// 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.exec;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableMap;
import com.google.common.collect.Lists;
import com.google.devtools.build.lib.actions.AbstractAction;
import com.google.devtools.build.lib.actions.ActionExecutionContext;
import com.google.devtools.build.lib.actions.BaseSpawn;
import com.google.devtools.build.lib.actions.ExecException;
import com.google.devtools.build.lib.actions.ResourceSet;
import com.google.devtools.build.lib.actions.UserExecException;
import com.google.devtools.build.lib.analysis.config.BinTools;
import com.google.devtools.build.lib.analysis.config.BuildConfiguration;
import com.google.devtools.build.lib.shell.CommandException;
import com.google.devtools.build.lib.util.CommandBuilder;
import com.google.devtools.build.lib.util.OsUtils;
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 java.io.IOException;
import java.util.List;
/**
* Helper class responsible for the symlink tree creation.
* Used to generate runfiles and fileset symlink farms.
*/
public final class SymlinkTreeHelper {
@VisibleForTesting
public static final String BUILD_RUNFILES = "build-runfiles" + OsUtils.executableExtension();
/**
* These actions run faster overall when serialized, because most of their
* cost is in the ext2 block allocator, and there's less seeking required if
* their directory creations get non-interleaved allocations. So we give them
* a huge resource cost.
*/
public static final ResourceSet RESOURCE_SET = ResourceSet.createWithRamCpuIo(1000, 0.5, 0.75);
private final Path inputManifest;
private final Path symlinkTreeRoot;
private final boolean filesetTree;
/**
* Creates SymlinkTreeHelper instance. Can be used independently of
* SymlinkTreeAction.
*
* @param inputManifest exec path to the input runfiles manifest
* @param symlinkTreeRoot the root of the symlink tree to be created
* @param filesetTree true if this is fileset symlink tree,
* false if this is a runfiles symlink tree.
*/
public SymlinkTreeHelper(Path inputManifest, Path symlinkTreeRoot,
boolean filesetTree) {
this.inputManifest = inputManifest;
this.symlinkTreeRoot = symlinkTreeRoot;
this.filesetTree = filesetTree;
}
public Path getOutputManifest() {
return symlinkTreeRoot;
}
/**
* Creates a symlink tree using a CommandBuilder. This means that the symlink
* tree will always be present on the developer's workstation. Useful when
* running commands locally.
*
* Warning: this method REALLY executes the command on the box Blaze was
* run on, without any kind of synchronization, locking, or anything else.
*
* @param config the configuration that is used for creating the symlink tree.
* @throws CommandException
*/
public void createSymlinksUsingCommand(Path execRoot,
BuildConfiguration config, BinTools binTools) throws CommandException {
List<String> argv = getSpawnArgumentList(execRoot, binTools);
CommandBuilder builder = new CommandBuilder();
builder.addArgs(argv);
builder.setWorkingDir(execRoot);
builder.build().execute();
}
/**
* Creates symlink tree using appropriate method. At this time tree
* always created using build-runfiles helper application.
*
* Note: method may try to acquire resources - meaning that it would
* block for undetermined period of time. If it is interrupted during
* that wait, ExecException will be thrown but interrupted bit will be
* preserved.
* @param action action instance that requested symlink tree creation
* @param actionExecutionContext Services that are in the scope of the action.
* @param enableRunfiles
*/
public void createSymlinks(
AbstractAction action,
ActionExecutionContext actionExecutionContext,
BinTools binTools,
ImmutableMap<String, String> shellEnvironment,
boolean enableRunfiles)
throws ExecException, InterruptedException {
if (enableRunfiles) {
List<String> args =
getSpawnArgumentList(
actionExecutionContext.getExecutor().getExecRoot(), binTools);
actionExecutionContext.getExecutor().getSpawnActionContext(action.getMnemonic()).exec(
new BaseSpawn.Local(args, shellEnvironment, action, RESOURCE_SET),
actionExecutionContext);
} else {
// Pretend we created the runfiles tree by copying the manifest
try {
FileSystemUtils.createDirectoryAndParents(symlinkTreeRoot);
FileSystemUtils.copyFile(inputManifest, symlinkTreeRoot.getChild("MANIFEST"));
} catch (IOException e) {
throw new UserExecException(e.getMessage(), e);
}
}
}
/**
* Returns the complete argument list build-runfiles has to be called with.
*/
private List<String> getSpawnArgumentList(Path execRoot, BinTools binTools) {
PathFragment path = binTools.getExecPath(BUILD_RUNFILES);
Preconditions.checkNotNull(path, BUILD_RUNFILES + " not found in embedded tools");
List<String> args = Lists.newArrayList();
args.add(path.getPathString());
if (filesetTree) {
args.add("--allow_relative");
args.add("--use_metadata");
}
args.add(inputManifest.relativeTo(execRoot).getPathString());
args.add(symlinkTreeRoot.relativeTo(execRoot).getPathString());
return args;
}
}