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

   1 /*
   2  * compress.c
   3  *
   4  * Generic functions for compression, wrapping around actual compression
   5  * implementations.
   6  */
   7
   8 /*
   9  * Copyright (C) 2013 Eric Biggers
  10  *
  11  * This file is part of wimlib, a library for working with WIM files.
  12  *
  13  * wimlib is free software; you can redistribute it and/or modify it under the
  14  * terms of the GNU General Public License as published by the Free
  15  * Software Foundation; either version 3 of the License, or (at your option)
  16  * any later version.
  17  *
  18  * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
  19  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
  20  * A PARTICULAR PURPOSE. See the GNU General Public License for more
  21  * details.
  22  *
  23  * You should have received a copy of the GNU General Public License
  24  * along with wimlib; if not, see http://www.gnu.org/licenses/.
  25  */
  26
  27 #ifdef HAVE_CONFIG_H
  28 #  include "config.h"
  29 #endif
  30
  31 #include "wimlib.h"
  32 #include "wimlib/compressor_ops.h"
  33 #include "wimlib/util.h"
  34
  35 struct wimlib_compressor {
  36         const struct compressor_ops *ops;
  37         void *private;
  38 };
  39
  40 static const struct compressor_ops *compressor_ops[] = {
  41         [WIMLIB_COMPRESSION_TYPE_LZX]    = &lzx_compressor_ops,
  42         [WIMLIB_COMPRESSION_TYPE_XPRESS] = &xpress_compressor_ops,
  43         [WIMLIB_COMPRESSION_TYPE_LZMS]   = &lzms_compressor_ops,
  44 };
  45
  46 static struct wimlib_compressor_params_header *
  47 compressor_default_params[ARRAY_LEN(compressor_ops)] = {
  48 };
  49
  50 static bool
  51 compressor_ctype_valid(int ctype)
  52 {
  53         return (ctype >= 0 &&
  54                 ctype < ARRAY_LEN(compressor_ops) &&
  55                 compressor_ops[ctype] != NULL);
  56 }
  57
  58 WIMLIBAPI int
  59 wimlib_set_default_compressor_params(enum wimlib_compression_type ctype,
  60                                      const struct wimlib_compressor_params_header *params)
  61 {
  62         struct wimlib_compressor_params_header *dup;
  63
  64         if (!compressor_ctype_valid(ctype))
  65                 return WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
  66
  67         dup = NULL;
  68         if (params) {
  69                 dup = memdup(params, params->size);
  70                 if (dup == NULL)
  71                         return WIMLIB_ERR_NOMEM;
  72         }
  73
  74         FREE(compressor_default_params[ctype]);
  75         compressor_default_params[ctype] = dup;
  76         return 0;
  77 }
  78
  79 void
  80 cleanup_compressor_params(void)
  81 {
  82         for (size_t i = 0; i < ARRAY_LEN(compressor_default_params); i++) {
  83                 FREE(compressor_default_params[i]);
  84                 compressor_default_params[i] = NULL;
  85         }
  86 }
  87
  88 WIMLIBAPI int
  89 wimlib_create_compressor(enum wimlib_compression_type ctype,
  90                          size_t max_block_size,
  91                          const struct wimlib_compressor_params_header *extra_params,
  92                          struct wimlib_compressor **c_ret)
  93 {
  94         struct wimlib_compressor *c;
  95
  96         if (c_ret == NULL)
  97                 return WIMLIB_ERR_INVALID_PARAM;
  98
  99         if (!compressor_ctype_valid(ctype))
 100                 return WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
 101
 102         c = MALLOC(sizeof(*c));
 103         if (c == NULL)
 104                 return WIMLIB_ERR_NOMEM;
 105         c->ops = compressor_ops[ctype];
 106         c->private = NULL;
 107         if (c->ops->create_compressor) {
 108                 const struct wimlib_compressor_params_header *params;
 109                 int ret;
 110
 111                 if (extra_params)
 112                         params = extra_params;
 113                 else
 114                         params = compressor_default_params[ctype];
 115                 ret = c->ops->create_compressor(max_block_size,
 116                                                 params, &c->private);
 117                 if (ret) {
 118                         FREE(c);
 119                         return ret;
 120                 }
 121         }
 122         *c_ret = c;
 123         return 0;
 124 }
 125
 126 WIMLIBAPI size_t
 127 wimlib_compress(const void *uncompressed_data, size_t uncompressed_size,
 128                 void *compressed_data, size_t compressed_size_avail,
 129                 struct wimlib_compressor *c)
 130 {
 131         return c->ops->compress(uncompressed_data, uncompressed_size,
 132                                 compressed_data, compressed_size_avail,
 133                                 c->private);
 134 }
 135
 136 WIMLIBAPI void
 137 wimlib_free_compressor(struct wimlib_compressor *c)
 138 {
 139         if (c) {
 140                 if (c->ops->free_compressor)
 141                         c->ops->free_compressor(c->private);
 142                 FREE(c);
 143         }
 144 }