blob: 6feb2b91321df81df27c0ac312f84eba7b608ae9 [file] [log] [blame]
// Copyright 2014 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.analysis;
import static com.google.common.collect.ImmutableList.toImmutableList;
import static java.nio.charset.StandardCharsets.ISO_8859_1;
import static java.nio.charset.StandardCharsets.UTF_8;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.collect.ImmutableList;
import com.google.devtools.build.lib.actions.AbstractAction;
import com.google.devtools.build.lib.actions.ActionExecutionContext;
import com.google.devtools.build.lib.actions.ActionKeyContext;
import com.google.devtools.build.lib.actions.ActionOwner;
import com.google.devtools.build.lib.actions.Artifact;
import com.google.devtools.build.lib.analysis.actions.AbstractFileWriteAction;
import com.google.devtools.build.lib.analysis.actions.DeterministicWriter;
import com.google.devtools.build.lib.analysis.starlark.UnresolvedSymlinkAction;
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.concurrent.ThreadSafety.Immutable;
import com.google.devtools.build.lib.events.EventHandler;
import com.google.devtools.build.lib.util.Fingerprint;
import com.google.devtools.build.lib.vfs.PathFragment;
import java.io.BufferedWriter;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.Writer;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;
import java.util.Map;
import javax.annotation.Nullable;
/**
* Creates a manifest file describing a symlink tree.
*
* <p>In addition to symlink trees (whose manifests are a tree position -> exec path map), this
* action can also create manifest consisting of just exec paths for historical reasons.
*
* <p>This action carefully avoids building the manifest content in memory because it can be large.
*/
@Immutable // if all ManifestWriter implementations are immutable
public final class SourceManifestAction extends AbstractFileWriteAction {
private static final String GUID = "07459553-a3d0-4d37-9d78-18ed942470f4";
private static final Comparator<Map.Entry<PathFragment, Artifact>> ENTRY_COMPARATOR =
(path1, path2) -> path1.getKey().getPathString().compareTo(path2.getKey().getPathString());
private final Artifact repoMappingManifest;
/**
* Interface for defining manifest formatting and reporting specifics. Implementations must be
* immutable.
*/
@VisibleForTesting
interface ManifestWriter {
/**
* Writes a single line of manifest output.
*
* @param manifestWriter the output stream
* @param rootRelativePath path of an entry relative to the manifest's root
* @param symlink (optional) symlink that resolves the above path
*/
void writeEntry(
Writer manifestWriter, PathFragment rootRelativePath, @Nullable Artifact symlink)
throws IOException;
/** Fulfills {@link com.google.devtools.build.lib.actions.AbstractAction#getMnemonic()} */
String getMnemonic();
/**
* Fulfills {@link com.google.devtools.build.lib.actions.AbstractAction#getRawProgressMessage()}
*/
String getRawProgressMessage();
/**
* Fulfills {@link AbstractFileWriteAction#isRemotable()}.
*
* @return
*/
boolean isRemotable();
}
/** The strategy we use to write manifest entries. */
private final ManifestWriter manifestWriter;
/** The runfiles for which to create the symlink tree. */
private final Runfiles runfiles;
private final boolean remotableSourceManifestActions;
private NestedSet<Artifact> symlinkArtifacts = null;
/**
* Creates a new AbstractSourceManifestAction instance using latin1 encoding to write the manifest
* file and with a specified root path for manifest entries.
*
* @param manifestWriter the strategy to use to write manifest entries
* @param owner the action owner
* @param primaryOutput the file to which to write the manifest
* @param runfiles runfiles
*/
@VisibleForTesting
SourceManifestAction(
ManifestWriter manifestWriter, ActionOwner owner, Artifact primaryOutput, Runfiles runfiles) {
this(manifestWriter, owner, primaryOutput, runfiles, null, false);
}
/**
* Creates a new AbstractSourceManifestAction instance using latin1 encoding to write the manifest
* file and with a specified root path for manifest entries.
*
* @param manifestWriter the strategy to use to write manifest entries
* @param owner the action owner
* @param primaryOutput the file to which to write the manifest
* @param runfiles runfiles
* @param repoMappingManifest the repository mapping manifest for runfiles
*/
public SourceManifestAction(
ManifestWriter manifestWriter,
ActionOwner owner,
Artifact primaryOutput,
Runfiles runfiles,
@Nullable Artifact repoMappingManifest,
boolean remotableSourceManifestActions) {
// The real set of inputs is computed in #getInputs().
super(owner, NestedSetBuilder.emptySet(Order.STABLE_ORDER), primaryOutput, false);
this.manifestWriter = manifestWriter;
this.runfiles = runfiles;
this.repoMappingManifest = repoMappingManifest;
this.remotableSourceManifestActions = remotableSourceManifestActions;
}
/**
* The manifest entry for a symlink artifact should contain the target of the symlink rather than
* its exec path. Reading the symlink target requires that the symlink artifact is declared as an
* input of this action. Since declaring all runfiles as inputs of the manifest action would
* unnecessarily delay its execution, this action exceptionally overrides {@link
* AbstractAction#getInputs()} and filters out the non-symlink runfiles by flattening the nested
* set of runfiles. Benchmarks confirmed that this does not regress performance.
*
* <p>Alternatives considered:
*
* <ul>
* <li>Having users separate normal artifacts from symlink artifacts during analysis: Makes it
* impossible to pass symlink artifacts to rules that aren't aware of them and requires the
* use of custom providers to pass symlinks to stage as inputs to actions.
* <li>Reaching into {@link ActionExecutionContext} to look up the generating action of symlink
* artifacts and retrieving the target from {@link UnresolvedSymlinkAction}: This would not
* work for symlinks whose target is determined in the execution phase.
* <li>Input discovery: Complex and error-prone in general and conceptually not necessary here -
* we already know what the inputs will be during analysis, we just want to delay the
* required computations.
* </ul>
*/
@Override
public synchronized NestedSet<Artifact> getInputs() {
if (symlinkArtifacts == null) {
ImmutableList<Artifact> symlinks =
runfiles.getArtifacts().toList().stream()
.filter(Artifact::isSymlink)
.collect(toImmutableList());
symlinkArtifacts = NestedSetBuilder.wrap(Order.STABLE_ORDER, symlinks);
}
return symlinkArtifacts;
}
@VisibleForTesting
public void writeOutputFile(OutputStream out, @Nullable EventHandler eventHandler)
throws IOException {
writeFile(
out,
runfiles.getRunfilesInputs(eventHandler, getOwner().getLocation(), repoMappingManifest));
}
/**
* Get the contents of a file internally using an in memory output stream.
*
* @return returns the file contents as a string.
*/
public String getFileContentsAsString(@Nullable EventHandler eventHandler) throws IOException {
ByteArrayOutputStream stream = new ByteArrayOutputStream();
writeOutputFile(stream, eventHandler);
return stream.toString(UTF_8);
}
@Override
public String getStarlarkContent() throws IOException {
return getFileContentsAsString(null);
}
@Override
public DeterministicWriter newDeterministicWriter(ActionExecutionContext ctx) {
final Map<PathFragment, Artifact> runfilesInputs =
runfiles.getRunfilesInputs(
ctx.getEventHandler(), getOwner().getLocation(), repoMappingManifest);
return out -> writeFile(out, runfilesInputs);
}
@Override
public boolean isRemotable() {
return remotableSourceManifestActions || manifestWriter.isRemotable();
}
/**
* Sort the entries in both the normal and root manifests and write the output file.
*
* @param out is the message stream to write errors to.
* @param output The actual mapping of the output manifest.
* @throws IOException
*/
private void writeFile(OutputStream out, Map<PathFragment, Artifact> output) throws IOException {
Writer manifestFile = new BufferedWriter(new OutputStreamWriter(out, ISO_8859_1));
List<Map.Entry<PathFragment, Artifact>> sortedManifest = new ArrayList<>(output.entrySet());
sortedManifest.sort(ENTRY_COMPARATOR);
for (Map.Entry<PathFragment, Artifact> line : sortedManifest) {
manifestWriter.writeEntry(manifestFile, line.getKey(), line.getValue());
}
manifestFile.flush();
}
@Override
public String getMnemonic() {
return manifestWriter.getMnemonic();
}
@Override
protected String getRawProgressMessage() {
return manifestWriter.getRawProgressMessage() + " for " + getOwner().getLabel();
}
@Override
protected void computeKey(
ActionKeyContext actionKeyContext,
@Nullable Artifact.ArtifactExpander artifactExpander,
Fingerprint fp) {
fp.addString(GUID);
fp.addBoolean(remotableSourceManifestActions);
runfiles.fingerprint(fp);
fp.addBoolean(repoMappingManifest != null);
if (repoMappingManifest != null) {
fp.addPath(repoMappingManifest.getExecPath());
}
}
@Override
public String describeKey() {
return String.format(
"GUID: %s\nremotableSourceManifestActions: %s\nrunfiles: %s\n",
GUID, remotableSourceManifestActions, runfiles.describeFingerprint());
}
/** Supported manifest writing strategies. */
public enum ManifestType implements ManifestWriter {
/**
* Writes each line as:
*
* <p>[rootRelativePath] [resolvingSymlink]
*
* <p>This strategy is suitable for creating an input manifest to a source view tree. Its output
* is a valid input to {@link com.google.devtools.build.lib.analysis.actions.SymlinkTreeAction}.
*/
SOURCE_SYMLINKS {
@Override
public void writeEntry(Writer manifestWriter, PathFragment rootRelativePath, Artifact symlink)
throws IOException {
manifestWriter.append(rootRelativePath.getPathString());
// This trailing whitespace is REQUIRED to process the single entry line correctly.
manifestWriter.append(' ');
if (symlink != null) {
if (symlink.isSymlink()) {
manifestWriter.append(symlink.getPath().readSymbolicLink().getPathString());
} else {
manifestWriter.append(symlink.getPath().getPathString());
}
}
manifestWriter.append('\n');
}
@Override
public String getMnemonic() {
return "SourceSymlinkManifest";
}
@Override
public String getRawProgressMessage() {
return "Creating source manifest";
}
@Override
public boolean isRemotable() {
// There is little gain to remoting these, since they include absolute path names inline.
return false;
}
},
/**
* Writes each line as:
*
* <p>[rootRelativePath]
*
* <p>This strategy is suitable for an input into a packaging system (notably .par) that
* consumes a list of all source files but needs that list to be constant with respect to how
* the user has their client laid out on local disk.
*/
SOURCES_ONLY {
@Override
public void writeEntry(Writer manifestWriter, PathFragment rootRelativePath, Artifact symlink)
throws IOException {
manifestWriter.append(rootRelativePath.getPathString());
manifestWriter.append('\n');
manifestWriter.flush();
}
@Override
public String getMnemonic() {
return "PackagingSourcesManifest";
}
@Override
public String getRawProgressMessage() {
return "Creating file sources list";
}
@Override
public boolean isRemotable() {
// Source-only symlink manifest has root-relative paths and does not include absolute paths.
return true;
}
}
}
}