Cache/retrieve extracted CIPD packages in local isolate cache

client/isolateserver.py

Index: client/isolateserver.py
diff --git a/client/isolateserver.py b/client/isolateserver.py
index c8feb0961a2e1e3785cf265c122b827c88771537..6d7ca1910699294b81f8fbcc678c3f0646c26134 100755
--- a/client/isolateserver.py
+++ b/client/isolateserver.py
@@ -364,6 +364,65 @@ def is_valid_file(path, size):
   return True
 
 
+def is_cached(ifile, cache):
+  """Determines if all the isolated file's contents are in the given LocalCache
+
+  """
+  files = ifile.data.get(u'files', {})
+  for f in files.keys():
+    # Can't do for f, props in files.keys() otherwise we see "too many
+    # values to unpack".
+    props = files.get(f, None)
+    if not props:
+      logging.warning('Problem getting info for %s', f)
+      return False
+    digest = props.get('h', None)
+    if not digest:
+      logging.warning('Hash can\'t be empty %s', f)
+      return False
+    if digest not in cache:
+      logging.info('File with digest %s is missing', digest)
+      return False
+  return True
+
+
+def extract(ifile, target_dir, cache):
+  """Extracts the isolated file's contents to target dir.
+
+  It stops if any couldn't be found.
+  """
+  files = ifile.data.get(u'files', {})
+  for f in files.keys():
+    # Can't do for f, props in files.keys() otherwise we see "too many
+    # values to unpack".
+    props = files.get(f, None)
+    if not props:
+      logging.warning('Problem getting info for %s', f)
+      return False
+    file_mode = props.get('m', None)
+    if file_mode:
+      # Ignore all bits apart from the user
+      file_mode &= 0700
+
+    dstpath = os.path.join(target_dir, f)
+    file_path.ensure_tree(os.path.dirname(dstpath))
+    digest = props.get('h', None)
+    if not digest:
+      logging.warning('Hash can\'t be empty %s', f)
+      return False
+    if digest not in cache:
+      logging.info('File with digest %s is missing', digest)
+      return False
+    srcpath = cache.getfileobj(digest).name
+
+    file_path.link_file(unicode(dstpath), unicode(srcpath),
+                        file_path.HARDLINK_WITH_FALLBACK)
+
+    if file_mode is not None:
+      fs.chmod(dstpath, file_mode)
+  return True
+
+
 class FileItem(Item):
   """A file to push to Storage.
 
@@ -1719,14 +1778,14 @@ def fetch_isolated(isolated_hash, storage, cache, outdir, use_symlinks):
   return bundle
 
 
-def directory_to_metadata(root, algo, blacklist):
+def directory_to_metadata(root, algo, blacklist, collapse_symlinks):
   """Returns the FileItem list and .isolated metadata for a directory."""
   root = file_path.get_native_path_case(root)
   paths = isolated_format.expand_directory_and_symlink(
       root, '.' + os.path.sep, blacklist, sys.platform != 'win32')
   metadata = {
     relpath: isolated_format.file_to_metadata(
-        os.path.join(root, relpath), {}, 0, algo, False)
+        os.path.join(root, relpath), {}, 0, algo, collapse_symlinks)
     for relpath in paths
   }
   for v in metadata.itervalues():
@@ -1772,7 +1831,7 @@ def archive_files_to_storage(storage, files, blacklist):
         if fs.isdir(filepath):
           # Uploading a whole directory.
           items, metadata = directory_to_metadata(
-              filepath, storage.hash_algo, blacklist)
+              filepath, storage.hash_algo, blacklist, False)
 
           # Create the .isolated file.
           if not tempdir: