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-rw-r--r--lib/comp/lz4.c106
1 files changed, 106 insertions, 0 deletions
diff --git a/lib/comp/lz4.c b/lib/comp/lz4.c
new file mode 100644
index 0000000..f9c753d
--- /dev/null
+++ b/lib/comp/lz4.c
@@ -0,0 +1,106 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+#include <stdbool.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+
+#include <lz4.h>
+#include <lz4hc.h>
+
+#include "internal.h"
+
+typedef struct {
+ compressor_t base;
+} lz4_compressor_t;
+
+typedef struct {
+ uint32_t version;
+ uint32_t flags;
+} lz4_options;
+
+#define LZ4LEGACY 1
+
+static int lz4_write_options(compressor_t *base, int fd)
+{
+ lz4_options opt = {
+ .version = htole32(LZ4LEGACY),
+ .flags = htole32(0),
+ };
+ (void)base;
+
+ return generic_write_options(fd, &opt, sizeof(opt));
+}
+
+static int lz4_read_options(compressor_t *base, int fd)
+{
+ lz4_options opt;
+ (void)base;
+
+ if (generic_read_options(fd, &opt, sizeof(opt)))
+ return -1;
+
+ opt.version = le32toh(opt.version);
+ opt.flags = le32toh(opt.flags);
+
+ if (opt.version != LZ4LEGACY) {
+ fprintf(stderr, "unsupported lz4 version '%d'\n", opt.version);
+ return -1;
+ }
+
+ return 0;
+}
+
+static ssize_t lz4_comp_block(compressor_t *base, const uint8_t *in,
+ size_t size, uint8_t *out, size_t outsize)
+{
+ int ret;
+ (void)base;
+
+ ret = LZ4_compress_default((void *)in, (void *)out, size, outsize);
+
+ if (ret < 0) {
+ fputs("internal error in lz4 compressor\n", stderr);
+ return -1;
+ }
+
+ return ret;
+}
+
+static ssize_t lz4_uncomp_block(compressor_t *base, const uint8_t *in,
+ size_t size, uint8_t *out, size_t outsize)
+{
+ int ret;
+ (void)base;
+
+ ret = LZ4_decompress_safe((void *)in, (void *)out, size, outsize);
+
+ if (ret < 0) {
+ fputs("internal error in lz4 decompressor\n", stderr);
+ return -1;
+ }
+
+ return ret;
+}
+
+static void lz4_destroy(compressor_t *base)
+{
+ free(base);
+}
+
+compressor_t *create_lz4_compressor(bool compress, size_t block_size)
+{
+ lz4_compressor_t *lz4 = calloc(1, sizeof(*lz4));
+ compressor_t *base = (compressor_t *)lz4;
+ (void)block_size;
+
+ if (lz4 == NULL) {
+ perror("creating lz4 compressor");
+ return NULL;
+ }
+
+ base->destroy = lz4_destroy;
+ base->do_block = compress ? lz4_comp_block : lz4_uncomp_block;
+ base->write_options = lz4_write_options;
+ base->read_options = lz4_read_options;
+ return base;
+}