Added ReferenceCache parser.

Added refrence storage to cas config.

buildgrid/_app/settings/cas.yml

@@ -7,7 +7,7 @@ server:
     tls-client-certs: null
 
 description: |
-  Just a CAS.
+  Just a CAS with some reference storage.
 
 instances:
   - name: main
@@ -24,3 +24,8 @@ instances:
 
       - !bytestream
         storage: *main-storage
+
+      - !reference-cache
+        storage: *main-storage
+        max_cached_refs: 256
+        allow_updates: true

buildgrid/_app/settings/parser.py

@@ -23,6 +23,7 @@ import yaml
 
 from buildgrid.server.controller import ExecutionController
 from buildgrid.server.actioncache.storage import ActionCache
+from buildgrid.server.referencestorage.storage import ReferenceCache
 from buildgrid.server.cas.instance import ByteStreamInstance, ContentAddressableStorageInstance
 from buildgrid.server.cas.storage.disk import DiskStorage
 from buildgrid.server.cas.storage.lru_memory_cache import LRUMemoryCache
@@ -126,10 +127,18 @@ class Action(YamlFactory):
 
     yaml_tag = u'!action-cache'
 
-    def __new__(cls, storage, max_cached_refs=0, allow_updates=True):
+    def __new__(cls, storage, max_cached_refs, allow_updates=True):
         return ActionCache(storage, max_cached_refs, allow_updates)
 
 
+class Reference(YamlFactory):
+
+    yaml_tag = u'!reference-cache'
+
+    def __new__(cls, storage, max_cached_refs, allow_updates=True):
+        return ReferenceCache(storage, max_cached_refs, allow_updates)
+
+
 class CAS(YamlFactory):
 
     yaml_tag = u'!cas'
@@ -160,9 +169,9 @@ def _parse_size(size):
 
 def get_parser():
 
-    yaml.SafeLoader.add_constructor(Execution.yaml_tag, Execution.from_yaml)
     yaml.SafeLoader.add_constructor(Execution.yaml_tag, Execution.from_yaml)
     yaml.SafeLoader.add_constructor(Action.yaml_tag, Action.from_yaml)
+    yaml.SafeLoader.add_constructor(Reference.yaml_tag, Reference.from_yaml)
     yaml.SafeLoader.add_constructor(Disk.yaml_tag, Disk.from_yaml)
     yaml.SafeLoader.add_constructor(LRU.yaml_tag, LRU.from_yaml)
     yaml.SafeLoader.add_constructor(S3.yaml_tag, S3.from_yaml)