001/* 002 * Licensed to the Apache Software Foundation (ASF) under one 003 * or more contributor license agreements. See the NOTICE file 004 * distributed with this work for additional information 005 * regarding copyright ownership. The ASF licenses this file 006 * to you under the Apache License, Version 2.0 (the 007 * "License"); you may not use this file except in compliance 008 * with the License. You may obtain a copy of the License at 009 * 010 * http://www.apache.org/licenses/LICENSE-2.0 011 * 012 * Unless required by applicable law or agreed to in writing, software 013 * distributed under the License is distributed on an "AS IS" BASIS, 014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 015 * See the License for the specific language governing permissions and 016 * limitations under the License. 017 */ 018package org.apache.hadoop.hbase.procedure2.store; 019 020import java.io.IOException; 021import java.util.Iterator; 022import java.util.List; 023import java.util.NoSuchElementException; 024import org.apache.hadoop.hbase.procedure2.Procedure; 025import org.apache.hadoop.hbase.procedure2.ProcedureUtil; 026import org.apache.hadoop.hbase.procedure2.store.ProcedureStore.ProcedureIterator; 027import org.apache.yetus.audience.InterfaceAudience; 028 029/** 030 * A procedure iterator which holds all the procedure protos in memory. For fast access. 031 */ 032@InterfaceAudience.Private 033public class InMemoryProcedureIterator implements ProcedureIterator { 034 035 private final List<ProtoAndProcedure> procs; 036 037 private Iterator<ProtoAndProcedure> iter; 038 039 private ProtoAndProcedure current; 040 041 public InMemoryProcedureIterator(List<ProtoAndProcedure> procs) { 042 this.procs = procs; 043 reset(); 044 } 045 046 @Override 047 public void reset() { 048 iter = procs.iterator(); 049 if (iter.hasNext()) { 050 current = iter.next(); 051 } else { 052 current = null; 053 } 054 } 055 056 @Override 057 public boolean hasNext() { 058 return current != null; 059 } 060 061 private void checkNext() { 062 if (!hasNext()) { 063 throw new NoSuchElementException(); 064 } 065 } 066 067 @Override 068 public boolean isNextFinished() { 069 checkNext(); 070 return ProcedureUtil.isFinished(current.getProto()); 071 } 072 073 private void moveToNext() { 074 if (iter.hasNext()) { 075 current = iter.next(); 076 } else { 077 current = null; 078 } 079 } 080 081 @Override 082 public void skipNext() { 083 checkNext(); 084 moveToNext(); 085 } 086 087 @Override 088 public Procedure<?> next() throws IOException { 089 checkNext(); 090 Procedure<?> proc = current.getProcedure(); 091 moveToNext(); 092 return proc; 093 } 094}