Deletes POLYMORPHIC strategy. ObjectCodec now uses runtime type information to select a codec.

PiperOrigin-RevId: 186378153

4 files changed, 3 insertions, 189 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/WorkspaceStatusValue.java b/src/main/java/com/google/devtools/build/lib/skyframe/WorkspaceStatusValue.java
index be647065d4..777dcbab4a 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/WorkspaceStatusValue.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/WorkspaceStatusValue.java
@@ -17,8 +17,7 @@ import com.google.devtools.build.lib.actions.ActionKeyContext;
 import com.google.devtools.build.lib.actions.ActionLookupValue;
 import com.google.devtools.build.lib.actions.Artifact;
 import com.google.devtools.build.lib.analysis.WorkspaceStatusAction;
-import com.google.devtools.build.lib.skyframe.serialization.ObjectCodec;
-import com.google.devtools.build.lib.skyframe.serialization.SingletonCodec;
+import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 import com.google.devtools.build.skyframe.SkyFunctionName;
 import com.google.devtools.build.skyframe.SkyKey;
 
@@ -55,10 +54,9 @@ public class WorkspaceStatusValue extends ActionLookupValue {
   }
 
   /** {@link SkyKey} for {@link WorkspaceStatusValue}. */
+  @AutoCodec(strategy = AutoCodec.Strategy.SINGLETON)
   public static class BuildInfoKey extends ActionLookupKey {
-    private static final BuildInfoKey INSTANCE = new BuildInfoKey();
-    public static final ObjectCodec<BuildInfoKey> CODEC =
-        SingletonCodec.of(INSTANCE, "build_info_key");
+    @AutoCodec.VisibleForSerialization static final BuildInfoKey INSTANCE = new BuildInfoKey();
 
     private BuildInfoKey() {}
 
@@ -66,6 +64,5 @@ public class WorkspaceStatusValue extends ActionLookupValue {
     public SkyFunctionName functionName() {
       return SkyFunctions.BUILD_INFO;
     }
-
   }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/serialization/PolymorphicHelper.java b/src/main/java/com/google/devtools/build/lib/skyframe/serialization/PolymorphicHelper.java
deleted file mode 100644
index b199ca6ce1..0000000000
--- a/src/main/java/com/google/devtools/build/lib/skyframe/serialization/PolymorphicHelper.java
+++ /dev/null
@@ -1,139 +0,0 @@
-// Copyright 2018 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.serialization;
-
-import com.google.devtools.build.lib.skyframe.serialization.strings.StringCodecs;
-import com.google.protobuf.CodedInputStream;
-import com.google.protobuf.CodedOutputStream;
-import java.io.IOException;
-import java.lang.reflect.Field;
-import java.util.Optional;
-import javax.annotation.Nullable;
-
-/** Helper methods for polymorphic codecs using reflection. */
-public class PolymorphicHelper {
-
-  private PolymorphicHelper() {}
-
-  /**
-   * Serializes a polymorphic type.
-   *
-   * @param dependency if null, it means that the parent, polymorphic type, provides no dependency.
-   *     It is valid for dependency to be non-null, with an enclosed null value. This means that
-   *     dependency itself is null (as opposed to non-existent).
-   */
-  @SuppressWarnings("unchecked")
-  public static void serialize(
-      SerializationContext context,
-      Object input,
-      Class<?> baseClass,
-      CodedOutputStream codedOut,
-      @Nullable Optional<?> dependency)
-      throws IOException, SerializationException {
-    if (input != null) {
-      try {
-        ClassAndCodec classAndCodec = getClassAndCodecInClassHierarchy(input, baseClass);
-        Class<?> clazz = classAndCodec.clazz;
-        Object codec = classAndCodec.codec;
-        codedOut.writeBoolNoTag(true);
-        StringCodecs.asciiOptimized().serialize(context, clazz.getName(), codedOut);
-        if (codec instanceof ObjectCodec) {
-          ((ObjectCodec) codec).serialize(context, input, codedOut);
-        } else {
-          throw new SerializationException(
-              clazz.getCanonicalName()
-                  + ".CODEC has unexpected type "
-                  + codec.getClass().getCanonicalName());
-        }
-      } catch (ReflectiveOperationException e) {
-        throw new SerializationException(input.getClass().getName(), e);
-      }
-    } else {
-      codedOut.writeBoolNoTag(false);
-    }
-  }
-
-  /**
-   * Deserializes a polymorphic type.
-   *
-   * @param dependency if null, it means that the parent, polymorphic type, provides no dependency.
-   *     It is valid for dependency to be non-null, with an enclosed null value. This means the
-   *     dependency itself is null (as opposed to non-existent).
-   */
-  @SuppressWarnings("unchecked")
-  public static Object deserialize(
-      DeserializationContext context, CodedInputStream codedIn, @Nullable Optional<?> dependency)
-      throws IOException, SerializationException {
-    Object deserialized = null;
-    if (codedIn.readBool()) {
-      String className = StringCodecs.asciiOptimized().deserialize(context, codedIn);
-      try {
-        Object codec = getCodec(Class.forName(className));
-        if (codec instanceof ObjectCodec) {
-          return ((ObjectCodec) codec).deserialize(context, codedIn);
-        } else {
-          throw new SerializationException(
-              className + ".CODEC has unexpected type " + codec.getClass().getCanonicalName());
-        }
-      } catch (ReflectiveOperationException e) {
-        throw new SerializationException(className, e);
-      }
-    }
-    return deserialized;
-  }
-
-  private static ClassAndCodec getClassAndCodecInClassHierarchy(Object input, Class<?> baseClass)
-      throws SerializationException, IllegalAccessException {
-    Class<?> clazz = input.getClass();
-    Field codecField = null;
-    while (!clazz.equals(baseClass)) {
-      try {
-        codecField = getCodecField(clazz);
-        break;
-      } catch (NoSuchFieldException e) {
-        clazz = clazz.getSuperclass();
-      }
-    }
-    if (clazz.equals(baseClass)) {
-      throw new SerializationException("Could not find codec for " + input.getClass());
-    }
-    return new ClassAndCodec(clazz, getValueOfField(codecField));
-  }
-
-  private static Field getCodecField(Class<?> clazz) throws NoSuchFieldException {
-    return clazz.getDeclaredField("CODEC");
-  }
-
-  private static Object getValueOfField(Field field) throws IllegalAccessException {
-    field.setAccessible(true);
-    return field.get(null);
-  }
-
-  /** Returns the static CODEC instance for {@code clazz}. */
-  private static Object getCodec(Class<?> clazz)
-      throws NoSuchFieldException, IllegalAccessException {
-    return getValueOfField(getCodecField(clazz));
-  }
-
-  private static class ClassAndCodec {
-    final Class<?> clazz;
-    final Object codec;
-
-    ClassAndCodec(Class<?> clazz, Object codec) {
-      this.clazz = clazz;
-      this.codec = codec;
-    }
-  }
-}
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/serialization/autocodec/AutoCodec.java b/src/main/java/com/google/devtools/build/lib/skyframe/serialization/autocodec/AutoCodec.java
index 0f597dbee1..cb88b0ae8e 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/serialization/autocodec/AutoCodec.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/serialization/autocodec/AutoCodec.java
@@ -62,16 +62,6 @@ public @interface AutoCodec {
      */
     PUBLIC_FIELDS,
     /**
-     * For use with abstract classes (enforced at compile time).
-     *
-     * <p>Uses reflection to determine the concrete subclass, stores the name of the subclass and
-     * uses its codec to serialize the data.
-     *
-     * <p>This is no longer needed and only adds useless overhead.
-     */
-    // TODO(shahan): delete this and all references to it
-    POLYMORPHIC,
-    /**
      * For use with classes that are singleton.
      *
      * <p>The serialized class must have a codec accessible, static INSTANCE field.
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/serialization/autocodec/AutoCodecProcessor.java b/src/main/java/com/google/devtools/build/lib/skyframe/serialization/autocodec/AutoCodecProcessor.java
index c3d14df9f2..935e97383c 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/serialization/autocodec/AutoCodecProcessor.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/serialization/autocodec/AutoCodecProcessor.java
@@ -21,7 +21,6 @@ import com.google.auto.value.AutoValue;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 import com.google.devtools.build.lib.skyframe.serialization.ObjectCodec;
-import com.google.devtools.build.lib.skyframe.serialization.PolymorphicHelper;
 import com.google.devtools.build.lib.skyframe.serialization.SerializationException;
 import com.google.devtools.build.lib.skyframe.serialization.autocodec.SerializationCodeGenerator.Marshaller;
 import com.squareup.javapoet.ClassName;
@@ -102,9 +101,6 @@ public class AutoCodecProcessor extends AbstractProcessor {
         case PUBLIC_FIELDS:
           codecClassBuilder = buildClassWithPublicFieldsStrategy(encodedType);
           break;
-        case POLYMORPHIC:
-          codecClassBuilder = buildClassWithPolymorphicStrategy(encodedType);
-          break;
         case SINGLETON:
           codecClassBuilder = buildClassWithSingletonStrategy(encodedType);
           break;
@@ -536,36 +532,6 @@ public class AutoCodecProcessor extends AbstractProcessor {
     return Optional.empty();
   }
 
-  private TypeSpec.Builder buildClassWithPolymorphicStrategy(TypeElement encodedType) {
-    if (!encodedType.getModifiers().contains(Modifier.ABSTRACT)) {
-      throw new IllegalArgumentException(
-          encodedType + " is not abstract, but POLYMORPHIC was selected as the strategy.");
-    }
-    TypeSpec.Builder codecClassBuilder = AutoCodecUtil.initializeCodecClassBuilder(encodedType);
-    codecClassBuilder.addMethod(buildPolymorphicSerializeMethod(encodedType));
-    codecClassBuilder.addMethod(buildPolymorphicDeserializeMethod(encodedType));
-    return codecClassBuilder;
-  }
-
-  private MethodSpec buildPolymorphicSerializeMethod(TypeElement encodedType) {
-    MethodSpec.Builder builder = AutoCodecUtil.initializeSerializeMethodBuilder(encodedType);
-    TypeName polyClass = TypeName.get(env.getTypeUtils().erasure(encodedType.asType()));
-      builder.addStatement(
-          "$T.serialize(context, input, $T.class, codedOut, null)",
-          PolymorphicHelper.class,
-          polyClass);
-    return builder.build();
-  }
-
-  private static MethodSpec buildPolymorphicDeserializeMethod(TypeElement encodedType) {
-    MethodSpec.Builder builder = AutoCodecUtil.initializeDeserializeMethodBuilder(encodedType);
-      builder.addStatement(
-          "return ($T) $T.deserialize(context, codedIn, null)",
-          TypeName.get(encodedType.asType()),
-          PolymorphicHelper.class);
-    return builder.build();
-  }
-
   private static TypeSpec.Builder buildClassWithSingletonStrategy(TypeElement encodedType) {
     TypeSpec.Builder codecClassBuilder = AutoCodecUtil.initializeCodecClassBuilder(encodedType);
     // Serialization is a no-op.