// Copyright 2016 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 com.google.common.base.MoreObjects;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.ImmutableSet;
import com.google.devtools.build.lib.cmdline.RepositoryName;
import com.google.devtools.build.lib.concurrent.ThreadSafety.ThreadSafe;
import com.google.devtools.build.lib.skyframe.RecursivePkgValue.RecursivePkgKey;
import com.google.devtools.build.lib.vfs.PathFragment;
import com.google.devtools.build.lib.vfs.RootedPath;
import com.google.devtools.build.skyframe.LegacySkyKey;
import com.google.devtools.build.skyframe.SkyKey;
import com.google.devtools.build.skyframe.SkyValue;
import java.util.Objects;
import javax.annotation.Nullable;
/**
* The value computed by {@link CollectPackagesUnderDirectoryFunction}. Contains a mapping for all
* its non-excluded directories to whether there are packages or error messages beneath them.
*
* <p>This value is used by {@link GraphBackedRecursivePackageProvider#getPackagesUnderDirectory} to
* help it traverse the graph and find the set of packages under a directory, recursively by {@link
* CollectPackagesUnderDirectoryFunction} which computes a value for a directory by aggregating
* results calculated from its subdirectories, and by {@link
* PrepareDepsOfTargetsUnderDirectoryFunction} which uses this value to find transitive targets to
* load.
*
* <p>Note that even though the {@link CollectPackagesUnderDirectoryFunction} is evaluated in part
* because of its side-effects (i.e. loading transitive dependencies of targets), this value
* interacts safely with change pruning, despite the fact that this value is a lossy representation
* of the packages beneath a directory (i.e. it doesn't care <b>which</b> packages are under a
* directory, just whether there are any). When the targets in a package change, the {@link
* PackageValue} that {@link CollectPackagesUnderDirectoryFunction} depends on will be invalidated,
* and the PrepareDeps function for that package's directory will be reevaluated, loading any new
* transitive dependencies. Change pruning may prevent the reevaluation of PrepareDeps for
* directories above that one, but they don't need to be re-run.
*/
public abstract class CollectPackagesUnderDirectoryValue implements SkyValue {
private final ImmutableMap<RootedPath, Boolean> subdirectoryTransitivelyContainsPackagesOrErrors;
CollectPackagesUnderDirectoryValue(
ImmutableMap<RootedPath, Boolean> subdirectoryTransitivelyContainsPackagesOrErrors) {
this.subdirectoryTransitivelyContainsPackagesOrErrors =
Preconditions.checkNotNull(subdirectoryTransitivelyContainsPackagesOrErrors);
}
/** Represents a successfully loaded package or a directory without a BUILD file. */
public static class NoErrorCollectPackagesUnderDirectoryValue
extends CollectPackagesUnderDirectoryValue {
public static final NoErrorCollectPackagesUnderDirectoryValue EMPTY =
new NoErrorCollectPackagesUnderDirectoryValue(
false, ImmutableMap.<RootedPath, Boolean>of());
private final boolean isDirectoryPackage;
private NoErrorCollectPackagesUnderDirectoryValue(
boolean isDirectoryPackage,
ImmutableMap<RootedPath, Boolean> subdirectoryTransitivelyContainsPackagesOrErrors) {
super(subdirectoryTransitivelyContainsPackagesOrErrors);
this.isDirectoryPackage = isDirectoryPackage;
}
@Override
public boolean isDirectoryPackage() {
return isDirectoryPackage;
}
@Nullable
@Override
public String getErrorMessage() {
return null;
}
@Override
public int hashCode() {
return Objects.hash(
isDirectoryPackage, getSubdirectoryTransitivelyContainsPackagesOrErrors());
}
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (!(o instanceof NoErrorCollectPackagesUnderDirectoryValue)) {
return false;
}
NoErrorCollectPackagesUnderDirectoryValue that =
(NoErrorCollectPackagesUnderDirectoryValue) o;
return this.isDirectoryPackage == that.isDirectoryPackage
&& Objects.equals(
this.getSubdirectoryTransitivelyContainsPackagesOrErrors(),
that.getSubdirectoryTransitivelyContainsPackagesOrErrors());
}
@Override
public String toString() {
return MoreObjects.toStringHelper(this)
.add("isDirectoryPackage", isDirectoryPackage)
.add(
"subdirectoryTransitivelyContainsPackagesOrErrors",
getSubdirectoryTransitivelyContainsPackagesOrErrors())
.toString();
}
}
/** Represents a directory with a BUILD file that failed to load. */
public static class ErrorCollectPackagesUnderDirectoryValue
extends CollectPackagesUnderDirectoryValue {
private final String errorMessage;
private ErrorCollectPackagesUnderDirectoryValue(
String errorMessage,
ImmutableMap<RootedPath, Boolean> subdirectoryTransitivelyContainsPackagesOrErrors) {
super(subdirectoryTransitivelyContainsPackagesOrErrors);
this.errorMessage = Preconditions.checkNotNull(errorMessage);
}
@Override
public boolean isDirectoryPackage() {
return false;
}
@Override
public String getErrorMessage() {
return errorMessage;
}
@Override
public int hashCode() {
return Objects.hash(errorMessage, getSubdirectoryTransitivelyContainsPackagesOrErrors());
}
@Override
public boolean equals(Object o) {
if (this == o) {
return true;
}
if (!(o instanceof ErrorCollectPackagesUnderDirectoryValue)) {
return false;
}
ErrorCollectPackagesUnderDirectoryValue that = (ErrorCollectPackagesUnderDirectoryValue) o;
return Objects.equals(this.errorMessage, that.errorMessage)
&& Objects.equals(
this.getSubdirectoryTransitivelyContainsPackagesOrErrors(),
that.getSubdirectoryTransitivelyContainsPackagesOrErrors());
}
@Override
public String toString() {
return MoreObjects.toStringHelper(this)
.add("errorMessage", errorMessage)
.add(
"subdirectoryTransitivelyContainsPackagesOrErrors",
getSubdirectoryTransitivelyContainsPackagesOrErrors())
.toString();
}
}
/**
* Constructs a {@link CollectPackagesUnderDirectoryValue} for a directory with a BUILD file that
* failed to load as a package.
*/
public static CollectPackagesUnderDirectoryValue ofError(
String errorMessage,
ImmutableMap<RootedPath, Boolean> subdirectoryTransitivelyContainsPackagesOrErrors) {
Preconditions.checkNotNull(errorMessage, "errorMessage");
return new ErrorCollectPackagesUnderDirectoryValue(
errorMessage, subdirectoryTransitivelyContainsPackagesOrErrors);
}
/**
* Constructs a {@link CollectPackagesUnderDirectoryValue} for a directory without a BUILD file or
* that has a BUILD file that successfully loads as a package.
*/
public static CollectPackagesUnderDirectoryValue ofNoError(
boolean isDirectoryPackage,
ImmutableMap<RootedPath, Boolean> subdirectoryTransitivelyContainsPackagesOrErrors) {
if (!isDirectoryPackage && subdirectoryTransitivelyContainsPackagesOrErrors.isEmpty()) {
return NoErrorCollectPackagesUnderDirectoryValue.EMPTY;
}
return new NoErrorCollectPackagesUnderDirectoryValue(
isDirectoryPackage, subdirectoryTransitivelyContainsPackagesOrErrors);
}
/**
* Returns whether there is a BUILD file in this directory that can be loaded as a package. If
* this returns {@code true}, then {@link #getErrorMessage()} returns {@code null}.
*/
public abstract boolean isDirectoryPackage();
/**
* Returns an error describing why the BUILD file in this directory cannot be loaded as a package,
* if there is one and it can't be. Otherwise returns {@code null}. If this returns non-{@code
* null}, then {@link #isDirectoryPackage()} returns {@code false}.
*/
@Nullable
public abstract String getErrorMessage();
/**
* Returns an {@link ImmutableMap} describing each immediate subdirectory of this directory and
* whether there are any packages, or BUILD files that couldn't be loaded, in or beneath that
* subdirectory.
*/
public final ImmutableMap<RootedPath, Boolean>
getSubdirectoryTransitivelyContainsPackagesOrErrors() {
return subdirectoryTransitivelyContainsPackagesOrErrors;
}
/** Create a collect packages under directory request. */
@ThreadSafe
static SkyKey key(
RepositoryName repository, RootedPath rootedPath, ImmutableSet<PathFragment> excludedPaths) {
return key(new RecursivePkgKey(repository, rootedPath, excludedPaths));
}
static SkyKey key(RecursivePkgKey recursivePkgKey) {
return LegacySkyKey.create(SkyFunctions.COLLECT_PACKAGES_UNDER_DIRECTORY, recursivePkgKey);
}
}