summaryrefslogtreecommitdiff
path: root/lib/sqfs/comp/zstd.c
diff options
context:
space:
mode:
Diffstat (limited to 'lib/sqfs/comp/zstd.c')
-rw-r--r--lib/sqfs/comp/zstd.c188
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());
+}