ByteBufferOutputStream.java

/*
 * Copyright 2022 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 androidx.camera.core.internal;

import androidx.annotation.NonNull;
import androidx.annotation.RequiresApi;

import java.io.EOFException;
import java.io.IOException;
import java.io.OutputStream;
import java.nio.ByteBuffer;

/**
 * A {@link OutputStream} that wraps around a {@link ByteBuffer}.
 */
@RequiresApi(21)
public final class ByteBufferOutputStream extends OutputStream {

    private final ByteBuffer mByteBuffer;

    public ByteBufferOutputStream(@NonNull ByteBuffer buf) {
        mByteBuffer = buf;
    }

    @Override
    public void write(int b) throws IOException {
        if (!mByteBuffer.hasRemaining()) {
            throw new EOFException("Output ByteBuffer has no bytes remaining.");
        }

        mByteBuffer.put((byte) b);
    }

    @Override
    public void write(byte[] b, int off, int len) throws IOException {
        if (b == null) {
            throw new NullPointerException();
        } else if ((off < 0) || (off > b.length) || (len < 0)
                || ((off + len) > b.length) || ((off + len) < 0)) {
            throw new IndexOutOfBoundsException();
        } else if (len == 0) {
            return;
        } else if (mByteBuffer.remaining() < len) {
            throw new EOFException("Output ByteBuffer has insufficient bytes remaining.");
        }

        mByteBuffer.put(b, off, len);
    }
}