/*
 * Copyright (c) 2017-present, Facebook, Inc.
 * 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.
 */
/* *********************************************************
*  Turn on Large Files support (>4GB) for 32-bit Linux/Unix
***********************************************************/
#if !defined(__64BIT__) || defined(__MINGW32__)       /* No point defining Large file for 64 bit but MinGW-w64 requires it */
#  if !defined(_FILE_OFFSET_BITS)
#    define _FILE_OFFSET_BITS 64                      /* turn off_t into a 64-bit type for ftello, fseeko */
#  endif
#  if !defined(_LARGEFILE_SOURCE)                     /* obsolete macro, replaced with _FILE_OFFSET_BITS */
#    define _LARGEFILE_SOURCE 1                       /* Large File Support extension (LFS) - fseeko, ftello */
#  endif
#  if defined(_AIX) || defined(__hpux)
#    define _LARGE_FILES                              /* Large file support on 32-bits AIX and HP-UX */
#  endif
#endif
/* ************************************************************
* Avoid fseek()'s 2GiB barrier with MSVC, macOS, *BSD, MinGW
***************************************************************/
#if defined(_MSC_VER) && _MSC_VER >= 1400
#   define LONG_SEEK _fseeki64
#elif !defined(__64BIT__) && (PLATFORM_POSIX_VERSION >= 200112L) /* No point defining Large file for 64 bit */
#  define LONG_SEEK fseeko
#elif defined(__MINGW32__) && !defined(__STRICT_ANSI__) && !defined(__NO_MINGW_LFS) && defined(__MSVCRT__)
#   define LONG_SEEK fseeko64
#elif defined(_WIN32) && !defined(__DJGPP__)
#   include <windows.h>
    static int LONG_SEEK(FILE* file, __int64 offset, int origin) {
        LARGE_INTEGER off;
        DWORD method;
        off.QuadPart = offset;
        if (origin == SEEK_END)
            method = FILE_END;
        else if (origin == SEEK_CUR)
            method = FILE_CURRENT;
        else
            method = FILE_BEGIN;
        if (SetFilePointerEx((HANDLE) _get_osfhandle(_fileno(file)), off, NULL, method))
            return 0;
        else
            return -1;
    }
#else
#   define LONG_SEEK fseek
#endif
#include <stdlib.h>  /* malloc, free */
#include <stdio.h>   /* FILE* */
#include <limits.h>  /* UNIT_MAX */
#include <assert.h>
#include <xxhash.h>
#include <zstd.h>
#include <zstd_errors.h>
#include "mem.h"
#include "zstd_seekable.h"
#undef ERROR
#define ERROR(name) ((size_t)-ZSTD_error_##name)
#define CHECK_IO(f) { int const errcod = (f); if (errcod < 0) return ERROR(seekableIO); }
#undef MIN
#undef MAX
#define MIN(a, b) ((a) < (b) ? (a) : (b))
#define MAX(a, b) ((a) > (b) ? (a) : (b))
#define ZSTD_SEEKABLE_NO_OUTPUT_PROGRESS_MAX 16
/* Special-case callbacks for FILE* and in-memory modes, so that we can treat
 * them the same way as the advanced API */
static int ZSTD_seekable_read_FILE(void* opaque, void* buffer, size_t n)
{
    size_t const result = fread(buffer, 1, n, (FILE*)opaque);
    if (result != n) {
        return -1;
    }
    return 0;
}
static int ZSTD_seekable_seek_FILE(void* opaque, long long offset, int origin)
{
    int const ret = LONG_SEEK((FILE*)opaque, offset, origin);
    if (ret) return ret;
    return fflush((FILE*)opaque);
}
typedef struct {
    const void *ptr;
    size_t size;
    size_t pos;
} buffWrapper_t;
static int ZSTD_seekable_read_buff(void* opaque, void* buffer, size_t n)
{
    buffWrapper_t* const buff = (buffWrapper_t*)opaque;
    assert(buff != NULL);
    if (buff->pos + n > buff->size) return -1;
    memcpy(buffer, (const BYTE*)buff->ptr + buff->pos, n);
    buff->pos += n;
    return 0;
}
static int ZSTD_seekable_seek_buff(void* opaque, long long offset, int origin)
{
    buffWrapper_t* const buff = (buffWrapper_t*) opaque;
    unsigned long long newOffset;
    assert(buff != NULL);
    switch (origin) {
    case SEEK_SET:
        assert(offset >= 0);
        newOffset = (unsigned long long)offset;
        break;
    case SEEK_CUR:
        newOffset = (unsigned long long)((long long)buff->pos + offset);
        break;
    case SEEK_END:
        newOffset = (unsigned long long)((long long)buff->size + offset);
        break;
    default:
        assert(0);  /* not possible */
    }
    if (newOffset > buff->size) {
        return -1;
    }
    buff->pos = newOffset;
    return 0;
}
typedef struct {
    U64 cOffset;
    U64 dOffset;
    U32 checksum;
} seekEntry_t;
struct ZSTD_seekTable_s {
    seekEntry_t* entries;
    size_t tableLen;
    int checksumFlag;
};
#define SEEKABLE_BUFF_SIZE ZSTD_BLOCKSIZE_MAX
struct ZSTD_seekable_s {
    ZSTD_DStream* dstream;
    ZSTD_seekTable seekTable;
    ZSTD_seekable_customFile src;
    U64 decompressedOffset;
    U32 curFrame;
    BYTE inBuff[SEEKABLE_BUFF_SIZE]; /* need to do our own input buffering */
    BYTE outBuff[SEEKABLE_BUFF_SIZE]; /* so we can efficiently decompress the
                                         starts of chunks before we get to the
                                         desired section */
    ZSTD_inBuffer in; /* maintain continuity across ZSTD_seekable_decompress operations */
    buffWrapper_t buffWrapper; /* for `src.opaque` in in-memory mode */
    XXH64_state_t *xxhState;
};
ZSTD_seekable* ZSTD_seekable_create(void)
{
    ZSTD_seekable* const zs = (ZSTD_seekable*)malloc(sizeof(ZSTD_seekable));
    if (zs == NULL) return NULL;
    /* also initializes stage to zsds_init */
    memset(zs, 0, sizeof(*zs));
    zs->dstream = ZSTD_createDStream();
    if (zs->dstream == NULL) {
        free(zs);
        return NULL;
    }
    return zs;
}
size_t ZSTD_seekable_free(ZSTD_seekable* zs)
{
    if (zs == NULL) return 0; /* support free on null */
    ZSTD_freeDStream(zs->dstream);
    free(zs->seekTable.entries);
    free(zs);
    return 0;
}
ZSTD_seekTable* ZSTD_seekTable_create_fromSeekable(const ZSTD_seekable* zs)
{
    ZSTD_seekTable* const st = (ZSTD_seekTable*)malloc(sizeof(ZSTD_seekTable));
    if (st==NULL) return NULL;
    st->checksumFlag = zs->seekTable.checksumFlag;
    st->tableLen = zs->seekTable.tableLen;
    /* Allocate an extra entry at the end to match logic of initial allocation */
    size_t const entriesSize = sizeof(seekEntry_t) * (zs->seekTable.tableLen + 1);
    seekEntry_t* const entries = (seekEntry_t*)malloc(entriesSize);
    if (entries==NULL) {
        free(st);
        return NULL;
    }
    memcpy(entries, zs->seekTable.entries, entriesSize);
    st->entries = entries;
    return st;
}
size_t ZSTD_seekTable_free(ZSTD_seekTable* st)
{
    if (st == NULL) return 0; /* support free on null */
    free(st->entries);
    free(st);
    return 0;
}
/** ZSTD_seekable_offsetToFrameIndex() :
 *  Performs a binary search to find the last frame with a decompressed offset
 *  <= pos
 *  @return : the frame's index */
unsigned ZSTD_seekable_offsetToFrameIndex(const ZSTD_seekable* zs, unsigned long long pos)
{
    return ZSTD_seekTable_offsetToFrameIndex(&zs->seekTable, pos);
}
unsigned ZSTD_seekTable_offsetToFrameIndex(const ZSTD_seekTable* st, unsigned long long pos)
{
    U32 lo = 0;
    U32 hi = (U32)st->tableLen;
    assert(st->tableLen <= UINT_MAX);
    if (pos >= st->entries[st->tableLen].dOffset) {
        return (unsigned)st->tableLen;
    }
    while (lo + 1 < hi) {
        U32 const mid = lo + ((hi - lo) >> 1);
        if (st->entries[mid].dOffset <= pos) {
            lo = mid;
        } else {
            hi = mid;
        }
    }
    return lo;
}
unsigned ZSTD_seekable_getNumFrames(const ZSTD_seekable* zs)
{
    return ZSTD_seekTable_getNumFrames(&zs->seekTable);
}
unsigned ZSTD_seekTable_getNumFrames(const ZSTD_seekTable* st)
{
    assert(st->tableLen <= UINT_MAX);
    return (unsigned)st->tableLen;
}
unsigned long long ZSTD_seekable_getFrameCompressedOffset(const ZSTD_seekable* zs, unsigned frameIndex)
{
    return ZSTD_seekTable_getFrameCompressedOffset(&zs->seekTable, frameIndex);
}
unsigned long long ZSTD_seekTable_getFrameCompressedOffset(const ZSTD_seekTable* st, unsigned frameIndex)
{
    if (frameIndex >= st->tableLen) return ZSTD_SEEKABLE_FRAMEINDEX_TOOLARGE;
    return st->entries[frameIndex].cOffset;
}
unsigned long long ZSTD_seekable_getFrameDecompressedOffset(const ZSTD_seekable* zs, unsigned frameIndex)
{
    return ZSTD_seekTable_getFrameDecompressedOffset(&zs->seekTable, frameIndex);
}
unsigned long long ZSTD_seekTable_getFrameDecompressedOffset(const ZSTD_seekTable* st, unsigned frameIndex)
{
    if (frameIndex >= st->tableLen) return ZSTD_SEEKABLE_FRAMEINDEX_TOOLARGE;
    return st->entries[frameIndex].dOffset;
}
size_t ZSTD_seekable_getFrameCompressedSize(const ZSTD_seekable* zs, unsigned frameIndex)
{
    return ZSTD_seekTable_getFrameCompressedSize(&zs->seekTable, frameIndex);
}
size_t ZSTD_seekTable_getFrameCompressedSize(const ZSTD_seekTable* st, unsigned frameIndex)
{
    if (frameIndex >= st->tableLen) return ERROR(frameIndex_tooLarge);
    return st->entries[frameIndex + 1].cOffset -
           st->entries[frameIndex].cOffset;
}
size_t ZSTD_seekable_getFrameDecompressedSize(const ZSTD_seekable* zs, unsigned frameIndex)
{
    return ZSTD_seekTable_getFrameDecompressedSize(&zs->seekTable, frameIndex);
}
size_t ZSTD_seekTable_getFrameDecompressedSize(const ZSTD_seekTable* st, unsigned frameIndex)
{
    if (frameIndex > st->tableLen) return ERROR(frameIndex_tooLarge);
    return st->entries[frameIndex + 1].dOffset -
           st->entries[frameIndex].dOffset;
}
static size_t ZSTD_seekable_loadSeekTable(ZSTD_seekable* zs)
{
    int checksumFlag;
    ZSTD_seekable_customFile src = zs->src;
    /* read the footer, fixed size */
    CHECK_IO(src.seek(src.opaque, -(int)ZSTD_seekTableFooterSize, SEEK_END));
    CHECK_IO(src.read(src.opaque, zs->inBuff, ZSTD_seekTableFooterSize));
    if (MEM_readLE32(zs->inBuff + 5) != ZSTD_SEEKABLE_MAGICNUMBER) {
        return ERROR(prefix_unknown);
    }
    {   BYTE const sfd = zs->inBuff[4];
        checksumFlag = sfd >> 7;
        /* check reserved bits */
        if ((sfd >> 2) & 0x1f) {
            return ERROR(corruption_detected);
    }   }
    {   U32 const numFrames = MEM_readLE32(zs->inBuff);
        U32 const sizePerEntry = 8 + (checksumFlag?4:0);
        U32 const tableSize = sizePerEntry * numFrames;
        U32 const frameSize = tableSize + ZSTD_seekTableFooterSize + ZSTD_SKIPPABLEHEADERSIZE;
        U32 remaining = frameSize - ZSTD_seekTableFooterSize; /* don't need to re-read footer */
        {   U32 const toRead = MIN(remaining, SEEKABLE_BUFF_SIZE);
            CHECK_IO(src.seek(src.opaque, -(S64)frameSize, SEEK_END));
            CHECK_IO(src.read(src.opaque, zs->inBuff, toRead));
            remaining -= toRead;
        }
        if (MEM_readLE32(zs->inBuff) != (ZSTD_MAGIC_SKIPPABLE_START | 0xE)) {
            return ERROR(prefix_unknown);
        }
        if (MEM_readLE32(zs->inBuff+4) + ZSTD_SKIPPABLEHEADERSIZE != frameSize) {
            return ERROR(prefix_unknown);
        }
        {   /* Allocate an extra entry at the end so that we can do size
             * computations on the last element without special case */
            seekEntry_t* const entries = (seekEntry_t*)malloc(sizeof(seekEntry_t) * (numFrames + 1));
            U32 idx = 0;
            U32 pos = 8;
            U64 cOffset = 0;
            U64 dOffset = 0;
            if (entries == NULL) return ERROR(memory_allocation);
            /* compute cumulative positions */
            for (; idx < numFrames; idx++) {
                if (pos + sizePerEntry > SEEKABLE_BUFF_SIZE) {
                    U32 const offset = SEEKABLE_BUFF_SIZE - pos;
                    U32 const toRead = MIN(remaining, SEEKABLE_BUFF_SIZE - offset);
                    memmove(zs->inBuff, zs->inBuff + pos, offset); /* move any data we haven't read yet */
                    CHECK_IO(src.read(src.opaque, zs->inBuff+offset, toRead));
                    remaining -= toRead;
                    pos = 0;
                }
                entries[idx].cOffset = cOffset;
                entries[idx].dOffset = dOffset;
                cOffset += MEM_readLE32(zs->inBuff + pos);
                pos += 4;
                dOffset += MEM_readLE32(zs->inBuff + pos);
                pos += 4;
                if (checksumFlag) {
                    entries[idx].checksum = MEM_readLE32(zs->inBuff + pos);
                    pos += 4;
                }
            }
            entries[numFrames].cOffset = cOffset;
            entries[numFrames].dOffset = dOffset;
            zs->seekTable.entries = entries;
            zs->seekTable.tableLen = numFrames;
            zs->seekTable.checksumFlag = checksumFlag;
            return 0;
        }
    }
}
size_t ZSTD_seekable_initBuff(ZSTD_seekable* zs, const void* src, size_t srcSize)
{
    zs->buffWrapper = (buffWrapper_t){src, srcSize, 0};
    {   ZSTD_seekable_customFile srcFile = {&zs->buffWrapper,
                                            &ZSTD_seekable_read_buff,
                                            &ZSTD_seekable_seek_buff};
        return ZSTD_seekable_initAdvanced(zs, srcFile); }
}
size_t ZSTD_seekable_initFile(ZSTD_seekable* zs, FILE* src)
{
    ZSTD_seekable_customFile srcFile = {src, &ZSTD_seekable_read_FILE,
                                        &ZSTD_seekable_seek_FILE};
    return ZSTD_seekable_initAdvanced(zs, srcFile);
}
size_t ZSTD_seekable_initAdvanced(ZSTD_seekable* zs, ZSTD_seekable_customFile src)
{
    zs->src = src;
    {   const size_t seekTableInit = ZSTD_seekable_loadSeekTable(zs);
        if (ZSTD_isError(seekTableInit)) return seekTableInit; }
    zs->decompressedOffset = (U64)-1;
    zs->curFrame = (U32)-1;
    {   const size_t dstreamInit = ZSTD_initDStream(zs->dstream);
        if (ZSTD_isError(dstreamInit)) return dstreamInit; }
    return 0;
}
size_t ZSTD_seekable_decompress(ZSTD_seekable* zs, void* dst, size_t len, unsigned long long offset)
{
    unsigned long long const eos = zs->seekTable.entries[zs->seekTable.tableLen].dOffset;
    if (offset + len > eos) {
        len = eos - offset;
    }
    U32 targetFrame = ZSTD_seekable_offsetToFrameIndex(zs, offset);
    U32 noOutputProgressCount = 0;
    size_t srcBytesRead = 0;
    do {
        /* check if we can continue from a previous decompress job */
        if (targetFrame != zs->curFrame || offset != zs->decompressedOffset) {
            zs->decompressedOffset = zs->seekTable.entries[targetFrame].dOffset;
            zs->curFrame = targetFrame;
            assert(zs->seekTable.entries[targetFrame].cOffset < LLONG_MAX);
            CHECK_IO(zs->src.seek(zs->src.opaque,
                                  (long long)zs->seekTable.entries[targetFrame].cOffset,
                                  SEEK_SET));
            zs->in = (ZSTD_inBuffer){zs->inBuff, 0, 0};
            XXH64_reset(zs->xxhState, 0);
            ZSTD_DCtx_reset(zs->dstream, ZSTD_reset_session_only);
            if (zs->buffWrapper.size && srcBytesRead > zs->buffWrapper.size) {
                return ERROR(seekableIO);
            }
        }
        while (zs->decompressedOffset < offset + len) {
            size_t toRead;
            ZSTD_outBuffer outTmp;
            size_t prevOutPos;
            size_t prevInPos;
            size_t forwardProgress;
            if (zs->decompressedOffset < offset) {
                /* dummy decompressions until we get to the target offset */
                outTmp = (ZSTD_outBuffer){zs->outBuff, MIN(SEEKABLE_BUFF_SIZE, offset - zs->decompressedOffset), 0};
            } else {
                outTmp = (ZSTD_outBuffer){dst, len, zs->decompressedOffset - offset};
            }
            prevOutPos = outTmp.pos;
            prevInPos = zs->in.pos;
            toRead = ZSTD_decompressStream(zs->dstream, &outTmp, &zs->in);
            if (ZSTD_isError(toRead)) {
                return toRead;
            }
            if (zs->seekTable.checksumFlag) {
                XXH64_update(zs->xxhState, (BYTE*)outTmp.dst + prevOutPos,
                             outTmp.pos - prevOutPos);
            }
            forwardProgress = outTmp.pos - prevOutPos;
            if (forwardProgress == 0) {
                if (noOutputProgressCount++ > ZSTD_SEEKABLE_NO_OUTPUT_PROGRESS_MAX) {
                    return ERROR(seekableIO);
                }
            } else {
                noOutputProgressCount = 0;
            }
            zs->decompressedOffset += forwardProgress;
            srcBytesRead += zs->in.pos - prevInPos;
            if (toRead == 0) {
                /* frame complete */
                /* verify checksum */
                if (zs->seekTable.checksumFlag &&
                    (XXH64_digest(zs->xxhState) & 0xFFFFFFFFU) !=
                            zs->seekTable.entries[targetFrame].checksum) {
                    return ERROR(corruption_detected);
                }
                if (zs->decompressedOffset < offset + len) {
                    /* go back to the start and force a reset of the stream */
                    targetFrame = ZSTD_seekable_offsetToFrameIndex(zs, zs->decompressedOffset);
                    /* in this case it will fail later with corruption_detected, since last block does not have checksum */
                    assert(targetFrame != zs->seekTable.tableLen);
                }
                break;
            }
            /* read in more data if we're done with this buffer */
            if (zs->in.pos == zs->in.size) {
                toRead = MIN(toRead, SEEKABLE_BUFF_SIZE);
                CHECK_IO(zs->src.read(zs->src.opaque, zs->inBuff, toRead));
                zs->in.size = toRead;
                zs->in.pos = 0;
            }
        }  /* while (zs->decompressedOffset < offset + len) */
    } while (zs->decompressedOffset != offset + len);
    return len;
}
size_t ZSTD_seekable_decompressFrame(ZSTD_seekable* zs, void* dst, size_t dstSize, unsigned frameIndex)
{
    if (frameIndex >= zs->seekTable.tableLen) {
        return ERROR(frameIndex_tooLarge);
    }
    {   size_t const decompressedSize =
                zs->seekTable.entries[frameIndex + 1].dOffset -
                zs->seekTable.entries[frameIndex].dOffset;
        if (dstSize < decompressedSize) {
            return ERROR(dstSize_tooSmall);
        }
        return ZSTD_seekable_decompress(
                zs, dst, decompressedSize,
                zs->seekTable.entries[frameIndex].dOffset);
    }
}

/*
 * Copyright (c) 2017-present, Facebook, Inc.
 * 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).
 */
#include <stdio.h>
#include <zstd.h>
#include <zstd_errors.h>
#include <stdlib.h>     /* malloc, free */
#include <limits.h>     /* UINT_MAX */
#include <assert.h>
#include <xxhash.h>
#include "mem.h" /* what is this? linux-kernel/mem.h => typedefs */
#include "zstd_seekable.h"
#define CHECK_Z(f) { size_t const ret = (f); if (ret != 0) return ret; }
#undef ERROR
#define ERROR(name) ((size_t)-ZSTD_error_##name)
#undef MIN
#undef MAX
#define MIN(a, b) ((a) < (b) ? (a) : (b))
#define MAX(a, b) ((a) > (b) ? (a) : (b))
typedef struct {
    U32 cSize;
    U32 dSize;
    U32 checksum;
} framelogEntry_t;
struct ZSTD_frameLog_s {
    framelogEntry_t* entries;
    U32 size;
    U32 capacity;
    int checksumFlag;
    /* for use when streaming out the seek table */
    U32 seekTablePos;
    U32 seekTableIndex;
} framelog_t;
struct ZSTD_seekable_CStream_s {
    ZSTD_CStream* cstream;
    ZSTD_frameLog framelog;
    U32 frameCSize;
    U32 frameDSize;
    XXH64_state_t *xxhState;
    U32 maxFrameSize;
    int writingSeekTable;
};
static size_t ZSTD_seekable_frameLog_allocVec(ZSTD_frameLog* fl)
{
    /* allocate some initial space */
    size_t const FRAMELOG_STARTING_CAPACITY = 16;
    fl->entries = (framelogEntry_t*)malloc(
            sizeof(framelogEntry_t) * FRAMELOG_STARTING_CAPACITY);
    if (fl->entries == NULL) return ERROR(memory_allocation);
    fl->capacity = (U32)FRAMELOG_STARTING_CAPACITY;
    return 0;
}
static size_t ZSTD_seekable_frameLog_freeVec(ZSTD_frameLog* fl)
{
    if (fl != NULL) free(fl->entries);
    return 0;
}
ZSTD_frameLog* ZSTD_seekable_createFrameLog(int checksumFlag)
{
    ZSTD_frameLog* const fl = (ZSTD_frameLog*)malloc(sizeof(ZSTD_frameLog));
    if (fl == NULL) return NULL;
    if (ZSTD_isError(ZSTD_seekable_frameLog_allocVec(fl))) {
        free(fl);
        return NULL;
    }
    fl->checksumFlag = checksumFlag;
    fl->seekTablePos = 0;
    fl->seekTableIndex = 0;
    fl->size = 0;
    return fl;
}
size_t ZSTD_seekable_freeFrameLog(ZSTD_frameLog* fl)
{
    ZSTD_seekable_frameLog_freeVec(fl);
    free(fl);
    return 0;
}
ZSTD_seekable_CStream* ZSTD_seekable_createCStream(void)
{
    ZSTD_seekable_CStream* const zcs = (ZSTD_seekable_CStream*)malloc(sizeof(ZSTD_seekable_CStream));
    if (zcs == NULL) return NULL;
    memset(zcs, 0, sizeof(*zcs));
    zcs->cstream = ZSTD_createCStream();
    if (zcs->cstream == NULL) goto failed1;
    if (ZSTD_isError(ZSTD_seekable_frameLog_allocVec(&zcs->framelog))) goto failed2;
    return zcs;
failed2:
    ZSTD_freeCStream(zcs->cstream);
failed1:
    free(zcs);
    return NULL;
}
size_t ZSTD_seekable_freeCStream(ZSTD_seekable_CStream* zcs)
{
    if (zcs == NULL) return 0; /* support free on null */
    ZSTD_freeCStream(zcs->cstream);
    ZSTD_seekable_frameLog_freeVec(&zcs->framelog);
    free(zcs);
    return 0;
}
size_t ZSTD_seekable_initCStream(ZSTD_seekable_CStream* zcs,
                                 int compressionLevel,
                                 int checksumFlag,
                                 unsigned maxFrameSize)
{
    zcs->framelog.size = 0;
    zcs->frameCSize = 0;
    zcs->frameDSize = 0;
    /* make sure maxFrameSize has a reasonable value */
    if (maxFrameSize > ZSTD_SEEKABLE_MAX_FRAME_DECOMPRESSED_SIZE) {
        return ERROR(frameParameter_unsupported);
    }
    zcs->maxFrameSize = maxFrameSize ?
                        maxFrameSize : ZSTD_SEEKABLE_MAX_FRAME_DECOMPRESSED_SIZE;
    zcs->framelog.checksumFlag = checksumFlag;
    if (zcs->framelog.checksumFlag) {
	zcs->xxhState = XXH64_createState();
        XXH64_reset(zcs->xxhState, 0);
    }
    zcs->framelog.seekTablePos = 0;
    zcs->framelog.seekTableIndex = 0;
    zcs->writingSeekTable = 0;
    return ZSTD_initCStream(zcs->cstream, compressionLevel);
}
size_t ZSTD_seekable_logFrame(ZSTD_frameLog* fl,
                              unsigned compressedSize,
                              unsigned decompressedSize,
                              unsigned checksum)
{
    if (fl->size == ZSTD_SEEKABLE_MAXFRAMES)
        return ERROR(frameIndex_tooLarge);
    /* grow the buffer if required */
    if (fl->size == fl->capacity) {
        /* exponential size increase for constant amortized runtime */
        size_t const newCapacity = fl->capacity * 2;
        framelogEntry_t* const newEntries = (framelogEntry_t*)realloc(fl->entries,
                sizeof(framelogEntry_t) * newCapacity);
        if (newEntries == NULL) return ERROR(memory_allocation);
        fl->entries = newEntries;
        assert(newCapacity <= UINT_MAX);
        fl->capacity = (U32)newCapacity;
    }
    fl->entries[fl->size] = (framelogEntry_t){
            compressedSize, decompressedSize, checksum
    };
    fl->size++;
    return 0;
}
size_t ZSTD_seekable_endFrame(ZSTD_seekable_CStream* zcs, ZSTD_outBuffer* output)
{
    size_t const prevOutPos = output->pos;
    /* end the frame */
    size_t ret = ZSTD_endStream(zcs->cstream, output);
    zcs->frameCSize += (U32)(output->pos - prevOutPos);
    /* need to flush before doing the rest */
    if (ret) return ret;
    /* frame done */
    /* store the frame data for later */
    ret = ZSTD_seekable_logFrame(
            &zcs->framelog, zcs->frameCSize, zcs->frameDSize,
            zcs->framelog.checksumFlag
                    ? XXH64_digest(zcs->xxhState) & 0xFFFFFFFFU
                    : 0);
    if (ret) return ret;
    /* reset for the next frame */
    zcs->frameCSize = 0;
    zcs->frameDSize = 0;
    ZSTD_CCtx_reset(zcs->cstream, ZSTD_reset_session_only);
    if (zcs->framelog.checksumFlag) XXH64_reset(zcs->xxhState, 0);
    return 0;
}
size_t ZSTD_seekable_compressStream(ZSTD_seekable_CStream* zcs, ZSTD_outBuffer* output, ZSTD_inBuffer* input)
{
    const BYTE* const inBase = (const BYTE*) input->src + input->pos;
    size_t inLen = input->size - input->pos;
    inLen = MIN(inLen, (size_t)(zcs->maxFrameSize - zcs->frameDSize));
    /* if we haven't finished flushing the last frame, don't start writing a new one */
    if (inLen > 0) {
        ZSTD_inBuffer inTmp = { inBase, inLen, 0 };
        size_t const prevOutPos = output->pos;
        size_t const ret = ZSTD_compressStream(zcs->cstream, output, &inTmp);
        if (zcs->framelog.checksumFlag) {
            XXH64_update(zcs->xxhState, inBase, inTmp.pos);
        }
        zcs->frameCSize += (U32)(output->pos - prevOutPos);
        zcs->frameDSize += (U32)inTmp.pos;
        input->pos += inTmp.pos;
        if (ZSTD_isError(ret)) return ret;
    }
    if (zcs->maxFrameSize == zcs->frameDSize) {
        /* log the frame and start over */
        size_t const ret = ZSTD_seekable_endFrame(zcs, output);
        if (ZSTD_isError(ret)) return ret;
        /* get the client ready for the next frame */
        return (size_t)zcs->maxFrameSize;
    }
    return (size_t)(zcs->maxFrameSize - zcs->frameDSize);
}
static inline size_t ZSTD_seekable_seekTableSize(const ZSTD_frameLog* fl)
{
    size_t const sizePerFrame = 8 + (fl->checksumFlag?4:0);
    size_t const seekTableLen = ZSTD_SKIPPABLEHEADERSIZE +
                                sizePerFrame * fl->size +
                                ZSTD_seekTableFooterSize;
    return seekTableLen;
}
static inline size_t ZSTD_stwrite32(ZSTD_frameLog* fl,
                                    ZSTD_outBuffer* output, U32 const value,
                                    U32 const offset)
{
    if (fl->seekTablePos < offset + 4) {
        BYTE tmp[4]; /* so that we can work with buffers too small to write a whole word to */
        size_t const lenWrite =
                MIN(output->size - output->pos, offset + 4 - fl->seekTablePos);
        MEM_writeLE32(tmp, value);
        memcpy((BYTE*)output->dst + output->pos,
               tmp + (fl->seekTablePos - offset), lenWrite);
        output->pos += lenWrite;
        fl->seekTablePos += (U32)lenWrite;
        if (lenWrite < 4) return ZSTD_seekable_seekTableSize(fl) - fl->seekTablePos;
    }
    return 0;
}
size_t ZSTD_seekable_writeSeekTable(ZSTD_frameLog* fl, ZSTD_outBuffer* output)
{
    /* seekTableIndex: the current index in the table and
     * seekTableSize: the amount of the table written so far
     *
     * This function is written this way so that if it has to return early
     * because of a small buffer, it can keep going where it left off.
     */
    size_t const sizePerFrame = 8 + (fl->checksumFlag?4:0);
    size_t const seekTableLen = ZSTD_seekable_seekTableSize(fl);
    CHECK_Z(ZSTD_stwrite32(fl, output, ZSTD_MAGIC_SKIPPABLE_START | 0xE, 0));
    assert(seekTableLen <= (size_t)UINT_MAX);
    CHECK_Z(ZSTD_stwrite32(fl, output, (U32)seekTableLen - ZSTD_SKIPPABLEHEADERSIZE, 4));
    while (fl->seekTableIndex < fl->size) {
        unsigned long long const start = ZSTD_SKIPPABLEHEADERSIZE + sizePerFrame * fl->seekTableIndex;
        assert(start + 8 <= UINT_MAX);
        CHECK_Z(ZSTD_stwrite32(fl, output,
                               fl->entries[fl->seekTableIndex].cSize,
                               (U32)start + 0));
        CHECK_Z(ZSTD_stwrite32(fl, output,
                               fl->entries[fl->seekTableIndex].dSize,
                               (U32)start + 4));
        if (fl->checksumFlag) {
            CHECK_Z(ZSTD_stwrite32(
                    fl, output, fl->entries[fl->seekTableIndex].checksum,
                    (U32)start + 8));
        }
        fl->seekTableIndex++;
    }
    assert(seekTableLen <= UINT_MAX);
    CHECK_Z(ZSTD_stwrite32(fl, output, fl->size,
                           (U32)seekTableLen - ZSTD_seekTableFooterSize));
    if (output->size - output->pos < 1) return seekTableLen - fl->seekTablePos;
    if (fl->seekTablePos < seekTableLen - 4) {
        BYTE const sfd = (BYTE)((fl->checksumFlag) << 7);
        ((BYTE*)output->dst)[output->pos] = sfd;
        output->pos++;
        fl->seekTablePos++;
    }
    CHECK_Z(ZSTD_stwrite32(fl, output, ZSTD_SEEKABLE_MAGICNUMBER,
                           (U32)seekTableLen - 4));
    if (fl->seekTablePos != seekTableLen) return ERROR(GENERIC);
    return 0;
}
size_t ZSTD_seekable_endStream(ZSTD_seekable_CStream* zcs, ZSTD_outBuffer* output)
{
    if (!zcs->writingSeekTable && zcs->frameDSize) {
        const size_t endFrame = ZSTD_seekable_endFrame(zcs, output);
        if (ZSTD_isError(endFrame)) return endFrame;
        /* return an accurate size hint */
        if (endFrame) return endFrame + ZSTD_seekable_seekTableSize(&zcs->framelog);
    }
    zcs->writingSeekTable = 1;
    return ZSTD_seekable_writeSeekTable(&zcs->framelog, output);
}

#ifndef ZSTDSEEKABLE_H
#define ZSTDSEEKABLE_H
/** 
 * Required includes:
 *  - stdio.h
 *  - zstd.h
 */ 
/** zstd.h: the ZSTD_SKIPPABLEHEADERSIZE is part of the "experimental" API and
 * currently confined to static-only. But that's not how we roll, is it?
 */
#define ZSTD_SKIPPABLEHEADERSIZE	8
#define ZSTD_seekTableFooterSize 9
#define ZSTD_SEEKABLE_MAGICNUMBER 0x8F92EAB1
#define ZSTD_SEEKABLE_MAXFRAMES 0x8000000U
/* Limit the maximum size to avoid any potential issues storing the compressed size */
#define ZSTD_SEEKABLE_MAX_FRAME_DECOMPRESSED_SIZE 0x80000000U
/*-****************************************************************************
*  Seekable Format
*
*  The seekable format splits the compressed data into a series of "frames",
*  each compressed individually so that decompression of a section in the
*  middle of an archive only requires zstd to decompress at most a frame's
*  worth of extra data, instead of the entire archive.
******************************************************************************/
typedef struct ZSTD_seekable_CStream_s ZSTD_seekable_CStream;
typedef struct ZSTD_seekable_s ZSTD_seekable;
typedef struct ZSTD_seekTable_s ZSTD_seekTable;
/*-****************************************************************************
*  Seekable compression - HowTo
*  A ZSTD_seekable_CStream object is required to tracking streaming operation.
*  Use ZSTD_seekable_createCStream() and ZSTD_seekable_freeCStream() to create/
*  release resources.
*
*  Streaming objects are reusable to avoid allocation and deallocation,
*  to start a new compression operation call ZSTD_seekable_initCStream() on the
*  compressor.
*
*  Data streamed to the seekable compressor will automatically be split into
*  frames of size `maxFrameSize` (provided in ZSTD_seekable_initCStream()),
*  or if none is provided, will be cut off whenever ZSTD_seekable_endFrame() is
*  called or when the default maximum frame size (2GB) is reached.
*
*  Use ZSTD_seekable_initCStream() to initialize a ZSTD_seekable_CStream object
*  for a new compression operation.
*  `maxFrameSize` indicates the size at which to automatically start a new
*  seekable frame.  `maxFrameSize == 0` implies the default maximum size.
*  `checksumFlag` indicates whether or not the seek table should include frame
*  checksums on the uncompressed data for verification.
*  @return : a size hint for input to provide for compression, or an error code
*            checkable with ZSTD_isError()
*
*  Use ZSTD_seekable_compressStream() repetitively to consume input stream.
*  The function will automatically update both `pos` fields.
*  Note that it may not consume the entire input, in which case `pos < size`,
*  and it's up to the caller to present again remaining data.
*  @return : a size hint, preferred nb of bytes to use as input for next
*            function call or an error code, which can be tested using
*            ZSTD_isError().
*            Note 1 : it's just a hint, to help latency a little, any other
*                     value will work fine.
*
*  At any time, call ZSTD_seekable_endFrame() to end the current frame and
*  start a new one.
*
*  ZSTD_seekable_endStream() will end the current frame, and then write the seek
*  table so that decompressors can efficiently find compressed frames.
*  ZSTD_seekable_endStream() may return a number > 0 if it was unable to flush
*  all the necessary data to `output`.  In this case, it should be called again
*  until all remaining data is flushed out and 0 is returned.
******************************************************************************/
/*===== Seekable compressor management =====*/
ZSTDLIB_API ZSTD_seekable_CStream* ZSTD_seekable_createCStream(void);
ZSTDLIB_API size_t ZSTD_seekable_freeCStream(ZSTD_seekable_CStream* zcs);
/*===== Seekable compression functions =====*/
ZSTDLIB_API size_t ZSTD_seekable_initCStream(ZSTD_seekable_CStream* zcs, int compressionLevel, int checksumFlag, unsigned maxFrameSize);
ZSTDLIB_API size_t ZSTD_seekable_compressStream(ZSTD_seekable_CStream* zcs, ZSTD_outBuffer* output, ZSTD_inBuffer* input);
ZSTDLIB_API size_t ZSTD_seekable_endFrame(ZSTD_seekable_CStream* zcs, ZSTD_outBuffer* output);
ZSTDLIB_API size_t ZSTD_seekable_endStream(ZSTD_seekable_CStream* zcs, ZSTD_outBuffer* output);
/*= Raw seek table API
 *  These functions allow for the seek table to be constructed directly.
 *  This table can then be appended to a file of concatenated frames.
 *  This allows the frames to be compressed independently, even in parallel,
 *  and compiled together afterward into a seekable archive.
 *
 *  Use ZSTD_seekable_createFrameLog() to allocate and initialize a tracking
 *  structure.
 *
 *  Call ZSTD_seekable_logFrame() once for each frame in the archive.
 *  checksum is optional, and will not be used if checksumFlag was 0 when the
 *  frame log was created.  If present, it should be the least significant 32
 *  bits of the XXH64 hash of the uncompressed data.
 *
 *  Call ZSTD_seekable_writeSeekTable to serialize the data into a seek table.
 *  If the entire table was written, the return value will be 0.  Otherwise,
 *  it will be equal to the number of bytes left to write. */
typedef struct ZSTD_frameLog_s ZSTD_frameLog;
ZSTDLIB_API ZSTD_frameLog* ZSTD_seekable_createFrameLog(int checksumFlag);
ZSTDLIB_API size_t ZSTD_seekable_freeFrameLog(ZSTD_frameLog* fl);
ZSTDLIB_API size_t ZSTD_seekable_logFrame(ZSTD_frameLog* fl, unsigned compressedSize, unsigned decompressedSize, unsigned checksum);
ZSTDLIB_API size_t ZSTD_seekable_writeSeekTable(ZSTD_frameLog* fl, ZSTD_outBuffer* output);
/*-****************************************************************************
*  Seekable decompression - HowTo
*  A ZSTD_seekable object is required to tracking the seekTable.
*
*  Call ZSTD_seekable_init* to initialize a ZSTD_seekable object with the
*  the seek table provided in the input.
*  There are three modes for ZSTD_seekable_init:
*    - ZSTD_seekable_initBuff() : An in-memory API.  The data contained in
*      `src` should be the entire seekable file, including the seek table.
*      `src` should be kept alive and unmodified until the ZSTD_seekable object
*      is freed or reset.
*    - ZSTD_seekable_initFile() : A simplified file API using stdio.  fread and
*      fseek will be used to access the required data for building the seek
*      table and doing decompression operations.  `src` should not be closed
*      or modified until the ZSTD_seekable object is freed or reset.
*    - ZSTD_seekable_initAdvanced() : A general API allowing the client to
*      provide its own read and seek callbacks.
*        + ZSTD_seekable_read() : read exactly `n` bytes into `buffer`.
*                                 Premature EOF should be treated as an error.
*        + ZSTD_seekable_seek() : seek the read head to `offset` from `origin`,
*                                 where origin is either SEEK_SET (beginning of
*                                 file), or SEEK_END (end of file).
*  Both functions should return a non-negative value in case of success, and a
*  negative value in case of failure.  If implementing using this API and
*  stdio, be careful with files larger than 4GB and fseek.  All of these
*  functions return an error code checkable with ZSTD_isError().
*
*  Call ZSTD_seekable_decompress to decompress `dstSize` bytes at decompressed
*  offset `offset`.  ZSTD_seekable_decompress may have to decompress the entire
*  prefix of the frame before the desired data if it has not already processed
*  this section. If ZSTD_seekable_decompress is called multiple times for a
*  consecutive range of data, it will efficiently retain the decompressor object
*  and avoid redecompressing frame prefixes.  The return value is the number of
*  bytes decompressed, or an error code checkable with ZSTD_isError().
*
*  The seek table access functions can be used to obtain the data contained
*  in the seek table.  If frameIndex is larger than the value returned by
*  ZSTD_seekable_getNumFrames(), they will return error codes checkable with
*  ZSTD_isError().  Note that since the offset access functions return
*  unsigned long long instead of size_t, in this case they will instead return
*  the value ZSTD_SEEKABLE_FRAMEINDEX_TOOLARGE.
******************************************************************************/
/*===== Seekable decompressor management =====*/
ZSTDLIB_API ZSTD_seekable* ZSTD_seekable_create(void);
ZSTDLIB_API size_t ZSTD_seekable_free(ZSTD_seekable* zs);
/*===== Seekable decompression functions =====*/
ZSTDLIB_API size_t ZSTD_seekable_initBuff(ZSTD_seekable* zs, const void* src, size_t srcSize);
ZSTDLIB_API size_t ZSTD_seekable_initFile(ZSTD_seekable* zs, FILE* src);
ZSTDLIB_API size_t ZSTD_seekable_decompress(ZSTD_seekable* zs, void* dst, size_t dstSize, unsigned long long offset);
ZSTDLIB_API size_t ZSTD_seekable_decompressFrame(ZSTD_seekable* zs, void* dst, size_t dstSize, unsigned frameIndex);
#define ZSTD_SEEKABLE_FRAMEINDEX_TOOLARGE (0ULL-2)
/*===== Seekable seek table access functions =====*/
ZSTDLIB_API unsigned ZSTD_seekable_getNumFrames(const ZSTD_seekable* zs);
ZSTDLIB_API unsigned long long ZSTD_seekable_getFrameCompressedOffset(const ZSTD_seekable* zs, unsigned frameIndex);
ZSTDLIB_API unsigned long long ZSTD_seekable_getFrameDecompressedOffset(const ZSTD_seekable* zs, unsigned frameIndex);
ZSTDLIB_API size_t ZSTD_seekable_getFrameCompressedSize(const ZSTD_seekable* zs, unsigned frameIndex);
ZSTDLIB_API size_t ZSTD_seekable_getFrameDecompressedSize(const ZSTD_seekable* zs, unsigned frameIndex);
ZSTDLIB_API unsigned ZSTD_seekable_offsetToFrameIndex(const ZSTD_seekable* zs, unsigned long long offset);
/*-****************************************************************************
*  Direct exploitation of the seekTable
*
*  Memory constrained use cases that manage multiple archives
*  benefit from retaining multiple archive seek tables
*  without retaining a ZSTD_seekable instance for each.
*
*  Below API allow the above-mentioned use cases
*  to initialize a ZSTD_seekable, extract its (smaller) ZSTD_seekTable,
*  then throw the ZSTD_seekable away to save memory.
*
*  Standard ZSTD operations can then be used
*  to decompress frames based on seek table offsets.
******************************************************************************/
/*===== Independent seek table management =====*/
ZSTDLIB_API ZSTD_seekTable* ZSTD_seekTable_create_fromSeekable(const ZSTD_seekable* zs);
ZSTDLIB_API size_t ZSTD_seekTable_free(ZSTD_seekTable* st);
/*===== Direct seek table access functions =====*/
ZSTDLIB_API unsigned ZSTD_seekTable_getNumFrames(const ZSTD_seekTable* st);
ZSTDLIB_API unsigned long long ZSTD_seekTable_getFrameCompressedOffset(const ZSTD_seekTable* st, unsigned frameIndex);
ZSTDLIB_API unsigned long long ZSTD_seekTable_getFrameDecompressedOffset(const ZSTD_seekTable* st, unsigned frameIndex);
ZSTDLIB_API size_t ZSTD_seekTable_getFrameCompressedSize(const ZSTD_seekTable* st, unsigned frameIndex);
ZSTDLIB_API size_t ZSTD_seekTable_getFrameDecompressedSize(const ZSTD_seekTable* st, unsigned frameIndex);
ZSTDLIB_API unsigned ZSTD_seekTable_offsetToFrameIndex(const ZSTD_seekTable* st, unsigned long long offset);
/*===== Seekable advanced I/O API =====*/
typedef int(ZSTD_seekable_read)(void* opaque, void* buffer, size_t n);
typedef int(ZSTD_seekable_seek)(void* opaque, long long offset, int origin);
typedef struct {
    void* opaque;
    ZSTD_seekable_read* read;
    ZSTD_seekable_seek* seek;
} ZSTD_seekable_customFile;
ZSTDLIB_API size_t ZSTD_seekable_initAdvanced(ZSTD_seekable* zs, ZSTD_seekable_customFile src);
#endif

/*
 * Copyright (c) Facebook, Inc.
 * 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.
 */
/* This file provides common libc dependencies that zstd requires.
 * The purpose is to allow replacing this file with a custom implementation
 * to compile zstd without libc support.
 */
/* Need:
 * NULL
 * INT_MAX
 * UINT_MAX
 * ZSTD_memcpy()
 * ZSTD_memset()
 * ZSTD_memmove()
 */
#ifndef ZSTD_DEPS_COMMON
#define ZSTD_DEPS_COMMON
#include <limits.h>
#include <stddef.h>
#include <string.h>
#if defined(__GNUC__) && __GNUC__ >= 4
# define ZSTD_memcpy(d,s,l) __builtin_memcpy((d),(s),(l))
# define ZSTD_memmove(d,s,l) __builtin_memmove((d),(s),(l))
# define ZSTD_memset(p,v,l) __builtin_memset((p),(v),(l))
#else
# define ZSTD_memcpy(d,s,l) memcpy((d),(s),(l))
# define ZSTD_memmove(d,s,l) memmove((d),(s),(l))
# define ZSTD_memset(p,v,l) memset((p),(v),(l))
#endif
#endif /* ZSTD_DEPS_COMMON */
/* Need:
 * ZSTD_malloc()
 * ZSTD_free()
 * ZSTD_calloc()
 */
#ifdef ZSTD_DEPS_NEED_MALLOC
#ifndef ZSTD_DEPS_MALLOC
#define ZSTD_DEPS_MALLOC
#include <stdlib.h>
#define ZSTD_malloc(s) malloc(s)
#define ZSTD_calloc(n,s) calloc((n), (s))
#define ZSTD_free(p) free((p))
#endif /* ZSTD_DEPS_MALLOC */
#endif /* ZSTD_DEPS_NEED_MALLOC */
/*
 * Provides 64-bit math support.
 * Need:
 * U64 ZSTD_div64(U64 dividend, U32 divisor)
 */
#ifdef ZSTD_DEPS_NEED_MATH64
#ifndef ZSTD_DEPS_MATH64
#define ZSTD_DEPS_MATH64
#define ZSTD_div64(dividend, divisor) ((dividend) / (divisor))
#endif /* ZSTD_DEPS_MATH64 */
#endif /* ZSTD_DEPS_NEED_MATH64 */
/* Need:
 * assert()
 */
#ifdef ZSTD_DEPS_NEED_ASSERT
#ifndef ZSTD_DEPS_ASSERT
#define ZSTD_DEPS_ASSERT
#include <assert.h>
#endif /* ZSTD_DEPS_ASSERT */
#endif /* ZSTD_DEPS_NEED_ASSERT */
/* Need:
 * ZSTD_DEBUG_PRINT()
 */
#ifdef ZSTD_DEPS_NEED_IO
#ifndef ZSTD_DEPS_IO
#define ZSTD_DEPS_IO
#include <stdio.h>
#define ZSTD_DEBUG_PRINT(...) fprintf(stderr, __VA_ARGS__)
#endif /* ZSTD_DEPS_IO */
#endif /* ZSTD_DEPS_NEED_IO */
/* Only requested when <stdint.h> is known to be present.
 * Need:
 * intptr_t
 */
#ifdef ZSTD_DEPS_NEED_STDINT
#ifndef ZSTD_DEPS_STDINT
#define ZSTD_DEPS_STDINT
#include <stdint.h>
#endif /* ZSTD_DEPS_STDINT */
#endif /* ZSTD_DEPS_NEED_STDINT */

/*
 * Copyright (c) Facebook, Inc.
 * 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.
 */
#ifndef ZSTD_PORTABILITY_MACROS_H
#define ZSTD_PORTABILITY_MACROS_H
/**
 * This header file contains macro definitions to support portability.
 * This header is shared between C and ASM code, so it MUST only
 * contain macro definitions. It MUST not contain any C code.
 *
 * This header ONLY defines macros to detect platforms/feature support.
 *
 */
/* compat. with non-clang compilers */
#ifndef __has_attribute
  #define __has_attribute(x) 0
#endif
/* compat. with non-clang compilers */
#ifndef __has_builtin
#  define __has_builtin(x) 0
#endif
/* compat. with non-clang compilers */
#ifndef __has_feature
#  define __has_feature(x) 0
#endif
/* detects whether we are being compiled under msan */
#ifndef ZSTD_MEMORY_SANITIZER
#  if __has_feature(memory_sanitizer)
#    define ZSTD_MEMORY_SANITIZER 1
#  else
#    define ZSTD_MEMORY_SANITIZER 0
#  endif
#endif
/* detects whether we are being compiled under asan */
#ifndef ZSTD_ADDRESS_SANITIZER
#  if __has_feature(address_sanitizer)
#    define ZSTD_ADDRESS_SANITIZER 1
#  elif defined(__SANITIZE_ADDRESS__)
#    define ZSTD_ADDRESS_SANITIZER 1
#  else
#    define ZSTD_ADDRESS_SANITIZER 0
#  endif
#endif
/* detects whether we are being compiled under dfsan */
#ifndef ZSTD_DATAFLOW_SANITIZER
# if __has_feature(dataflow_sanitizer)
#  define ZSTD_DATAFLOW_SANITIZER 1
# else
#  define ZSTD_DATAFLOW_SANITIZER 0
# endif
#endif
/* Mark the internal assembly functions as hidden  */
#ifdef __ELF__
# define ZSTD_HIDE_ASM_FUNCTION(func) .hidden func
#else
# define ZSTD_HIDE_ASM_FUNCTION(func)
#endif
/* Enable runtime BMI2 dispatch based on the CPU.
 * Enabled for clang & gcc >=4.8 on x86 when BMI2 isn't enabled by default.
 */
#ifndef DYNAMIC_BMI2
  #if ((defined(__clang__) && __has_attribute(__target__)) \
      || (defined(__GNUC__) \
          && (__GNUC__ >= 5 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 8)))) \
      && (defined(__x86_64__) || defined(_M_X64)) \
      && !defined(__BMI2__)
  #  define DYNAMIC_BMI2 1
  #else
  #  define DYNAMIC_BMI2 0
  #endif
#endif
/**
 * Only enable assembly for GNUC compatible compilers,
 * because other platforms may not support GAS assembly syntax.
 *
 * Only enable assembly for Linux / MacOS, other platforms may
 * work, but they haven't been tested. This could likely be
 * extended to BSD systems.
 *
 * Disable assembly when MSAN is enabled, because MSAN requires
 * 100% of code to be instrumented to work.
 */
#if defined(__GNUC__)
#  if defined(__linux__) || defined(__linux) || defined(__APPLE__)
#    if ZSTD_MEMORY_SANITIZER
#      define ZSTD_ASM_SUPPORTED 0
#    elif ZSTD_DATAFLOW_SANITIZER
#      define ZSTD_ASM_SUPPORTED 0
#    else
#      define ZSTD_ASM_SUPPORTED 1
#    endif
#  else
#    define ZSTD_ASM_SUPPORTED 0
#  endif
#else
#  define ZSTD_ASM_SUPPORTED 0
#endif
/**
 * Determines whether we should enable assembly for x86-64
 * with BMI2.
 *
 * Enable if all of the following conditions hold:
 * - ASM hasn't been explicitly disabled by defining ZSTD_DISABLE_ASM
 * - Assembly is supported
 * - We are compiling for x86-64 and either:
 *   - DYNAMIC_BMI2 is enabled
 *   - BMI2 is supported at compile time
 */
#if !defined(ZSTD_DISABLE_ASM) &&                                 \
    ZSTD_ASM_SUPPORTED &&                                         \
    defined(__x86_64__) &&                                        \
    (DYNAMIC_BMI2 || defined(__BMI2__))
# define ZSTD_ENABLE_ASM_X86_64_BMI2 1
#else
# define ZSTD_ENABLE_ASM_X86_64_BMI2 0
#endif
/*
 * For x86 ELF targets, add .note.gnu.property section for Intel CET in
 * assembly sources when CET is enabled.
 */
#if defined(__ELF__) && (defined(__x86_64__) || defined(__i386__)) \
    && defined(__has_include)
# if __has_include(<cet.h>)
#  include <cet.h>
# endif
#endif
#endif /* ZSTD_PORTABILITY_MACROS_H */

/*
 * Copyright (c) Yann Collet, Facebook, Inc.
 * 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.
 */
#ifndef MEM_H_MODULE
#define MEM_H_MODULE
#if defined (__cplusplus)
extern "C" {
#endif
/*-****************************************
*  Dependencies
******************************************/
#include <stddef.h>  /* size_t, ptrdiff_t */
#include "compiler.h"  /* __has_builtin */
#include "debug.h"  /* DEBUG_STATIC_ASSERT */
#include "zstd_deps.h"  /* ZSTD_memcpy */
/*-****************************************
*  Compiler specifics
******************************************/
#if defined(_MSC_VER)   /* Visual Studio */
#   include <stdlib.h>  /* _byteswap_ulong */
#   include <intrin.h>  /* _byteswap_* */
#endif
#if defined(__GNUC__)
#  define MEM_STATIC static __inline __attribute__((unused))
#elif defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */)
#  define MEM_STATIC static inline
#elif defined(_MSC_VER)
#  define MEM_STATIC static __inline
#else
#  define MEM_STATIC static  /* this version may generate warnings for unused static functions; disable the relevant warning */
#endif
/*-**************************************************************
*  Basic Types
*****************************************************************/
#if  !defined (__VMS) && (defined (__cplusplus) || (defined (__STDC_VERSION__) && (__STDC_VERSION__ >= 199901L) /* C99 */) )
#  if defined(_AIX)
#    include <inttypes.h>
#  else
#    include <stdint.h> /* intptr_t */
#  endif
  typedef   uint8_t BYTE;
  typedef   uint8_t U8;
  typedef    int8_t S8;
  typedef  uint16_t U16;
  typedef   int16_t S16;
  typedef  uint32_t U32;
  typedef   int32_t S32;
  typedef  uint64_t U64;
  typedef   int64_t S64;
#else
# include <limits.h>
#if CHAR_BIT != 8
#  error "this implementation requires char to be exactly 8-bit type"
#endif
  typedef unsigned char      BYTE;
  typedef unsigned char      U8;
  typedef   signed char      S8;
#if USHRT_MAX != 65535
#  error "this implementation requires short to be exactly 16-bit type"
#endif
  typedef unsigned short      U16;
  typedef   signed short      S16;
#if UINT_MAX != 4294967295
#  error "this implementation requires int to be exactly 32-bit type"
#endif
  typedef unsigned int        U32;
  typedef   signed int        S32;
/* note : there are no limits defined for long long type in C90.
 * limits exist in C99, however, in such case, <stdint.h> is preferred */
  typedef unsigned long long  U64;
  typedef   signed long long  S64;
#endif
/*-**************************************************************
*  Memory I/O API
*****************************************************************/
/*=== Static platform detection ===*/
MEM_STATIC unsigned MEM_32bits(void);
MEM_STATIC unsigned MEM_64bits(void);
MEM_STATIC unsigned MEM_isLittleEndian(void);
/*=== Native unaligned read/write ===*/
MEM_STATIC U16 MEM_read16(const void* memPtr);
MEM_STATIC U32 MEM_read32(const void* memPtr);
MEM_STATIC U64 MEM_read64(const void* memPtr);
MEM_STATIC size_t MEM_readST(const void* memPtr);
MEM_STATIC void MEM_write16(void* memPtr, U16 value);
MEM_STATIC void MEM_write32(void* memPtr, U32 value);
MEM_STATIC void MEM_write64(void* memPtr, U64 value);
/*=== Little endian unaligned read/write ===*/
MEM_STATIC U16 MEM_readLE16(const void* memPtr);
MEM_STATIC U32 MEM_readLE24(const void* memPtr);
MEM_STATIC U32 MEM_readLE32(const void* memPtr);
MEM_STATIC U64 MEM_readLE64(const void* memPtr);
MEM_STATIC size_t MEM_readLEST(const void* memPtr);
MEM_STATIC void MEM_writeLE16(void* memPtr, U16 val);
MEM_STATIC void MEM_writeLE24(void* memPtr, U32 val);
MEM_STATIC void MEM_writeLE32(void* memPtr, U32 val32);
MEM_STATIC void MEM_writeLE64(void* memPtr, U64 val64);
MEM_STATIC void MEM_writeLEST(void* memPtr, size_t val);
/*=== Big endian unaligned read/write ===*/
MEM_STATIC U32 MEM_readBE32(const void* memPtr);
MEM_STATIC U64 MEM_readBE64(const void* memPtr);
MEM_STATIC size_t MEM_readBEST(const void* memPtr);
MEM_STATIC void MEM_writeBE32(void* memPtr, U32 val32);
MEM_STATIC void MEM_writeBE64(void* memPtr, U64 val64);
MEM_STATIC void MEM_writeBEST(void* memPtr, size_t val);
/*=== Byteswap ===*/
MEM_STATIC U32 MEM_swap32(U32 in);
MEM_STATIC U64 MEM_swap64(U64 in);
MEM_STATIC size_t MEM_swapST(size_t in);
/*-**************************************************************
*  Memory I/O Implementation
*****************************************************************/
/* MEM_FORCE_MEMORY_ACCESS :
 * By default, access to unaligned memory is controlled by `memcpy()`, which is safe and portable.
 * Unfortunately, on some target/compiler combinations, the generated assembly is sub-optimal.
 * The below switch allow to select different access method for improved performance.
 * Method 0 (default) : use `memcpy()`. Safe and portable.
 * Method 1 : `__packed` statement. It depends on compiler extension (i.e., not portable).
 *            This method is safe if your compiler supports it, and *generally* as fast or faster than `memcpy`.
 * Method 2 : direct access. This method is portable but violate C standard.
 *            It can generate buggy code on targets depending on alignment.
 *            In some circumstances, it's the only known way to get the most performance (i.e. GCC + ARMv6)
 * See http://fastcompression.blogspot.fr/2015/08/accessing-unaligned-memory.html for details.
 * Prefer these methods in priority order (0 > 1 > 2)
 */
#ifndef MEM_FORCE_MEMORY_ACCESS   /* can be defined externally, on command line for example */
#  if defined(__INTEL_COMPILER) || defined(__GNUC__) || defined(__ICCARM__)
#    define MEM_FORCE_MEMORY_ACCESS 1
#  endif
#endif
MEM_STATIC unsigned MEM_32bits(void) { return sizeof(size_t)==4; }
MEM_STATIC unsigned MEM_64bits(void) { return sizeof(size_t)==8; }
MEM_STATIC unsigned MEM_isLittleEndian(void)
{
#if defined(__BYTE_ORDER__) && defined(__ORDER_LITTLE_ENDIAN__) && (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
    return 1;
#elif defined(__BYTE_ORDER__) && defined(__ORDER_BIG_ENDIAN__) && (__BYTE_ORDER__ == __ORDER_BIG_ENDIAN__)
    return 0;
#elif defined(__clang__) && __LITTLE_ENDIAN__
    return 1;
#elif defined(__clang__) && __BIG_ENDIAN__
    return 0;
#elif defined(_MSC_VER) && (_M_AMD64 || _M_IX86)
    return 1;
#elif defined(__DMC__) && defined(_M_IX86)
    return 1;
#else
    const union { U32 u; BYTE c[4]; } one = { 1 };   /* don't use static : performance detrimental  */
    return one.c[0];
#endif
}
#if defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==2)
/* violates C standard, by lying on structure alignment.
Only use if no other choice to achieve best performance on target platform */
MEM_STATIC U16 MEM_read16(const void* memPtr) { return *(const U16*) memPtr; }
MEM_STATIC U32 MEM_read32(const void* memPtr) { return *(const U32*) memPtr; }
MEM_STATIC U64 MEM_read64(const void* memPtr) { return *(const U64*) memPtr; }
MEM_STATIC size_t MEM_readST(const void* memPtr) { return *(const size_t*) memPtr; }
MEM_STATIC void MEM_write16(void* memPtr, U16 value) { *(U16*)memPtr = value; }
MEM_STATIC void MEM_write32(void* memPtr, U32 value) { *(U32*)memPtr = value; }
MEM_STATIC void MEM_write64(void* memPtr, U64 value) { *(U64*)memPtr = value; }
#elif defined(MEM_FORCE_MEMORY_ACCESS) && (MEM_FORCE_MEMORY_ACCESS==1)
/* __pack instructions are safer, but compiler specific, hence potentially problematic for some compilers */
/* currently only defined for gcc and icc */
#if defined(_MSC_VER) || (defined(__INTEL_COMPILER) && defined(WIN32))
    __pragma( pack(push, 1) )
    typedef struct { U16 v; } unalign16;
    typedef struct { U32 v; } unalign32;
    typedef struct { U64 v; } unalign64;
    typedef struct { size_t v; } unalignArch;
    __pragma( pack(pop) )
#else
    typedef struct { U16 v; } __attribute__((packed)) unalign16;
    typedef struct { U32 v; } __attribute__((packed)) unalign32;
    typedef struct { U64 v; } __attribute__((packed)) unalign64;
    typedef struct { size_t v; } __attribute__((packed)) unalignArch;
#endif
MEM_STATIC U16 MEM_read16(const void* ptr) { return ((const unalign16*)ptr)->v; }
MEM_STATIC U32 MEM_read32(const void* ptr) { return ((const unalign32*)ptr)->v; }
MEM_STATIC U64 MEM_read64(const void* ptr) { return ((const unalign64*)ptr)->v; }
MEM_STATIC size_t MEM_readST(const void* ptr) { return ((const unalignArch*)ptr)->v; }
MEM_STATIC void MEM_write16(void* memPtr, U16 value) { ((unalign16*)memPtr)->v = value; }
MEM_STATIC void MEM_write32(void* memPtr, U32 value) { ((unalign32*)memPtr)->v = value; }
MEM_STATIC void MEM_write64(void* memPtr, U64 value) { ((unalign64*)memPtr)->v = value; }
#else
/* default method, safe and standard.
   can sometimes prove slower */
MEM_STATIC U16 MEM_read16(const void* memPtr)
{
    U16 val; ZSTD_memcpy(&val, memPtr, sizeof(val)); return val;
}
MEM_STATIC U32 MEM_read32(const void* memPtr)
{
    U32 val; ZSTD_memcpy(&val, memPtr, sizeof(val)); return val;
}
MEM_STATIC U64 MEM_read64(const void* memPtr)
{
    U64 val; ZSTD_memcpy(&val, memPtr, sizeof(val)); return val;
}
MEM_STATIC size_t MEM_readST(const void* memPtr)
{
    size_t val; ZSTD_memcpy(&val, memPtr, sizeof(val)); return val;
}
MEM_STATIC void MEM_write16(void* memPtr, U16 value)
{
    ZSTD_memcpy(memPtr, &value, sizeof(value));
}
MEM_STATIC void MEM_write32(void* memPtr, U32 value)
{
    ZSTD_memcpy(memPtr, &value, sizeof(value));
}
MEM_STATIC void MEM_write64(void* memPtr, U64 value)
{
    ZSTD_memcpy(memPtr, &value, sizeof(value));
}
#endif /* MEM_FORCE_MEMORY_ACCESS */
MEM_STATIC U32 MEM_swap32_fallback(U32 in)
{
    return  ((in << 24) & 0xff000000 ) |
            ((in <<  8) & 0x00ff0000 ) |
            ((in >>  8) & 0x0000ff00 ) |
            ((in >> 24) & 0x000000ff );
}
MEM_STATIC U32 MEM_swap32(U32 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 MEM_swap32_fallback(in);
#endif
}
MEM_STATIC U64 MEM_swap64_fallback(U64 in)
{
     return  ((in << 56) & 0xff00000000000000ULL) |
            ((in << 40) & 0x00ff000000000000ULL) |
            ((in << 24) & 0x0000ff0000000000ULL) |
            ((in << 8)  & 0x000000ff00000000ULL) |
            ((in >> 8)  & 0x00000000ff000000ULL) |
            ((in >> 24) & 0x0000000000ff0000ULL) |
            ((in >> 40) & 0x000000000000ff00ULL) |
            ((in >> 56) & 0x00000000000000ffULL);
}
MEM_STATIC U64 MEM_swap64(U64 in)
{
#if defined(_MSC_VER)     /* Visual Studio */
    return _byteswap_uint64(in);
#elif (defined (__GNUC__) && (__GNUC__ * 100 + __GNUC_MINOR__ >= 403)) \
  || (defined(__clang__) && __has_builtin(__builtin_bswap64))
    return __builtin_bswap64(in);
#else
    return MEM_swap64_fallback(in);
#endif
}
MEM_STATIC size_t MEM_swapST(size_t in)
{
    if (MEM_32bits())
        return (size_t)MEM_swap32((U32)in);
    else
        return (size_t)MEM_swap64((U64)in);
}
/*=== Little endian r/w ===*/
MEM_STATIC U16 MEM_readLE16(const void* memPtr)
{
    if (MEM_isLittleEndian())
        return MEM_read16(memPtr);
    else {
        const BYTE* p = (const BYTE*)memPtr;
        return (U16)(p[0] + (p[1]<<8));
    }
}
MEM_STATIC void MEM_writeLE16(void* memPtr, U16 val)
{
    if (MEM_isLittleEndian()) {
        MEM_write16(memPtr, val);
    } else {
        BYTE* p = (BYTE*)memPtr;
        p[0] = (BYTE)val;
        p[1] = (BYTE)(val>>8);
    }
}
MEM_STATIC U32 MEM_readLE24(const void* memPtr)
{
    return (U32)MEM_readLE16(memPtr) + ((U32)(((const BYTE*)memPtr)[2]) << 16);
}
MEM_STATIC void MEM_writeLE24(void* memPtr, U32 val)
{
    MEM_writeLE16(memPtr, (U16)val);
    ((BYTE*)memPtr)[2] = (BYTE)(val>>16);
}
MEM_STATIC U32 MEM_readLE32(const void* memPtr)
{
    if (MEM_isLittleEndian())
        return MEM_read32(memPtr);
    else
        return MEM_swap32(MEM_read32(memPtr));
}
MEM_STATIC void MEM_writeLE32(void* memPtr, U32 val32)
{
    if (MEM_isLittleEndian())
        MEM_write32(memPtr, val32);
    else
        MEM_write32(memPtr, MEM_swap32(val32));
}
MEM_STATIC U64 MEM_readLE64(const void* memPtr)
{
    if (MEM_isLittleEndian())
        return MEM_read64(memPtr);
    else
        return MEM_swap64(MEM_read64(memPtr));
}
MEM_STATIC void MEM_writeLE64(void* memPtr, U64 val64)
{
    if (MEM_isLittleEndian())
        MEM_write64(memPtr, val64);
    else
        MEM_write64(memPtr, MEM_swap64(val64));
}
MEM_STATIC size_t MEM_readLEST(const void* memPtr)
{
    if (MEM_32bits())
        return (size_t)MEM_readLE32(memPtr);
    else
        return (size_t)MEM_readLE64(memPtr);
}
MEM_STATIC void MEM_writeLEST(void* memPtr, size_t val)
{
    if (MEM_32bits())
        MEM_writeLE32(memPtr, (U32)val);
    else
        MEM_writeLE64(memPtr, (U64)val);
}
/*=== Big endian r/w ===*/
MEM_STATIC U32 MEM_readBE32(const void* memPtr)
{
    if (MEM_isLittleEndian())
        return MEM_swap32(MEM_read32(memPtr));
    else
        return MEM_read32(memPtr);
}
MEM_STATIC void MEM_writeBE32(void* memPtr, U32 val32)
{
    if (MEM_isLittleEndian())
        MEM_write32(memPtr, MEM_swap32(val32));
    else
        MEM_write32(memPtr, val32);
}
MEM_STATIC U64 MEM_readBE64(const void* memPtr)
{
    if (MEM_isLittleEndian())
        return MEM_swap64(MEM_read64(memPtr));
    else
        return MEM_read64(memPtr);
}
MEM_STATIC void MEM_writeBE64(void* memPtr, U64 val64)
{
    if (MEM_isLittleEndian())
        MEM_write64(memPtr, MEM_swap64(val64));
    else
        MEM_write64(memPtr, val64);
}
MEM_STATIC size_t MEM_readBEST(const void* memPtr)
{
    if (MEM_32bits())
        return (size_t)MEM_readBE32(memPtr);
    else
        return (size_t)MEM_readBE64(memPtr);
}
MEM_STATIC void MEM_writeBEST(void* memPtr, size_t val)
{
    if (MEM_32bits())
        MEM_writeBE32(memPtr, (U32)val);
    else
        MEM_writeBE64(memPtr, (U64)val);
}
/* code only tested on 32 and 64 bits systems */
MEM_STATIC void MEM_check(void) { DEBUG_STATIC_ASSERT((sizeof(size_t)==4) || (sizeof(size_t)==8)); }
#if defined (__cplusplus)
}
#endif
#endif /* MEM_H_MODULE */

/* ******************************************************************
 * debug
 * Part of FSE library
 * Copyright (c) Yann Collet, Facebook, Inc.
 *
 * You can contact the author at :
 * - Source repository : https://github.com/Cyan4973/FiniteStateEntropy
 *
 * 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.
****************************************************************** */
/*
 * The purpose of this header is to enable debug functions.
 * They regroup assert(), DEBUGLOG() and RAWLOG() for run-time,
 * and DEBUG_STATIC_ASSERT() for compile-time.
 *
 * By default, DEBUGLEVEL==0, which means run-time debug is disabled.
 *
 * Level 1 enables assert() only.
 * Starting level 2, traces can be generated and pushed to stderr.
 * The higher the level, the more verbose the traces.
 *
 * It's possible to dynamically adjust level using variable g_debug_level,
 * which is only declared if DEBUGLEVEL>=2,
 * and is a global variable, not multi-thread protected (use with care)
 */
#ifndef DEBUG_H_12987983217
#define DEBUG_H_12987983217
#if defined (__cplusplus)
extern "C" {
#endif
/* static assert is triggered at compile time, leaving no runtime artefact.
 * static assert only works with compile-time constants.
 * Also, this variant can only be used inside a function. */
#define DEBUG_STATIC_ASSERT(c) (void)sizeof(char[(c) ? 1 : -1])
/* DEBUGLEVEL is expected to be defined externally,
 * typically through compiler command line.
 * Value must be a number. */
#ifndef DEBUGLEVEL
#  define DEBUGLEVEL 0
#endif
/* recommended values for DEBUGLEVEL :
 * 0 : release mode, no debug, all run-time checks disabled
 * 1 : enables assert() only, no display
 * 2 : reserved, for currently active debug path
 * 3 : events once per object lifetime (CCtx, CDict, etc.)
 * 4 : events once per frame
 * 5 : events once per block
 * 6 : events once per sequence (verbose)
 * 7+: events at every position (*very* verbose)
 *
 * It's generally inconvenient to output traces > 5.
 * In which case, it's possible to selectively trigger high verbosity levels
 * by modifying g_debug_level.
 */
#if (DEBUGLEVEL>=1)
#  define ZSTD_DEPS_NEED_ASSERT
#  include "zstd_deps.h"
#else
#  ifndef assert   /* assert may be already defined, due to prior #include <assert.h> */
#    define assert(condition) ((void)0)   /* disable assert (default) */
#  endif
#endif
#if (DEBUGLEVEL>=2)
#  define ZSTD_DEPS_NEED_IO
#  include "zstd_deps.h"
extern int g_debuglevel; /* the variable is only declared,
                            it actually lives in debug.c,
                            and is shared by the whole process.
                            It's not thread-safe.
                            It's useful when enabling very verbose levels
                            on selective conditions (such as position in src) */
#  define RAWLOG(l, ...) {                                       \
                if (l<=g_debuglevel) {                           \
                    ZSTD_DEBUG_PRINT(__VA_ARGS__);               \
            }   }
#  define DEBUGLOG(l, ...) {                                     \
                if (l<=g_debuglevel) {                           \
                    ZSTD_DEBUG_PRINT(__FILE__ ": " __VA_ARGS__); \
                    ZSTD_DEBUG_PRINT(" \n");                     \
            }   }
#else
#  define RAWLOG(l, ...)      {}    /* disabled */
#  define DEBUGLOG(l, ...)    {}    /* disabled */
#endif
#if defined (__cplusplus)
}
#endif
#endif /* DEBUG_H_12987983217 */

/*
 * Copyright (c) Yann Collet, Facebook, Inc.
 * 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.
 */
#ifndef ZSTD_COMPILER_H
#define ZSTD_COMPILER_H
#include "portability_macros.h"
/*-*******************************************************
*  Compiler specifics
*********************************************************/
/* force inlining */
#if !defined(ZSTD_NO_INLINE)
#if (defined(__GNUC__) && !defined(__STRICT_ANSI__)) || defined(__cplusplus) || defined(__STDC_VERSION__) && __STDC_VERSION__ >= 199901L   /* C99 */
#  define INLINE_KEYWORD inline
#else
#  define INLINE_KEYWORD
#endif
#if defined(__GNUC__) || defined(__ICCARM__)
#  define FORCE_INLINE_ATTR __attribute__((always_inline))
#elif defined(_MSC_VER)
#  define FORCE_INLINE_ATTR __forceinline
#else
#  define FORCE_INLINE_ATTR
#endif
#else
#define INLINE_KEYWORD
#define FORCE_INLINE_ATTR
#endif
/**
  On MSVC qsort requires that functions passed into it use the __cdecl calling conversion(CC).
  This explicitly marks such functions as __cdecl so that the code will still compile
  if a CC other than __cdecl has been made the default.
*/
#if  defined(_MSC_VER)
#  define WIN_CDECL __cdecl
#else
#  define WIN_CDECL
#endif
/**
 * FORCE_INLINE_TEMPLATE is used to define C "templates", which take constant
 * parameters. They must be inlined for the compiler to eliminate the constant
 * branches.
 */
#define FORCE_INLINE_TEMPLATE static INLINE_KEYWORD FORCE_INLINE_ATTR
/**
 * HINT_INLINE is used to help the compiler generate better code. It is *not*
 * used for "templates", so it can be tweaked based on the compilers
 * performance.
 *
 * gcc-4.8 and gcc-4.9 have been shown to benefit from leaving off the
 * always_inline attribute.
 *
 * clang up to 5.0.0 (trunk) benefit tremendously from the always_inline
 * attribute.
 */
#if !defined(__clang__) && defined(__GNUC__) && __GNUC__ >= 4 && __GNUC_MINOR__ >= 8 && __GNUC__ < 5
#  define HINT_INLINE static INLINE_KEYWORD
#else
#  define HINT_INLINE static INLINE_KEYWORD FORCE_INLINE_ATTR
#endif
/* UNUSED_ATTR tells the compiler it is okay if the function is unused. */
#if defined(__GNUC__)
#  define UNUSED_ATTR __attribute__((unused))
#else
#  define UNUSED_ATTR
#endif
/* force no inlining */
#ifdef _MSC_VER
#  define FORCE_NOINLINE static __declspec(noinline)
#else
#  if defined(__GNUC__) || defined(__ICCARM__)
#    define FORCE_NOINLINE static __attribute__((__noinline__))
#  else
#    define FORCE_NOINLINE static
#  endif
#endif
/* target attribute */
#if defined(__GNUC__) || defined(__ICCARM__)
#  define TARGET_ATTRIBUTE(target) __attribute__((__target__(target)))
#else
#  define TARGET_ATTRIBUTE(target)
#endif
/* Target attribute for BMI2 dynamic dispatch.
 * Enable lzcnt, bmi, and bmi2.
 * We test for bmi1 & bmi2. lzcnt is included in bmi1.
 */
#define BMI2_TARGET_ATTRIBUTE TARGET_ATTRIBUTE("lzcnt,bmi,bmi2")
/* prefetch
 * can be disabled, by declaring NO_PREFETCH build macro */
#if defined(NO_PREFETCH)
#  define PREFETCH_L1(ptr)  (void)(ptr)  /* disabled */
#  define PREFETCH_L2(ptr)  (void)(ptr)  /* disabled */
#else
#  if defined(_MSC_VER) && (defined(_M_X64) || defined(_M_I86))  /* _mm_prefetch() is not defined outside of x86/x64 */
#    include <mmintrin.h>   /* https://msdn.microsoft.com/fr-fr/library/84szxsww(v=vs.90).aspx */
#    define PREFETCH_L1(ptr)  _mm_prefetch((const char*)(ptr), _MM_HINT_T0)
#    define PREFETCH_L2(ptr)  _mm_prefetch((const char*)(ptr), _MM_HINT_T1)
#  elif defined(__GNUC__) && ( (__GNUC__ >= 4) || ( (__GNUC__ == 3) && (__GNUC_MINOR__ >= 1) ) )
#    define PREFETCH_L1(ptr)  __builtin_prefetch((ptr), 0 /* rw==read */, 3 /* locality */)
#    define PREFETCH_L2(ptr)  __builtin_prefetch((ptr), 0 /* rw==read */, 2 /* locality */)
#  elif defined(__aarch64__)
#    define PREFETCH_L1(ptr)  __asm__ __volatile__("prfm pldl1keep, %0" ::"Q"(*(ptr)))
#    define PREFETCH_L2(ptr)  __asm__ __volatile__("prfm pldl2keep, %0" ::"Q"(*(ptr)))
#  else
#    define PREFETCH_L1(ptr) (void)(ptr)  /* disabled */
#    define PREFETCH_L2(ptr) (void)(ptr)  /* disabled */
#  endif
#endif  /* NO_PREFETCH */
#define CACHELINE_SIZE 64
#define PREFETCH_AREA(p, s)  {            \
    const char* const _ptr = (const char*)(p);  \
    size_t const _size = (size_t)(s);     \
    size_t _pos;                          \
    for (_pos=0; _pos<_size; _pos+=CACHELINE_SIZE) {  \
        PREFETCH_L2(_ptr + _pos);         \
    }                                     \
}
/* vectorization
 * older GCC (pre gcc-4.3 picked as the cutoff) uses a different syntax,
 * and some compilers, like Intel ICC and MCST LCC, do not support it at all. */
#if !defined(__INTEL_COMPILER) && !defined(__clang__) && defined(__GNUC__) && !defined(__LCC__)
#  if (__GNUC__ == 4 && __GNUC_MINOR__ > 3) || (__GNUC__ >= 5)
#    define DONT_VECTORIZE __attribute__((optimize("no-tree-vectorize")))
#  else
#    define DONT_VECTORIZE _Pragma("GCC optimize(\"no-tree-vectorize\")")
#  endif
#else
#  define DONT_VECTORIZE
#endif
/* Tell the compiler that a branch is likely or unlikely.
 * Only use these macros if it causes the compiler to generate better code.
 * If you can remove a LIKELY/UNLIKELY annotation without speed changes in gcc
 * and clang, please do.
 */
#if defined(__GNUC__)
#define LIKELY(x) (__builtin_expect((x), 1))
#define UNLIKELY(x) (__builtin_expect((x), 0))
#else
#define LIKELY(x) (x)
#define UNLIKELY(x) (x)
#endif
/* disable warnings */
#ifdef _MSC_VER    /* Visual Studio */
#  include <intrin.h>                    /* For Visual 2005 */
#  pragma warning(disable : 4100)        /* disable: C4100: unreferenced formal parameter */
#  pragma warning(disable : 4127)        /* disable: C4127: conditional expression is constant */
#  pragma warning(disable : 4204)        /* disable: C4204: non-constant aggregate initializer */
#  pragma warning(disable : 4214)        /* disable: C4214: non-int bitfields */
#  pragma warning(disable : 4324)        /* disable: C4324: padded structure */
#endif
/*Like DYNAMIC_BMI2 but for compile time determination of BMI2 support*/
#ifndef STATIC_BMI2
#  if defined(_MSC_VER) && (defined(_M_X64) || defined(_M_I86))
#    ifdef __AVX2__  //MSVC does not have a BMI2 specific flag, but every CPU that supports AVX2 also supports BMI2
#       define STATIC_BMI2 1
#    endif
#  elif defined(__BMI2__) && defined(__x86_64__) && defined(__GNUC__)
#    define STATIC_BMI2 1
#  endif
#endif
#ifndef STATIC_BMI2
    #define STATIC_BMI2 0
#endif
/* compile time determination of SIMD support */
#if !defined(ZSTD_NO_INTRINSICS)
#  if defined(__SSE2__) || defined(_M_AMD64) || (defined (_M_IX86) && defined(_M_IX86_FP) && (_M_IX86_FP >= 2))
#    define ZSTD_ARCH_X86_SSE2
#  endif
#  if defined(__ARM_NEON) || defined(_M_ARM64)
#    define ZSTD_ARCH_ARM_NEON
#  endif
#
#  if defined(ZSTD_ARCH_X86_SSE2)
#    include <emmintrin.h>
#  elif defined(ZSTD_ARCH_ARM_NEON)
#    include <arm_neon.h>
#  endif
#endif
/* C-language Attributes are added in C23. */
#if defined(__STDC_VERSION__) && (__STDC_VERSION__ > 201710L) && defined(__has_c_attribute)
# define ZSTD_HAS_C_ATTRIBUTE(x) __has_c_attribute(x)
#else
# define ZSTD_HAS_C_ATTRIBUTE(x) 0
#endif
/* Only use C++ attributes in C++. Some compilers report support for C++
 * attributes when compiling with C.
 */
#if defined(__cplusplus) && defined(__has_cpp_attribute)
# define ZSTD_HAS_CPP_ATTRIBUTE(x) __has_cpp_attribute(x)
#else
# define ZSTD_HAS_CPP_ATTRIBUTE(x) 0
#endif
/* Define ZSTD_FALLTHROUGH macro for annotating switch case with the 'fallthrough' attribute.
 * - C23: https://en.cppreference.com/w/c/language/attributes/fallthrough
 * - CPP17: https://en.cppreference.com/w/cpp/language/attributes/fallthrough
 * - Else: __attribute__((__fallthrough__))
 */
#ifndef ZSTD_FALLTHROUGH
# if ZSTD_HAS_C_ATTRIBUTE(fallthrough)
#  define ZSTD_FALLTHROUGH [[fallthrough]]
# elif ZSTD_HAS_CPP_ATTRIBUTE(fallthrough)
#  define ZSTD_FALLTHROUGH [[fallthrough]]
# elif __has_attribute(__fallthrough__)
/* Leading semicolon is to satisfy gcc-11 with -pedantic. Without the semicolon
 * gcc complains about: a label can only be part of a statement and a declaration is not a statement.
 */
#  define ZSTD_FALLTHROUGH ; __attribute__((__fallthrough__))
# else
#  define ZSTD_FALLTHROUGH
# endif
#endif
/*-**************************************************************
*  Alignment check
*****************************************************************/
/* this test was initially positioned in mem.h,
 * but this file is removed (or replaced) for linux kernel
 * so it's now hosted in compiler.h,
 * which remains valid for both user & kernel spaces.
 */
#ifndef ZSTD_ALIGNOF
# if defined(__GNUC__) || defined(_MSC_VER)
/* covers gcc, clang & MSVC */
/* note : this section must come first, before C11,
 * due to a limitation in the kernel source generator */
#  define ZSTD_ALIGNOF(T) __alignof(T)
# elif defined(__STDC_VERSION__) && (__STDC_VERSION__ >= 201112L)
/* C11 support */
#  include <stdalign.h>
#  define ZSTD_ALIGNOF(T) alignof(T)
# else
/* No known support for alignof() - imperfect backup */
#  define ZSTD_ALIGNOF(T) (sizeof(void*) < sizeof(T) ? sizeof(void*) : sizeof(T))
# endif
#endif /* ZSTD_ALIGNOF */
/*-**************************************************************
*  Sanitizer
*****************************************************************/
#if ZSTD_MEMORY_SANITIZER
/* Not all platforms that support msan provide sanitizers/msan_interface.h.
 * We therefore declare the functions we need ourselves, rather than trying to
 * include the header file... */
#include <stddef.h>  /* size_t */
#define ZSTD_DEPS_NEED_STDINT
#include "zstd_deps.h"  /* intptr_t */
/* Make memory region fully initialized (without changing its contents). */
void __msan_unpoison(const volatile void *a, size_t size);
/* Make memory region fully uninitialized (without changing its contents).
   This is a legacy interface that does not update origin information. Use
   __msan_allocated_memory() instead. */
void __msan_poison(const volatile void *a, size_t size);
/* Returns the offset of the first (at least partially) poisoned byte in the
   memory range, or -1 if the whole range is good. */
intptr_t __msan_test_shadow(const volatile void *x, size_t size);
#endif
#if ZSTD_ADDRESS_SANITIZER
/* Not all platforms that support asan provide sanitizers/asan_interface.h.
 * We therefore declare the functions we need ourselves, rather than trying to
 * include the header file... */
#include <stddef.h>  /* size_t */
/**
 * Marks a memory region (<c>[addr, addr+size)</c>) as unaddressable.
 *
 * This memory must be previously allocated by your program. Instrumented
 * code is forbidden from accessing addresses in this region until it is
 * unpoisoned. This function is not guaranteed to poison the entire region -
 * it could poison only a subregion of <c>[addr, addr+size)</c> due to ASan
 * alignment restrictions.
 *
 * \note This function is not thread-safe because no two threads can poison or
 * unpoison memory in the same memory region simultaneously.
 *
 * \param addr Start of memory region.
 * \param size Size of memory region. */
void __asan_poison_memory_region(void const volatile *addr, size_t size);
/**
 * Marks a memory region (<c>[addr, addr+size)</c>) as addressable.
 *
 * This memory must be previously allocated by your program. Accessing
 * addresses in this region is allowed until this region is poisoned again.
 * This function could unpoison a super-region of <c>[addr, addr+size)</c> due
 * to ASan alignment restrictions.
 *
 * \note This function is not thread-safe because no two threads can
 * poison or unpoison memory in the same memory region simultaneously.
 *
 * \param addr Start of memory region.
 * \param size Size of memory region. */
void __asan_unpoison_memory_region(void const volatile *addr, size_t size);
#endif
#endif /* ZSTD_COMPILER_H */

CC = cc
CFLAGS = -Wall -D_POSIX_C_SOURCE=200809L -std=c99
RM = rm -rf

CC ?= cc
CFLAGS ?= -Wall -D_POSIX_C_SOURCE=200809L -std=c99
PKG_CONFIG ?= pkg-config
RM ?= rm -rf
ZSTD_LIB = $(shell ${PKG_CONFIG} --libs libzstd)
XXHASH_LIB = $(shell ${PKG_CONFIG} --libs libxxhash)

OBJS += zstdseek_compress.o
OBJS += zstdseek_decompress.o

	$(CC) $(CFLAGS) -o $@ $(LDFLAGS) $(OBJS)

	$(CC) $(CFLAGS) -o $@ $(LDFLAGS) $(OBJS) $(ZSTD_LIB) $(XXHASH_LIB)