1 files changed, 159 insertions, 0 deletions
diff --git a/lib/sqfs/comp/lz4.c b/lib/sqfs/comp/lz4.c
new file mode 100644
index 0000000..abb6c5c
--- /dev/null
+++ b/lib/sqfs/comp/lz4.c
@@ -0,0 +1,159 @@
+/* SPDX-License-Identifier: GPL-3.0-or-later */
+/*
+ * lz4.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 <lz4.h>
+#include <lz4hc.h>
+
+#include "internal.h"
+
+typedef struct {
+	compressor_t base;
+	bool high_compression;
+} lz4_compressor_t;
+
+typedef struct {
+	uint32_t version;
+	uint32_t flags;
+} lz4_options;
+
+#define LZ4LEGACY 1
+#define LZ4_FLAG_HC 0x01
+
+static int lz4_write_options(compressor_t *base, int fd)
+{
+	lz4_compressor_t *lz4 = (lz4_compressor_t *)base;
+	lz4_options opt = {
+		.version = htole32(LZ4LEGACY),
+		.flags = htole32(lz4->high_compression ? LZ4_FLAG_HC : 0),
+	};
+
+	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)
+{
+	lz4_compressor_t *lz4 = (lz4_compressor_t *)base;
+	int ret;
+
+	if (lz4->high_compression) {
+		ret = LZ4_compress_HC((void *)in, (void *)out,
+				      size, outsize, LZ4HC_CLEVEL_MAX);
+	} else {
+		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 compressor_t *lz4_create_copy(compressor_t *cmp)
+{
+	lz4_compressor_t *lz4 = malloc(sizeof(*lz4));
+
+	if (lz4 == NULL) {
+		perror("creating additional lz4 compressor");
+		return NULL;
+	}
+
+	memcpy(lz4, cmp, sizeof(*lz4));
+	return (compressor_t *)lz4;
+}
+
+static void lz4_destroy(compressor_t *base)
+{
+	free(base);
+}
+
+compressor_t *create_lz4_compressor(bool compress, size_t block_size,
+				    char *options)
+{
+	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;
+	}
+
+	lz4->high_compression = false;
+
+	if (options != NULL) {
+		if (strcmp(options, "hc") == 0) {
+			lz4->high_compression = true;
+		} else {
+			fputs("Unsupported extra options for lz4 "
+			      "compressor.\n", stderr);
+			free(lz4);
+			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;
+	base->create_copy = lz4_create_copy;
+	return base;
+}
+
+void compressor_lz4_print_help(void)
+{
+	fputs("Available options for lz4 compressor:\n"
+	      "\n"
+	      "    hc    If present, use slower but better compressing\n"
+	      "          variant of lz4.\n"
+	      "\n",
+	      stdout);
+}