android-34/com/android/networkstack/tethering/companionproxy/util/ReadableByteBuffer.java

package com.android.networkstack.tethering.companionproxy.util;

/**
 * Allows reading from a buffer of bytes. The data can be read and thus removed,
 * or peeked at without disturbing the buffer state.
 *
 * @hide
 */
public interface ReadableByteBuffer {
    /** Returns the size of the buffered data. */
    int size();

    /**
     * Returns the maximum amount of the buffered data.
     *
     * The caller may use this method in combination with peekBytes()
     * to estimate when the buffer needs to be emptied using readData().
     */
    int capacity();

    /** Clears all buffered data. */
    void clear();

    /** Returns a single byte at the given offset. */
    byte peek(int offset);

    /** Copies an array of bytes from the given offset to "dst". */
    void peekBytes(int offset, byte[] dst, int dstPos, int dstLen);

    /** Reads and removes an array of bytes from the head of the buffer. */
    void readBytes(byte[] dst, int dstPos, int dstLen);

    /** Returns the amount of contiguous readable data. */
    int getDirectReadSize();

    /** Returns the position of contiguous readable data. */
    int getDirectReadPos();

    /** Returns the buffer reference for direct read operation. */
    byte[] getDirectReadBuffer();

    /** Must be called after performing a direct read using getDirectReadBuffer(). */
    void accountForDirectRead(int len);
}