Added gzip file support to lorry

The new 'gzip' lorry file is practical for any gzipped single file
repositories, this can be useful for some static blob resources,
such as fonts.

Change-Id: I931e15e4c1291d820db82d0fc764aa767d3df9ab

1 files changed, 61 insertions, 0 deletions

diff --git a/lorry.gzip-importer b/lorry.gzip-importer
new file mode 100755
index 0000000..c1c7215
--- /dev/null
+++ b/lorry.gzip-importer
@@ -0,0 +1,61 @@
+#!/usr/bin/env python
+
+# gzip archive frontend for git-fast-import
+
+from os import popen, path
+from os.path import splitext
+from os.path import getmtime
+from sys import argv, exit, hexversion, stderr
+from gzip import GzipFile
+import struct
+
+if len(argv) < 2:
+    print 'usage:', argv[0], '<gzipfile>...'
+    exit(1)
+
+branch_name = 'master'
+branch_ref = 'refs/heads/%s' % branch_name
+committer_name = 'Lorry Gzip Importer'
+committer_email = 'lorry-gzip-importer@lorry'
+
+fast_import = popen('git fast-import --quiet', 'w')
+def printlines(list):
+    for str in list:
+        fast_import.write(str + "\n")
+
+# The size of a gzip file is stored in the last 4 bytes
+def uncompressedsize(filename):
+    with open(filename) as f:
+        f.seek(-4, 2)
+        return struct.unpack('I', f.read(4))[0]
+
+for zipfile in argv[1:]:
+
+    # Gzip does have an encoded mtime, however Python's GzipFile
+    # just ignores it, so we just yank the mtime of the zip file itself.
+    mtime = getmtime (zipfile);
+    file_size = uncompressedsize (zipfile);
+    zip = GzipFile(zipfile, 'rb')
+
+    printlines(('blob', 'mark :1', 'data ' + str(file_size)))
+    fast_import.write(zip.read() + "\n")
+
+    committer = committer_name + ' <' + committer_email + '> %d +0000' % \
+        mtime
+
+    zipfile_basename = path.basename(zipfile)
+    printlines(('commit ' + branch_ref, 'committer ' + committer, \
+        'data <<EOM', 'Imported from ' + zipfile_basename + '.', 'EOM', \
+        '', 'deleteall'))
+
+    last_dot = zipfile_basename[:-1].rfind('.')
+    unzipped_file = zipfile_basename[:last_dot]
+    fast_import.write('M 100644 :1 ' + unzipped_file + '\n');
+
+    zipname, _ = splitext(zipfile_basename)
+    printlines(('',  'tag ' + zipname, \
+        'from ' + branch_ref, 'tagger ' + committer, \
+        'data <<EOM', 'Package ' + zipfile, 'EOM', ''))
+
+if fast_import.close():
+    exit(1)