diff options
| -rw-r--r-- | mkfs.ubifs/compr.c | 91 |
1 files changed, 76 insertions, 15 deletions
diff --git a/mkfs.ubifs/compr.c b/mkfs.ubifs/compr.c index 73c7a01..8ed2904 100644 --- a/mkfs.ubifs/compr.c +++ b/mkfs.ubifs/compr.c @@ -48,7 +48,7 @@ static int zlib_deflate(void *in_buf, size_t in_len, void *out_buf, strm.zfree = NULL; /* - * Match exactly the zlib parameters used by the linux kernel crypto + * Match exactly the zlib parameters used by the Linux kernel crypto * API. */ if (deflateInit2(&strm, DEFLATE_DEF_LEVEL, Z_DEFLATED, @@ -108,29 +108,82 @@ static int no_compress(void *in_buf, size_t in_len, void *out_buf, 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_lzo) + 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 = 1; + int ret; if (in_len < UBIFS_MIN_COMPR_LEN) { no_compress(in_buf, in_len, out_buf, out_len); return MKFS_UBIFS_COMPR_NONE; } - 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; - break; + 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); @@ -144,11 +197,19 @@ 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); |