diff options
author | David Oberhollenzer <david.oberhollenzer@sigma-star.at> | 2019-08-31 16:22:31 +0200 |
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committer | David Oberhollenzer <david.oberhollenzer@sigma-star.at> | 2019-08-31 16:22:31 +0200 |
commit | 9b3d958fb7c37855a63ed75707281c61dc1d44c4 (patch) | |
tree | 053c117a09a7eb83b2d17dc582668979cf344102 /lib/sqfs/comp/zstd.c | |
parent | f7801346c0913032e99105088b962a986edb24f4 (diff) |
Merge libcompress.a into libsquashfs.a
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Diffstat (limited to 'lib/sqfs/comp/zstd.c')
-rw-r--r-- | lib/sqfs/comp/zstd.c | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/lib/sqfs/comp/zstd.c b/lib/sqfs/comp/zstd.c new file mode 100644 index 0000000..e206338 --- /dev/null +++ b/lib/sqfs/comp/zstd.c @@ -0,0 +1,188 @@ +/* SPDX-License-Identifier: GPL-3.0-or-later */ +/* + * zstd.c + * + * Copyright (C) 2019 David Oberhollenzer <goliath@infraroot.at> + */ +#include "config.h" + +#include <stdbool.h> +#include <stdlib.h> +#include <string.h> +#include <stdio.h> +#include <ctype.h> + +#include <zstd.h> + +#include "internal.h" + +#define ZSTD_DEFAULT_COMPRESSION_LEVEL 15 + +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) +{ + 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) +{ + 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, + size_t size, uint8_t *out, size_t outsize) +{ + zstd_compressor_t *zstd = (zstd_compressor_t *)base; + size_t ret; + + ret = ZSTD_compressCCtx(zstd->zctx, out, outsize, in, size, + zstd->level); + + if (ZSTD_isError(ret)) { + fprintf(stderr, "internal error in ZSTD compressor: %s\n", + ZSTD_getErrorName(ret)); + return -1; + } + + return ret < size ? ret : 0; +} + +static ssize_t zstd_uncomp_block(compressor_t *base, const uint8_t *in, + size_t size, uint8_t *out, size_t outsize) +{ + size_t ret; + (void)base; + + ret = ZSTD_decompress(out, outsize, in, size); + + if (ZSTD_isError(ret)) { + fprintf(stderr, "error uncompressing ZSTD compressed data: %s", + ZSTD_getErrorName(ret)); + return -1; + } + + return ret; +} + +static compressor_t *zstd_create_copy(compressor_t *cmp) +{ + zstd_compressor_t *zstd = malloc(sizeof(*zstd)); + + if (zstd == NULL) { + perror("creating additional zstd compressor"); + return NULL; + } + + memcpy(zstd, cmp, sizeof(*zstd)); + + zstd->zctx = ZSTD_createCCtx(); + + if (zstd->zctx == NULL) { + fputs("error creating addtional zstd compression context\n", + stderr); + free(zstd); + return NULL; + } + + return (compressor_t *)zstd; +} + +static void zstd_destroy(compressor_t *base) +{ + zstd_compressor_t *zstd = (zstd_compressor_t *)base; + + ZSTD_freeCCtx(zstd->zctx); + free(zstd); +} + +compressor_t *create_zstd_compressor(bool compress, size_t block_size, + char *options) +{ + zstd_compressor_t *zstd = calloc(1, sizeof(*zstd)); + compressor_t *base = (compressor_t *)zstd; + size_t i; + (void)block_size; + + if (zstd == NULL) { + perror("creating zstd compressor"); + 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); + free(zstd); + return NULL; + } + + base->destroy = zstd_destroy; + base->do_block = compress ? zstd_comp_block : zstd_uncomp_block; + base->write_options = zstd_write_options; + base->read_options = zstd_read_options; + base->create_copy = zstd_create_copy; + 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()); +} |