@Override
public SkyValue fetch(Rule rule, Path outputDirectory, Environment env)
throws SkyFunctionException {
AggregatingAttributeMapper mapper = AggregatingAttributeMapper.of(rule);
PathFragment pathFragment = new PathFragment(mapper.get("path", Type.STRING));
try {
FileSystem fs = outputDirectory.getFileSystem();
if (fs.supportsSymbolicLinksNatively()) {
outputDirectory.createSymbolicLink(pathFragment);
} else {
FileSystemUtils.createDirectoryAndParents(outputDirectory);
FileSystemUtils.copyTreesBelow(
fs.getPath(getTargetPath(rule, getWorkspace())), outputDirectory);
}
} catch (IOException e) {
throw new RepositoryFunctionException(
new IOException(
"Could not create symlink to repository " + pathFragment + ": " + e.getMessage()),
Transience.TRANSIENT);
}
FileValue repositoryValue = getRepositoryDirectory(outputDirectory, env);
if (repositoryValue == null) {
// TODO(bazel-team): If this returns null, we unnecessarily recreate the symlink above on the
// second execution.
return null;
}
if (!repositoryValue.isDirectory()) {
throw new RepositoryFunctionException(
new IOException(rule + " must specify an existing directory"), Transience.TRANSIENT);
}
return RepositoryValue.create(outputDirectory);
}
/**
* Symlinks a BUILD file from the local filesystem into the external repository's root.
*
* @param rule the rule that declares the build_file path.
* @param workspaceDirectory the workspace root for the build.
* @param directoryValue the FileValue corresponding to the external repository's root directory.
* @param env the Skyframe environment.
* @return the file value of the symlink created.
* @throws
* com.google.devtools.build.lib.bazel.repository.RepositoryFunction.RepositoryFunctionException
* if the BUILD file specified does not exist or cannot be linked.
*/
protected RepositoryValue symlinkBuildFile(
Rule rule, Path workspaceDirectory, FileValue directoryValue, Environment env)
throws RepositoryFunctionException {
AggregatingAttributeMapper mapper = AggregatingAttributeMapper.of(rule);
PathFragment buildFile = new PathFragment(mapper.get("build_file", Type.STRING));
Path buildFileTarget = workspaceDirectory.getRelative(buildFile);
if (!buildFileTarget.exists()) {
throw new RepositoryFunctionException(
new EvalException(
rule.getLocation(),
String.format(
"In %s the 'build_file' attribute does not specify an existing file "
+ "(%s does not exist)",
rule, buildFileTarget)),
Transience.PERSISTENT);
}
RootedPath rootedBuild;
if (buildFile.isAbsolute()) {
rootedBuild =
RootedPath.toRootedPath(
buildFileTarget.getParentDirectory(),
new PathFragment(buildFileTarget.getBaseName()));
} else {
rootedBuild = RootedPath.toRootedPath(workspaceDirectory, buildFile);
}
SkyKey buildFileKey = FileValue.key(rootedBuild);
FileValue buildFileValue;
try {
buildFileValue =
(FileValue)
env.getValueOrThrow(
buildFileKey,
IOException.class,
FileSymlinkException.class,
InconsistentFilesystemException.class);
if (buildFileValue == null) {
return null;
}
} catch (IOException | FileSymlinkException | InconsistentFilesystemException e) {
throw new RepositoryFunctionException(
new IOException("Cannot lookup " + buildFile + ": " + e.getMessage()),
Transience.TRANSIENT);
}
Path buildFilePath = directoryValue.realRootedPath().asPath().getRelative("BUILD");
if (createSymbolicLink(buildFilePath, buildFileTarget, env) == null) {
return null;
}
return RepositoryValue.createNew(directoryValue, buildFileValue);
}
protected SkyValue compute(Environment env, Rule rule) throws RepositoryFunctionException {
// The output directory is always under .external-repository (to stay out of the way of
// artifacts from this repository) and uses the rule's name to avoid conflicts with other
// remote repository rules. For example, suppose you had the following WORKSPACE file:
//
// http_archive(name = "png", url = "http://example.com/downloads/png.tar.gz", sha256 = "...")
//
// This would download png.tar.gz to .external-repository/png/png.tar.gz.
Path outputDirectory = getExternalRepositoryDirectory().getRelative(rule.getName());
FileValue directoryValue = createDirectory(outputDirectory, env);
if (directoryValue == null) {
return null;
}
AggregatingAttributeMapper mapper = AggregatingAttributeMapper.of(rule);
URL url = null;
try {
url = new URL(mapper.get("url", Type.STRING));
} catch (MalformedURLException e) {
throw new RepositoryFunctionException(
new EvalException(rule.getLocation(), "Error parsing URL: " + e.getMessage()),
Transience.PERSISTENT);
}
String sha256 = mapper.get("sha256", Type.STRING);
HttpDownloader downloader = new HttpDownloader(url, sha256, outputDirectory);
try {
Path archiveFile = downloader.download();
outputDirectory =
DecompressorFactory.create(
rule.getTargetKind(), rule.getName(), archiveFile, outputDirectory)
.decompress();
} catch (IOException e) {
// Assumes all IO errors transient.
throw new RepositoryFunctionException(e, Transience.TRANSIENT);
} catch (DecompressorException e) {
throw new RepositoryFunctionException(new IOException(e.getMessage()), Transience.TRANSIENT);
}
return new RepositoryValue(outputDirectory, directoryValue);
}
protected static PathFragment getTargetPath(Rule rule) throws RepositoryFunctionException {
AggregatingAttributeMapper mapper = AggregatingAttributeMapper.of(rule);
String path = mapper.get("path", Type.STRING);
PathFragment pathFragment = new PathFragment(path);
if (!pathFragment.isAbsolute()) {
throw new RepositoryFunctionException(
new EvalException(
rule.getLocation(),
"In " + rule + " the 'path' attribute must specify an absolute path"),
Transience.PERSISTENT);
}
return pathFragment;
}
