add_inode: support LZX compression

src/decomp.cpp

@@ -16,6 +16,9 @@
  * along with Ntfs2btrfs. If not, see <https://www.gnu.org/licenses/>. */
 
 #include "ntfs2btrfs.h"
+#include "ebiggers/system_compression.h"
+
+#define LZX_CHUNK_SIZE 32768
 
 using namespace std;
 
@@ -144,3 +147,35 @@ string lznt1_decompress(string_view compdata, uint64_t size) {
 
  return ret;
 }
+
+string do_lzx_decompress(const string_view& compdata, uint64_t size) {
+ auto ctx = lzx_allocate_decompressor(LZX_CHUNK_SIZE);
+
+ if (!ctx)
+ throw formatted_error(FMT_STRING("lzx_allocate_decompressor returned NULL."));
+
+ uint64_t num_chunks = (size + LZX_CHUNK_SIZE - 1) / LZX_CHUNK_SIZE;
+ auto offsets = (uint32_t*)compdata.data();
+
+ string ret;
+
+ ret.resize(size);
+
+ for (uint64_t i = 0; i < num_chunks; i++) {
+ uint64_t off = (num_chunks - 1) * sizeof(uint32_t);
+ if (i != 0)
+ off += offsets[i - 1];
+
+ auto err = lzx_decompress(ctx, compdata.data() + off, compdata.length() - off, ret.data() + (i * LZX_CHUNK_SIZE),
+ i == num_chunks - 1 ? (ret.length() - (i * LZX_CHUNK_SIZE)) : LZX_CHUNK_SIZE);
+
+ if (err != 0) {
+ lzx_free_decompressor(ctx);
+ throw formatted_error(FMT_STRING("lzx_decompress returned {}."), err);
+ }
+ }
+
+ lzx_free_decompressor(ctx);
+
+ return ret;
+}

src/ebiggers/system_compression.h

@@ -17,8 +17,11 @@
  * this program. If not, see <http:https://www.gnu.org/licenses/>.
  */
 
-#ifndef _NTFS_SYSTEM_COMPRESSION_H
-#define _NTFS_SYSTEM_COMPRESSION_H
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
 
 #include <stddef.h>
 #include <sys/types.h>
@@ -55,4 +58,6 @@ extern int lzx_decompress(struct lzx_decompressor *decompressor,
 
 extern void lzx_free_decompressor(struct lzx_decompressor *decompressor);
 
-#endif /* _NTFS_SYSTEM_COMPRESSION_H */
+#ifdef __cplusplus
+}
+#endif

src/ntfs2btrfs.cpp

@@ -2064,7 +2064,9 @@ static void add_inode(root& r, uint64_t inode, uint64_t ntfs_inode, bool& is_dir
  throw formatted_error(FMT_STRING("FIXME - FILE_PROVIDER_COMPRESSION_XPRESS4K WofCompressedData"));
 
  case FILE_PROVIDER_COMPRESSION_LZX:
- throw formatted_error(FMT_STRING("FIXME - FILE_PROVIDER_COMPRESSION_LZX WofCompressedData"));
+ mappings.clear();
+ inline_data = do_lzx_decompress(wof_compressed_data, file_size);
+ break;
 
  case FILE_PROVIDER_COMPRESSION_XPRESS8K:
  throw formatted_error(FMT_STRING("FIXME - FILE_PROVIDER_COMPRESSION_XPRESS8K WofCompressedData"));

src/ntfs2btrfs.h

@@ -260,3 +260,4 @@ void process_fixups(MULTI_SECTOR_HEADER* header, uint64_t length, unsigned int s
 
 // decomp.cpp
 std::string lznt1_decompress(std::string_view compdata, uint64_t size);
+std::string do_lzx_decompress(const std::string_view& compdata, uint64_t size);