Add useful implementations of TransitionFactory.

Eventually, the FooTransition classes should be refactored to be FooTransitionFactory directly, but this can be done after all uses are updated. Part of work on bazelbuild#7814.
katre · Mar 25, 2019 · 0408420 · 0408420
1 parent 738c3e2
commit 0408420
Show file tree

Hide file tree

Showing 6 changed files with 222 additions and 0 deletions.
diff --git a/src/main/java/com/google/devtools/build/lib/BUILD b/src/main/java/com/google/devtools/build/lib/BUILD
@@ -452,6 +452,7 @@ java_library(
         "//src/main/java/com/google/devtools/common/options",
         "//src/main/java/com/google/devtools/common/options:invocation_policy",
         "//src/main/protobuf:invocation_policy_java_proto",
+        "//third_party:auto_value",
         "//third_party:guava",
         "//third_party:jsr305",
     ],

diff --git a/src/main/java/com/google/devtools/build/lib/analysis/config/HostTransition.java b/src/main/java/com/google/devtools/build/lib/analysis/config/HostTransition.java
@@ -13,7 +13,10 @@
 // limitations under the License.
 package com.google.devtools.build.lib.analysis.config;
 
+import com.google.auto.value.AutoValue;
 import com.google.devtools.build.lib.analysis.config.transitions.PatchTransition;
+import com.google.devtools.build.lib.analysis.config.transitions.TransitionFactory;
+import com.google.devtools.build.lib.analysis.config.transitions.TransitionFactory.TransitionFactoryData;
 import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 
 /** Dynamic transition to the host configuration. */
@@ -50,4 +53,37 @@ public BuildOptions patch(BuildOptions options) {
       return options.createHostOptions();
     }
   }
+
+  /** Returns a {@link TransitionFactory} instance that generates the host transition. */
+  public static <T extends TransitionFactoryData> TransitionFactory<T> createFactory() {
+    return new AutoValue_HostTransition_Factory<>();
+  }
+
+  /**
+   * Returns {@code true} if the given {@link TransitionFactory} is an instance of the host
+   * transition.
+   */
+  public static <T extends TransitionFactoryData> boolean isInstance(
+      TransitionFactory<T> instance) {
+    return instance instanceof Factory;
+  }
+
+  /** A {@link TransitionFactory} implementation that generates the host transition. */
+  @AutoValue
+  abstract static class Factory<T extends TransitionFactoryData> implements TransitionFactory<T> {
+    @Override
+    public PatchTransition create(TransitionFactoryData unused) {
+      return INSTANCE;
+    }
+
+    @Override
+    public boolean isHost() {
+      return true;
+    }
+
+    @Override
+    public boolean isFinal() {
+      return true;
+    }
+  }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/config/TransitionFactories.java b/src/main/java/com/google/devtools/build/lib/analysis/config/TransitionFactories.java
@@ -0,0 +1,68 @@
+package com.google.devtools.build.lib.analysis.config;
+
+import com.google.auto.value.AutoValue;
+import com.google.devtools.build.lib.analysis.config.transitions.ConfigurationTransition;
+import com.google.devtools.build.lib.analysis.config.transitions.NoTransition;
+import com.google.devtools.build.lib.analysis.config.transitions.NullTransition;
+import com.google.devtools.build.lib.analysis.config.transitions.SplitTransition;
+import com.google.devtools.build.lib.analysis.config.transitions.TransitionFactory;
+import com.google.devtools.build.lib.analysis.config.transitions.TransitionFactory.TransitionFactoryData;
+
+/** Useful implementations of {@link TransitionFactory}. */
+// This class is in lib.analysis.config in order to access HostTransition, which is not visible to
+// lib.analysis.config.transitions.
+public final class TransitionFactories {
+  // Don't instantiate this class.
+  private TransitionFactories() {}
+
+  /** Returns a {@link TransitionFactory} that wraps a static transition. */
+  public static <T extends TransitionFactoryData> TransitionFactory<T> of(
+      ConfigurationTransition transition) {
+    if (transition instanceof HostTransition) {
+      return HostTransition.createFactory();
+    } else if (transition instanceof NoTransition) {
+      return NoTransition.createFactory();
+    } else if (transition instanceof NullTransition) {
+      return NullTransition.createFactory();
+    } else if (transition instanceof SplitTransition) {
+      return split((SplitTransition) transition);
+    }
+    return new AutoValue_TransitionFactories_IdentityFactory(transition);
+  }
+
+  /** Returns a {@link TransitionFactory} that wraps a static split transition. */
+  public static <T extends TransitionFactoryData> TransitionFactory<T> split(
+      SplitTransition splitTransition) {
+    return new AutoValue_TransitionFactories_SplitTransitionFactory<T>(splitTransition);
+  }
+
+  /** A {@link TransitionFactory} implementation that wraps a static transition. */
+  @AutoValue
+  abstract static class IdentityFactory<T extends TransitionFactoryData>
+      implements TransitionFactory<T> {
+
+    abstract ConfigurationTransition transition();
+
+    @Override
+    public ConfigurationTransition create(T data) {
+      return transition();
+    }
+  }
+
+  /** A {@link TransitionFactory} implementation that wraps a split transition. */
+  @AutoValue
+  abstract static class SplitTransitionFactory<T extends TransitionFactoryData>
+      implements TransitionFactory<T> {
+    abstract SplitTransition splitTransition();
+
+    @Override
+    public SplitTransition create(T data) {
+      return splitTransition();
+    }
+
+    @Override
+    public boolean isSplit() {
+      return true;
+    }
+  }
+}
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/config/transitions/NoTransition.java b/src/main/java/com/google/devtools/build/lib/analysis/config/transitions/NoTransition.java
@@ -13,7 +13,9 @@
 // limitations under the License.
 package com.google.devtools.build.lib.analysis.config.transitions;
 
+import com.google.auto.value.AutoValue;
 import com.google.devtools.build.lib.analysis.config.BuildOptions;
+import com.google.devtools.build.lib.analysis.config.transitions.TransitionFactory.TransitionFactoryData;
 import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 
 /** No-op configuration transition. */
@@ -27,4 +29,27 @@ private NoTransition() {}
   public BuildOptions patch(BuildOptions options) {
     return options;
   }
+
+  /** Returns a {@link TransitionFactory} instance that generates the no transition. */
+  public static <T extends TransitionFactoryData> TransitionFactory<T> createFactory() {
+    return new AutoValue_NoTransition_Factory<>();
+  }
+
+  /**
+   * Returns {@code true} if the given {@link TransitionFactory} is an instance of the no
+   * transition.
+   */
+  public static <T extends TransitionFactoryData> boolean isInstance(
+      TransitionFactory<T> instance) {
+    return instance instanceof Factory;
+  }
+
+  /** A {@link TransitionFactory} implementation that generates the no transition. */
+  @AutoValue
+  abstract static class Factory<T extends TransitionFactoryData> implements TransitionFactory<T> {
+    @Override
+    public ConfigurationTransition create(TransitionFactoryData unused) {
+      return INSTANCE;
+    }
+  }
 }
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/config/transitions/NullTransition.java b/src/main/java/com/google/devtools/build/lib/analysis/config/transitions/NullTransition.java
@@ -13,7 +13,9 @@
 // limitations under the License.
 package com.google.devtools.build.lib.analysis.config.transitions;
 
+import com.google.auto.value.AutoValue;
 import com.google.devtools.build.lib.analysis.config.BuildOptions;
+import com.google.devtools.build.lib.analysis.config.transitions.TransitionFactory.TransitionFactoryData;
 import com.google.devtools.build.lib.skyframe.serialization.autocodec.AutoCodec;
 
 /** A {@link PatchTransition} to a null configuration. */
@@ -32,4 +34,32 @@ public BuildOptions patch(BuildOptions options) {
             + "method to get results we know ahead of time. If there's ever a need to properly "
             + "implement this method we can always do so.");
   }
+
+  /** Returns a {@link TransitionFactory} instance that generates the null transition. */
+  public static <T extends TransitionFactoryData> TransitionFactory<T> createFactory() {
+    return new AutoValue_NullTransition_Factory<>();
+  }
+
+  /**
+   * Returns {@code true} if the given {@link TransitionFactory} is an instance of the null
+   * transition.
+   */
+  public static <T extends TransitionFactoryData> boolean isInstance(
+      TransitionFactory<T> instance) {
+    return instance instanceof Factory;
+  }
+
+  /** A {@link TransitionFactory} implementation that generates the null transition. */
+  @AutoValue
+  abstract static class Factory<T extends TransitionFactoryData> implements TransitionFactory<T> {
+    @Override
+    public ConfigurationTransition create(TransitionFactoryData unused) {
+      return INSTANCE;
+    }
+
+    @Override
+    public boolean isFinal() {
+      return true;
+    }
+  }
 }
diff --git a/src/test/java/com/google/devtools/build/lib/analysis/config/TransitionFactoriesTest.java b/src/test/java/com/google/devtools/build/lib/analysis/config/TransitionFactoriesTest.java
@@ -0,0 +1,62 @@
+package com.google.devtools.build.lib.analysis.config;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import com.google.common.collect.ImmutableList;
+import com.google.devtools.build.lib.analysis.config.transitions.NoTransition;
+import com.google.devtools.build.lib.analysis.config.transitions.NullTransition;
+import com.google.devtools.build.lib.analysis.config.transitions.SplitTransition;
+import com.google.devtools.build.lib.analysis.config.transitions.TransitionFactory;
+import com.google.devtools.build.lib.analysis.config.transitions.TransitionFactory.TransitionFactoryData;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** Tests for {@link TransitionFactories}. */
+@RunWith(JUnit4.class)
+public class TransitionFactoriesTest {
+
+  @Test
+  public void hostTransition() {
+    TransitionFactory<TransitionFactoryData> factory =
+        TransitionFactories.of(HostTransition.INSTANCE);
+    assertThat(factory).isNotNull();
+    assertThat(HostTransition.isInstance(factory)).isTrue();
+    assertThat(factory.isHost()).isTrue();
+    assertThat(factory.isSplit()).isFalse();
+    assertThat(factory.isFinal()).isTrue();
+  }
+
+  @Test
+  public void noTransition() {
+    TransitionFactory<TransitionFactoryData> factory =
+        TransitionFactories.of(NoTransition.INSTANCE);
+    assertThat(factory).isNotNull();
+    assertThat(NoTransition.isInstance(factory)).isTrue();
+    assertThat(factory.isHost()).isFalse();
+    assertThat(factory.isSplit()).isFalse();
+    assertThat(factory.isFinal()).isFalse();
+  }
+
+  @Test
+  public void nullTransition() {
+    TransitionFactory<TransitionFactoryData> factory =
+        TransitionFactories.of(NullTransition.INSTANCE);
+    assertThat(factory).isNotNull();
+    assertThat(NullTransition.isInstance(factory)).isTrue();
+    assertThat(factory.isHost()).isFalse();
+    assertThat(factory.isSplit()).isFalse();
+    assertThat(factory.isFinal()).isTrue();
+  }
+
+  @Test
+  public void splitTransition() {
+    TransitionFactory<TransitionFactoryData> factory =
+        TransitionFactories.of(
+            (SplitTransition) buildOptions -> ImmutableList.of(buildOptions.clone()));
+    assertThat(factory).isNotNull();
+    assertThat(factory.isHost()).isFalse();
+    assertThat(factory.isSplit()).isTrue();
+    assertThat(factory.isFinal()).isFalse();
+  }
+}