/*
* Copyright 2013-present Facebook, Inc.
*
* 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.facebook.buck.apple.xcode;
import com.google.common.collect.Sets;
import java.util.Set;
/**
* Generator for Global ID (GID) which are present on every xcode project object.
*
* The GID is a 96 bit identifier that's unique on a per-project basis.
*/
public class GidGenerator {
private final Set<String> generatedAndReservedIds;
public GidGenerator(Set<String> reservedIds) {
generatedAndReservedIds = Sets.newHashSet(reservedIds);
}
/**
* Generate a stable GID based on the class name and hash of some object info.
*
* GIDs generated this way will be in the form of
* {@code <class-name-hash-32> <obj-hash-32> <counter-32>}
*/
public String generateGid(String pbxClassName, int hash) {
int counter = 0;
String gid;
do {
gid = String.format("%08X%08X%08X", pbxClassName.hashCode(), hash, counter++);
} while (generatedAndReservedIds.contains(gid));
generatedAndReservedIds.add(gid);
return gid;
}
}