@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);
}
