src/test/java/com/google/devtools/build/lib/skyframe/ArtifactFunctionTest.java

// 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.skyframe.FileArtifactValue.create;
import static org.junit.Assert.assertArrayEquals;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertNull;
import static org.junit.Assert.assertSame;
import static org.junit.Assert.fail;

import com.google.common.base.Predicates;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Iterables;
import com.google.common.testing.EqualsTester;
import com.google.devtools.build.lib.actions.Action;
import com.google.devtools.build.lib.actions.Action.MiddlemanType;
import com.google.devtools.build.lib.actions.Artifact;
import com.google.devtools.build.lib.actions.MissingInputFileException;
import com.google.devtools.build.lib.actions.Root;
import com.google.devtools.build.lib.actions.util.TestAction.DummyAction;
import com.google.devtools.build.lib.events.NullEventHandler;
import com.google.devtools.build.lib.pkgcache.PathPackageLocator;
import com.google.devtools.build.lib.skyframe.ActionLookupValue.ActionLookupKey;
import com.google.devtools.build.lib.testutil.TestUtils;
import com.google.devtools.build.lib.util.BlazeClock;
import com.google.devtools.build.lib.util.Pair;
import com.google.devtools.build.lib.util.io.TimestampGranularityMonitor;
import com.google.devtools.build.lib.vfs.FileStatus;
import com.google.devtools.build.lib.vfs.FileSystemUtils;
import com.google.devtools.build.lib.vfs.Path;
import com.google.devtools.build.lib.vfs.PathFragment;
import com.google.devtools.build.lib.vfs.inmemoryfs.InMemoryFileSystem;
import com.google.devtools.build.skyframe.EvaluationResult;
import com.google.devtools.build.skyframe.InMemoryMemoizingEvaluator;
import com.google.devtools.build.skyframe.MemoizingEvaluator;
import com.google.devtools.build.skyframe.RecordingDifferencer;
import com.google.devtools.build.skyframe.SequentialBuildDriver;
import com.google.devtools.build.skyframe.SkyFunction;
import com.google.devtools.build.skyframe.SkyFunctionName;
import com.google.devtools.build.skyframe.SkyKey;
import com.google.devtools.build.skyframe.SkyValue;

import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.junit.runners.JUnit4;

import java.io.IOException;
import java.util.Arrays;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
import java.util.UUID;
import java.util.concurrent.atomic.AtomicReference;

/**
 * Tests for {@link ArtifactFunction}.
 */
// Doesn't actually need any particular Skyframe, but is only relevant to Skyframe full mode.
@RunWith(JUnit4.class)
public class ArtifactFunctionTest {
  private static final SkyKey OWNER_KEY = new SkyKey(SkyFunctions.ACTION_LOOKUP, "OWNER");
  private static final ActionLookupKey ALL_OWNER = new SingletonActionLookupKey();

  private Set<Action> actions;
  private boolean fastDigest = false;
  private RecordingDifferencer differencer = new RecordingDifferencer();
  private SequentialBuildDriver driver;
  private MemoizingEvaluator evaluator;
  private Path root;
  private TimestampGranularityMonitor tsgm = new TimestampGranularityMonitor(BlazeClock.instance());

  @Before
  public final void setUp() throws Exception  {
    setupRoot(new CustomInMemoryFs());
    AtomicReference<PathPackageLocator> pkgLocator =
        new AtomicReference<>(PathPackageLocator.EMPTY);
    ExternalFilesHelper externalFilesHelper = new ExternalFilesHelper(pkgLocator);
    differencer = new RecordingDifferencer();
    evaluator =
        new InMemoryMemoizingEvaluator(
            ImmutableMap.of(
                SkyFunctions.FILE_STATE, new FileStateFunction(tsgm, externalFilesHelper),
                SkyFunctions.FILE, new FileFunction(pkgLocator, tsgm, externalFilesHelper),
                SkyFunctions.ARTIFACT, new ArtifactFunction(Predicates.<PathFragment>alwaysFalse()),
                SkyFunctions.ACTION_EXECUTION, new SimpleActionExecutionFunction()),
            differencer);
    driver = new SequentialBuildDriver(evaluator);
    PrecomputedValue.BUILD_ID.set(differencer, UUID.randomUUID());
    actions = new HashSet<>();
  }

  private void setupRoot(CustomInMemoryFs fs) {
    root = fs.getPath(TestUtils.tmpDir());
  }

  private void assertFileArtifactValueMatches(boolean expectDigest) throws Throwable {
    Artifact output = createDerivedArtifact("output");
    Path path = output.getPath();
    file(path, "contents");
    assertValueMatches(path.stat(), expectDigest ? path.getMD5Digest() : null, evaluateFAN(output));
  }

  @Test
  public void testBasicArtifact() throws Throwable {
    fastDigest = false;
    assertFileArtifactValueMatches(/*expectDigest=*/ true);
  }

  @Test
  public void testBasicArtifactWithXattr() throws Throwable {
    fastDigest = true;
    assertFileArtifactValueMatches(/*expectDigest=*/ true);
  }

  @Test
  public void testMissingNonMandatoryArtifact() throws Throwable {
    Artifact input = createSourceArtifact("input1");
    assertNotNull(evaluateArtifactValue(input, /*mandatory=*/ false));
  }

  @Test
  public void testMissingMandatoryArtifact() throws Throwable {
    Artifact input = createSourceArtifact("input1");
    try {
      evaluateArtifactValue(input, /*mandatory=*/ true);
      fail();
    } catch (MissingInputFileException ex) {
      // Expected.
    }
  }

  @Test
  public void testMiddlemanArtifact() throws Throwable {
    Artifact output = createDerivedArtifact("output");
    Artifact input1 = createSourceArtifact("input1");
    Artifact input2 = createDerivedArtifact("input2");
    Action action =
        new DummyAction(
            ImmutableList.of(input1, input2), output, MiddlemanType.AGGREGATING_MIDDLEMAN);
    // Overwrite default generating action with this one.
    for (Iterator<Action> it = actions.iterator(); it.hasNext(); ) {
      if (it.next().getOutputs().contains(output)) {
        it.remove();
        break;
      }
    }
    actions.add(action);
    file(input2.getPath(), "contents");
    file(input1.getPath(), "source contents");
    evaluate(
        Iterables.toArray(
            ArtifactValue.mandatoryKeys(ImmutableSet.of(input2, input1, input2)), SkyKey.class));
    ArtifactValue value = evaluateArtifactValue(output);
    assertThat(((AggregatingArtifactValue) value).getInputs())
        .containsExactly(Pair.of(input1, create(input1)), Pair.of(input2, create(input2)));
  }

  @Test
  public void testIOException() throws Exception {
    fastDigest = false;
    final IOException exception = new IOException("beep");
    setupRoot(
        new CustomInMemoryFs() {
          @Override
          public byte[] getMD5Digest(Path path) throws IOException {
            throw exception;
          }
        });
    Artifact artifact = createDerivedArtifact("no-read");
    writeFile(artifact.getPath(), "content");
    try {
      create(createDerivedArtifact("no-read"));
      fail();
    } catch (IOException e) {
      assertSame(exception, e);
    }
  }

  /**
   * Tests that ArtifactFunction rethrows transitive {@link IOException}s as
   * {@link MissingInputFileException}s.
   */
  @Test
  public void testIOException_EndToEnd() throws Throwable {
    final IOException exception = new IOException("beep");
    setupRoot(
        new CustomInMemoryFs() {
          @Override
          public FileStatus stat(Path path, boolean followSymlinks) throws IOException {
            if (path.getBaseName().equals("bad")) {
              throw exception;
            }
            return super.stat(path, followSymlinks);
          }
        });
    try {
      evaluateArtifactValue(createSourceArtifact("bad"));
      fail();
    } catch (MissingInputFileException e) {
      assertThat(e.getMessage()).contains(exception.getMessage());
    }
  }

  @Test
  public void testNoMtimeIfNonemptyFile() throws Exception {
    Artifact artifact = createDerivedArtifact("no-digest");
    Path path = artifact.getPath();
    writeFile(path, "hello"); //Non-empty file.
    FileArtifactValue value = create(artifact);
    assertArrayEquals(path.getMD5Digest(), value.getDigest());
    try {
      value.getModifiedTime();
      fail("mtime for non-empty file should not be stored.");
    } catch (IllegalStateException e) {
      // Expected.
    }
  }

  @Test
  public void testDirectory() throws Exception {
    Artifact artifact = createDerivedArtifact("dir");
    Path path = artifact.getPath();
    FileSystemUtils.createDirectoryAndParents(path);
    path.setLastModifiedTime(1L);
    FileArtifactValue value = create(artifact);
    assertNull(value.getDigest());
    assertEquals(1L, value.getModifiedTime());
  }

  // Empty files need to store their mtimes, so touching an empty file
  // can be used to trigger rebuilds.
  @Test
  public void testEmptyFile() throws Exception {
    Artifact artifact = createDerivedArtifact("empty");
    Path path = artifact.getPath();
    writeFile(path, "");
    path.setLastModifiedTime(1L);
    FileArtifactValue value = create(artifact);
    assertArrayEquals(path.getMD5Digest(), value.getDigest());
    assertEquals(1L, value.getModifiedTime());
    assertEquals(0L, value.getSize());
  }

  @Test
  public void testEquality() throws Exception {
    Artifact artifact1 = createDerivedArtifact("artifact1");
    Artifact artifact2 = createDerivedArtifact("artifact2");
    Artifact diffDigest = createDerivedArtifact("diffDigest");
    Artifact diffMtime = createDerivedArtifact("diffMtime");
    Artifact empty1 = createDerivedArtifact("empty1");
    Artifact empty2 = createDerivedArtifact("empty2");
    Artifact empty3 = createDerivedArtifact("empty3");
    Artifact dir1 = createDerivedArtifact("dir1");
    Artifact dir2 = createDerivedArtifact("dir2");
    Artifact dir3 = createDerivedArtifact("dir3");
    Path path1 = artifact1.getPath();
    Path path2 = artifact2.getPath();
    Path digestPath = diffDigest.getPath();
    Path mtimePath = diffMtime.getPath();
    writeFile(artifact1.getPath(), "content");
    writeFile(artifact2.getPath(), "content");
    path1.setLastModifiedTime(0);
    path2.setLastModifiedTime(0);
    writeFile(diffDigest.getPath(), "1234567"); // Same size as artifact1.
    digestPath.setLastModifiedTime(0);
    writeFile(mtimePath, "content");
    mtimePath.setLastModifiedTime(1);
    Path emptyPath1 = empty1.getPath();
    Path emptyPath2 = empty2.getPath();
    Path emptyPath3 = empty3.getPath();
    writeFile(emptyPath1, "");
    writeFile(emptyPath2, "");
    writeFile(emptyPath3, "");
    emptyPath1.setLastModifiedTime(0L);
    emptyPath2.setLastModifiedTime(1L);
    emptyPath3.setLastModifiedTime(1L);
    Path dirPath1 = dir1.getPath();
    Path dirPath2 = dir2.getPath();
    Path dirPath3 = dir3.getPath();
    FileSystemUtils.createDirectoryAndParents(dirPath1);
    FileSystemUtils.createDirectoryAndParents(dirPath2);
    FileSystemUtils.createDirectoryAndParents(dirPath3);
    dirPath1.setLastModifiedTime(0L);
    dirPath2.setLastModifiedTime(1L);
    dirPath3.setLastModifiedTime(1L);
    EqualsTester equalsTester = new EqualsTester();
    equalsTester
        .addEqualityGroup(create(artifact1), create(artifact2), create(diffMtime))
        .addEqualityGroup(create(empty1))
        .addEqualityGroup(create(empty2), create(empty3))
        .addEqualityGroup(create(dir1))
        .addEqualityGroup(create(dir2), create(dir3))
        .testEquals();
  }

  private void file(Path path, String contents) throws Exception {
    FileSystemUtils.createDirectoryAndParents(path.getParentDirectory());
    writeFile(path, contents);
  }

  private Artifact createSourceArtifact(String path) {
    return new Artifact(new PathFragment(path), Root.asSourceRoot(root));
  }

  private Artifact createDerivedArtifact(String path) {
    PathFragment execPath = new PathFragment("out").getRelative(path);
    Path fullPath = root.getRelative(execPath);
    Artifact output =
        new Artifact(
            fullPath, Root.asDerivedRoot(root, root.getRelative("out")), execPath, ALL_OWNER);
    actions.add(new DummyAction(ImmutableList.<Artifact>of(), output));
    return output;
  }

  private void assertValueMatches(FileStatus file, byte[] digest, FileArtifactValue value)
      throws IOException {
    assertEquals(file.getSize(), value.getSize());
    if (digest == null) {
      assertNull(value.getDigest());
      assertEquals(file.getLastModifiedTime(), value.getModifiedTime());
    } else {
      assertArrayEquals(digest, value.getDigest());
    }
  }

  private FileArtifactValue evaluateFAN(Artifact artifact) throws Throwable {
    return ((FileArtifactValue) evaluateArtifactValue(artifact));
  }

  private ArtifactValue evaluateArtifactValue(Artifact artifact) throws Throwable {
    return evaluateArtifactValue(artifact, /*isMandatory=*/ true);
  }

  private ArtifactValue evaluateArtifactValue(Artifact artifact, boolean mandatory)
      throws Throwable {
    SkyKey key = ArtifactValue.key(artifact, mandatory);
    EvaluationResult<ArtifactValue> result = evaluate(ImmutableList.of(key).toArray(new SkyKey[0]));
    if (result.hasError()) {
      throw result.getError().getException();
    }
    return result.get(key);
  }

  private void setGeneratingActions() {
    if (evaluator.getExistingValueForTesting(OWNER_KEY) == null) {
      differencer.inject(ImmutableMap.of(OWNER_KEY, new ActionLookupValue(actions)));
    }
  }

  private <E extends SkyValue> EvaluationResult<E> evaluate(SkyKey... keys)
      throws InterruptedException {
    setGeneratingActions();
    return driver.evaluate(
        Arrays.asList(keys), /*keepGoing=*/
        false,
        SkyframeExecutor.DEFAULT_THREAD_COUNT,
        NullEventHandler.INSTANCE);
  }

  private static void writeFile(Path path, String contents) throws IOException {
    FileSystemUtils.createDirectoryAndParents(path.getParentDirectory());
    FileSystemUtils.writeContentAsLatin1(path, contents);
  }

  private static class SingletonActionLookupKey extends ActionLookupKey {
    @Override
    SkyKey getSkyKey() {
      return OWNER_KEY;
    }

    @Override
    SkyFunctionName getType() {
      throw new UnsupportedOperationException();
    }
  }

  /** Value Builder for actions that just stats and stores the output file (which must exist). */
  private class SimpleActionExecutionFunction implements SkyFunction {
    @Override
    public SkyValue compute(SkyKey skyKey, Environment env) {
      Map<Artifact, FileValue> artifactData = new HashMap<>();
      Action action = (Action) skyKey.argument();
      Artifact output = Iterables.getOnlyElement(action.getOutputs());
      FileArtifactValue value;
      if (action.getActionType() == MiddlemanType.NORMAL) {
        try {
          FileValue fileValue = ActionMetadataHandler.fileValueFromArtifact(output, null, tsgm);
          artifactData.put(output, fileValue);
          value = FileArtifactValue.create(output, fileValue);
        } catch (IOException e) {
          throw new IllegalStateException(e);
        }
      } else {
        value = FileArtifactValue.DEFAULT_MIDDLEMAN;
      }
      return new ActionExecutionValue(artifactData, ImmutableMap.of(output, value));
    }

    @Override
    public String extractTag(SkyKey skyKey) {
      return null;
    }
  }

  /** InMemoryFileSystem that can pretend to do a fast digest. */
  private class CustomInMemoryFs extends InMemoryFileSystem {
    @Override
    protected String getFastDigestFunctionType(Path path) {
      return fastDigest ? "MD5" : null;
    }

    @Override
    protected byte[] getFastDigest(Path path) throws IOException {
      return fastDigest ? getMD5Digest(path) : null;
    }
  }
}