| /* |
| * 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 com.google.common.primitives.Chars; |
| import com.google.common.primitives.Ints; |
| import com.google.common.primitives.Longs; |
| import com.google.common.primitives.Shorts; |
| import com.google.errorprone.annotations.CanIgnoreReturnValue; |
| import java.nio.ByteBuffer; |
| import java.nio.ByteOrder; |
| |
| /** |
| * 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 |
| */ |
| @CanIgnoreReturnValue |
| 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]); |
| } |
| } |
| |
| /** Updates this hasher with bytes from the given buffer. */ |
| protected void update(ByteBuffer b) { |
| if (b.hasArray()) { |
| update(b.array(), b.arrayOffset() + b.position(), b.remaining()); |
| b.position(b.limit()); |
| } else { |
| for (int remaining = b.remaining(); remaining > 0; remaining--) { |
| update(b.get()); |
| } |
| } |
| } |
| |
| /** 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 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; |
| } |
| |
| @Override |
| public Hasher putBytes(ByteBuffer bytes) { |
| update(bytes); |
| 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); |
| } |
| } |