diff options
Diffstat (limited to 'ubifs-utils/mkfs.ubifs/compr.c')
| -rw-r--r-- | ubifs-utils/mkfs.ubifs/compr.c | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/ubifs-utils/mkfs.ubifs/compr.c b/ubifs-utils/mkfs.ubifs/compr.c new file mode 100644 index 0000000..34b2f60 --- /dev/null +++ b/ubifs-utils/mkfs.ubifs/compr.c @@ -0,0 +1,219 @@ +/* + * Copyright (C) 2008 Nokia Corporation. + * Copyright (C) 2008 University of Szeged, Hungary + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program; if not, write to the Free Software Foundation, Inc., 51 + * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + * + * Authors: Artem Bityutskiy + * Adrian Hunter + * Zoltan Sogor + */ + +#include <stdlib.h> +#include <stdio.h> +#include <stdint.h> +#include <string.h> +#include <lzo/lzo1x.h> +#include <linux/types.h> + +#define crc32 __zlib_crc32 +#include <zlib.h> +#undef crc32 + +#include "compr.h" +#include "mkfs.ubifs.h" + +static void *lzo_mem; +static unsigned long long errcnt = 0; +static struct ubifs_info *c = &info_; + +#define DEFLATE_DEF_LEVEL Z_DEFAULT_COMPRESSION +#define DEFLATE_DEF_WINBITS 11 +#define DEFLATE_DEF_MEMLEVEL 8 + +static int zlib_deflate(void *in_buf, size_t in_len, void *out_buf, + size_t *out_len) +{ + z_stream strm; + + strm.zalloc = NULL; + strm.zfree = NULL; + + /* + * Match exactly the zlib parameters used by the Linux kernel crypto + * API. + */ + if (deflateInit2(&strm, DEFLATE_DEF_LEVEL, Z_DEFLATED, + -DEFLATE_DEF_WINBITS, DEFLATE_DEF_MEMLEVEL, + Z_DEFAULT_STRATEGY)) { + errcnt += 1; + return -1; + } + + strm.next_in = in_buf; + strm.avail_in = in_len; + strm.total_in = 0; + + strm.next_out = out_buf; + strm.avail_out = *out_len; + strm.total_out = 0; + + if (deflate(&strm, Z_FINISH) != Z_STREAM_END) { + deflateEnd(&strm); + errcnt += 1; + return -1; + } + + if (deflateEnd(&strm) != Z_OK) { + errcnt += 1; + return -1; + } + + *out_len = strm.total_out; + + return 0; +} + +static int lzo_compress(void *in_buf, size_t in_len, void *out_buf, + size_t *out_len) +{ + lzo_uint len; + int ret; + + len = *out_len; + ret = lzo1x_999_compress(in_buf, in_len, out_buf, &len, lzo_mem); + *out_len = len; + + if (ret != LZO_E_OK) { + errcnt += 1; + return -1; + } + + return 0; +} + +static int no_compress(void *in_buf, size_t in_len, void *out_buf, + size_t *out_len) +{ + memcpy(out_buf, in_buf, in_len); + *out_len = in_len; + return 0; +} + +static char *zlib_buf; + +static int favor_lzo_compress(void *in_buf, size_t in_len, void *out_buf, + size_t *out_len, int *type) +{ + int lzo_ret, zlib_ret; + size_t lzo_len, zlib_len; + + lzo_len = zlib_len = *out_len; + lzo_ret = lzo_compress(in_buf, in_len, out_buf, &lzo_len); + zlib_ret = zlib_deflate(in_buf, in_len, zlib_buf, &zlib_len); + + if (lzo_ret && zlib_ret) + /* Both compressors failed */ + return -1; + + if (!lzo_ret && !zlib_ret) { + double percent; + + /* Both compressors succeeded */ + if (lzo_len <= zlib_len ) + goto select_lzo; + + percent = (double)zlib_len / (double)lzo_len; + percent *= 100; + if (percent > 100 - c->favor_percent) + goto select_lzo; + goto select_zlib; + } + + if (lzo_ret) + /* Only zlib compressor succeeded */ + goto select_zlib; + + /* Only LZO compressor succeeded */ + +select_lzo: + *out_len = lzo_len; + *type = MKFS_UBIFS_COMPR_LZO; + return 0; + +select_zlib: + *out_len = zlib_len; + *type = MKFS_UBIFS_COMPR_ZLIB; + memcpy(out_buf, zlib_buf, zlib_len); + return 0; +} + +int compress_data(void *in_buf, size_t in_len, void *out_buf, size_t *out_len, + int type) +{ + int ret; + + if (in_len < UBIFS_MIN_COMPR_LEN) { + no_compress(in_buf, in_len, out_buf, out_len); + return MKFS_UBIFS_COMPR_NONE; + } + + if (c->favor_lzo) + ret = favor_lzo_compress(in_buf, in_len, out_buf, out_len, &type); + else { + switch (type) { + case MKFS_UBIFS_COMPR_LZO: + ret = lzo_compress(in_buf, in_len, out_buf, out_len); + break; + case MKFS_UBIFS_COMPR_ZLIB: + ret = zlib_deflate(in_buf, in_len, out_buf, out_len); + break; + case MKFS_UBIFS_COMPR_NONE: + ret = 1; + break; + default: + errcnt += 1; + ret = 1; + break; + } + } + if (ret || *out_len >= in_len) { + no_compress(in_buf, in_len, out_buf, out_len); + return MKFS_UBIFS_COMPR_NONE; + } + return type; +} + +int init_compression(void) +{ + lzo_mem = malloc(LZO1X_999_MEM_COMPRESS); + if (!lzo_mem) + return -1; + + zlib_buf = malloc(UBIFS_BLOCK_SIZE * WORST_COMPR_FACTOR); + if (!zlib_buf) { + free(lzo_mem); + return -1; + } + + return 0; +} + +void destroy_compression(void) +{ + free(zlib_buf); + free(lzo_mem); + if (errcnt) + fprintf(stderr, "%llu compression errors occurred\n", errcnt); +} |