/*
* Copyright (C) 2015 The Android Open Source Project
*
* 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.android.tools.rpclib.binary;
import org.jetbrains.annotations.NotNull;
import javax.xml.bind.DatatypeConverter;
import java.io.IOException;
import java.nio.ByteBuffer;
import java.util.Arrays;
/**
* A binary resource handle. These are used as 20-byte-unique identifiers to an immutable object or
* immutable data. They are often returned from RPC calls and if the client already has the object
* or data cached locally, offer a way to avoid an unnecessary transfer of data from the server.
*/
public class Handle {
private static final int SIZE = 20;
@NotNull private final byte[] mValue = new byte[SIZE];
private final int mHashCode;
public Handle(@NotNull byte[] value) {
assert value.length == SIZE;
System.arraycopy(value, 0, mValue, 0, SIZE);
mHashCode = ByteBuffer.wrap(mValue).getInt();
}
public Handle(@NotNull Decoder d) throws IOException {
assert d.stream().read(mValue) == SIZE;
mHashCode = ByteBuffer.wrap(mValue).getInt();
}
public void encode(@NotNull Encoder e) throws IOException {
e.stream().write(mValue);
}
@Override
public boolean equals(Object other) {
if (!(other instanceof Handle)) {
return false;
}
if (other == this) {
return true;
}
return Arrays.equals(mValue, ((Handle)other).mValue);
}
@Override
public String toString() {
return DatatypeConverter.printHexBinary(mValue).toLowerCase();
}
@Override
public int hashCode() {
return mHashCode;
}
}