tools/perf/util/zlib.c

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