diff options
Diffstat (limited to 'lib/zlib/gzlib.c')
-rw-r--r-- | lib/zlib/gzlib.c | 582 |
1 files changed, 582 insertions, 0 deletions
diff --git a/lib/zlib/gzlib.c b/lib/zlib/gzlib.c new file mode 100644 index 0000000..29fc448 --- /dev/null +++ b/lib/zlib/gzlib.c @@ -0,0 +1,582 @@ +/* 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 _lseeki64 +#else +#if defined(_LARGEFILE64_SOURCE) && _LFS64_LARGEFILE-0 +# define LSEEK lseek64 +#else +# define LSEEK lseek +#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) { + 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 */ + } + else /* for writing ... */ + state->reset = 0; /* no deflateReset pending */ + 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(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 == GZ_WRITE ? + O_TRUNC : + O_APPEND))); + + /* open the file with the appropriate flags (or just use fd) */ + state->fd = fd > -1 ? fd : ( +#ifdef WIDECHAR + fd == -2 ? _wopen(path, oflag, 0666) : +#endif + open((const char *)path, oflag, 0666)); + if (state->fd == -1) { + free(state->path); + free(state); + return NULL; + } + if (state->mode == GZ_APPEND) { + LSEEK(state->fd, 0, SEEK_END); /* so gzoffset() is correct */ + state->mode = GZ_WRITE; /* simplify later checks */ + } + + /* save the current position for rewinding (only if reading) */ + if (state->mode == GZ_READ) { + state->start = LSEEK(state->fd, 0, SEEK_CUR); + if (state->start == -1) state->start = 0; + } + + /* initialize stream */ + gz_reset(state); + + /* return stream */ + return (gzFile)state; +} + +/* -- see zlib.h -- */ +gzFile ZEXPORT gzopen(const char *path, const char *mode) { + return gz_open(path, -1, mode); +} + +/* -- see zlib.h -- */ +gzFile ZEXPORT gzopen64(const char *path, const char *mode) { + return gz_open(path, -1, mode); +} + +/* -- see zlib.h -- */ +gzFile ZEXPORT gzdopen(int fd, const char *mode) { + char *path; /* identifier for error messages */ + gzFile gz; + + if (fd == -1 || (path = (char *)malloc(7 + 3 * sizeof(int))) == NULL) + return NULL; +#if !defined(NO_snprintf) && !defined(NO_vsnprintf) + (void)snprintf(path, 7 + 3 * sizeof(int), "<fd:%d>", fd); +#else + sprintf(path, "<fd:%d>", fd); /* for debugging */ +#endif + gz = gz_open(path, fd, mode); + free(path); + return gz; +} + +/* -- 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) { + gz_statep state; + + /* get internal structure and check integrity */ + if (file == NULL) + return -1; + state = (gz_statep)file; + if (state->mode != GZ_READ && state->mode != GZ_WRITE) + return -1; + + /* make sure we haven't already allocated memory */ + if (state->size != 0) + return -1; + + /* check and set requested size */ + if ((size << 1) < size) + return -1; /* need to be able to double it */ + if (size < 8) + size = 8; /* needed to behave well with flushing */ + state->want = size; + return 0; +} + +/* -- see zlib.h -- */ +int ZEXPORT gzrewind(gzFile file) { + gz_statep state; + + /* get internal structure */ + if (file == NULL) + return -1; + state = (gz_statep)file; + + /* check that we're reading and that there's no error */ + if (state->mode != GZ_READ || + (state->err != Z_OK && state->err != Z_BUF_ERROR)) + return -1; + + /* back up and start over */ + if (LSEEK(state->fd, state->start, SEEK_SET) == -1) + return -1; + gz_reset(state); + return 0; +} + +/* -- see zlib.h -- */ +z_off64_t ZEXPORT gzseek64(gzFile file, z_off64_t offset, int whence) { + unsigned n; + z_off64_t ret; + gz_statep state; + + /* get internal structure and check integrity */ + if (file == NULL) + return -1; + state = (gz_statep)file; + if (state->mode != GZ_READ && state->mode != GZ_WRITE) + return -1; + + /* check that there's no error */ + if (state->err != Z_OK && state->err != Z_BUF_ERROR) + return -1; + + /* can only seek from start or relative to current position */ + if (whence != SEEK_SET && whence != SEEK_CUR) + return -1; + + /* normalize offset to a SEEK_CUR specification */ + if (whence == SEEK_SET) + offset -= state->x.pos; + else if (state->seek) + offset += state->skip; + state->seek = 0; + + /* if within raw area while reading, just go there */ + if (state->mode == GZ_READ && state->how == COPY && + state->x.pos + offset >= 0) { + ret = LSEEK(state->fd, offset - (z_off64_t)state->x.have, SEEK_CUR); + if (ret == -1) + return -1; + state->x.have = 0; + state->eof = 0; + state->past = 0; + state->seek = 0; + gz_error(state, Z_OK, NULL); + state->strm.avail_in = 0; + state->x.pos += offset; + return state->x.pos; + } + + /* calculate skip amount, rewinding if needed for back seek when reading */ + if (offset < 0) { + if (state->mode != GZ_READ) /* writing -- can't go backwards */ + return -1; + offset += state->x.pos; + if (offset < 0) /* before start of file! */ + return -1; + if (gzrewind(file) == -1) /* rewind, then skip to offset */ + return -1; + } + + /* if reading, skip what's in output buffer (one less gzgetc() check) */ + if (state->mode == GZ_READ) { + n = GT_OFF(state->x.have) || (z_off64_t)state->x.have > offset ? + (unsigned)offset : state->x.have; + state->x.have -= n; + state->x.next += n; + state->x.pos += n; + offset -= n; + } + + /* request skip (if not zero) */ + if (offset) { + state->seek = 1; + state->skip = offset; + } + return state->x.pos + offset; +} + +/* -- see zlib.h -- */ +z_off_t ZEXPORT gzseek(gzFile file, z_off_t offset, int whence) { + z_off64_t ret; + + ret = gzseek64(file, (z_off64_t)offset, whence); + return ret == (z_off_t)ret ? (z_off_t)ret : -1; +} + +/* -- see zlib.h -- */ +z_off64_t ZEXPORT gztell64(gzFile file) { + gz_statep state; + + /* get internal structure and check integrity */ + if (file == NULL) + return -1; + state = (gz_statep)file; + if (state->mode != GZ_READ && state->mode != GZ_WRITE) + return -1; + + /* return position */ + return state->x.pos + (state->seek ? state->skip : 0); +} + +/* -- see zlib.h -- */ +z_off_t ZEXPORT gztell(gzFile file) { + z_off64_t ret; + + ret = gztell64(file); + return ret == (z_off_t)ret ? (z_off_t)ret : -1; +} + +/* -- see zlib.h -- */ +z_off64_t ZEXPORT gzoffset64(gzFile file) { + z_off64_t offset; + gz_statep state; + + /* get internal structure and check integrity */ + if (file == NULL) + return -1; + state = (gz_statep)file; + if (state->mode != GZ_READ && state->mode != GZ_WRITE) + return -1; + + /* compute and return effective offset in file */ + offset = LSEEK(state->fd, 0, SEEK_CUR); + if (offset == -1) + return -1; + if (state->mode == GZ_READ) /* reading */ + offset -= state->strm.avail_in; /* don't count buffered input */ + return offset; +} + +/* -- see zlib.h -- */ +z_off_t ZEXPORT gzoffset(gzFile file) { + z_off64_t ret; + + ret = gzoffset64(file); + return ret == (z_off_t)ret ? (z_off_t)ret : -1; +} + +/* -- see zlib.h -- */ +int ZEXPORT gzeof(gzFile file) { + gz_statep state; + + /* get internal structure and check integrity */ + if (file == NULL) + return 0; + state = (gz_statep)file; + if (state->mode != GZ_READ && state->mode != GZ_WRITE) + return 0; + + /* return end-of-file state */ + return state->mode == GZ_READ ? state->past : 0; +} + +/* -- see zlib.h -- */ +const char * ZEXPORT gzerror(gzFile file, int *errnum) { + gz_statep state; + + /* get internal structure and check integrity */ + if (file == NULL) + return NULL; + state = (gz_statep)file; + if (state->mode != GZ_READ && state->mode != GZ_WRITE) + return NULL; + + /* return error information */ + if (errnum != NULL) + *errnum = state->err; + return state->err == Z_MEM_ERROR ? "out of memory" : + (state->msg == NULL ? "" : state->msg); +} + +/* -- see zlib.h -- */ +void ZEXPORT gzclearerr(gzFile file) { + gz_statep state; + + /* get internal structure and check integrity */ + if (file == NULL) + return; + state = (gz_statep)file; + if (state->mode != GZ_READ && state->mode != GZ_WRITE) + return; + + /* clear error and end-of-file */ + if (state->mode == GZ_READ) { + state->eof = 0; + state->past = 0; + } + gz_error(state, Z_OK, NULL); +} + +/* 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) { + /* free previously allocated message and clear */ + if (state->msg != NULL) { + if (state->err != Z_MEM_ERROR) + free(state->msg); + state->msg = NULL; + } + + /* if fatal, set state->x.have to 0 so that the gzgetc() macro fails */ + if (err != Z_OK && err != Z_BUF_ERROR) + state->x.have = 0; + + /* set error code, and if no message, then done */ + state->err = err; + if (msg == NULL) + return; + + /* for an out of memory error, return literal string when requested */ + if (err == Z_MEM_ERROR) + return; + + /* construct error message with path */ + if ((state->msg = (char *)malloc(strlen(state->path) + strlen(msg) + 3)) == + NULL) { + state->err = Z_MEM_ERROR; + return; + } +#if !defined(NO_snprintf) && !defined(NO_vsnprintf) + (void)snprintf(state->msg, strlen(state->path) + strlen(msg) + 3, + "%s%s%s", state->path, ": ", msg); +#else + strcpy(state->msg, state->path); + strcat(state->msg, ": "); + strcat(state->msg, msg); +#endif +} + +#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 |