Complete the diff generating functionality.

endpoints/api.py

@@ -1,5 +1,6 @@
 import logging
 import stripe
+import re
 
 from flask import request, make_response, jsonify, abort
 from flask.ext.login import login_required, current_user, logout_user
@@ -7,6 +8,8 @@ from flask.ext.principal import identity_changed, AnonymousIdentity
 from functools import wraps
 from collections import defaultdict
 
+import storage
+
 from data import model
 from app import app
 from util.email import send_confirmation_email, send_recovery_email
@@ -17,8 +20,9 @@ from auth.permissions import (ReadRepositoryPermission,
                               AdministerRepositoryPermission)
 from endpoints import registry
 from endpoints.web import common_login
-import re
 
+
+store = storage.load()
 logger = logging.getLogger(__name__)
 
 
@@ -366,11 +370,13 @@ def list_repository_images(namespace, repository):
 def get_repository_changes(namespace, repository, image_id):
   permission = ReadRepositoryPermission(namespace, repository)
   if permission.can() or model.repository_is_public(namespace, repository):
-    return jsonify({
-      'added': [],
-      'changed': [],
-      'removed': []
-    })
+    diffs_path = store.image_file_diffs_path(namespace, repository, image_id)
+
+    try:
+      response_json = store.get_content(diffs_path)
+      return make_response(response_json)
+    except IOError:
+      abort(404)
 
   abort(403)
 

endpoints/registry.py

@@ -1,4 +1,3 @@
-
 import logging
 import json
 
@@ -11,7 +10,7 @@ import storage
 
 from app import app
 from auth.auth import process_auth, extract_namespace_repo_from_session
-from util import checksums
+from util import checksums, changes
 from auth.permissions import (ReadRepositoryPermission,
                               ModifyRepositoryPermission)
 from data import model
@@ -315,6 +314,49 @@ def delete_repository_storage(namespace, repository):
 
 
 def process_image_changes(namespace, repository, image_id):
-  return
+  logger.debug('Generating diffs for image: %s' % image_id)
+
+  image_diffs_path = store.image_file_diffs_path(namespace, repository,
+                                                 image_id)
+  if store.exists(image_diffs_path):
+    logger.debug('Diffs already exist for image: %s' % image_id)
+    return
+
   image = model.get_image_by_id(namespace, repository, image_id)
-  model.get_parent_images()
+  parents = model.get_parent_images(image)
+
+  # Compute the diffs and fs for the parent first if necessary
+  parent_trie_path = None
+  if parents:
+    parent_trie_path = process_image_changes(namespace, repository,
+                                             parents[-1].docker_image_id)
+
+  # Read in the collapsed layer state of the filesystem for the parent
+  parent_trie = changes.empty_fs()
+  if parent_trie_path:
+    with store.stream_read_file(parent_trie_path) as parent_trie_stream:
+      parent_trie.read(parent_trie_stream)
+
+  # Read in the file entries from the layer tar file
+  layer_path = store.image_layer_path(namespace, repository, image_id)
+  with store.stream_read_file(layer_path) as layer_tar_stream:
+    removed_files = set()
+    layer_files = changes.files_and_dirs_from_tar(layer_tar_stream,
+                                                  removed_files)
+
+    new_metadata = changes.compute_new_diffs_and_fs(parent_trie, layer_files,
+                                                    removed_files)
+  (new_trie, added, changed, removed) = new_metadata
+
+  # Write out the new trie
+  new_trie_path = store.image_file_trie_path(namespace, repository, image_id)
+  store.put_content(new_trie_path, new_trie.tobytes())
+
+  # Write out the diffs
+  diffs = {}
+  sections = ('added', 'changed', 'removed')
+  for section, source_trie in zip(sections, new_metadata[1:]):
+    diffs[section] = list(source_trie)
+  store.put_content(image_diffs_path, json.dumps(diffs, indent=2))
+
+  return new_trie_path

storage/__init__.py

@@ -58,9 +58,9 @@ class Storage(object):
     return '{0}/{1}/{2}/{3}/files.trie'.format(self.images, namespace,
                                                repository, image_id)
 
-  def image_file_diffs_trie_path(self, namespace, repository, image_id):
-    return '{0}/{1}/{2}/{3}/diffs.pkl'.format(self.images, namespace,
-                                              repository, image_id)
+  def image_file_diffs_path(self, namespace, repository, image_id):
+    return '{0}/{1}/{2}/{3}/diffs.json'.format(self.images, namespace,
+                                               repository, image_id)
 
   def get_content(self, path):
     raise NotImplementedError
@@ -71,6 +71,9 @@ class Storage(object):
   def stream_read(self, path):
     raise NotImplementedError
 
+  def stream_read_file(self, path):
+    raise NotImplementedError
+
   def stream_write(self, path, fp):
     raise NotImplementedError
 

storage/local.py

@@ -38,6 +38,10 @@ class LocalStorage(Storage):
                     break
                 yield buf
 
+    def stream_read_file(self, path):
+        path = self._init_path(path)
+        return open(path, mode='rb')
+
     def stream_write(self, path, fp):
         # Size is mandatory
         path = self._init_path(path, create=True)

storage/s3.py

@@ -60,6 +60,13 @@ class S3Storage(Storage):
                 break
             yield buf
 
+    def stream_read_file(self, path):
+        path = self._init_path(path)
+        key = boto.s3.key.Key(self._s3_bucket, path)
+        if not key.exists():
+            raise IOError('No such key: \'{0}\''.format(path))
+        return key
+
     def stream_write(self, path, fp):
         # Minimum size of upload part size on S3 is 5MB
         buffer_size = 5 * 1024 * 1024

util/changes.py

@@ -1,5 +1,6 @@
 import marisa_trie
 import os
+import tarfile
 
 
 AUFS_METADATA = u'.wh..wh.'
@@ -8,33 +9,34 @@ AUFS_WHITEOUT = u'.wh.'
 AUFS_WHITEOUT_PREFIX_LENGTH = len(AUFS_WHITEOUT)
 
 
-def files_and_dirs(root_path, removed_prefix_collector):
-  for root, dirs, files in os.walk(unicode(root_path)):
+def files_and_dirs_from_tar(source_stream, removed_prefix_collector):
+  tar_stream = tarfile.open(mode='r|*', fileobj=source_stream)
+  
+  for tar_info in tar_stream:
+    absolute = os.path.relpath(unicode(tar_info.name), './')
+    filename = os.path.basename(absolute)
 
-    rel_root = os.path.relpath(root, root_path)
-    yield rel_root
+    if (filename.startswith(AUFS_METADATA) or
+        absolute.startswith(AUFS_METADATA)):
+      # Skip
+      continue
 
-    for one_file in files:
-      if one_file.startswith(AUFS_METADATA):
-        # Skip
-        continue
+    elif filename.startswith(AUFS_WHITEOUT):
+      filename = filename[AUFS_WHITEOUT_PREFIX_LENGTH:]
+      removed_prefix_collector.add(absolute)
+      continue
 
-      elif one_file.startswith(AUFS_WHITEOUT):
-        filename = one_file[AUFS_WHITEOUT_PREFIX_LENGTH:]
-        removed_prefix_collector.add(os.path.join(rel_root, filename))
-        continue
-
-      else:
-        yield os.path.join(rel_root, one_file)
+    else:
+      yield absolute
 
 
-def compute_removed(base_trie, removed_prefixes):
+def __compute_removed(base_trie, removed_prefixes):
   for prefix in removed_prefixes:
     for filename in base_trie.keys(prefix):
       yield filename
 
 
-def compute_added_changed(base_trie, delta_trie):
+def __compute_added_changed(base_trie, delta_trie):
   added = set()
   changed = set()
 
@@ -47,10 +49,27 @@ def compute_added_changed(base_trie, delta_trie):
   return added, changed
 
 
-def new_fs(base_trie, added, removed):
+def __new_fs(base_trie, added, removed):
   for filename in base_trie.keys():
     if filename not in removed:
       yield filename
 
   for filename in added:
-    yield filename
+    yield filename
+
+
+def empty_fs():
+  return marisa_trie.Trie()
+
+
+def compute_new_diffs_and_fs(base_trie, filename_source,
+                             removed_prefix_collector):
+  new_trie = marisa_trie.Trie(filename_source)
+  (new_added, new_changed) = __compute_added_changed(base_trie, new_trie)
+
+  new_removed = marisa_trie.Trie(__compute_removed(base_trie,
+                                                   removed_prefix_collector))
+
+  new_fs = marisa_trie.Trie(__new_fs(base_trie, new_added, new_removed))
+
+  return (new_fs, new_added, new_changed, new_removed.keys())