| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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 org.apache.jackrabbit.oak.segment; |
| |
| import static java.util.Arrays.copyOf; |
| import static java.util.Arrays.fill; |
| |
| import java.util.Iterator; |
| |
| import com.google.common.collect.AbstractIterator; |
| |
| import org.jetbrains.annotations.NotNull; |
| |
| /** |
| * A thread-safe, mutable record table. |
| */ |
| class MutableRecordNumbers implements RecordNumbers { |
| private int[] recordEntries; |
| private int size; |
| |
| public MutableRecordNumbers() { |
| recordEntries = new int[16384]; |
| fill(recordEntries, -1); |
| } |
| |
| @Override |
| public int getOffset(int recordNumber) { |
| int recordEntry = getRecordEntry(recordEntries, recordNumber); |
| |
| if (recordEntry == -1) { |
| synchronized (this) { |
| recordEntry = getRecordEntry(recordEntries, recordNumber); |
| } |
| } |
| return recordEntry; |
| } |
| |
| private static int getRecordEntry(int[] entries, int index) { |
| return index * 2 >= entries.length |
| ? -1 |
| : entries[index * 2]; |
| } |
| |
| @NotNull |
| @Override |
| public synchronized Iterator<Entry> iterator() { |
| return new AbstractIterator<Entry>() { |
| final int[] entries = copyOf(recordEntries, size * 2); |
| int index = 0; |
| |
| @Override |
| protected Entry computeNext() { |
| if (index < entries.length) { |
| return new Entry() { |
| final int recordNumber = index/2; |
| final int offset = entries[index++]; |
| final RecordType type = RecordType.values()[entries[index++]]; |
| |
| @Override |
| public int getRecordNumber() { |
| return recordNumber; |
| } |
| |
| @Override |
| public int getOffset() { |
| return offset; |
| } |
| |
| @Override |
| public RecordType getType() { |
| return type; |
| } |
| }; |
| } else { |
| return endOfData(); |
| } |
| } |
| }; |
| } |
| |
| /** |
| * Return the size of this table. |
| * |
| * @return the size of this table. |
| */ |
| public synchronized int size() { |
| return size; |
| } |
| |
| /** |
| * Add a new offset to this table and generate a record number for it. |
| * |
| * @param type the type of the record. |
| * @param offset an offset to be added to this table. |
| * @return the record number associated to the offset. |
| */ |
| synchronized int addRecord(RecordType type, int offset) { |
| if (recordEntries.length <= size * 2) { |
| recordEntries = copyOf(recordEntries, recordEntries.length * 2); |
| fill(recordEntries, recordEntries.length/2, recordEntries.length, -1); |
| } |
| recordEntries[2 * size] = offset; |
| recordEntries[2 * size + 1] = type.ordinal(); |
| return size++; |
| } |
| |
| } |