Introduce a new SkyValue that merely contains the workspace name. The workspace name is needed for package loading, and so splitting out this computation into a separate skyframe node that can be change-pruned gives us better incrementality; previously we'd need to reload all packages on a WORKSPACE file change.

N.B.
(i) This CL doesn't solve all the other performance issues with //external in Bazel/Blaze since it's still inefficiently used for resolving labels like @foo//bar:baz.
(ii) This CL doesn't address the wasteful invalidation + change pruning of all the packages.

--
PiperOrigin-RevId: 146925369
MOS_MIGRATED_REVID=146925369

1 files changed, 89 insertions, 0 deletions

diff --git a/src/test/java/com/google/devtools/build/lib/skyframe/WorkspaceNameFunctionTest.java b/src/test/java/com/google/devtools/build/lib/skyframe/WorkspaceNameFunctionTest.java
new file mode 100644
index 0000000000..fbb1e644ef
--- /dev/null
+++ b/src/test/java/com/google/devtools/build/lib/skyframe/WorkspaceNameFunctionTest.java
@@ -0,0 +1,89 @@
+// 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 static com.google.devtools.build.skyframe.EvaluationResultSubjectFactory.assertThatEvaluationResult;
+
+import com.google.common.testing.EqualsTester;
+import com.google.devtools.build.lib.analysis.util.BuildViewTestCase;
+import com.google.devtools.build.lib.packages.NoSuchPackageException;
+import com.google.devtools.build.lib.skyframe.util.SkyframeExecutorTestUtils;
+import com.google.devtools.build.lib.vfs.FileSystemUtils;
+import com.google.devtools.build.lib.vfs.ModifiedFileSet;
+import com.google.devtools.build.lib.vfs.PathFragment;
+import com.google.devtools.build.skyframe.EvaluationResult;
+import com.google.devtools.build.skyframe.SkyKey;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+/** Tests for {@link WorkspaceNameValue} and {@link WorkspaceNameFunction}. */
+@RunWith(JUnit4.class)
+public class WorkspaceNameFunctionTest extends BuildViewTestCase {
+  private final SkyKey key = WorkspaceNameValue.key();
+
+  private EvaluationResult<WorkspaceNameValue> eval() throws InterruptedException {
+    getSkyframeExecutor().invalidateFilesUnderPathForTesting(
+        reporter,
+        ModifiedFileSet.builder().modify(new PathFragment("WORKSPACE")).build(),
+        rootDirectory);
+    return SkyframeExecutorTestUtils.evaluate(
+        getSkyframeExecutor(), key, /*keepGoing=*/ false, reporter);
+  }
+
+  @Test
+  public void testNormal() throws Exception {
+    scratch.overwriteFile("WORKSPACE", "workspace(name = 'good')");
+    assertThatEvaluationResult(eval())
+        .hasEntryThat(key)
+        .isEqualTo(WorkspaceNameValue.withName("good"));
+  }
+
+  @Test
+  public void testErrorInExternalPkg() throws Exception {
+    reporter.removeHandler(failFastHandler);
+    scratch.overwriteFile("WORKSPACE", "workspace(bad)");
+    assertThatEvaluationResult(eval())
+        .hasEntryThat(key)
+        .isEqualTo(WorkspaceNameValue.withError());
+    assertContainsEvent("name 'bad' is not defined");
+  }
+
+  @Test
+  public void testTransitiveSkyframeError() throws Exception {
+    reporter.removeHandler(failFastHandler);
+    scratch.deleteFile("WORKSPACE");
+    FileSystemUtils.ensureSymbolicLink(scratch.resolve("WORKSPACE"), "WORKSPACE");
+    // Transitive errors from WorkspaceNameValue should manifest themselves as
+    // NoSuchPackageExceptions.
+    assertThatEvaluationResult(eval())
+        .hasErrorEntryForKeyThat(key)
+        .hasExceptionThat()
+        .isInstanceOf(NoSuchPackageException.class);
+  }
+
+  @Test
+  public void testEqualsAndHashCode(){
+    new EqualsTester()
+        .addEqualityGroup(
+            WorkspaceNameValue.withError(),
+            WorkspaceNameValue.withError())
+        .addEqualityGroup(
+            WorkspaceNameValue.withName("foo"),
+            WorkspaceNameValue.withName("foo"))
+        .addEqualityGroup(
+            WorkspaceNameValue.withName("bar"),
+            WorkspaceNameValue.withName("bar"));
+  }
+}