tools/perf/util/zlib.c

   1 #include <fcntl.h>
   2 #include <stdio.h>
   3 #include <unistd.h>
   4 #include <sys/stat.h>
   5 #include <sys/mman.h>
   6 #include <zlib.h>
   7
   8 #include "util/compress.h"
   9 #include "util/util.h"
  10 #include "util/debug.h"
  11
  12
  13 #define CHUNK_SIZE  16384
  14
  15 int gzip_decompress_to_file(const char *input, int output_fd)
  16 {
  17         int ret = Z_STREAM_ERROR;
  18         int input_fd;
  19         void *ptr;
  20         int len;
  21         struct stat stbuf;
  22         unsigned char buf[CHUNK_SIZE];
  23         z_stream zs = {
  24                 .zalloc         = Z_NULL,
  25                 .zfree          = Z_NULL,
  26                 .opaque         = Z_NULL,
  27                 .avail_in       = 0,
  28                 .next_in        = Z_NULL,
  29         };
  30
  31         input_fd = open(input, O_RDONLY);
  32         if (input_fd < 0)
  33                 return -1;
  34
  35         if (fstat(input_fd, &stbuf) < 0)
  36                 goto out_close;
  37
  38         ptr = mmap(NULL, stbuf.st_size, PROT_READ, MAP_PRIVATE, input_fd, 0);
  39         if (ptr == MAP_FAILED)
  40                 goto out_close;
  41
  42         if (inflateInit2(&zs, 16 + MAX_WBITS) != Z_OK)
  43                 goto out_unmap;
  44
  45         zs.next_in = ptr;
  46         zs.avail_in = stbuf.st_size;
  47
  48         do {
  49                 zs.next_out = buf;
  50                 zs.avail_out = CHUNK_SIZE;
  51
  52                 ret = inflate(&zs, Z_NO_FLUSH);
  53                 switch (ret) {
  54                 case Z_NEED_DICT:
  55                         ret = Z_DATA_ERROR;
  56                         /* fall through */
  57                 case Z_DATA_ERROR:
  58                 case Z_MEM_ERROR:
  59                         goto out;
  60                 default:
  61                         break;
  62                 }
  63
  64                 len = CHUNK_SIZE - zs.avail_out;
  65                 if (writen(output_fd, buf, len) != len) {
  66                         ret = Z_DATA_ERROR;
  67                         goto out;
  68                 }
  69
  70         } while (ret != Z_STREAM_END);
  71
  72 out:
  73         inflateEnd(&zs);
  74 out_unmap:
  75         munmap(ptr, stbuf.st_size);
  76 out_close:
  77         close(input_fd);
  78
  79         return ret == Z_STREAM_END ? 0 : -1;
  80 }