- Merge branch 'master' into sha-lom

- Extract out the tar handling from streamlayerformat into tarlayerformat
- Add a new tarfileappender class to make it easy to append data to gzipped tars
- Fix the gzipwrap to properly close
- Have the .git injection use the new appender

util/gzipwrap.py

@@ -1,12 +1,19 @@
 from gzip import GzipFile
 
+# 256K buffer to Gzip
+GZIP_BUFFER_SIZE = 1024 * 256
+
 class GzipWrap(object):
   def __init__(self, input, filename=None, compresslevel=1):
     self.input = iter(input)
     self.buffer = ''
     self.zipper = GzipFile(filename, mode='wb', fileobj=self, compresslevel=compresslevel)
+    self.is_done = False
     
   def read(self, size=-1):
+    if self.is_done:
+      return ''
+
     # If the buffer already has enough bytes, then simply pop them off of
     # the beginning and return them.
     if len(self.buffer) >= size:
@@ -21,7 +28,7 @@ class GzipWrap(object):
 
       input_size = 0
       input_buffer = ''
-      while input_size < 1024 * 256:  # 256K buffer to Gzip
+      while input_size < GZIP_BUFFER_SIZE:
         try:
           s = self.input.next()
           input_buffer += s
@@ -34,6 +41,8 @@ class GzipWrap(object):
 
       if is_done:
         self.zipper.flush()
+        self.zipper.close()
+        self.is_done = True
 
       if len(self.buffer) >= size or is_done:
         ret = self.buffer[0:size]