#include <stdio.h> | |
#include <unistd.h> | |
#include <sys/stat.h> | |
#include <sys/mman.h> | |
#include <zlib.h> | |
#include "util/compress.h" | |
#include "util/util.h" | |
#include "util/debug.h" | |
#define CHUNK_SIZE 16384 | |
int gzip_decompress_to_file(const char *input, int output_fd) | |
{ | |
int ret = Z_STREAM_ERROR; | |
int input_fd; | |
void *ptr; | |
int len; | |
struct stat stbuf; | |
unsigned char buf[CHUNK_SIZE]; | |
z_stream zs = { | |
.zalloc = Z_NULL, | |
.zfree = Z_NULL, | |
.opaque = Z_NULL, | |
.avail_in = 0, | |
.next_in = Z_NULL, | |
}; | |
input_fd = open(input, O_RDONLY); | |
if (input_fd < 0) | |
return -1; | |
if (fstat(input_fd, &stbuf) < 0) | |
goto out_close; | |
ptr = mmap(NULL, stbuf.st_size, PROT_READ, MAP_PRIVATE, input_fd, 0); | |
if (ptr == MAP_FAILED) | |
goto out_close; | |
if (inflateInit2(&zs, 16 + MAX_WBITS) != Z_OK) | |
goto out_unmap; | |
zs.next_in = ptr; | |
zs.avail_in = stbuf.st_size; | |
do { | |
zs.next_out = buf; | |
zs.avail_out = CHUNK_SIZE; | |
ret = inflate(&zs, Z_NO_FLUSH); | |
switch (ret) { | |
case Z_NEED_DICT: | |
ret = Z_DATA_ERROR; | |
/* fall through */ | |
case Z_DATA_ERROR: | |
case Z_MEM_ERROR: | |
goto out; | |
default: | |
break; | |
} | |
len = CHUNK_SIZE - zs.avail_out; | |
if (writen(output_fd, buf, len) != len) { | |
ret = Z_DATA_ERROR; | |
goto out; | |
} | |
} while (ret != Z_STREAM_END); | |
out: | |
inflateEnd(&zs); | |
out_unmap: | |
munmap(ptr, stbuf.st_size); | |
out_close: | |
close(input_fd); | |
return ret == Z_STREAM_END ? 0 : -1; | |
} |