diff options
| -rw-r--r-- | lib/comp/zstd.c | 67 |
1 files changed, 61 insertions, 6 deletions
diff --git a/lib/comp/zstd.c b/lib/comp/zstd.c index 4cbef38..2868cbf 100644 --- a/lib/comp/zstd.c +++ b/lib/comp/zstd.c @@ -3,6 +3,7 @@ #include <stdlib.h> #include <string.h> #include <stdio.h> +#include <ctype.h> #include <zstd.h> @@ -13,19 +14,36 @@ typedef struct { compressor_t base; ZSTD_CCtx *zctx; + int level; } zstd_compressor_t; +typedef struct { + uint32_t level; +} zstd_options_t; + static int zstd_write_options(compressor_t *base, int fd) { - (void)base; (void)fd; - return 0; + zstd_compressor_t *zstd = (zstd_compressor_t *)base; + zstd_options_t opt; + (void)fd; + + if (zstd->level == ZSTD_DEFAULT_COMPRESSION_LEVEL) + return 0; + + opt.level = htole32(zstd->level); + return generic_write_options(fd, &opt, sizeof(opt)); } static int zstd_read_options(compressor_t *base, int fd) { - (void)base; (void)fd; - fputs("zstd extra options are not yet implemented\n", stderr); - return -1; + zstd_options_t opt; + (void)base; + + if (generic_read_options(fd, &opt, sizeof(opt))) + return -1; + + opt.level = le32toh(opt.level); + return 0; } static ssize_t zstd_comp_block(compressor_t *base, const uint8_t *in, @@ -35,7 +53,7 @@ static ssize_t zstd_comp_block(compressor_t *base, const uint8_t *in, size_t ret; ret = ZSTD_compressCCtx(zstd->zctx, out, outsize, in, size, - ZSTD_DEFAULT_COMPRESSION_LEVEL); + zstd->level); if (ZSTD_isError(ret)) { fputs("internal error in ZSTD compressor\n", stderr); @@ -74,6 +92,7 @@ compressor_t *create_zstd_compressor(bool compress, size_t block_size, { zstd_compressor_t *zstd = calloc(1, sizeof(*zstd)); compressor_t *base = (compressor_t *)zstd; + size_t i; (void)block_size; if (zstd == NULL) { @@ -81,6 +100,27 @@ compressor_t *create_zstd_compressor(bool compress, size_t block_size, return NULL; } + zstd->level = ZSTD_DEFAULT_COMPRESSION_LEVEL; + + if (options != NULL) { + if (strncmp(options, "level=", 6) == 0) { + options += 6; + + for (i = 0; isdigit(options[i]); ++i) + ; + + if (i == 0 || options[i] != '\0' || i > 6) + goto fail_level; + + zstd->level = atoi(options); + + if (zstd->level < 1 || zstd->level > ZSTD_maxCLevel()) + goto fail_level; + } else { + goto fail_opt; + } + } + zstd->zctx = ZSTD_createCCtx(); if (zstd->zctx == NULL) { fputs("error creating zstd compression context\n", stderr); @@ -93,8 +133,23 @@ compressor_t *create_zstd_compressor(bool compress, size_t block_size, base->write_options = zstd_write_options; base->read_options = zstd_read_options; return base; +fail_level: + fprintf(stderr, "zstd compression level must be a number in the range " + "1...%d\n", ZSTD_maxCLevel()); + free(zstd); + return NULL; +fail_opt: + fputs("Unsupported extra options for zstd compressor\n", stderr); + free(zstd); + return NULL; } void compressor_zstd_print_help(void) { + printf("Available options for zstd compressor:\n" + "\n" + " level=<value> Set compression level. Defaults to %d.\n" + " Maximum is %d.\n" + "\n", + ZSTD_DEFAULT_COMPRESSION_LEVEL, ZSTD_maxCLevel()); } |