| /* |
| * 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.db; |
| |
| import java.nio.ByteBuffer; |
| import java.util.Comparator; |
| |
| import org.apache.cassandra.dht.IPartitioner; |
| import org.apache.cassandra.dht.Token; |
| import org.apache.cassandra.dht.Token.KeyBound; |
| import org.apache.cassandra.utils.ByteBufferUtil; |
| import org.apache.cassandra.utils.MurmurHash; |
| import org.apache.cassandra.utils.IFilter.FilterKey; |
| |
| /** |
| * Represents a decorated key, handy for certain operations |
| * where just working with strings gets slow. |
| * |
| * We do a lot of sorting of DecoratedKeys, so for speed, we assume that tokens correspond one-to-one with keys. |
| * This is not quite correct in the case of RandomPartitioner (which uses MD5 to hash keys to tokens); |
| * if this matters, you can subclass RP to use a stronger hash, or use a non-lossy tokenization scheme (as in the |
| * OrderPreservingPartitioner classes). |
| */ |
| public abstract class DecoratedKey implements PartitionPosition, FilterKey |
| { |
| public static final Comparator<DecoratedKey> comparator = new Comparator<DecoratedKey>() |
| { |
| public int compare(DecoratedKey o1, DecoratedKey o2) |
| { |
| return o1.compareTo(o2); |
| } |
| }; |
| |
| private final Token token; |
| |
| public DecoratedKey(Token token) |
| { |
| assert token != null; |
| this.token = token; |
| } |
| |
| @Override |
| public int hashCode() |
| { |
| return getKey().hashCode(); // hash of key is enough |
| } |
| |
| @Override |
| public boolean equals(Object obj) |
| { |
| if (this == obj) |
| return true; |
| if (obj == null || !(obj instanceof DecoratedKey)) |
| return false; |
| |
| DecoratedKey other = (DecoratedKey)obj; |
| return ByteBufferUtil.compareUnsigned(getKey(), other.getKey()) == 0; // we compare faster than BB.equals for array backed BB |
| } |
| |
| public int compareTo(PartitionPosition pos) |
| { |
| if (this == pos) |
| return 0; |
| |
| // delegate to Token.KeyBound if needed |
| if (!(pos instanceof DecoratedKey)) |
| return -pos.compareTo(this); |
| |
| DecoratedKey otherKey = (DecoratedKey) pos; |
| int cmp = getToken().compareTo(otherKey.getToken()); |
| return cmp == 0 ? ByteBufferUtil.compareUnsigned(getKey(), otherKey.getKey()) : cmp; |
| } |
| |
| public static int compareTo(IPartitioner partitioner, ByteBuffer key, PartitionPosition position) |
| { |
| // delegate to Token.KeyBound if needed |
| if (!(position instanceof DecoratedKey)) |
| return -position.compareTo(partitioner.decorateKey(key)); |
| |
| DecoratedKey otherKey = (DecoratedKey) position; |
| int cmp = partitioner.getToken(key).compareTo(otherKey.getToken()); |
| return cmp == 0 ? ByteBufferUtil.compareUnsigned(key, otherKey.getKey()) : cmp; |
| } |
| |
| public IPartitioner getPartitioner() |
| { |
| return getToken().getPartitioner(); |
| } |
| |
| public KeyBound minValue() |
| { |
| return getPartitioner().getMinimumToken().minKeyBound(); |
| } |
| |
| public boolean isMinimum() |
| { |
| // A DecoratedKey can never be the minimum position on the ring |
| return false; |
| } |
| |
| public PartitionPosition.Kind kind() |
| { |
| return PartitionPosition.Kind.ROW_KEY; |
| } |
| |
| @Override |
| public String toString() |
| { |
| String keystring = getKey() == null ? "null" : ByteBufferUtil.bytesToHex(getKey()); |
| return "DecoratedKey(" + getToken() + ", " + keystring + ")"; |
| } |
| |
| public Token getToken() |
| { |
| return token; |
| } |
| |
| public abstract ByteBuffer getKey(); |
| |
| public void filterHash(long[] dest) |
| { |
| ByteBuffer key = getKey(); |
| MurmurHash.hash3_x64_128(key, key.position(), key.remaining(), 0, dest); |
| } |
| } |