// Copyright 2015 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.query2.engine;
import com.google.common.collect.ImmutableList;
import com.google.devtools.build.lib.query2.engine.QueryEnvironment.Argument;
import com.google.devtools.build.lib.query2.engine.QueryEnvironment.ArgumentType;
import com.google.devtools.build.lib.query2.engine.QueryEnvironment.QueryFunction;
import com.google.devtools.build.lib.query2.engine.QueryUtil.Processor;
import java.util.List;
import java.util.Set;
import java.util.concurrent.ForkJoinPool;
/**
* A visible(x, y) query expression, which computes the subset of nodes in y
* that are visible from all nodes in x.
*
*
expr ::= VISIBILE '(' expr ',' expr ')'
*
* Example: return targets from the package //bar/baz that are visible to //foo.
*
*
* visible(//foo, //bar/baz:*)
*
*/
public class VisibleFunction implements QueryFunction {
@Override
public String getName() {
return "visible";
}
@Override
public int getMandatoryArguments() {
return 2;
}
@Override
public List getArgumentTypes() {
return ImmutableList.of(ArgumentType.EXPRESSION, ArgumentType.EXPRESSION);
}
private static class ProcessorImpl implements Processor {
private final QueryEnvironment env;
private final Set toSet;
private ProcessorImpl(QueryEnvironment env, Set toSet) {
this.env = env;
this.toSet = toSet;
}
@Override
public void process(Iterable partialResult, Callback callback)
throws QueryException, InterruptedException {
for (T t : partialResult) {
if (visibleToAll(env, toSet, t)) {
callback.process(ImmutableList.of(t));
}
}
}
}
private static void doEval(
QueryEnvironment env,
VariableContext context,
List args,
Callback callback) throws QueryException, InterruptedException {
Set toSet = QueryUtil.evalAll(env, context, args.get(0).getExpression());
env.eval(
args.get(1).getExpression(),
context,
QueryUtil.compose(new ProcessorImpl(env, toSet), callback));
}
@Override
public void eval(
QueryEnvironment env,
VariableContext context,
QueryExpression expression,
List args,
Callback callback) throws QueryException, InterruptedException {
doEval(env, context, args, callback);
}
@Override
public void parEval(
QueryEnvironment env,
VariableContext context,
QueryExpression expression,
List args,
ThreadSafeCallback callback,
ForkJoinPool forkJoinPool) throws QueryException, InterruptedException {
doEval(env, context, args, callback);
}
/** Returns true if {@code target} is visible to all targets in {@code toSet}. */
private static boolean visibleToAll(QueryEnvironment env, Set toSet, T target)
throws QueryException, InterruptedException {
for (T to : toSet) {
if (!visible(env, to, target)) {
return false;
}
}
return true;
}
/** Returns true if the target {@code from} is visible to the target {@code to}. */
public static boolean visible(QueryEnvironment env, T to, T from)
throws QueryException, InterruptedException {
Set> visiblePackages = env.getAccessor().getVisibility(from);
for (QueryVisibility spec : visiblePackages) {
if (spec.contains(to)) {
return true;
}
}
return false;
}
}