wimlib.net Git - wimlib/blob - src/zstd_compress.c

   1 #ifdef HAVE_CONFIG_H
   2 #  include "config.h"
   3 #endif
   4
   5 #include "wimlib/error.h"
   6 #include "wimlib/compressor_ops.h"
   7 #include "wimlib/util.h"
   8
   9 #include <zstd.h>
  10
  11 struct zstd_compressor {
  12         unsigned compression_level;
  13         ZSTD_CCtx *cctx;
  14 };
  15
  16 static u64
  17 zstd_get_needed_memory(size_t max_bufsize, unsigned compression_level,
  18                        bool destructive)
  19 {
  20         return sizeof(struct zstd_compressor);
  21 }
  22
  23 static int
  24 zstd_create_compressor(size_t max_bufsize, unsigned compression_level,
  25                        bool destructive, void **c_ret)
  26 {
  27         struct zstd_compressor *c;
  28
  29         c = MALLOC(sizeof(*c));
  30         if (!c)
  31                 goto oom;
  32
  33         c->cctx = ZSTD_createCCtx();
  34         if (!c->cctx)
  35                 goto oom;
  36
  37         c->compression_level = compression_level / 5;
  38         c->compression_level = max(c->compression_level, 1);
  39         c->compression_level = min(c->compression_level, ZSTD_maxCLevel());
  40
  41         *c_ret = c;
  42         return 0;
  43
  44 oom:
  45         FREE(c);
  46         return WIMLIB_ERR_NOMEM;
  47 }
  48
  49 static size_t
  50 zstd_compress(const void *in, size_t in_nbytes,
  51               void *out, size_t out_nbytes_avail, void *_c)
  52 {
  53         struct zstd_compressor *c = _c;
  54         size_t res;
  55
  56         res = ZSTD_compressCCtx(c->cctx, out, out_nbytes_avail, in, in_nbytes,
  57                                 c->compression_level);
  58
  59         if (ZSTD_isError(res))
  60                 return 0;
  61         return res;
  62 }
  63
  64 static void
  65 zstd_free_compressor(void *_c)
  66 {
  67         struct zstd_compressor *c = _c;
  68
  69         FREE(c->cctx);
  70         FREE(c);
  71 }
  72
  73 const struct compressor_ops zstd_compressor_ops = {
  74         .get_needed_memory      = zstd_get_needed_memory,
  75         .create_compressor      = zstd_create_compressor,
  76         .compress               = zstd_compress,
  77         .free_compressor        = zstd_free_compressor,
  78 };
  79