chromium/third_party/zlib/gzlib.c

/* gzlib.c -- zlib functions common to reading and writing gzip files
 * Copyright (C) 2004-2019 Mark Adler
 * For conditions of distribution and use, see copyright notice in zlib.h
 */

#include "gzguts.h"

#if defined(_WIN32) && !defined(__BORLANDC__)
#define LSEEK …
#define OPEN …
#else
#if defined(_LARGEFILE64_SOURCE) && _LFS64_LARGEFILE-0
#define LSEEK …
#define OPEN …
#else
#define LSEEK …
#define OPEN …
#endif
#endif

#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(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(gz_statep state) { … }

/* Open a gzip file either by name or file descriptor. */
local gzFile gz_open(const void *path, int fd, const char *mode) { … }

/* -- see zlib.h -- */
gzFile ZEXPORT gzopen(const char *path, const char *mode) { … }

/* -- see zlib.h -- */
gzFile ZEXPORT gzopen64(const char *path, const char *mode) { … }

/* -- see zlib.h -- */
gzFile ZEXPORT gzdopen(int fd, const char *mode) { … }

/* -- see zlib.h -- */
#ifdef WIDECHAR
gzFile ZEXPORT gzopen_w(const wchar_t *path, const char *mode) {
    return gz_open(path, -2, mode);
}
#endif

/* -- see zlib.h -- */
int ZEXPORT gzbuffer(gzFile file, unsigned size) { … }

/* -- see zlib.h -- */
int ZEXPORT gzrewind(gzFile file) { … }

/* -- see zlib.h -- */
z_off64_t ZEXPORT gzseek64(gzFile file, z_off64_t offset, int whence) { … }

/* -- see zlib.h -- */
z_off_t ZEXPORT gzseek(gzFile file, z_off_t offset, int whence) { … }

/* -- see zlib.h -- */
z_off64_t ZEXPORT gztell64(gzFile file) { … }

/* -- see zlib.h -- */
z_off_t ZEXPORT gztell(gzFile file) { … }

/* -- see zlib.h -- */
z_off64_t ZEXPORT gzoffset64(gzFile file) { … }

/* -- see zlib.h -- */
z_off_t ZEXPORT gzoffset(gzFile file) { … }

/* -- see zlib.h -- */
int ZEXPORT gzeof(gzFile file) { … }

/* -- see zlib.h -- */
const char * ZEXPORT gzerror(gzFile file, int *errnum) { … }

/* -- see zlib.h -- */
void ZEXPORT gzclearerr(gzFile file) { … }

/* Create an error message in allocated memory and set state->err and
   state->msg accordingly.  Free any previous error message already there.  Do
   not try to free or allocate space if the error is Z_MEM_ERROR (out of
   memory).  Simply save the error message as a static string.  If there is an
   allocation failure constructing the error message, then convert the error to
   out of memory. */
void ZLIB_INTERNAL gz_error(gz_statep state, int err, const char *msg) { … }

#ifndef INT_MAX
/* portably return maximum value for an int (when limits.h presumed not
   available) -- we need to do this to cover cases where 2's complement not
   used, since C standard permits 1's complement and sign-bit representations,
   otherwise we could just use ((unsigned)-1) >> 1 */
unsigned ZLIB_INTERNAL gz_intmax(void) {
    unsigned p, q;

    p = 1;
    do {
        q = p;
        p <<= 1;
        p++;
    } while (p > q);
    return q >> 1;
}
#endif