Add a chunks_finished to BaseDiskFileWriter

BaseDiskFileWriter will track md5 and expose upload_size, etag via the
chunks_finished method.

The BaseDiskFileReader already tracks the md5/etag via _iter_etag, for
parity we add a _chunks_etag to the BaseDiskFileReader.

Instead of returning the upload_size and hexdigest every call to write,
we return the tuple from chunks_finished.

Change-Id: I26c58719cff5fde941d0248c250a0204e0379ae5

swift/obj/diskfile.py

@@ -39,7 +39,7 @@ import os
 import re
 import time
 import uuid
-import hashlib
+from hashlib import md5
 import logging
 import traceback
 import xattr
@@ -194,14 +194,14 @@ def read_metadata(fd, add_missing_checksum=False):
         # exist. This is fine; it just means that this object predates the
         # introduction of metadata checksums.
         if add_missing_checksum:
-            new_checksum = hashlib.md5(metadata).hexdigest()
+            new_checksum = md5(metadata).hexdigest()
             try:
                 xattr.setxattr(fd, METADATA_CHECKSUM_KEY, new_checksum)
             except (IOError, OSError) as e:
                 logging.error("Error adding metadata: %s" % e)
 
     if metadata_checksum:
-        computed_checksum = hashlib.md5(metadata).hexdigest().encode('ascii')
+        computed_checksum = md5(metadata).hexdigest().encode('ascii')
         if metadata_checksum != computed_checksum:
             raise DiskFileBadMetadataChecksum(
                 "Metadata checksum mismatch for %s: "
@@ -226,7 +226,7 @@ def write_metadata(fd, metadata, xattr_size=65536):
     :param metadata: metadata to write
     """
     metastr = pickle.dumps(_encode_metadata(metadata), PICKLE_PROTOCOL)
-    metastr_md5 = hashlib.md5(metastr).hexdigest().encode('ascii')
+    metastr_md5 = md5(metastr).hexdigest().encode('ascii')
     key = 0
     try:
         while metastr:
@@ -1084,7 +1084,7 @@ class BaseDiskFileManager(object):
 
         :param path: full path to directory
         """
-        hashes = defaultdict(hashlib.md5)
+        hashes = defaultdict(md5)
         try:
             path_contents = sorted(os.listdir(path))
         except OSError as err:
@@ -1626,6 +1626,7 @@ class BaseDiskFileWriter(object):
         self._fd = None
         self._tmppath = None
         self._size = size
+        self._chunks_etag = md5()
         self._bytes_per_sync = bytes_per_sync
         self._diskfile = diskfile
         self.next_part_power = next_part_power
@@ -1716,13 +1717,10 @@ class BaseDiskFileWriter(object):
         For this implementation, the data is written into a temporary file.
 
         :param chunk: the chunk of data to write as a string object
-
-        :returns: the total number of bytes written to an object
         """
-
         if not self._fd:
             raise ValueError('Writer is not open')
-
+        self._chunks_etag.update(chunk)
         while chunk:
             written = os.write(self._fd, chunk)
             self._upload_size += written
@@ -1735,7 +1733,13 @@ class BaseDiskFileWriter(object):
             drop_buffer_cache(self._fd, self._last_sync, diff)
             self._last_sync = self._upload_size
 
-        return self._upload_size
+    def chunks_finished(self):
+        """
+        Expose internal stats about written chunks.
+
+        :returns: a tuple, (upload_size, etag)
+        """
+        return self._upload_size, self._chunks_etag.hexdigest()
 
     def _finalize_put(self, metadata, target_path, cleanup):
         # Write the metadata before calling fsync() so that both data and
@@ -1940,7 +1944,7 @@ class BaseDiskFileReader(object):
     def _init_checks(self):
         if self._fp.tell() == 0:
             self._started_at_0 = True
-            self._iter_etag = hashlib.md5()
+            self._iter_etag = md5()
 
     def _update_checks(self, chunk):
         if self._iter_etag:

swift/obj/mem_diskfile.py

@@ -103,6 +103,7 @@ class DiskFileWriter(object):
         self._name = name
         self._fp = None
         self._upload_size = 0
+        self._chunks_etag = hashlib.md5()
 
     def open(self):
         """
@@ -130,7 +131,15 @@ class DiskFileWriter(object):
         """
         self._fp.write(chunk)
         self._upload_size += len(chunk)
-        return self._upload_size
+        self._chunks_etag.update(chunk)
+
+    def chunks_finished(self):
+        """
+        Expose internal stats about written chunks.
+
+        :returns: a tuple, (upload_size, etag)
+        """
+        return self._upload_size, self._chunks_etag.hexdigest()
 
     def put(self, metadata):
         """

swift/obj/server.py

@@ -796,12 +796,9 @@ class ObjectController(BaseStorageServer):
                 headers={'X-Backend-Timestamp': orig_timestamp.internal})
         orig_delete_at = int(orig_metadata.get('X-Delete-At') or 0)
         upload_expiration = time.time() + self.max_upload_time
-        etag = md5()
         elapsed_time = 0
         try:
             with disk_file.create(size=fsize) as writer:
-                upload_size = 0
-
                 # If the proxy wants to send us object metadata after the
                 # object body, it sets some headers. We have to tell the
                 # proxy, in the 100 Continue response, that we're able to
@@ -853,13 +850,13 @@ class ObjectController(BaseStorageServer):
                         if start_time > upload_expiration:
                             self.logger.increment('PUT.timeouts')
                             return HTTPRequestTimeout(request=request)
-                        etag.update(chunk)
-                        upload_size = writer.write(chunk)
+                        writer.write(chunk)
                         elapsed_time += time.time() - start_time
                 except ChunkReadError:
                     return HTTPClientDisconnect(request=request)
                 except ChunkReadTimeout:
                     return HTTPRequestTimeout(request=request)
+                upload_size, etag = writer.chunks_finished()
                 if upload_size:
                     self.logger.transfer_rate(
                         'PUT.' + device + '.timing', elapsed_time,
@@ -874,7 +871,6 @@ class ObjectController(BaseStorageServer):
 
                 request_etag = (footer_meta.get('etag') or
                                 request.headers.get('etag', '')).lower()
-                etag = etag.hexdigest()
                 if request_etag and request_etag != etag:
                     return HTTPUnprocessableEntity(request=request)
                 metadata = {

test/unit/obj/test_diskfile.py

@@ -3571,7 +3571,6 @@ class DiskFileMixin(BaseDiskFileTestMixin):
             except IndexError:
                 data = archives[0]
 
-        etag = md5()
         if ts:
             timestamp = Timestamp(ts)
         else:
@@ -3582,9 +3581,8 @@ class DiskFileMixin(BaseDiskFileTestMixin):
             prealloc_size = None
 
         with df.create(size=prealloc_size) as writer:
-            upload_size = writer.write(data)
-            etag.update(data)
-            etag = etag.hexdigest()
+            writer.write(data)
+            upload_size, etag = writer.chunks_finished()
             metadata = {
                 'ETag': etag,
                 'X-Timestamp': timestamp.internal,

test/unit/proxy/test_server.py

@@ -5863,7 +5863,8 @@ class BaseTestECObjectController(BaseTestObjectController):
         prolis = _test_sockets[0]
         prosrv = _test_servers[0]
         sock = connect_tcp(('localhost', prolis.getsockname()[1]))
-        with mock.patch('swift.obj.server.md5', busted_md5_constructor):
+        with mock.patch('swift.obj.diskfile.md5',
+                        busted_md5_constructor):
             fd = sock.makefile()
             fd.write('PUT /v1/a/%s/pimento HTTP/1.1\r\n'
                      'Host: localhost\r\n'