src/test/java/com/google/devtools/build/lib/skyframe/TimestampBuilderMediumTest.java - bazel - Git at Google

 // Copyright 2015 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.common.truth.Truth.assertThat;
 import static com.google.devtools.build.lib.testutil.MoreAsserts.assertThrows;

 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Iterables;
 import com.google.devtools.build.lib.actions.Artifact;
 import com.google.devtools.build.lib.actions.cache.CompactPersistentActionCache;
 import com.google.devtools.build.lib.collect.nestedset.NestedSet;
 import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder;
 import com.google.devtools.build.lib.collect.nestedset.Order;
 import com.google.devtools.build.lib.testutil.BlazeTestUtils;
 import com.google.devtools.build.lib.testutil.Suite;
 import com.google.devtools.build.lib.testutil.TestSpec;
 import com.google.devtools.build.lib.vfs.FileSystemUtils;
 import com.google.devtools.build.lib.vfs.Path;
 import com.google.devtools.build.lib.vfs.UnixGlob;
 import java.io.IOException;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
 import org.junit.runners.JUnit4;

 /**
  * These tests belong to {@link TimestampBuilderTest}, but they're in a separate class for now
  * because they are a little slower.
  */
 @TestSpec(size = Suite.MEDIUM_TESTS)
 @RunWith(JUnit4.class)
 public class TimestampBuilderMediumTest extends TimestampBuilderTestCase {
   private Path cacheRoot;
   private CompactPersistentActionCache cache;

   @Before
   public final void setCache() throws Exception  {
     // BlazeRuntime.setupLogging(Level.FINEST);  // Uncomment this for debugging.

     cacheRoot = scratch.dir("cacheRoot");
     cache = createCache();
   }

   private CompactPersistentActionCache createCache() throws IOException {
     return new CompactPersistentActionCache(cacheRoot, clock);
   }

   private static NestedSet<Artifact> asNestedSet(Artifact... artifacts) {
     return NestedSetBuilder.create(Order.STABLE_ORDER, artifacts);
   }

   /**
    * Creates and returns a new caching builder based on a given {@code cache}.
    */
   private Builder persistentBuilder(CompactPersistentActionCache cache) throws Exception {
     return createBuilder(cache);
   }

   // TODO(blaze-team): (2009) :
   // - test timestamp monotonicity is not required (i.e. set mtime backwards)
   // - test change of key causes rebuild

   @Test
   public void testUnneededInputs() throws Exception {
     Artifact hello = createSourceArtifact("hello");
     FileSystemUtils.createDirectoryAndParents(hello.getPath().getParentDirectory());
     FileSystemUtils.writeContentAsLatin1(hello.getPath(), "content1");
     Artifact optional = createSourceArtifact("hello.optional");
     Artifact goodbye = createDerivedArtifact("goodbye");
     Button button = createActionButton(asNestedSet(hello, optional), ImmutableSet.of(goodbye));

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), goodbye);
     assertThat(button.pressed).isTrue(); // built

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), goodbye);
     assertThat(button.pressed).isFalse(); // not rebuilt

     // Creating a new persistent cache does not cause a rebuild
     cache.save();
     cache = createCache();
     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), hello);
     assertThat(button.pressed).isFalse(); // not rebuilt

     BlazeTestUtils.makeEmptyFile(optional.getPath());
     FileSystemUtils.writeContentAsLatin1(hello.getPath(), "content2");

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), goodbye);
     assertThat(button.pressed).isTrue(); // built

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), goodbye);
     assertThat(button.pressed).isFalse(); // not rebuilt

     optional.getPath().delete();
     FileSystemUtils.writeContentAsLatin1(hello.getPath(), "content3");

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), goodbye);
     assertThat(button.pressed).isTrue(); // built

     // Creating a new persistent cache does not cause a rebuild
     cache.save();
     cache = createCache();
     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), hello);
     assertThat(button.pressed).isFalse(); // not rebuilt
   }

   @Test
   public void testPersistentCache_ModifyingInputCausesActionReexecution() throws Exception {
     // /hello -> [action] -> /goodbye
     Artifact hello = createSourceArtifact("hello");
     BlazeTestUtils.makeEmptyFile(hello.getPath());
     Artifact goodbye = createDerivedArtifact("goodbye");
     Button button = createActionButton(asNestedSet(hello), ImmutableSet.of(goodbye));

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), goodbye);
     assertThat(button.pressed).isTrue(); // built

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), goodbye);
     assertThat(button.pressed).isFalse(); // not rebuilt

     hello.getPath().setWritable(true);
     FileSystemUtils.writeContentAsLatin1(hello.getPath(), "new content");

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), goodbye);
     assertThat(button.pressed).isTrue(); // rebuilt

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), goodbye);
     assertThat(button.pressed).isFalse(); // not rebuilt

     // Creating a new persistent cache does not cause a rebuild
     cache.save();
     buildArtifacts(persistentBuilder(createCache()), goodbye);
     assertThat(button.pressed).isFalse(); // not rebuilt
   }

   @Test
   public void testModifyingInputCausesActionReexecution() throws Exception {
     // /hello -> [action] -> /goodbye
     Artifact hello = createSourceArtifact("hello");
     FileSystemUtils.createDirectoryAndParents(hello.getPath().getParentDirectory());
     FileSystemUtils.writeContentAsLatin1(hello.getPath(), "content1");
     Artifact goodbye = createDerivedArtifact("goodbye");
     Button button = createActionButton(asNestedSet(hello), ImmutableSet.of(goodbye));

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), goodbye);
     assertThat(button.pressed).isTrue(); // built

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), goodbye);
     assertThat(button.pressed).isFalse(); // not rebuilt

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), goodbye);
     assertThat(button.pressed).isFalse(); // still not rebuilt

     FileSystemUtils.writeContentAsLatin1(hello.getPath(), "content2");

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), goodbye);
     assertThat(button.pressed).isTrue(); // rebuilt

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), goodbye);
     assertThat(button.pressed).isFalse(); // not rebuilt

     // Creating a new persistent cache does not cause a rebuild
     cache.save();
     buildArtifacts(persistentBuilder(createCache()), goodbye);
     assertThat(button.pressed).isFalse(); // not rebuilt
   }

   @Test
   public void testArtifactOrderingDoesNotMatter() throws Exception {
     // (/hello,/there) -> [action] -> /goodbye

     Artifact hello = createSourceArtifact("hello");
     Artifact there = createSourceArtifact("there");
     FileSystemUtils.createDirectoryAndParents(hello.getPath().getParentDirectory());
     FileSystemUtils.writeContentAsLatin1(hello.getPath(), "hello");
     FileSystemUtils.writeContentAsLatin1(there.getPath(), "there");
     Artifact goodbye = createDerivedArtifact("goodbye");
     Button button = createActionButton(asNestedSet(hello, there), ImmutableSet.of(goodbye));

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), goodbye);
     assertThat(button.pressed).isTrue(); // built

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), goodbye);
     assertThat(button.pressed).isFalse(); // not rebuilt

     // Now create duplicate graph, with swapped order.
     clearActions();
     Artifact goodbye2 = createDerivedArtifact("goodbye");
     Button button2 = createActionButton(asNestedSet(there, hello), ImmutableSet.of(goodbye2));

     button2.pressed = false;
     buildArtifacts(persistentBuilder(cache), goodbye);
     assertThat(button2.pressed).isFalse(); // still not rebuilt
   }

   @Test
   public void testOldCacheKeysAreCleanedUp() throws Exception {
     // [action1] -> (/goodbye), cache key will be /goodbye
     Artifact goodbye = createDerivedArtifact("goodbye");
     FileSystemUtils.createDirectoryAndParents(goodbye.getPath().getParentDirectory());
     FileSystemUtils.writeContentAsLatin1(goodbye.getPath(), "test");
     Button button = createActionButton(emptyNestedSet, ImmutableSet.of(goodbye));

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), goodbye);
     assertThat(button.pressed).isTrue(); // built

     // action1 is cached using the cache key /goodbye.
     assertThat(cache.get(goodbye.getExecPathString())).isNotNull();

     // [action2] -> (/hello,/goodbye), cache key will be /hello
     clearActions();
     Artifact hello = createDerivedArtifact("hello");
     Artifact goodbye2 = createDerivedArtifact("goodbye");
     Button button2 = createActionButton(emptyNestedSet, ImmutableSet.of(hello, goodbye2));

     button2.pressed = false;
     buildArtifacts(persistentBuilder(cache), hello, goodbye2);
     assertThat(button2.pressed).isTrue(); // rebuilt

     // action2 is cached using the cache key /hello.
     assertThat(cache.get(hello.getExecPathString())).isNotNull();

     // Now, action1 should no longer be in the cache.
     assertThat(cache.get(goodbye.getExecPathString())).isNull();
   }

   @Test
   public void testArtifactNamesMatter() throws Exception {
     // /hello -> [action] -> /goodbye

     Artifact hello = createSourceArtifact("hello");
     FileSystemUtils.createDirectoryAndParents(hello.getPath().getParentDirectory());
     FileSystemUtils.writeContentAsLatin1(hello.getPath(), "hello");
     Artifact goodbye = createDerivedArtifact("goodbye");
     Button button = createActionButton(asNestedSet(hello), ImmutableSet.of(goodbye));

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), goodbye);
     assertThat(button.pressed).isTrue(); // built

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), goodbye);
     assertThat(button.pressed).isFalse(); // not rebuilt

     // Now create duplicate graph, replacing "hello" with "hi".
     clearActions();
     Artifact hi = createSourceArtifact("hi");
     FileSystemUtils.createDirectoryAndParents(hi.getPath().getParentDirectory());
     FileSystemUtils.writeContentAsLatin1(hi.getPath(), "hello");
     Artifact goodbye2 = createDerivedArtifact("goodbye");
     Button button2 = createActionButton(asNestedSet(hi), ImmutableSet.of(goodbye2));

     button2.pressed = false;
     buildArtifacts(persistentBuilder(cache), goodbye2);
     assertThat(button2.pressed).isTrue(); // name changed. must rebuild.
   }

   /**
    * Tests that changing timestamp of the input file without changing it content
    * does not cause action reexecution when metadata cache uses file digests in
    * addition to the timestamp.
    */
   @Test
   public void testModifyingTimestampOnlyDoesNotCauseActionReexecution() throws Exception {
     // /hello -> [action] -> /goodbye
     Artifact hello = createSourceArtifact("hello");
     FileSystemUtils.createDirectoryAndParents(hello.getPath().getParentDirectory());
     FileSystemUtils.writeContentAsLatin1(hello.getPath(), "content1");
     Artifact goodbye = createDerivedArtifact("goodbye");
     Button button = createActionButton(asNestedSet(hello), ImmutableSet.of(goodbye));

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), goodbye);
     assertThat(button.pressed).isTrue(); // built

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), goodbye);
     assertThat(button.pressed).isFalse(); // not rebuilt

     // Creating a new persistent caches, including metadata cache does not cause
     // a rebuild
     cache.save();
     Builder builder = persistentBuilder(createCache());
     buildArtifacts(builder, goodbye);
     assertThat(button.pressed).isFalse(); // not rebuilt
   }

   @Test
   public void testPersistentCache_ModifyingOutputCausesActionReexecution() throws Exception {
     // [action] -> /hello
     Artifact hello = createDerivedArtifact("hello");
     Button button = createActionButton(emptyNestedSet, ImmutableSet.of(hello));

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), hello);
     assertThat(button.pressed).isTrue(); // built

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), hello);
     assertThat(button.pressed).isFalse(); // not rebuilt

     hello.getPath().setWritable(true);
     FileSystemUtils.writeContentAsLatin1(hello.getPath(), "new content");

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), hello);
     assertThat(button.pressed).isTrue(); // rebuilt

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), hello);
     assertThat(button.pressed).isFalse(); // not rebuilt

     // Creating a new persistent cache does not cause a rebuild
     cache.save();
     buildArtifacts(persistentBuilder(createCache()), hello);
     assertThat(button.pressed).isFalse(); // not rebuilt
   }

   @Test
   public void testPersistentCache_missingFilenameIndexCausesActionReexecution() throws Exception {
     // [action] -> /hello
     Artifact hello = createDerivedArtifact("hello");
     Button button = createActionButton(emptyNestedSet, ImmutableSet.of(hello));

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), hello);
     assertThat(button.pressed).isTrue(); // built

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), hello);
     assertThat(button.pressed).isFalse(); // not rebuilt

     hello.getPath().setWritable(true);
     FileSystemUtils.writeContentAsLatin1(hello.getPath(), "new content");

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), hello);
     assertThat(button.pressed).isTrue(); // rebuilt

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), hello);
     assertThat(button.pressed).isFalse(); // not rebuilt

     // Creating a new persistent cache does not cause a rebuild
     cache.save();

     // Remove filename index file.
     assertThat(
             Iterables.getOnlyElement(
                     UnixGlob.forPath(cacheRoot).addPattern("filename_index*").globInterruptible())
                 .delete())
         .isTrue();

     // Now first cache creation attempt should cause IOException while renaming corrupted files.
     // Second attempt will initialize empty cache, causing rebuild.
     IOException e = assertThrows(IOException.class, () -> createCache());
     assertThat(e)
         .hasMessageThat()
         .isEqualTo("Failed action cache referential integrity check: empty index");

     buildArtifacts(persistentBuilder(createCache()), hello);
     assertThat(button.pressed).isTrue(); // rebuilt due to the missing filename index
   }

   @Test
   public void testPersistentCache_failedIntegrityCheckCausesActionReexecution() throws Exception {
     // [action] -> /hello
     Artifact hello = createDerivedArtifact("hello");
     Button button = createActionButton(emptyNestedSet, ImmutableSet.of(hello));

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), hello);
     assertThat(button.pressed).isTrue(); // built

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), hello);
     assertThat(button.pressed).isFalse(); // not rebuilt

     hello.getPath().setWritable(true);
     FileSystemUtils.writeContentAsLatin1(hello.getPath(), "new content");

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), hello);
     assertThat(button.pressed).isTrue(); // rebuilt

     button.pressed = false;
     buildArtifacts(persistentBuilder(cache), hello);
     assertThat(button.pressed).isFalse(); // not rebuilt

     cache.save();

     // Get filename index path and store a copy of it.
     Path indexPath =
         Iterables.getOnlyElement(
             UnixGlob.forPath(cacheRoot).addPattern("filename_index*").globInterruptible());
     Path indexCopy = scratch.resolve("index_copy");
     FileSystemUtils.copyFile(indexPath, indexCopy);

     // Add extra records to the action cache and indexer.
     Artifact helloExtra = createDerivedArtifact("hello_extra");
     Button buttonExtra = createActionButton(emptyNestedSet, ImmutableSet.of(helloExtra));
     buildArtifacts(persistentBuilder(cache), helloExtra);
     assertThat(buttonExtra.pressed).isTrue(); // built

     cache.save();
     assertThat(indexPath.getFileSize()).isGreaterThan(indexCopy.getFileSize());

     // Validate current cache.
     buildArtifacts(persistentBuilder(createCache()), hello);
     assertThat(button.pressed).isFalse(); // not rebuilt

     // Restore outdated file index.
     FileSystemUtils.copyFile(indexCopy, indexPath);

     // Now first cache creation attempt should cause IOException while renaming corrupted files.
     // Second attempt will initialize empty cache, causing rebuild.
     IOException e = assertThrows(IOException.class, () -> createCache());
     assertThat(e).hasMessageThat().contains("Failed action cache referential integrity check");

     // Validate cache with incorrect (out-of-date) filename index.
     buildArtifacts(persistentBuilder(createCache()), hello);
     assertThat(button.pressed).isTrue(); // rebuilt due to the out-of-date index
   }
 }
	// Copyright 2015 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.common.truth.Truth.assertThat;
	import static com.google.devtools.build.lib.testutil.MoreAsserts.assertThrows;

	import com.google.common.collect.ImmutableSet;
	import com.google.common.collect.Iterables;
	import com.google.devtools.build.lib.actions.Artifact;
	import com.google.devtools.build.lib.actions.cache.CompactPersistentActionCache;
	import com.google.devtools.build.lib.collect.nestedset.NestedSet;
	import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder;
	import com.google.devtools.build.lib.collect.nestedset.Order;
	import com.google.devtools.build.lib.testutil.BlazeTestUtils;
	import com.google.devtools.build.lib.testutil.Suite;
	import com.google.devtools.build.lib.testutil.TestSpec;
	import com.google.devtools.build.lib.vfs.FileSystemUtils;
	import com.google.devtools.build.lib.vfs.Path;
	import com.google.devtools.build.lib.vfs.UnixGlob;
	import java.io.IOException;
	import org.junit.Before;
	import org.junit.Test;
	import org.junit.runner.RunWith;
	import org.junit.runners.JUnit4;

	/**
	* These tests belong to {@link TimestampBuilderTest}, but they're in a separate class for now
	* because they are a little slower.
	*/
	@TestSpec(size = Suite.MEDIUM_TESTS)
	@RunWith(JUnit4.class)
	public class TimestampBuilderMediumTest extends TimestampBuilderTestCase {
	private Path cacheRoot;
	private CompactPersistentActionCache cache;

	@Before
	public final void setCache() throws Exception {
	// BlazeRuntime.setupLogging(Level.FINEST); // Uncomment this for debugging.

	cacheRoot = scratch.dir("cacheRoot");
	cache = createCache();
	}

	private CompactPersistentActionCache createCache() throws IOException {
	return new CompactPersistentActionCache(cacheRoot, clock);
	}

	private static NestedSet<Artifact> asNestedSet(Artifact... artifacts) {
	return NestedSetBuilder.create(Order.STABLE_ORDER, artifacts);
	}

	/**
	* Creates and returns a new caching builder based on a given {@code cache}.
	*/
	private Builder persistentBuilder(CompactPersistentActionCache cache) throws Exception {
	return createBuilder(cache);
	}

	// TODO(blaze-team): (2009) :
	// - test timestamp monotonicity is not required (i.e. set mtime backwards)
	// - test change of key causes rebuild

	@Test
	public void testUnneededInputs() throws Exception {
	Artifact hello = createSourceArtifact("hello");
	FileSystemUtils.createDirectoryAndParents(hello.getPath().getParentDirectory());
	FileSystemUtils.writeContentAsLatin1(hello.getPath(), "content1");
	Artifact optional = createSourceArtifact("hello.optional");
	Artifact goodbye = createDerivedArtifact("goodbye");
	Button button = createActionButton(asNestedSet(hello, optional), ImmutableSet.of(goodbye));

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), goodbye);
	assertThat(button.pressed).isTrue(); // built

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), goodbye);
	assertThat(button.pressed).isFalse(); // not rebuilt

	// Creating a new persistent cache does not cause a rebuild
	cache.save();
	cache = createCache();
	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), hello);
	assertThat(button.pressed).isFalse(); // not rebuilt

	BlazeTestUtils.makeEmptyFile(optional.getPath());
	FileSystemUtils.writeContentAsLatin1(hello.getPath(), "content2");

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), goodbye);
	assertThat(button.pressed).isTrue(); // built

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), goodbye);
	assertThat(button.pressed).isFalse(); // not rebuilt

	optional.getPath().delete();
	FileSystemUtils.writeContentAsLatin1(hello.getPath(), "content3");

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), goodbye);
	assertThat(button.pressed).isTrue(); // built

	// Creating a new persistent cache does not cause a rebuild
	cache.save();
	cache = createCache();
	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), hello);
	assertThat(button.pressed).isFalse(); // not rebuilt
	}

	@Test
	public void testPersistentCache_ModifyingInputCausesActionReexecution() throws Exception {
	// /hello -> [action] -> /goodbye
	Artifact hello = createSourceArtifact("hello");
	BlazeTestUtils.makeEmptyFile(hello.getPath());
	Artifact goodbye = createDerivedArtifact("goodbye");
	Button button = createActionButton(asNestedSet(hello), ImmutableSet.of(goodbye));

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), goodbye);
	assertThat(button.pressed).isTrue(); // built

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), goodbye);
	assertThat(button.pressed).isFalse(); // not rebuilt

	hello.getPath().setWritable(true);
	FileSystemUtils.writeContentAsLatin1(hello.getPath(), "new content");

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), goodbye);
	assertThat(button.pressed).isTrue(); // rebuilt

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), goodbye);
	assertThat(button.pressed).isFalse(); // not rebuilt

	// Creating a new persistent cache does not cause a rebuild
	cache.save();
	buildArtifacts(persistentBuilder(createCache()), goodbye);
	assertThat(button.pressed).isFalse(); // not rebuilt
	}

	@Test
	public void testModifyingInputCausesActionReexecution() throws Exception {
	// /hello -> [action] -> /goodbye
	Artifact hello = createSourceArtifact("hello");
	FileSystemUtils.createDirectoryAndParents(hello.getPath().getParentDirectory());
	FileSystemUtils.writeContentAsLatin1(hello.getPath(), "content1");
	Artifact goodbye = createDerivedArtifact("goodbye");
	Button button = createActionButton(asNestedSet(hello), ImmutableSet.of(goodbye));

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), goodbye);
	assertThat(button.pressed).isTrue(); // built

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), goodbye);
	assertThat(button.pressed).isFalse(); // not rebuilt

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), goodbye);
	assertThat(button.pressed).isFalse(); // still not rebuilt

	FileSystemUtils.writeContentAsLatin1(hello.getPath(), "content2");

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), goodbye);
	assertThat(button.pressed).isTrue(); // rebuilt

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), goodbye);
	assertThat(button.pressed).isFalse(); // not rebuilt

	// Creating a new persistent cache does not cause a rebuild
	cache.save();
	buildArtifacts(persistentBuilder(createCache()), goodbye);
	assertThat(button.pressed).isFalse(); // not rebuilt
	}

	@Test
	public void testArtifactOrderingDoesNotMatter() throws Exception {
	// (/hello,/there) -> [action] -> /goodbye

	Artifact hello = createSourceArtifact("hello");
	Artifact there = createSourceArtifact("there");
	FileSystemUtils.createDirectoryAndParents(hello.getPath().getParentDirectory());
	FileSystemUtils.writeContentAsLatin1(hello.getPath(), "hello");
	FileSystemUtils.writeContentAsLatin1(there.getPath(), "there");
	Artifact goodbye = createDerivedArtifact("goodbye");
	Button button = createActionButton(asNestedSet(hello, there), ImmutableSet.of(goodbye));

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), goodbye);
	assertThat(button.pressed).isTrue(); // built

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), goodbye);
	assertThat(button.pressed).isFalse(); // not rebuilt

	// Now create duplicate graph, with swapped order.
	clearActions();
	Artifact goodbye2 = createDerivedArtifact("goodbye");
	Button button2 = createActionButton(asNestedSet(there, hello), ImmutableSet.of(goodbye2));

	button2.pressed = false;
	buildArtifacts(persistentBuilder(cache), goodbye);
	assertThat(button2.pressed).isFalse(); // still not rebuilt
	}

	@Test
	public void testOldCacheKeysAreCleanedUp() throws Exception {
	// [action1] -> (/goodbye), cache key will be /goodbye
	Artifact goodbye = createDerivedArtifact("goodbye");
	FileSystemUtils.createDirectoryAndParents(goodbye.getPath().getParentDirectory());
	FileSystemUtils.writeContentAsLatin1(goodbye.getPath(), "test");
	Button button = createActionButton(emptyNestedSet, ImmutableSet.of(goodbye));

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), goodbye);
	assertThat(button.pressed).isTrue(); // built

	// action1 is cached using the cache key /goodbye.
	assertThat(cache.get(goodbye.getExecPathString())).isNotNull();

	// [action2] -> (/hello,/goodbye), cache key will be /hello
	clearActions();
	Artifact hello = createDerivedArtifact("hello");
	Artifact goodbye2 = createDerivedArtifact("goodbye");
	Button button2 = createActionButton(emptyNestedSet, ImmutableSet.of(hello, goodbye2));

	button2.pressed = false;
	buildArtifacts(persistentBuilder(cache), hello, goodbye2);
	assertThat(button2.pressed).isTrue(); // rebuilt

	// action2 is cached using the cache key /hello.
	assertThat(cache.get(hello.getExecPathString())).isNotNull();

	// Now, action1 should no longer be in the cache.
	assertThat(cache.get(goodbye.getExecPathString())).isNull();
	}

	@Test
	public void testArtifactNamesMatter() throws Exception {
	// /hello -> [action] -> /goodbye

	Artifact hello = createSourceArtifact("hello");
	FileSystemUtils.createDirectoryAndParents(hello.getPath().getParentDirectory());
	FileSystemUtils.writeContentAsLatin1(hello.getPath(), "hello");
	Artifact goodbye = createDerivedArtifact("goodbye");
	Button button = createActionButton(asNestedSet(hello), ImmutableSet.of(goodbye));

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), goodbye);
	assertThat(button.pressed).isTrue(); // built

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), goodbye);
	assertThat(button.pressed).isFalse(); // not rebuilt

	// Now create duplicate graph, replacing "hello" with "hi".
	clearActions();
	Artifact hi = createSourceArtifact("hi");
	FileSystemUtils.createDirectoryAndParents(hi.getPath().getParentDirectory());
	FileSystemUtils.writeContentAsLatin1(hi.getPath(), "hello");
	Artifact goodbye2 = createDerivedArtifact("goodbye");
	Button button2 = createActionButton(asNestedSet(hi), ImmutableSet.of(goodbye2));

	button2.pressed = false;
	buildArtifacts(persistentBuilder(cache), goodbye2);
	assertThat(button2.pressed).isTrue(); // name changed. must rebuild.
	}

	/**
	* Tests that changing timestamp of the input file without changing it content
	* does not cause action reexecution when metadata cache uses file digests in
	* addition to the timestamp.
	*/
	@Test
	public void testModifyingTimestampOnlyDoesNotCauseActionReexecution() throws Exception {
	// /hello -> [action] -> /goodbye
	Artifact hello = createSourceArtifact("hello");
	FileSystemUtils.createDirectoryAndParents(hello.getPath().getParentDirectory());
	FileSystemUtils.writeContentAsLatin1(hello.getPath(), "content1");
	Artifact goodbye = createDerivedArtifact("goodbye");
	Button button = createActionButton(asNestedSet(hello), ImmutableSet.of(goodbye));

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), goodbye);
	assertThat(button.pressed).isTrue(); // built

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), goodbye);
	assertThat(button.pressed).isFalse(); // not rebuilt

	// Creating a new persistent caches, including metadata cache does not cause
	// a rebuild
	cache.save();
	Builder builder = persistentBuilder(createCache());
	buildArtifacts(builder, goodbye);
	assertThat(button.pressed).isFalse(); // not rebuilt
	}

	@Test
	public void testPersistentCache_ModifyingOutputCausesActionReexecution() throws Exception {
	// [action] -> /hello
	Artifact hello = createDerivedArtifact("hello");
	Button button = createActionButton(emptyNestedSet, ImmutableSet.of(hello));

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), hello);
	assertThat(button.pressed).isTrue(); // built

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), hello);
	assertThat(button.pressed).isFalse(); // not rebuilt

	hello.getPath().setWritable(true);
	FileSystemUtils.writeContentAsLatin1(hello.getPath(), "new content");

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), hello);
	assertThat(button.pressed).isTrue(); // rebuilt

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), hello);
	assertThat(button.pressed).isFalse(); // not rebuilt

	// Creating a new persistent cache does not cause a rebuild
	cache.save();
	buildArtifacts(persistentBuilder(createCache()), hello);
	assertThat(button.pressed).isFalse(); // not rebuilt
	}

	@Test
	public void testPersistentCache_missingFilenameIndexCausesActionReexecution() throws Exception {
	// [action] -> /hello
	Artifact hello = createDerivedArtifact("hello");
	Button button = createActionButton(emptyNestedSet, ImmutableSet.of(hello));

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), hello);
	assertThat(button.pressed).isTrue(); // built

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), hello);
	assertThat(button.pressed).isFalse(); // not rebuilt

	hello.getPath().setWritable(true);
	FileSystemUtils.writeContentAsLatin1(hello.getPath(), "new content");

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), hello);
	assertThat(button.pressed).isTrue(); // rebuilt

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), hello);
	assertThat(button.pressed).isFalse(); // not rebuilt

	// Creating a new persistent cache does not cause a rebuild
	cache.save();

	// Remove filename index file.
	assertThat(
	Iterables.getOnlyElement(
	UnixGlob.forPath(cacheRoot).addPattern("filename_index*").globInterruptible())
	.delete())
	.isTrue();

	// Now first cache creation attempt should cause IOException while renaming corrupted files.
	// Second attempt will initialize empty cache, causing rebuild.
	IOException e = assertThrows(IOException.class, () -> createCache());
	assertThat(e)
	.hasMessageThat()
	.isEqualTo("Failed action cache referential integrity check: empty index");

	buildArtifacts(persistentBuilder(createCache()), hello);
	assertThat(button.pressed).isTrue(); // rebuilt due to the missing filename index
	}

	@Test
	public void testPersistentCache_failedIntegrityCheckCausesActionReexecution() throws Exception {
	// [action] -> /hello
	Artifact hello = createDerivedArtifact("hello");
	Button button = createActionButton(emptyNestedSet, ImmutableSet.of(hello));

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), hello);
	assertThat(button.pressed).isTrue(); // built

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), hello);
	assertThat(button.pressed).isFalse(); // not rebuilt

	hello.getPath().setWritable(true);
	FileSystemUtils.writeContentAsLatin1(hello.getPath(), "new content");

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), hello);
	assertThat(button.pressed).isTrue(); // rebuilt

	button.pressed = false;
	buildArtifacts(persistentBuilder(cache), hello);
	assertThat(button.pressed).isFalse(); // not rebuilt

	cache.save();

	// Get filename index path and store a copy of it.
	Path indexPath =
	Iterables.getOnlyElement(
	UnixGlob.forPath(cacheRoot).addPattern("filename_index*").globInterruptible());
	Path indexCopy = scratch.resolve("index_copy");
	FileSystemUtils.copyFile(indexPath, indexCopy);

	// Add extra records to the action cache and indexer.
	Artifact helloExtra = createDerivedArtifact("hello_extra");
	Button buttonExtra = createActionButton(emptyNestedSet, ImmutableSet.of(helloExtra));
	buildArtifacts(persistentBuilder(cache), helloExtra);
	assertThat(buttonExtra.pressed).isTrue(); // built

	cache.save();
	assertThat(indexPath.getFileSize()).isGreaterThan(indexCopy.getFileSize());

	// Validate current cache.
	buildArtifacts(persistentBuilder(createCache()), hello);
	assertThat(button.pressed).isFalse(); // not rebuilt

	// Restore outdated file index.
	FileSystemUtils.copyFile(indexCopy, indexPath);

	// Now first cache creation attempt should cause IOException while renaming corrupted files.
	// Second attempt will initialize empty cache, causing rebuild.
	IOException e = assertThrows(IOException.class, () -> createCache());
	assertThat(e).hasMessageThat().contains("Failed action cache referential integrity check");

	// Validate cache with incorrect (out-of-date) filename index.
	buildArtifacts(persistentBuilder(createCache()), hello);
	assertThat(button.pressed).isTrue(); // rebuilt due to the out-of-date index
	}
	}