feat(dwarfsextract): add --format-options

This allows users to pass custom libarchive options of the specific output
format. Eg. `mtree:sha256` or `zstd:compression-level=9`.

doc/dwarfsextract.md

@@ -67,6 +67,12 @@ to disk:
   if no output directory is specified). For a full list of supported formats,
   see libarchive-formats(5).
 
+- `--format-options=`*options*:
+
+  Comma-separated libarchive options for the specific output format.
+  The options are passed to libarchive. For a full list of options for each
+  output format, see archive_write_set_options(3).
+
 - `--continue-on-error`:
   Try to continue with extraction even when errors are encountered. This
   only applies to errors when reading from the file system image. Errors

include/dwarfs/utility/filesystem_extractor.h

@@ -63,12 +63,14 @@ class filesystem_extractor {
   static void add_library_dependencies(library_dependencies& deps);
 
   void
-  open_archive(std::filesystem::path const& output, std::string const& format) {
-    impl_->open_archive(output, format);
+  open_archive(std::filesystem::path const& output, std::string const& format,
+               std::string const& format_options = "") {
+    impl_->open_archive(output, format, format_options);
   }
 
-  void open_stream(std::ostream& os, std::string const& format) {
-    impl_->open_stream(os, format);
+  void open_stream(std::ostream& os, std::string const& format,
+                   std::string const& format_options = "") {
+    impl_->open_stream(os, format, format_options);
   }
 
   void open_disk(std::filesystem::path const& output) {
@@ -94,9 +96,11 @@ class filesystem_extractor {
    public:
     virtual ~impl() = default;
 
-    virtual void open_archive(std::filesystem::path const& output,
-                              std::string const& format) = 0;
-    virtual void open_stream(std::ostream& os, std::string const& format) = 0;
+    virtual void
+    open_archive(std::filesystem::path const& output, std::string const& format,
+                 std::string const& format_options = "") = 0;
+    virtual void open_stream(std::ostream& os, std::string const& format,
+                             std::string const& format_options) = 0;
     virtual void open_disk(std::filesystem::path const& output) = 0;
     virtual void close() = 0;
     virtual bool

src/utility/filesystem_extractor.cpp

@@ -122,16 +122,20 @@ class filesystem_extractor_ final : public filesystem_extractor::impl {
     }
   }
 
-  void open_archive(std::filesystem::path const& output [[maybe_unused]],
-                    std::string const& format [[maybe_unused]]) override {
+  void
+  open_archive(std::filesystem::path const& output [[maybe_unused]],
+               std::string const& format [[maybe_unused]],
+               std::string const& format_options [[maybe_unused]]) override {
 #ifdef DWARFS_FILESYSTEM_EXTRACTOR_NO_OPEN_FORMAT
     DWARFS_THROW(runtime_error, "open_archive() not supported in this build");
 #else
-    LOG_DEBUG << "opening archive file in " << format << " format";
+    LOG_DEBUG << "opening archive file in " << format
+              << " format with options '" << format_options << "'";
 
     a_ = ::archive_write_new();
 
     check_result(::archive_write_set_format_by_name(a_, format.c_str()));
+    check_result(::archive_write_set_options(a_, format_options.c_str()));
     check_result(::archive_write_set_bytes_in_last_block(a_, 1));
 
 #ifdef _WIN32
@@ -144,8 +148,10 @@ class filesystem_extractor_ final : public filesystem_extractor::impl {
 #endif
   }
 
-  void open_stream(std::ostream& os [[maybe_unused]],
-                   std::string const& format [[maybe_unused]]) override {
+  void
+  open_stream(std::ostream& os [[maybe_unused]],
+              std::string const& format [[maybe_unused]],
+              std::string const& format_options [[maybe_unused]]) override {
 #ifdef DWARFS_FILESYSTEM_EXTRACTOR_NO_OPEN_FORMAT
     DWARFS_THROW(runtime_error, "open_stream() not supported in this build");
 #else
@@ -162,11 +168,13 @@ class filesystem_extractor_ final : public filesystem_extractor::impl {
     iot_ = std::make_unique<std::thread>(
         [this, &os, fd = pipefd_[0]] { pump(os, fd); });
 
-    LOG_DEBUG << "opening archive stream in " << format << " format";
+    LOG_DEBUG << "opening archive stream in " << format
+              << " format with options '" << format_options << "'";
 
     a_ = ::archive_write_new();
 
     check_result(::archive_write_set_format_by_name(a_, format.c_str()));
+    check_result(::archive_write_set_options(a_, format_options.c_str()));
     check_result(::archive_write_set_bytes_in_last_block(a_, 1));
     check_result(::archive_write_open_fd(a_, pipefd_[1]));
 #endif

test/manpage_test.cpp

@@ -194,6 +194,7 @@ TEST_P(manpage_coverage_test, options) {
   if (tool_name == "dwarfsextract") {
 #ifdef DWARFS_FILESYSTEM_EXTRACTOR_NO_OPEN_FORMAT
     man_opts.erase("format");
+    man_opts.erase("format-options");
 #endif
     man_opts.erase("pattern");
   }

test/tool_main_test.cpp

@@ -2253,11 +2253,14 @@ INSTANTIATE_TEST_SUITE_P(dwarfs, mkdwarfs_progress_test,
 #ifndef DWARFS_FILESYSTEM_EXTRACTOR_NO_OPEN_FORMAT
 TEST(dwarfsextract_test, mtree) {
   auto t = dwarfsextract_tester::create_with_image();
-  ASSERT_EQ(0, t.run({"-i", "image.dwarfs", "-f", "mtree"})) << t.err();
+  ASSERT_EQ(0, t.run({"-i", "image.dwarfs", "-f", "mtree", "--format-options",
+                      "mtree:sha256"}))
+      << t.err();
   auto out = t.out();
   EXPECT_TRUE(out.starts_with("#mtree")) << out;
   EXPECT_THAT(out, ::testing::HasSubstr("type=dir"));
   EXPECT_THAT(out, ::testing::HasSubstr("type=file"));
+  EXPECT_THAT(out, ::testing::HasSubstr("sha256digest="));
 }
 
 TEST(dwarfsextract_test, patterns) {

tools/src/dwarfsextract_main.cpp

@@ -72,7 +72,7 @@ int dwarfsextract_main(int argc, sys_char** argv, iolayer const& iol) {
   std::string cache_size_str, image_offset;
   logger_options logopts;
 #ifndef DWARFS_FILESYSTEM_EXTRACTOR_NO_OPEN_FORMAT
-  std::string format;
+  std::string format, format_options;
 #endif
 #if DWARFS_PERFMON_ENABLED
   std::string perfmon_str;
@@ -100,6 +100,9 @@ int dwarfsextract_main(int argc, sys_char** argv, iolayer const& iol) {
     ("format,f",
         po::value<std::string>(&format),
         "output format")
+    ("format-options",
+        po::value<std::string>(&format_options),
+        "comma-separated libarchive options for the specific output format")
 #endif
     ("continue-on-error",
         po::value<bool>(&continue_on_error)->zero_tokens(),
@@ -228,9 +231,9 @@ int dwarfsextract_main(int argc, sys_char** argv, iolayer const& iol) {
       }
 
       if (stream) {
-        fsx.open_stream(*stream, format);
+        fsx.open_stream(*stream, format, format_options);
       } else {
-        fsx.open_archive(iol.os->canonical(output), format);
+        fsx.open_archive(iol.os->canonical(output), format, format_options);
       }
     }
 #endif