| // 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.query2.query.output; |
| |
| import com.google.common.hash.HashFunction; |
| import com.google.devtools.build.lib.events.EventHandler; |
| import com.google.devtools.build.lib.graph.Digraph; |
| import com.google.devtools.build.lib.packages.Target; |
| import com.google.devtools.build.lib.query2.engine.QueryEnvironment; |
| import com.google.devtools.build.lib.query2.engine.QueryException; |
| import com.google.devtools.build.lib.query2.engine.QueryExpression; |
| import com.google.devtools.build.lib.query2.query.aspectresolvers.AspectResolver; |
| import java.io.IOException; |
| import java.io.OutputStream; |
| import java.io.Serializable; |
| import javax.annotation.Nullable; |
| |
| /** |
| * Interface for classes which order, format and print the result of a Blaze |
| * graph query. |
| */ |
| public abstract class OutputFormatter implements Serializable { |
| |
| /** Returns the user-visible name of the output formatter. */ |
| public abstract String getName(); |
| |
| /** |
| * Workaround for a bug in {@link java.nio.channels.Channels#newChannel(OutputStream)}, which |
| * attempts to close the output stream on interrupt, which can cause a deadlock if there is an |
| * ongoing write. If this formatter uses Channels.newChannel, then it must return false here, and |
| * perform its own buffering. |
| */ |
| public boolean canBeBuffered() { |
| return true; |
| } |
| |
| /** |
| * Verifies that the environment and expression are compatible with this formatter, throws a |
| * {@link QueryException} if not. |
| */ |
| public void verifyCompatible(QueryEnvironment<?> env, QueryExpression expr) |
| throws QueryException {} |
| |
| /** |
| * Format the result (a set of target nodes implicitly ordered according to the graph maintained |
| * by the QueryEnvironment), and print it to "out". |
| */ |
| public abstract void output( |
| QueryOptions options, |
| Digraph<Target> result, |
| OutputStream out, |
| AspectResolver aspectProvider, |
| @Nullable EventHandler eventHandler, |
| HashFunction hashFunction) |
| throws IOException, InterruptedException; |
| } |