| /* |
| * 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.cassandra.io.sstable; |
| |
| import java.nio.ByteBuffer; |
| import java.util.Objects; |
| import java.util.concurrent.atomic.AtomicInteger; |
| import java.util.function.Supplier; |
| import java.util.regex.Pattern; |
| import java.util.stream.Stream; |
| |
| import com.google.common.base.Preconditions; |
| |
| /** |
| * Generation identifier based on sequence of integers. |
| * This has been the standard implementation in C* since inception. |
| */ |
| public class SequenceBasedSSTableId implements SSTableId, Comparable<SequenceBasedSSTableId> |
| { |
| public final int generation; |
| |
| public SequenceBasedSSTableId(final int generation) |
| { |
| assert generation >= 0; |
| |
| this.generation = generation; |
| } |
| |
| @Override |
| public int compareTo(SequenceBasedSSTableId o) |
| { |
| if (o == null) |
| return 1; |
| else if (o == this) |
| return 0; |
| |
| return Integer.compare(this.generation, o.generation); |
| } |
| |
| @Override |
| public boolean equals(Object o) |
| { |
| if (this == o) return true; |
| if (o == null || getClass() != o.getClass()) |
| return false; |
| SequenceBasedSSTableId that = (SequenceBasedSSTableId) o; |
| return generation == that.generation; |
| } |
| |
| @Override |
| public int hashCode() |
| { |
| return Objects.hash(generation); |
| } |
| |
| @Override |
| public ByteBuffer asBytes() |
| { |
| ByteBuffer bytes = ByteBuffer.allocate(Integer.BYTES); |
| bytes.putInt(0, generation); |
| return bytes; |
| } |
| |
| @Override |
| public String toString() |
| { |
| return String.valueOf(generation); |
| } |
| |
| public static class Builder implements SSTableId.Builder<SequenceBasedSSTableId> |
| { |
| public final static Builder instance = new Builder(); |
| |
| private final static Pattern PATTERN = Pattern.compile("\\d+"); |
| |
| /** |
| * Generates a sequential number to represent an sstables identifier. The first generated identifier will be |
| * greater by one than the largest generation number found across the provided existing identifiers. |
| */ |
| @Override |
| public Supplier<SequenceBasedSSTableId> generator(Stream<SSTableId> existingIdentifiers) |
| { |
| int value = existingIdentifiers.filter(SequenceBasedSSTableId.class::isInstance) |
| .map(SequenceBasedSSTableId.class::cast) |
| .mapToInt(id -> id.generation) |
| .max() |
| .orElse(0); |
| |
| AtomicInteger fileIndexGenerator = new AtomicInteger(value); |
| return () -> new SequenceBasedSSTableId(fileIndexGenerator.incrementAndGet()); |
| } |
| |
| @Override |
| public boolean isUniqueIdentifier(String str) |
| { |
| return str != null && !str.isEmpty() && str.length() <= 10 && PATTERN.matcher(str).matches(); |
| } |
| |
| @Override |
| public boolean isUniqueIdentifier(ByteBuffer bytes) |
| { |
| return bytes != null && bytes.remaining() == Integer.BYTES && bytes.getInt(0) >= 0; |
| } |
| |
| @Override |
| public SequenceBasedSSTableId fromString(String token) throws IllegalArgumentException |
| { |
| return new SequenceBasedSSTableId(Integer.parseInt(token)); |
| } |
| |
| @Override |
| public SequenceBasedSSTableId fromBytes(ByteBuffer bytes) throws IllegalArgumentException |
| { |
| Preconditions.checkArgument(bytes.remaining() == Integer.BYTES, "Buffer does not have a valid number of bytes remaining. Expecting: %s but was: %s", Integer.BYTES, bytes.remaining()); |
| return new SequenceBasedSSTableId(bytes.getInt(0)); |
| } |
| } |
| } |