compression: Zero out mtime in gzip files for deterministic results

2 files changed, 3 insertions, 3 deletions

diff --git a/gemato/compression.py b/gemato/compression.py
index 4a3c9c6..cb3fa5a 100644
--- a/gemato/compression.py
+++ b/gemato/compression.py
@@ -50,9 +50,9 @@ def open_compressed_file(suffix, f, mode='rb'):
                 def read1(self, *args, **kwargs):
                     return self.read(*args, **kwargs)
 
-            return FixedGzipFile(fileobj=f, mode=mode)
+            return FixedGzipFile(fileobj=f, mode=mode, mtime=0)
 
-        return gzip.GzipFile(fileobj=f, mode=mode)
+        return gzip.GzipFile(fileobj=f, mode=mode, mtime=0)
     elif suffix == "bz2" and bz2 is not None:
         return bz2.BZ2File(f, mode=mode)
     elif suffix == "lzma" and lzma is not None:
diff --git a/utils/gen_fast_manifest.py b/utils/gen_fast_manifest.py
index ccba791..049761f 100755
--- a/utils/gen_fast_manifest.py
+++ b/utils/gen_fast_manifest.py
@@ -107,7 +107,7 @@ def gen_manifest(top_dir):
 
     manifest_data = b'\n'.join(manifest_entries) + b'\n'
     if len(manifest_data) > 4096 and not compat_mode:
-        with gzip.GzipFile(os.path.join(top_dir, 'Manifest.gz'), 'wb') as f:
+        with gzip.GzipFile(os.path.join(top_dir, 'Manifest.gz'), 'wb', mtime=0) as f:
             f.write(manifest_data)
         if had_manifest:
             os.unlink(os.path.join(top_dir, 'Manifest'))