// Copyright 2016 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.flags;
package com.google.devtools.build.lib.flags;

import com.google.common.collect.ImmutableSet;

/** Cache mapping a command to the names of all commands it inherits from, including itself. */
public interface CommandNameCache {
  /** Class that exists only to expose a static instance variable that can be set and retrieved. */
  class CommandNameCacheInstance implements CommandNameCache {
    public static final CommandNameCacheInstance INSTANCE = new CommandNameCacheInstance();
    private CommandNameCache delegate;

    private CommandNameCacheInstance() {}

    /** Only for use by {@code BlazeRuntime}. */
    public void setCommandNameCache(CommandNameCache cache) {
      // Can be set multiple times in tests.
      this.delegate = cache;
    }

    @Override
    public ImmutableSet<String> get(String commandName) {
      return delegate.get(commandName);
    }
  }

  /** Returns the names of all commands {@code commandName} inherits from, including itself. */
  ImmutableSet<String> get(String commandName);
}