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         [WIMLIB_COMPRESSION_TYPE_LZX]    = NULL,
  49         [WIMLIB_COMPRESSION_TYPE_XPRESS] = NULL,
  50         [WIMLIB_COMPRESSION_TYPE_LZMS]   = NULL,
  51 };
  52
  53 static bool
  54 compressor_ctype_valid(int ctype)
  55 {
  56         return (ctype >= 0 &&
  57                 ctype < ARRAY_LEN(compressor_ops) &&
  58                 compressor_ops[ctype] != NULL);
  59 }
  60
  61 WIMLIBAPI int
  62 wimlib_set_default_compressor_params(enum wimlib_compression_type ctype,
  63                                      const struct wimlib_compressor_params_header *params)
  64 {
  65         struct wimlib_compressor_params_header *dup;
  66
  67         if (!compressor_ctype_valid(ctype))
  68                 return WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
  69
  70         dup = NULL;
  71         if (params) {
  72                 dup = memdup(params, params->size);
  73                 if (dup == NULL)
  74                         return WIMLIB_ERR_NOMEM;
  75         }
  76
  77         FREE(compressor_default_params[ctype]);
  78         compressor_default_params[ctype] = dup;
  79         return 0;
  80 }
  81
  82 void
  83 cleanup_compressor_params(void)
  84 {
  85         for (size_t i = 0; i < ARRAY_LEN(compressor_default_params); i++) {
  86                 FREE(compressor_default_params[i]);
  87                 compressor_default_params[i] = NULL;
  88         }
  89 }
  90
  91 WIMLIBAPI int
  92 wimlib_create_compressor(enum wimlib_compression_type ctype,
  93                          size_t max_block_size,
  94                          const struct wimlib_compressor_params_header *extra_params,
  95                          struct wimlib_compressor **c_ret)
  96 {
  97         struct wimlib_compressor *c;
  98
  99         if (c_ret == NULL)
 100                 return WIMLIB_ERR_INVALID_PARAM;
 101
 102         if (!compressor_ctype_valid(ctype))
 103                 return WIMLIB_ERR_INVALID_COMPRESSION_TYPE;
 104
 105         c = MALLOC(sizeof(*c));
 106         if (c == NULL)
 107                 return WIMLIB_ERR_NOMEM;
 108         c->ops = compressor_ops[ctype];
 109         c->private = NULL;
 110         if (c->ops->create_compressor) {
 111                 const struct wimlib_compressor_params_header *params;
 112                 int ret;
 113
 114                 if (extra_params)
 115                         params = extra_params;
 116                 else
 117                         params = compressor_default_params[ctype];
 118                 ret = c->ops->create_compressor(max_block_size,
 119                                                 params, &c->private);
 120                 if (ret) {
 121                         FREE(c);
 122                         return ret;
 123                 }
 124         }
 125         *c_ret = c;
 126         return 0;
 127 }
 128
 129 WIMLIBAPI size_t
 130 wimlib_compress(const void *uncompressed_data, size_t uncompressed_size,
 131                 void *compressed_data, size_t compressed_size_avail,
 132                 struct wimlib_compressor *c)
 133 {
 134         return c->ops->compress(uncompressed_data, uncompressed_size,
 135                                 compressed_data, compressed_size_avail,
 136                                 c->private);
 137 }
 138
 139 WIMLIBAPI void
 140 wimlib_free_compressor(struct wimlib_compressor *c)
 141 {
 142         if (c) {
 143                 if (c->ops->free_compressor)
 144                         c->ops->free_compressor(c->private);
 145                 FREE(c);
 146         }
 147 }