From 551dd3879c288a2b6b6fbaca5c09c04fbe994ff4 Mon Sep 17 00:00:00 2001
From: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Date: Tue, 13 Dec 2022 09:15:19 +0100
Subject: Split stream compression out of libio

Move it to a separate libxfrm library, where it can be independently
tested as well. The bulk of the new code is also mainly test cases
for the compressors.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
---
 bin/tar2sqfs/Makemodule.am |  2 +-
 bin/tar2sqfs/options.c     |  8 +++----
 bin/tar2sqfs/tar2sqfs.c    | 60 ++++++++++++++++++++++++++++------------------
 bin/tar2sqfs/tar2sqfs.h    |  1 +
 4 files changed, 43 insertions(+), 28 deletions(-)

(limited to 'bin/tar2sqfs')

diff --git a/bin/tar2sqfs/Makemodule.am b/bin/tar2sqfs/Makemodule.am
index a9c503f..faa2948 100644
--- a/bin/tar2sqfs/Makemodule.am
+++ b/bin/tar2sqfs/Makemodule.am
@@ -1,7 +1,7 @@
 tar2sqfs_SOURCES = bin/tar2sqfs/tar2sqfs.c bin/tar2sqfs/tar2sqfs.h
 tar2sqfs_SOURCES += bin/tar2sqfs/options.c bin/tar2sqfs/process_tarball.c
 tar2sqfs_CFLAGS = $(AM_CFLAGS) $(PTHREAD_CFLAGS)
-tar2sqfs_LDADD = libcommon.a libsquashfs.la libtar.a libio.a
+tar2sqfs_LDADD = libcommon.a libsquashfs.la libtar.a libio.a libxfrm.a
 tar2sqfs_LDADD += libfstree.a libcompat.a libfstree.a libutil.a $(LZO_LIBS)
 tar2sqfs_LDADD += $(ZLIB_LIBS) $(XZ_LIBS) $(ZSTD_LIBS) $(BZIP2_LIBS)
 tar2sqfs_LDADD += $(PTHREAD_LIBS)
diff --git a/bin/tar2sqfs/options.c b/bin/tar2sqfs/options.c
index 94e7036..f2185a6 100644
--- a/bin/tar2sqfs/options.c
+++ b/bin/tar2sqfs/options.c
@@ -94,15 +94,15 @@ char *root_becomes = NULL;
 
 static void input_compressor_print_available(void)
 {
-	int i = IO_COMPRESSOR_MIN;
+	int i = XFRM_COMPRESSOR_MIN;
 	const char *name;
 
 	fputs("\nSupported tar compression formats:\n", stdout);
 
-	while (i <= IO_COMPRESSOR_MAX) {
-		name = io_compressor_name_from_id(i);
+	while (i <= XFRM_COMPRESSOR_MAX) {
+		name = xfrm_compressor_name_from_id(i);
 
-		if (io_compressor_exists(i))
+		if (name != NULL)
 			printf("\t%s\n", name);
 
 		++i;
diff --git a/bin/tar2sqfs/tar2sqfs.c b/bin/tar2sqfs/tar2sqfs.c
index 572eb10..9257fed 100644
--- a/bin/tar2sqfs/tar2sqfs.c
+++ b/bin/tar2sqfs/tar2sqfs.c
@@ -32,12 +32,45 @@ static int tar_probe(const sqfs_u8 *data, size_t size)
 	return 0;
 }
 
+static istream_t *magic_autowrap(istream_t *strm)
+{
+	xfrm_stream_t *xfrm = NULL;
+	istream_t *wrapper = NULL;
+	const sqfs_u8 *data;
+	size_t avail;
+	int ret;
+
+	ret = istream_precache(strm);
+	if (ret != 0)
+		goto out;
+
+	data = strm->buffer + strm->buffer_offset;
+	avail = strm->buffer_used - strm->buffer_offset;
+
+	ret = tar_probe(data, avail);
+	if (ret > 0)
+		return strm;
+
+	ret = xfrm_compressor_id_from_magic(data, avail);
+	if (ret <= 0)
+		return strm;
+
+	xfrm = decompressor_stream_create(ret);
+	if (xfrm == NULL)
+		goto out;
+
+	wrapper = istream_xfrm_create(strm, xfrm);
+out:
+	sqfs_drop(strm);
+	sqfs_drop(xfrm);
+	return wrapper;
+}
+
 int main(int argc, char **argv)
 {
 	int status = EXIT_FAILURE;
 	istream_t *input_file = NULL;
 	sqfs_writer_t sqfs;
-	int ret;
 
 	process_args(argc, argv);
 
@@ -45,28 +78,9 @@ int main(int argc, char **argv)
 	if (input_file == NULL)
 		return EXIT_FAILURE;
 
-	ret = istream_detect_compressor(input_file, tar_probe);
-	if (ret < 0)
-		goto out_if;
-
-	if (ret > 0) {
-		istream_t *strm;
-
-		if (!io_compressor_exists(ret)) {
-			fprintf(stderr,
-				"%s: %s compression is not supported.\n",
-				istream_get_filename(input_file),
-				io_compressor_name_from_id(ret));
-			goto out_if;
-		}
-
-		strm = istream_compressor_create(input_file, ret);
-		sqfs_drop(input_file);
-		input_file = strm;
-
-		if (input_file == NULL)
-			return EXIT_FAILURE;
-	}
+	input_file = magic_autowrap(input_file);
+	if (input_file == NULL)
+		return EXIT_FAILURE;
 
 	memset(&sqfs, 0, sizeof(sqfs));
 	if (sqfs_writer_init(&sqfs, &cfg))
diff --git a/bin/tar2sqfs/tar2sqfs.h b/bin/tar2sqfs/tar2sqfs.h
index 6e4d123..a21774b 100644
--- a/bin/tar2sqfs/tar2sqfs.h
+++ b/bin/tar2sqfs/tar2sqfs.h
@@ -14,6 +14,7 @@
 #include "util/util.h"
 #include "tar/tar.h"
 #include "tar/format.h"
+#include "xfrm/compress.h"
 #include "io/xfrm.h"
 
 #include <stdlib.h>
-- 
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