001/** 002 * Copyright 2015 DuraSpace, Inc. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016package org.fcrepo.mint; 017 018import static com.codahale.metrics.MetricRegistry.name; 019import static java.util.UUID.randomUUID; 020 021import java.util.stream.IntStream; 022import java.util.StringJoiner; 023 024import org.fcrepo.metrics.RegistryService; 025import org.fcrepo.kernel.api.services.functions.HierarchicalIdentifierSupplier; 026 027import com.codahale.metrics.Timer; 028 029/** 030 * PID minter that creates hierarchical IDs for a UUID 031 * 032 * @author awoods 033 */ 034public class UUIDPathMinter implements HierarchicalIdentifierSupplier { 035 036 static final Timer timer = RegistryService.getInstance().getMetrics().timer( 037 name(UUIDPathMinter.class, "mint")); 038 039 private final int length; 040 041 private final int count; 042 043 /** 044 * Configure the path minter using some reasonable defaults for the length 045 * and count of the branch nodes 046 */ 047 public UUIDPathMinter() { 048 this(DEFAULT_LENGTH, DEFAULT_COUNT); 049 } 050 051 /** 052 * Configure the path minter for the length of the keys and depth of the 053 * branch node prefix 054 * 055 * @param length how long the branch node identifiers should be 056 * @param count how many branch nodes should be inserted 057 */ 058 public UUIDPathMinter(final int length, final int count) { 059 super(); 060 this.length = length; 061 this.count = count; 062 } 063 064 /** 065 * Mint a unique identifier as a UUID 066 * 067 * @return uuid 068 */ 069 @Override 070 public String get() { 071 072 try (final Timer.Context context = timer.time()) { 073 final String s = randomUUID().toString(); 074 075 if (length == 0 || count == 0) { 076 return s; 077 } 078 079 final StringJoiner joiner = new StringJoiner("/", "", "/" + s); 080 IntStream.rangeClosed(0, count - 1) 081 .forEach(x -> joiner.add(s.substring(x * length, (x + 1) * length))); 082 083 return joiner.toString(); 084 } 085 } 086}