[RFC PATCH v0 3/4] erofs-utils: mkfs: add LZMA algorithm support

[Gao Xiang]

From: Gao Xiang <hsiangkao at aol.com>

This patch adds LZMA compression algorithms to erofs-utils
compression framework by using upstream liblzma.

Cc: Lasse Collin <lasse.collin at tukaani.org>
Signed-off-by: Gao Xiang <hsiangkao at aol.com>
---
 include/erofs_fs.h       |  3 +-
 lib/Makefile.am          |  1 +
 lib/compress.c           |  5 ++-
 lib/compressor.c         |  1 +
 lib/compressor.h         |  1 +
 lib/compressor_liblzma.c | 93 ++++++++++++++++++++++++++++++++++++++++
 6 files changed, 102 insertions(+), 2 deletions(-)
 create mode 100644 lib/compressor_liblzma.c

diff --git a/include/erofs_fs.h b/include/erofs_fs.h
index a69f179a51a5..24772043cb8b 100644
--- a/include/erofs_fs.h
+++ b/include/erofs_fs.h
@@ -193,7 +193,8 @@ static inline unsigned int erofs_xattr_entry_size(struct erofs_xattr_entry *e)
 
 /* available compression algorithm types (for h_algorithmtype) */
 enum {
-	Z_EROFS_COMPRESSION_LZ4	= 0,
+	Z_EROFS_COMPRESSION_LZ4		= 0,
+	Z_EROFS_COMPRESSION_LZMA	= 1,
 	Z_EROFS_COMPRESSION_MAX
 };
 
diff --git a/lib/Makefile.am b/lib/Makefile.am
index e048a16d73f2..e9b3255a2653 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -14,3 +14,4 @@ endif
 endif
 
 liberofs_la_CFLAGS += -I/tmp/xz-test/include
+liberofs_la_SOURCES += compressor_liblzma.c
diff --git a/lib/compress.c b/lib/compress.c
index 2e8deaf81907..d77998fb6857 100644
--- a/lib/compress.c
+++ b/lib/compress.c
@@ -493,6 +493,8 @@ static int erofs_get_compress_algorithm_id(const char *name)
 {
 	if (!strcmp(name, "lz4") || !strcmp(name, "lz4hc"))
 		return Z_EROFS_COMPRESSION_LZ4;
+	if (!strcmp(name, "lzma"))
+		return Z_EROFS_COMPRESSION_LZMA;
 	return -ENOTSUP;
 }
 
@@ -511,7 +513,8 @@ int z_erofs_compress_init(void)
 	 * clear LZ4_0PADDING feature for old kernel compatibility.
 	 */
 	if (!cfg.c_compr_alg_master ||
-	    strncmp(cfg.c_compr_alg_master, "lz4", 3))
+	    (strncmp(cfg.c_compr_alg_master, "lz4", 3) &&
+	     strcmp(cfg.c_compr_alg_master, "lzma")))
 		erofs_sb_clear_lz4_0padding();
 
 	if (!cfg.c_compr_alg_master)
diff --git a/lib/compressor.c b/lib/compressor.c
index e28aa8f934c0..cc39fc7a685a 100644
--- a/lib/compressor.c
+++ b/lib/compressor.c
@@ -19,6 +19,7 @@ static struct erofs_compressor *compressors[] = {
 #endif
 		&erofs_compressor_lz4,
 #endif
+		&erofs_compressor_lzma,
 };
 
 int erofs_compress_destsize(struct erofs_compress *c,
diff --git a/lib/compressor.h b/lib/compressor.h
index 8c4e72cfa8b9..e783ca1de509 100644
--- a/lib/compressor.h
+++ b/lib/compressor.h
@@ -45,6 +45,7 @@ struct erofs_compress {
 /* list of compression algorithms */
 extern struct erofs_compressor erofs_compressor_lz4;
 extern struct erofs_compressor erofs_compressor_lz4hc;
+extern struct erofs_compressor erofs_compressor_lzma;
 
 int erofs_compress_destsize(struct erofs_compress *c,
 			    void *src, unsigned int *srcsize,
diff --git a/lib/compressor_liblzma.c b/lib/compressor_liblzma.c
new file mode 100644
index 000000000000..af135c2cd32b
--- /dev/null
+++ b/lib/compressor_liblzma.c
@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * erofs-utils/lib/compressor_liblzma.c
+ *
+ * Copyright (C) 2018-2019 HUAWEI, Inc.
+ *             http://www.huawei.com/
+ * Created by Gao Xiang <gaoxiang25 at huawei.com>
+ */
+#include <stdlib.h>
+#include <lzma.h>
+#include "erofs/internal.h"
+#include "compressor.h"
+
+struct erofs_liblzma_context {
+	lzma_options_lzma opt;
+	lzma_stream strm;
+};
+
+static int erofs_liblzma_compress_destsize(struct erofs_compress *c,
+					   void *src, unsigned int *srcsize,
+					   void *dst, unsigned int dstsize)
+{
+	struct erofs_liblzma_context *ctx = c->private_data;
+	lzma_stream *strm = &ctx->strm;
+
+	lzma_ret ret = lzma_erofs_encoder(strm, &ctx->opt);
+	if (ret != LZMA_OK)
+		return -EFAULT;
+
+	strm->next_in = src;
+	strm->avail_in = *srcsize;
+	strm->next_out = dst;
+	strm->avail_out = dstsize;
+
+	ret = lzma_code(strm, LZMA_FINISH);
+	if (ret != LZMA_STREAM_END)
+		return -EBADMSG;
+
+	*srcsize = strm->total_in;
+	return strm->total_out;
+}
+
+static int erofs_compressor_liblzma_exit(struct erofs_compress *c)
+{
+	struct erofs_liblzma_context *ctx = c->private_data;
+
+	if (!ctx)
+		return -EINVAL;
+
+	lzma_end(&ctx->strm);
+	free(ctx);
+	return 0;
+}
+
+static int erofs_compressor_liblzma_setlevel(struct erofs_compress *c,
+					     int compression_level)
+{
+	struct erofs_liblzma_context *ctx = c->private_data;
+
+	if (compression_level < 0)
+		compression_level = LZMA_PRESET_DEFAULT;
+
+	if (lzma_lzma_preset(&ctx->opt, compression_level))
+		return -EINVAL;
+
+	ctx->opt.dict_size = 64U << 10;
+	c->compression_level = compression_level;
+	return 0;
+}
+
+static int erofs_compressor_liblzma_init(struct erofs_compress *c)
+{
+	struct erofs_liblzma_context *ctx;
+
+	c->alg = &erofs_compressor_lzma;
+	ctx = malloc(sizeof(*ctx));
+	if (!ctx)
+		return -ENOMEM;
+	ctx->strm = (lzma_stream)LZMA_STREAM_INIT;
+	c->private_data = ctx;
+	return 0;
+}
+
+struct erofs_compressor erofs_compressor_lzma = {
+	.name = "lzma",
+	.default_level = LZMA_PRESET_DEFAULT,
+	.best_level = LZMA_PRESET_EXTREME,
+	.init = erofs_compressor_liblzma_init,
+	.exit = erofs_compressor_liblzma_exit,
+	.setlevel = erofs_compressor_liblzma_setlevel,
+	.compress_destsize = erofs_liblzma_compress_destsize,
+};
+
-- 
2.24.0