Open-source some more serialization codecs, and create a PrecomputedValue codec. Since PrecomputedValues can contain any value, give them access to an ObjectCodecs instance so we don't have to have a whitelist inside PrecomputedValueCodec.

PiperOrigin-RevId: 168624137

1 files changed, 64 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/PrecomputedValueCodec.java b/src/main/java/com/google/devtools/build/lib/skyframe/PrecomputedValueCodec.java
new file mode 100644
index 0000000000..cae35b468a
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/PrecomputedValueCodec.java
@@ -0,0 +1,64 @@
+// Copyright 2017 The Bazel Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.devtools.build.lib.skyframe;
+
+import com.google.devtools.build.lib.skyframe.serialization.ObjectCodec;
+import com.google.devtools.build.lib.skyframe.serialization.ObjectCodecs;
+import com.google.devtools.build.lib.skyframe.serialization.SerializationException;
+import com.google.devtools.build.lib.util.Preconditions;
+import com.google.protobuf.CodedInputStream;
+import com.google.protobuf.CodedOutputStream;
+import java.io.IOException;
+import java.util.function.Supplier;
+
+/**
+ * {@link ObjectCodec} for {@link PrecomputedValue} objects. Because {@link PrecomputedValue}
+ * objects can theoretically contain any kind of value object as their value, an {@link
+ * ObjectCodecs} instance must be accessible to this codec during serialization/deserialization, so
+ * that it can handle the arbitrary objects it's given.
+ */
+public class PrecomputedValueCodec implements ObjectCodec<PrecomputedValue> {
+  private final Supplier<ObjectCodecs> objectCodecsSupplier;
+
+  public PrecomputedValueCodec(Supplier<ObjectCodecs> objectCodecsSupplier) {
+    this.objectCodecsSupplier = objectCodecsSupplier;
+  }
+
+  @Override
+  public Class<PrecomputedValue> getEncodedClass() {
+    return PrecomputedValue.class;
+  }
+
+  @Override
+  public void serialize(PrecomputedValue obj, CodedOutputStream codedOut)
+      throws SerializationException, IOException {
+    ObjectCodecs objectCodecs = objectCodecsSupplier.get();
+    Object val = obj.get();
+    Preconditions.checkState(!(val instanceof PrecomputedValue), "recursive precomputed: %s", obj);
+    // TODO(janakr): this assumes the classifier is the class of the object. This should be enforced
+    // by the ObjectCodecs instance.
+    String classifier = val.getClass().getName();
+    codedOut.writeStringNoTag(classifier);
+    objectCodecs.serialize(classifier, val, codedOut);
+  }
+
+  @Override
+  public PrecomputedValue deserialize(CodedInputStream codedIn)
+      throws SerializationException, IOException {
+    ObjectCodecs objectCodecs = objectCodecsSupplier.get();
+    Object val = objectCodecs.deserialize(codedIn.readBytes(), codedIn);
+    return new PrecomputedValue(val);
+  }
+}