path: root/src/external/zlib/gzlib.c

/* gzlib.c -- zlib functions common to reading and writing gzip files
 * Copyright (C) 2004-2017 Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

#include "gzguts.h"

#if defined(_WIN32) && !defined(__BORLANDC__) && !defined(__MINGW32__)
#  define LSEEK _lseeki64
#else
#if defined(_LARGEFILE64_SOURCE) && _LFS64_LARGEFILE-0
#  define LSEEK lseek64
#else
#  define LSEEK lseek
#endif
#endif

/* Local functions */
local void gz_reset OF((gz_statep));
local gzFile gz_open OF((const void *, int, const char *));

#if defined UNDER_CE

/* Map the Windows error number in ERROR to a locale-dependent error message
   string and return a pointer to it.  Typically, the values for ERROR come
   from GetLastError.

   The string pointed to shall not be modified by the application, but may be
   overwritten by a subsequent call to gz_strwinerror

   The gz_strwinerror function does not change the current setting of
   GetLastError. */
char ZLIB_INTERNAL *gz_strwinerror (error)
     DWORD error;
{
    static char buf[1024];

    wchar_t *msgbuf;
    DWORD lasterr = GetLastError();
    DWORD chars = FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM
        | FORMAT_MESSAGE_ALLOCATE_BUFFER,
        NULL,
        error,
        0, /* Default language */
        (LPVOID)&msgbuf,
        0,
        NULL);
    if (chars != 0) {
        /* If there is an \r\n appended, zap it.  */
        if (chars >= 2
            && msgbuf[chars - 2] == '\r' && msgbuf[chars - 1] == '\n') {
            chars -= 2;
            msgbuf[chars] = 0;
        }

        if (chars > sizeof (buf) - 1) {
            chars = sizeof (buf) - 1;
            msgbuf[chars] = 0;
        }

        wcstombs(buf, msgbuf, chars + 1);
        LocalFree(msgbuf);
    }
    else {
        sprintf(buf, "unknown win32 error (%ld)", error);
    }

    SetLastError(lasterr);
    return buf;
}

#endif /* UNDER_CE */

/* Reset gzip file state */
local void gz_reset(state)
    gz_statep state;
{
    state->x.have = 0;              /* no output data available */
    if (state->mode == GZ_READ) {   /* for reading ... */
        state->eof = 0;             /* not at end of file */
        state->past = 0;            /* have not read past end yet */
        state->how = LOOK;          /* look for gzip header */
    }
    state->seek = 0;                /* no seek request pending */
    gz_error(state, Z_OK, NULL);    /* clear error */
    state->x.pos = 0;               /* no uncompressed data yet */
    state->strm.avail_in = 0;       /* no input data yet */
}

/* Open a gzip file either by name or file descriptor. */
local gzFile gz_open(path, fd, mode)
    const void *path;
    int fd;
    const char *mode;
{
    gz_statep state;
    z_size_t len;
    int oflag;
#ifdef O_CLOEXEC
    int cloexec = 0;
#endif
#ifdef O_EXCL
    int exclusive = 0;
#endif

    /* check input */
    if (path == NULL)
        return NULL;

    /* allocate gzFile structure to return */
    state = (gz_statep)malloc(sizeof(gz_state));
    if (state == NULL)
        return NULL;
    state->size = 0;            /* no buffers allocated yet */
    state->want = GZBUFSIZE;    /* requested buffer size */
    state->msg = NULL;          /* no error message yet */

    /* interpret mode */
    state->mode = GZ_NONE;
    state->level = Z_DEFAULT_COMPRESSION;
    state->strategy = Z_DEFAULT_STRATEGY;
    state->direct = 0;
    while (*mode) {
        if (*mode >= '0' && *mode <= '9')
            state->level = *mode - '0';
        else
            switch (*mode) {
            case 'r':
                state->mode = GZ_READ;
                break;
#ifndef NO_GZCOMPRESS
            case 'w':
                state->mode = GZ_WRITE;
                break;
            case 'a':
                state->mode = GZ_APPEND;
                break;
#endif
            case '+':       /* can't read and write at the same time */
                free(state);
                return NULL;
            case 'b':       /* ignore -- will request binary anyway */
                break;
#ifdef O_CLOEXEC
            case 'e':
                cloexec = 1;
                break;
#endif
#ifdef O_EXCL
            case 'x':
                exclusive = 1;
                break;
#endif
            case 'f':
                state->strategy = Z_FILTERED;
                break;
            case 'h':
                state->strategy = Z_HUFFMAN_ONLY;
                break;
            case 'R':
                state->strategy = Z_RLE;
                break;
            case 'F':
                state->strategy = Z_FIXED;
                break;
            case 'T':
                state->direct = 1;
                break;
            default:        /* could consider as an error, but just ignore */
                ;
            }
        mode++;
    }

    /* must provide an "r", "w", or "a" */
    if (state->mode == GZ_NONE) {
        free(state);
        return NULL;
    }

    /* can't force transparent read */
    if (state->mode == GZ_READ) {
        if (state->direct) {
            free(state);
            return NULL;
        }
        state->direct = 1;      /* for empty file */
    }

    /* save the path name for error messages */
#ifdef WIDECHAR
    if (fd == -2) {
        len = wcstombs(NULL, path, 0);
        if (len == (z_size_t)-1)
            len = 0;
    }
    else
#endif
        len = strlen((const char *)path);
    state->path = (char *)malloc(len + 1);
    if (state->path == NULL) {
        free(state);
        return NULL;
    }
#ifdef WIDECHAR
    if (fd == -2)
        if (len)
            wcstombs(state->path, path, len + 1);
        else
            *(state->path) = 0;
    else
#endif
#if !defined(NO_snprintf) && !defined(NO_vsnprintf)
        (void)snprintf(state->path, len + 1, "%s", (const char *)path);
#else
        strcpy(state->path, path);
#endif

    /* compute the flags for open() */
    oflag =
#ifdef O_LARGEFILE
        O_LARGEFILE |
#endif
#ifdef O_BINARY
        O_BINARY |
#endif
#ifdef O_CLOEXEC
        (cloexec ? O_CLOEXEC : 0) |
#endif
        (state->mode == GZ_READ ?
         O_RDONLY :
         (O_WRONLY | O_CREAT |
#ifdef O_EXCL
          (exclusive ? O_EXCL : 0) |
#endif
          (state->mode