamEnd) return Z_STREAM_END;
zwc->outBuffer.dst = strm->next_out;
zwc->outBuffer.size = strm->avail_out;
zwc->outBuffer.pos = 0;
bytesLeft = ZSTD_endStream(zwc->zbc, &zwc->outBuffer);
LOG_WRAPPERC("deflate ZSTD_endStream dstCapacity=%d bytesLeft=%d\n", (int)strm->avail_out, (int)bytesLeft);
if (ZSTD_isError(bytesLeft)) return ZWRAPC_finishWithError(zwc, strm, 0);
strm->next_out += zwc->outBuffer.pos;
strm->total_out += zwc->outBuffer.pos;
strm->avail_out -= zwc->outBuffer.pos;
if (bytesLeft == 0) {
zwc->streamEnd = 1;
LOG_WRAPPERC("Z_STREAM_END2 strm->total_in=%d strm->avail_out=%d strm->total_out=%d\n",
(int)strm->total_in, (int)strm->avail_out, (int)strm->total_out);
return Z_STREAM_END;
} }
else
if (flush == Z_SYNC_FLUSH || flush == Z_PARTIAL_FLUSH) {
size_t bytesLeft;
zwc->outBuffer.dst = strm->next_out;
zwc->outBuffer.size = strm->avail_out;
zwc->outBuffer.pos = 0;
bytesLeft = ZSTD_flushStream(zwc->zbc, &zwc->outBuffer);
LOG_WRAPPERC("deflate ZSTD_flushStream dstCapacity=%d bytesLeft=%d\n", (int)strm->avail_out, (int)bytesLeft);
if (ZSTD_isError(bytesLeft)) return ZWRAPC_finishWithError(zwc, strm, 0);
strm->next_out += zwc->outBuffer.pos;
strm->total_out += zwc->outBuffer.pos;
strm->avail_out -= zwc->outBuffer.pos;
}
LOG_WRAPPERC("- deflate3 flush=%d avail_in=%d avail_out=%d total_in=%d total_out=%d\n", (int)flush, (int)strm->avail_in, (int)strm->avail_out, (int)strm->total_in, (int)strm->total_out);
return Z_OK;
}

ZEXTERN int ZEXPORT z_deflateEnd _Z_OF((z_streamp strm))
{
if (!g_ZWRAP_useZSTDcompression) {
LOG_WRAPPERC("- deflateEnd\n");
return deflateEnd(strm);
}
LOG_WRAPPERC("- deflateEnd total_in=%d total_out=%d\n", (int)(strm->total_in), (int)(strm->total_out));
{ size_t errorCode;
ZWRAP_CCtx* zwc = (ZWRAP_CCtx*) strm->state;
if (zwc == NULL) return Z_OK; /* structures are already freed */
strm->state = NULL;
errorCode = ZWRAP_freeCCtx(zwc);
if (ZSTD_isError(errorCode)) return Z_STREAM_ERROR;
}
return Z_OK;
}

ZEXTERN uLong ZEXPORT z_deflateBound _Z_OF((z_streamp strm,
uLong sourceLen))
{
if (!g_ZWRAP_useZSTDcompression)
return deflateBound(strm, sourceLen);

return ZSTD_compressBound(sourceLen);
}

ZEXTERN int ZEXPORT z_deflateParams _Z_OF((z_streamp strm,
int level,
int strategy))
{
if (!g_ZWRAP_useZSTDcompression) {
LOG_WRAPPERC("- deflateParams level=%d strategy=%d\n", level, strategy);
return deflateParams(strm, level, strategy);
}

return Z_OK;
}

/* === Decompression === */

typedef enum { ZWRAP_ZLIB_STREAM, ZWRAP_ZSTD_STREAM, ZWRAP_UNKNOWN_STREAM } ZWRAP_stream_type;

typedef struct {
ZSTD_DStream* zbd;
char headerBuf[16]; /* must be >= ZSTD_frameHeaderSize_min */
int errorCount;
unsigned long long totalInBytes; /* we need it as strm->total_in can be reset by user */
ZWRAP_state_t decompState;
ZSTD_inBuffer inBuffer;
ZSTD_outBuffer outBuffer;

/* zlib params */
int stream_size;
char *version;
int windowBits;
ZSTD_customMem customMem;
z_stream allocFunc; /* just to copy zalloc, zfree, opaque */
} ZWRAP_DCtx;

static void ZWRAP_initDCtx(ZWRAP_DCtx* zwd)
{
zwd->errorCount = 0;
zwd->outBuffer.pos = 0;
zwd->outBuffer.size = 0;
}

static ZWRAP_DCtx* ZWRAP_createDCtx(z_streamp strm)
{
ZWRAP_DCtx* zwd;
ZSTD_customMem customMem = { NULL, NULL, NULL };

if (strm->zalloc && strm->zfree) {
customMem.customAlloc = ZWRAP_allocFunction;
customMem.customFree = ZWRAP_freeFunction;
}
customMem.opaque = strm;

zwd = (ZWRAP_DCtx*)ZWRAP_customCalloc(sizeof(ZWRAP_DCtx), customMem);
if (zwd == NULL) return NULL;
zwd->allocFunc = *strm;
customMem.opaque = &zwd->allocFunc;
zwd->customMem = customMem;

ZWRAP_initDCtx(zwd);
return zwd;
}

static size_t ZWRAP_freeDCtx(ZWRAP_DCtx* zwd)
{
if (zwd==NULL) return 0; /* support free on null */
ZSTD_freeDStream(zwd->zbd);
ZWRAP_customFree(zwd->version, zwd->customMem);
ZWRAP_customFree(zwd, zwd->customMem);
return 0;
}

int ZWRAP_isUsingZSTDdecompression(z_streamp strm)
{
if (strm == NULL) return 0;
return (strm->reserved == ZWRAP_ZSTD_STREAM);
}

static int ZWRAPD_finishWithError(ZWRAP_DCtx* zwd, z_streamp strm, int error)
{
LOG_WRAPPERD("- ZWRAPD_finishWithError=%d\n", error);
ZWRAP_freeDCtx(zwd);
strm->state = NULL;
return (error) ? error : Z_STREAM_ERROR;
}

static int ZWRAPD_finishWithErrorMsg(z_streamp strm, char* message)
{
ZWRAP_DCtx* const zwd = (ZWRAP_DCtx*) strm->state;
strm->msg = message;
if (zwd == NULL) return Z_STREAM_ERROR;

return ZWRAPD_finishWithError(zwd, strm, 0);
}

ZEXTERN int ZEXPORT z_inflateInit_ _Z_OF((z_streamp strm,
const char* version, int stream_size))
{
if (g_ZWRAPdecompressionType == ZWRAP_FORCE_ZLIB) {
strm->reserved = ZWRAP_ZLIB_STREAM;
return inflateInit(strm);
}

{ ZWRAP_DCtx* const zwd = ZWRAP_createDCtx(strm);
LOG_WRAPPERD("- inflateInit\n");
if (zwd == NULL) return ZWRAPD_finishWithError(zwd, strm, 0);

zwd->version = (char*)ZWRAP_customMalloc(strlen(version)+1, zwd->customMem);
if (zwd->version == NULL) return ZWRAPD_finishWithError(zwd, strm, 0);
strcpy(zwd->version, version);

zwd->stream_size = stream_size;
zwd->totalInBytes = 0;
strm->state = convert_into_sis(zwd);
strm->total_in = 0;
strm->total_out = 0;
strm->reserved = ZWRAP_UNKNOWN_STREAM;
strm->adler = 0;
}

return Z_OK;
}

ZEXTERN int ZEXPORT z_inflateInit2_ _Z_OF((z_streamp strm, int windowBits,
const char *version, int stream_size))
{
if (g_ZWRAPdecompressionType == ZWRAP_FORCE_ZLIB) {
return inflateInit2_(strm, windowBits, version, stream_size);
}

{ int const ret = z_inflateInit_ (strm, version, stream_size);
LOG_WRAPPERD("- inflateInit2 windowBits=%d\n", windowBits);
if (ret == Z_OK) {
ZWRAP_DCtx* const zwd = (ZWRAP_DCtx*)strm->state;
if (zwd == NULL) return Z_STREAM_ERROR;
zwd->windowBits = windowBits;
}
return ret;
}
}

int ZWRAP_inflateReset_keepDict(z_streamp strm)
{
LOG_WRAPPERD("- ZWRAP_inflateReset_keepDict\n");
if (g_ZWRAPdecompressionType == ZWRAP_FORCE_ZLIB || !strm->reserved)
return inflateReset(strm);

{ ZWRAP_DCtx* const zwd = (ZWRAP_DCtx*) strm->state;
if (zwd == NULL) return Z_STREAM_ERROR;
ZWRAP_initDCtx(zwd);
zwd->decompState = ZWRAP_useReset;
zwd->totalInBytes = 0;
}

strm->total_in = 0;
strm->total_out = 0;
return Z_OK;
}

ZEXTERN int ZEXPORT z_inflateReset _Z_OF((z_streamp strm))
{
LOG_WRAPPERD("- inflateReset\n");
if (g_ZWRAPdecompressionType == ZWRAP_FORCE_ZLIB || !strm->reserved)
return inflateReset(strm);

{ int const ret = ZWRAP_inflateReset_keepDict(strm);
if (ret != Z_OK) return ret; }

{ ZWRAP_DCtx* const zwd = (ZWRAP_DCtx*) strm->state;
if (zwd == NULL) return Z_STREAM_ERROR;
zwd->decompState = ZWRAP_useInit; }

return Z_OK;
}

#if ZLIB_VERNUM >= 0x1240
ZEXTERN int ZEXPORT z_inflateReset2 _Z_OF((z_streamp strm,
int windowBits))
{
if (g_ZWRAPdecompressionType == ZWRAP_FORCE_ZLIB || !strm->reserved)
return inflateReset2(strm, windowBits);

{ int const ret = z_inflateReset (strm);
if (ret == Z_OK) {
ZWRAP_DCtx* const zwd = (ZWRAP_DCtx*)strm->state;
if (zwd == NULL) return Z_STREAM_ERROR;
zwd->windowBits = windowBits;
}
return ret;
}
}
#endif

ZEXTERN int ZEXPORT z_inflateSetDictionary _Z_OF((z_streamp strm,
const Bytef *dictionary,
uInt dictLength))
{
LOG_WRAPPERD("- inflateSetDictionary\n");
if (g_ZWRAPdecompressionType == ZWRAP_FORCE_ZLIB || !strm->reserved)
return inflateSetDictionary(strm, dictionary, dictLength);

{ ZWRAP_DCtx* const zwd = (ZWRAP_DCtx*) strm->state;
if (zwd == NULL || zwd->zbd == NULL) return Z_STREAM_ERROR;
{ size_t const resetErr = ZSTD_DCtx_reset(zwd->zbd, ZSTD_reset_session_only);
if (ZSTD_isError(resetErr)) return ZWRAPD_finishWithError(zwd, strm, 0); }
{ size_t const loadErr = ZSTD_DCtx_loadDictionary(zwd->zbd, dictionary, dictLength);
if (ZSTD_isError(loadErr)) return ZWRAPD_finishWithError(zwd, strm, 0); }
zwd->decompState = ZWRAP_useReset;

if (zwd->totalInBytes == ZSTD_HEADERSIZE) {
zwd->inBuffer.src = zwd->headerBuf;
zwd->inBuffer.size = zwd->totalInBytes;
zwd->inBuffer.pos = 0;
zwd->outBuffer.dst = strm->next_out;
zwd->outBuffer.size = 0;
zwd->outBuffer.pos = 0;
{ size_t const errorCode = ZSTD_decompressStream(zwd->zbd, &zwd->outBuffer, &zwd->inBuffer);
LOG_WRAPPERD("inflateSetDictionary ZSTD_decompressStream errorCode=%d srcSize=%d dstCapacity=%d\n",
(int)errorCode, (int)zwd->inBuffer.size, (int)zwd->outBuffer.size);
if (zwd->inBuffer.pos < zwd->outBuffer.size || ZSTD_isError(errorCode)) {
LOG_WRAPPERD("ERROR: ZSTD_decompressStream %s\n",
ZSTD_getErrorName(errorCode));
return ZWRAPD_finishWithError(zwd, strm, 0);
} } } }

return Z_OK;
}

ZEXTERN int ZEXPORT z_inflate _Z_OF((z_streamp strm, int flush))
{
ZWRAP_DCtx* zwd;

if (g_ZWRAPdecompressionType == ZWRAP_FORCE_ZLIB || !strm->reserved) {
int const result = inflate(strm, flush);
LOG_WRAPPERD("- inflate2 flush=%d avail_in=%d avail_out=%d total_in=%d total_out=%d res=%d\n",
(int)flush, (int)strm->avail_in, (int)strm->avail_out, (int)strm->total_in, (int)strm->total_out, result);
return result;
}

if (strm->avail_in <= 0) return Z_OK;

zwd = (ZWRAP_DCtx*) strm->state;
LOG_WRAPPERD("- inflate1 flush=%d avail_in=%d avail_out=%d total_in=%d total_out=%d\n",
(int)flush, (int)strm->avail_in, (int)strm->avail_out, (int)strm->total_in, (int)strm->total_out);

if (zwd == NULL) return Z_STREAM_ERROR;
if (zwd->decompState == ZWRAP_streamEnd) return Z_STREAM_END;

if (zwd->totalInBytes < ZLIB_HEADERSIZE) {
if (zwd->totalInBytes == 0 && strm->avail_in >= ZLIB_HEADERSIZE) {
if (ZWRAP_readLE32(strm->next_in) != ZSTD_MAGICNUMBER) {
{ int const initErr = (zwd->windowBits) ?
inflateInit2_(strm, zwd->windowBits, zwd->version, zwd->stream_size) :
inflateInit_(strm, zwd->version, zwd->stream_size);
LOG_WRAPPERD("ZLIB inflateInit errorCode=%d\n", initErr);
if (initErr != Z_OK) return ZWRAPD_finishWithError(zwd, strm, initErr);
}

strm->reserved = ZWRAP_ZLIB_STREAM;
{ size_t const freeErr = ZWRAP_freeDCtx(zwd);
if (ZSTD_isError(freeErr)) goto error; }

{ int const result = (flush == Z_INFLATE_SYNC) ?
inflateSync(strm) :
inflate(strm, flush);
LOG_WRAPPERD("- inflate3 flush=%d avail_in=%d avail_out=%d total_in=%d total_out=%d res=%d\n",
(int)flush, (int)strm->avail_in, (int)strm->avail_out, (int)strm->total_in, (int)strm->total_out, res);
return result;
} }
} else { /* ! (zwd->totalInBytes == 0 && strm->avail_in >= ZLIB_HEADERSIZE) */
size_t const srcSize = MIN(strm->avail_in, ZLIB_HEADERSIZE - zwd->totalInBytes);
memcpy(zwd->headerBuf+zwd->totalInBytes, strm->next_in, srcSize);
strm->total_in += srcSize;
zwd->totalInBytes += srcSize;
strm->next_in += srcSize;
strm->avail_in -= srcSize;
if (zwd->totalInBytes < ZLIB_HEADERSIZE) return Z_OK;

if (ZWRAP_readLE32(zwd->headerBuf) != ZSTD_MAGICNUMBER) {
z_stream strm2;
strm2.next_in = strm->next_in;
strm2.avail_in = strm->avail_in;
strm2.next_out = strm->next_out;
strm2.avail_out = strm->avail_out;

{ int const initErr = (zwd->windowBits) ?
inflateInit2_(strm, zwd->windowBits, zwd->version, zwd->stream_size) :
inflateInit_(strm, zwd->version, zwd->stream_size);
LOG_WRAPPERD("ZLIB inflateInit errorCode=%d\n", initErr);
if (initErr != Z_OK) return ZWRAPD_finishWithError(zwd, strm, initErr);
}

/* inflate header */
strm->next_in = (unsigned char*)zwd->headerBuf;
strm->avail_in = ZLIB_HEADERSIZE;
strm->avail_out = 0;
{ int const dErr = inflate(strm, Z_NO_FLUSH);
LOG_WRAPPERD("ZLIB inflate errorCode=%d strm->avail_in=%d\n",
dErr, (int)strm->avail_in);
if (dErr != Z_OK)
return ZWRAPD_finishWithError(zwd, strm, dErr);
}
if (strm->avail_in > 0) goto error;

strm->next_in = strm2.next_in;
strm->avail_in = strm2.avail_in;
strm->next_out = strm2.next_out;
strm->avail_out = strm2.avail_out;

strm->reserved = ZWRAP_ZLIB_STREAM; /* mark as zlib stream */
{ size_t const freeErr = ZWRAP_freeDCtx(zwd);
if (ZSTD_isError(freeErr)) goto error; }

{ int const result = (flush == Z_INFLATE_SYNC) ?
inflateSync(strm) :
inflate(strm, flush);
LOG_WRAPPERD("- inflate2 flush=%d avail_in=%d avail_out=%d total_in=%d total_out=%d res=%d\n",
(int)flush, (int)strm->avail_in, (int)strm->avail_out, (int)strm->total_in, (int)strm->total_out, res);
return result;
} } } /* if ! (zwd->totalInBytes == 0 && strm->avail_in >= ZLIB_HEADERSIZE) */
} /* (zwd->totalInBytes < ZLIB_HEADERSIZE) */

strm->reserved = ZWRAP_ZSTD_STREAM; /* mark as zstd steam */

if (flush == Z_INFLATE_SYNC) { strm->msg = "inflateSync is not supported!"; goto error; }

if (!zwd->zbd) {
zwd->zbd = ZSTD_createDStream_advanced(zwd->customMem);
if (zwd->zbd == NULL) { LOG_WRAPPERD("ERROR: ZSTD_createDStream_advanced\n"); goto error; }
zwd->decompState = ZWRAP_useInit;
}

if (zwd->totalInBytes < ZSTD_HEADERSIZE) {
if (zwd->totalInBytes == 0 && strm->avail_in >= ZSTD_HEADERSIZE) {
if (zwd->decompState == ZWRAP_useInit) {
size_t const initErr = ZSTD_initDStream(zwd->zbd);
if (ZSTD_isError(initErr)) {
LOG_WRAPPERD("ERROR: ZSTD_initDStream errorCode=%s\n",
ZSTD_getErrorName(initErr));
goto error;
}
} else {
size_t const resetErr = ZSTD_DCtx_reset(zwd->zbd, ZSTD_reset_session_only);
if (ZSTD_isError(resetErr)) goto error;
}
} else {
size_t const srcSize = MIN(strm->avail_in, ZSTD_HEADERSIZE - zwd->totalInBytes);
memcpy(zwd->headerBuf+zwd->totalInBytes, strm->next_in, srcSize);
strm->total_in += srcSize;
zwd->totalInBytes += srcSize;
strm->next_in += srcSize;
strm->avail_in -= srcSize;
if (zwd->totalInBytes < ZSTD_HEADERSIZE) return Z_OK;

if (zwd->decompState == ZWRAP_useInit) {
size_t const initErr = ZSTD_initDStream(zwd->zbd);
if (ZSTD_isError(initErr)) {
LOG_WRAPPERD("ERROR: ZSTD_initDStream errorCode=%s\n",
ZSTD_getErrorName(initErr));
goto error;
}
} else {
size_t const resetErr = ZSTD_DCtx_reset(zwd->zbd, ZSTD_reset_session_only);
if (ZSTD_isError(resetErr)) goto error;
}

zwd->inBuffer.src = zwd->headerBuf;
zwd->inBuffer.size = ZSTD_HEADERSIZE;
zwd->inBuffer.pos = 0;
zwd->outBuffer.dst = strm->next_out;
zwd->outBuffer.size = 0;
zwd->outBuffer.pos = 0;
{ size_t const dErr = ZSTD_decompressStream(zwd->zbd, &zwd->outBuffer, &zwd->inBuffer);
LOG_WRAPPERD("inflate ZSTD_decompressStream1 errorCode=%d srcSize=%d dstCapacity=%d\n",
(int)dErr, (int)zwd->inBuffer.size, (int)zwd->outBuffer.size);
if (ZSTD_isError(dErr)) {
LOG_WRAPPERD("ERROR: ZSTD_decompressStream1 %s\n", ZSTD_getErrorName(dErr));
goto error;
} }
if (zwd->inBuffer.pos != zwd->inBuffer.size) goto error; /* not consumed */
}
} /* (zwd->totalInBytes < ZSTD_HEADERSIZE) */

zwd->inBuffer.src = strm->next_in;
zwd->inBuffer.size = strm->avail_in;
zwd->inBuffer.pos = 0;
zwd->outBuffer.dst = strm->next_out;
zwd->outBuffer.size = strm->avail_out;
zwd->outBuffer.pos = 0;
{ size_t const dErr = ZSTD_decompressStream(zwd->zbd, &zwd->outBuffer, &zwd->inBuffer);
LOG_WRAPPERD("inflate ZSTD_decompressStream2 errorCode=%d srcSize=%d dstCapacity=%d\n",
(int)dErr, (int)strm->avail_in, (int)strm->avail_out);
if (ZSTD_isError(dErr)) {
zwd->errorCount++;
LOG_WRAPPERD("ERROR: ZSTD_decompressStream2 %s zwd->errorCount=%d\n",
ZSTD_getErrorName(dErr), zwd->errorCount);
if (zwd->errorCount<=1) return Z_NEED_DICT; else goto error;
}
LOG_WRAPPERD("inflate inBuffer.pos=%d inBuffer.size=%d outBuffer.pos=%d outBuffer.size=%d o\n",
(int)zwd->inBuffer.pos, (int)zwd->inBuffer.size, (int)zwd->outBuffer.pos, (int)zwd->outBuffer.size);
strm->next_out += zwd->outBuffer.pos;
strm->total_out += zwd->outBuffer.pos;
strm->avail_out -= zwd->outBuffer.pos;
strm->total_in += zwd->inBuffer.pos;
zwd->totalInBytes += zwd->inBuffer.pos;
strm->next_in += zwd->inBuffer.pos;
strm->avail_in -= zwd->inBuffer.pos;
if (dErr == 0) {
LOG_WRAPPERD("inflate Z_STREAM_END1 avail_in=%d avail_out=%d total_in=%d total_out=%d\n",
(int)strm->avail_in, (int)strm->avail_out, (int)strm->total_in, (int)strm->total_out);
zwd->decompState = ZWRAP_streamEnd;
return Z_STREAM_END;
}
} /* dErr lifetime */

LOG_WRAPPERD("- inflate2 flush=%d avail_in=%d avail_out=%d total_in=%d total_out=%d res=%d\n",
(int)flush, (int)strm->avail_in, (int)strm->avail_out, (int)strm->total_in, (int)strm->total_out, Z_OK);
return Z_OK;

error:
return ZWRAPD_finishWithError(zwd, strm, 0);
}

ZEXTERN int ZEXPORT z_inflateEnd _Z_OF((z_streamp strm))
{
if (g_ZWRAPdecompressionType == ZWRAP_FORCE_ZLIB || !strm->reserved)
return inflateEnd(strm);

LOG_WRAPPERD("- inflateEnd total_in=%d total_out=%d\n",
(int)(strm->total_in), (int)(strm->total_out));
{ ZWRAP_DCtx* const zwd = (ZWRAP_DCtx*) strm->state;
if (zwd == NULL) return Z_OK; /* structures are already freed */
{ size_t const freeErr = ZWRAP_freeDCtx(zwd);
if (ZSTD_isError(freeErr)) return Z_STREAM_ERROR; }
strm->state = NULL;
}
return Z_OK;
}

ZEXTERN int ZEXPORT z_inflateSync _Z_OF((z_streamp strm))
{
if (g_ZWRAPdecompressionType == ZWRAP_FORCE_ZLIB || !strm->reserved) {
return inflateSync(strm);
}

return z_inflate(strm, Z_INFLATE_SYNC);
}

/* Advanced compression functions */
ZEXTERN int ZEXPORT z_deflateCopy _Z_OF((z_streamp dest,
z_streamp source))
{
if (!g_ZWRAP_useZSTDcompression)
return deflateCopy(dest, source);
return ZWRAPC_finishWithErrorMsg(source, "deflateCopy is not supported!");
}

ZEXTERN int ZEXPORT z_deflateTune _Z_OF((z_streamp strm,
int good_length,
int max_lazy,
int nice_length,
int max_chain))
{
if (!g_ZWRAP_useZSTDcompression)
return deflateTune(strm, good_length, max_lazy, nice_length, max_chain);
return ZWRAPC_finishWithErrorMsg(strm, "deflateTune is not supported!");
}

#if ZLIB_VERNUM >= 0x1260
ZEXTERN int ZEXPORT z_deflatePending _Z_OF((z_streamp strm,
unsigned *pending,
int *bits))
{
if (!g_ZWRAP_useZSTDcompression)
return deflatePending(strm, pending, bits);
return ZWRAPC_finishWithErrorMsg(strm, "deflatePending is not supported!");
}
#endif

ZEXTERN int ZEXPORT z_deflatePrime _Z_OF((z_streamp strm,
int bits,
int value))
{
if (!g_ZWRAP_useZSTDcompression)
return deflatePrime(strm, bits, value);
return ZWRAPC_finishWithErrorMsg(strm, "deflatePrime is not supported!");
}

ZEXTERN int ZEXPORT z_deflateSetHeader _Z_OF((z_streamp strm,
gz_headerp head))
{
if (!g_ZWRAP_useZSTDcompression)
return deflateSetHeader(strm, head);
return ZWRAPC_finishWithErrorMsg(strm, "deflateSetHeader is not supported!");
}

/* Advanced decompression functions */
#if ZLIB_VERNUM >= 0x1280
ZEXTERN int ZEXPORT z_inflateGetDictionary _Z_OF((z_streamp strm,
Bytef *dictionary,
uInt *dictLength))
{
if (g_ZWRAPdecompressionType == ZWRAP_FORCE_ZLIB || !strm->reserved)
return inflateGetDictionary(strm, dictionary, dictLength);
return ZWRAPD_finishWithErrorMsg(strm, "inflateGetDictionary is not supported!");
}
#endif

ZEXTERN int ZEXPORT z_inflateCopy _Z_OF((z_streamp dest,
z_streamp source))
{
if (g_ZWRAPdecompressionType == ZWRAP_FORCE_ZLIB || !source->reserved)
return inflateCopy(dest, source);
return ZWRAPD_finishWithErrorMsg(source, "inflateCopy is not supported!");
}

#if ZLIB_VERNUM >= 0x1240
ZEXTERN long ZEXPORT z_inflateMark _Z_OF((z_streamp strm))
{
if (g_ZWRAPdecompressionType == ZWRAP_FORCE_ZLIB || !strm->reserved)
return inflateMark(strm);
return ZWRAPD_finishWithErrorMsg(strm, "inflateMark is not supported!");
}
#endif

ZEXTERN int ZEXPORT z_inflatePrime _Z_OF((z_streamp strm,
int bits,
int value))
{
if (g_ZWRAPdecompressionType == ZWRAP_FORCE_ZLIB || !strm->reserved)
return inflatePrime(strm, bits, value);
return ZWRAPD_finishWithErrorMsg(strm, "inflatePrime is not supported!");
}

ZEXTERN int ZEXPORT z_inflateGetHeader _Z_OF((z_streamp strm,
gz_headerp head))
{
if (g_ZWRAPdecompressionType == ZWRAP_FORCE_ZLIB || !strm->reserved)
return inflateGetHeader(strm, head);
return ZWRAPD_finishWithErrorMsg(strm, "inflateGetHeader is not supported!");
}

ZEXTERN int ZEXPORT z_inflateBackInit_ _Z_OF((z_streamp strm, int windowBits,
unsigned char FAR *window,
const char *version,
int stream_size))
{
if (g_ZWRAPdecompressionType == ZWRAP_FORCE_ZLIB || !strm->reserved)
return inflateBackInit_(strm, windowBits, window, version, stream_size);
return ZWRAPD_finishWithErrorMsg(strm, "inflateBackInit is not supported!");
}

ZEXTERN int ZEXPORT z_inflateBack _Z_OF((z_streamp strm,
in_func in, void FAR *in_desc,
out_func out, void FAR *out_desc))
{
if (g_ZWRAPdecompressionType == ZWRAP_FORCE_ZLIB || !strm->reserved)
return inflateBack(strm, in, in_desc, out, out_desc);
return ZWRAPD_finishWithErrorMsg(strm, "inflateBack is not supported!");
}

ZEXTERN int ZEXPORT z_inflateBackEnd _Z_OF((z_streamp strm))
{
if (g_ZWRAPdecompressionType == ZWRAP_FORCE_ZLIB || !strm->reserved)
return inflateBackEnd(strm);
return ZWRAPD_finishWithErrorMsg(strm, "inflateBackEnd is not supported!");
}

ZEXTERN uLong ZEXPORT z_zlibCompileFlags _Z_OF((void)) { return zlibCompileFlags(); }

/* === utility functions === */
#ifndef Z_SOLO

ZEXTERN int ZEXPORT z_compress _Z_OF((Bytef *dest, uLongf *destLen,
const Bytef *source, uLong sourceLen))
{
if (!g_ZWRAP_useZSTDcompression)
return compress(dest, destLen, source, sourceLen);

{ size_t dstCapacity = *destLen;
size_t const cSize = ZSTD_compress(dest, dstCapacity,
source, sourceLen,
ZWRAP_DEFAULT_CLEVEL);
LOG_WRAPPERD("z_compress sourceLen=%d dstCapacity=%d\n",
(int)sourceLen, (int)dstCapacity);
if (ZSTD_isError(cSize)) return Z_STREAM_ERROR;
*destLen = cSize;
}
return Z_OK;
}

ZEXTERN int ZEXPORT z_compress2 _Z_OF((Bytef *dest, uLongf *destLen,
const Bytef *source, uLong sourceLen,
int level))
{
if (!g_ZWRAP_useZSTDcompression)
return compress2(dest, destLen, source, sourceLen, level);

{ size_t dstCapacity = *destLen;
size_t const cSize = ZSTD_compress(dest, dstCapacity, source, sourceLen, level);
if (ZSTD_isError(cSize)) return Z_STREAM_ERROR;
*destLen = cSize;
}
return Z_OK;
}

ZEXTERN uLong ZEXPORT z_compressBound _Z_OF((uLong sourceLen))
{
if (!g_ZWRAP_useZSTDcompression)
return compressBound(sourceLen);

return ZSTD_compressBound(sourceLen);
}

ZEXTERN int ZEXPORT z_uncompress _Z_OF((Bytef *dest, uLongf *destLen,
const Bytef *source, uLong sourceLen))
{
if (!ZSTD_isFrame(source, sourceLen))
return uncompress(dest, destLen, source, sourceLen);

{ size_t dstCapacity = *destLen;
size_t const dSize = ZSTD_decompress(dest, dstCapacity, source, sourceLen);
if (ZSTD_isError(dSize)) return Z_STREAM_ERROR;
*destLen = dSize;
}
return Z_OK;
}

#endif /* !Z_SOLO */

/* checksum functions */

ZEXTERN uLong ZEXPORT z_adler32 _Z_OF((uLong adler, const Bytef *buf, uInt len))
{
return adler32(adler, buf, len);
}

ZEXTERN uLong ZEXPORT z_crc32 _Z_OF((uLong crc, const Bytef *buf, uInt len))
{
return crc32(crc, buf, len);
}

#if ZLIB_VERNUM >= 0x12B0
ZEXTERN uLong ZEXPORT z_adler32_z _Z_OF((uLong adler, const Bytef *buf, z_size_t len))
{
return adler32_z(adler, buf, len);
}

ZEXTERN uLong ZEXPORT z_crc32_z _Z_OF((uLong crc, const Bytef *buf, z_size_t len))
{
return crc32_z(crc, buf, len);
}
#endif

#if ZLIB_VERNUM >= 0x1270
ZEXTERN const z_crc_t FAR * ZEXPORT z_get_crc_table _Z_OF((void))
{
return get_crc_table();
}
#endif

/* Error function */
ZEXTERN const char * ZEXPORT z_zError _Z_OF((int err))
{
/* Just use zlib Error function */
return zError(err);
}