125 lines
2.8 KiB
Java
125 lines
2.8 KiB
Java
|
/*
|
||
|
|
* Copyright (C) 2012 The Guava Authors
|
||
|
|
*
|
||
|
|
* Licensed 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 com.google.common.hash;
|
||
|
|
|
||
|
|
import static com.google.common.base.Preconditions.checkNotNull;
|
||
|
|
import static com.google.common.base.Preconditions.checkPositionIndexes;
|
||
|
|
|
||
|
|
import java.nio.ByteBuffer;
|
||
|
|
import java.nio.ByteOrder;
|
||
|
|
|
||
|
|
import com.google.common.primitives.Chars;
|
||
|
|
import com.google.common.primitives.Ints;
|
||
|
|
import com.google.common.primitives.Longs;
|
||
|
|
import com.google.common.primitives.Shorts;
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Abstract {@link Hasher} that handles converting primitives to bytes using a
|
||
|
|
* scratch {@code
|
||
|
|
* ByteBuffer} and streams all bytes to a sink to compute the hash.
|
||
|
|
*
|
||
|
|
* @author Colin Decker
|
||
|
|
*/
|
||
|
|
abstract class AbstractByteHasher extends AbstractHasher {
|
||
|
|
|
||
|
|
private final ByteBuffer scratch = ByteBuffer.allocate(8).order(ByteOrder.LITTLE_ENDIAN);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Updates this hasher with the given byte.
|
||
|
|
*/
|
||
|
|
protected abstract void update(byte b);
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Updates this hasher with the given bytes.
|
||
|
|
*/
|
||
|
|
protected void update(byte[] b) {
|
||
|
|
update(b, 0, b.length);
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Updates this hasher with {@code len} bytes starting at {@code off} in the
|
||
|
|
* given buffer.
|
||
|
|
*/
|
||
|
|
protected void update(byte[] b, int off, int len) {
|
||
|
|
for (int i = off; i < off + len; i++) {
|
||
|
|
update(b[i]);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
@Override
|
||
|
|
public Hasher putByte(byte b) {
|
||
|
|
update(b);
|
||
|
|
return this;
|
||
|
|
}
|
||
|
|
|
||
|
|
@Override
|
||
|
|
public Hasher putBytes(byte[] bytes) {
|
||
|
|
checkNotNull(bytes);
|
||
|
|
update(bytes);
|
||
|
|
return this;
|
||
|
|
}
|
||
|
|
|
||
|
|
@Override
|
||
|
|
public Hasher putBytes(byte[] bytes, int off, int len) {
|
||
|
|
checkPositionIndexes(off, off + len, bytes.length);
|
||
|
|
update(bytes, off, len);
|
||
|
|
return this;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Updates the sink with the given number of bytes from the buffer.
|
||
|
|
*/
|
||
|
|
private Hasher update(int bytes) {
|
||
|
|
try {
|
||
|
|
update(scratch.array(), 0, bytes);
|
||
|
|
} finally {
|
||
|
|
scratch.clear();
|
||
|
|
}
|
||
|
|
return this;
|
||
|
|
}
|
||
|
|
|
||
|
|
@Override
|
||
|
|
public Hasher putShort(short s) {
|
||
|
|
scratch.putShort(s);
|
||
|
|
return update(Shorts.BYTES);
|
||
|
|
}
|
||
|
|
|
||
|
|
@Override
|
||
|
|
public Hasher putInt(int i) {
|
||
|
|
scratch.putInt(i);
|
||
|
|
return update(Ints.BYTES);
|
||
|
|
}
|
||
|
|
|
||
|
|
@Override
|
||
|
|
public Hasher putLong(long l) {
|
||
|
|
scratch.putLong(l);
|
||
|
|
return update(Longs.BYTES);
|
||
|
|
}
|
||
|
|
|
||
|
|
@Override
|
||
|
|
public Hasher putChar(char c) {
|
||
|
|
scratch.putChar(c);
|
||
|
|
return update(Chars.BYTES);
|
||
|
|
}
|
||
|
|
|
||
|
|
@Override
|
||
|
|
public <T> Hasher putObject(T instance, Funnel<? super T> funnel) {
|
||
|
|
funnel.funnel(instance, this);
|
||
|
|
return this;
|
||
|
|
}
|
||
|
|
}
|