ui-snapshot: add support for zstd compression

This patch adds support for zstd [0] compressed snapshots (*.tar.zst).
We enable multiple working threads (-T0), but keep default compression
level. The latter can be influenced by environment variable.

[0] https://www.zstd.net/

Signed-off-by: Christian Hesse <mail@eworm.de>

1 files changed, 7 insertions, 0 deletions

diff --git a/ui-snapshot.c b/ui-snapshot.c
index 92cde42..556d3ed 100644
--- a/ui-snapshot.c
+++ b/ui-snapshot.c
@@ -91,6 +91,12 @@ static int write_tar_xz_archive(const char *hex, const char *prefix)
         return write_compressed_tar_archive(hex, prefix, argv);
 }
 
+static int write_tar_zstd_archive(const char *hex, const char *prefix)
+{
+        char *argv[] = { "zstd", "-T0", NULL };
+        return write_compressed_tar_archive(hex, prefix, argv);
+}
+
 const struct cgit_snapshot_format cgit_snapshot_formats[] = {
         /* .tar must remain the 0 index */
         { ".tar",       "application/x-tar",    write_tar_archive       },
@@ -98,6 +104,7 @@ const struct cgit_snapshot_format cgit_snapshot_formats[] = {
         { ".tar.bz2",   "application/x-bzip2",  write_tar_bzip2_archive },
         { ".tar.lz",    "application/x-lzip",   write_tar_lzip_archive  },
         { ".tar.xz",    "application/x-xz",     write_tar_xz_archive    },
+        { ".tar.zst",   "application/x-zstd",   write_tar_zstd_archive  },
         { ".zip",       "application/x-zip",    write_zip_archive       },
         { NULL }
 };