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The Ionic Java SDK provides an easy-to-use interface to the Ionic Platform.

There is a newer version: 2.9.0

package com.ionic.sdk.core.io;

import java.io.InputStream;

/**
 * Use this class to enable write access to an input stream, in order to buffer bytes.  This is needed to implement
 * Ionic file ciphers.
 */
public final class ByteQueueInputStream extends InputStream {

    /**
     * Buffer of bytes which may be read from and written to, allowing for buffered handling of the data stream.
     */
    private final ByteQueue byteQueue;

    /**
     * Intermediate buffer for data to be read from this stream.  This single byte array is used to transfer data
     * from the ByteQueue API (which takes byte[]) to the InputStream "read()" API (which takes a single byte).
     */
    private final byte[] byteBuffer;

    /**
     * Constructor.
     *
     * @param blockSize the size in bytes of each {@link ByteBlock} managed by the member queue
     */
    public ByteQueueInputStream(final int blockSize) {
        this.byteQueue = new ByteQueue(blockSize);
        this.byteBuffer = new byte[1];
    }

    /**
     * Write additional bytes to the buffer, which will then be consumed by the InputStream "read()" operation.
     *
     * @param bytes the bytes that should be written to the internal buffer
     */
    public void addBytes(final byte[] bytes) {
        byteQueue.addData(bytes, 0, bytes.length);
    }

    @Override
    public int read() {
        int b = -1;
        if (byteQueue.available() > 0) {
            byteQueue.removeData(byteBuffer, 0, byteBuffer.length);
            b = byteBuffer[0] & BYTE_MASK;
        }
        return b;
    }

    @Override
    public int read(final byte[] bytes, final int offset, final int len) {
        final int countToRead = Math.min(len, byteQueue.available());
        return byteQueue.removeData(bytes, offset, countToRead);
    }

    @Override
    public int available() {
        return byteQueue.available();
    }

    /**
     * Mask used to filter out high order bits of int to make a byte.
     */
    private static final int BYTE_MASK = (1 << Byte.SIZE) - 1;
}