/*
 * Hunt - A refined core library for D programming language.
 *
 * Copyright (C) 2018-2019 HuntLabs
 *
 * Website: https://www.huntlabs.net/
 *
 * Licensed under the Apache-2.0 License.
 *
 */

module hunt.io.Common;

import hunt.collection.ByteBuffer;
import hunt.Exceptions;
import hunt.util.Common;
import hunt.logging;
import hunt.concurrency.CountingCallback;

import std.algorithm;


/**
 * Serializability of a class is enabled by the class implementing the
 * java.io.Serializable interface.
 *
 * <p><strong>Warning: Deserialization of untrusted data is inherently dangerous
 * and should be avoided. Untrusted data should be carefully validated according to the
 * "Serialization and Deserialization" section of the
 * {@extLink secure_coding_guidelines_javase Secure Coding Guidelines for Java SE}.
 * {@extLink serialization_filter_guide Serialization Filtering} describes best
 * practices for defensive use of serial filters.
 * </strong></p>
 *
 * Classes that do not implement this
 * interface will not have any of their state serialized or
 * deserialized.  All subtypes of a serializable class are themselves
 * serializable.  The serialization interface has no methods or fields
 * and serves only to identify the semantics of being serializable. <p>
 *
 * To allow subtypes of non-serializable classes to be serialized, the
 * subtype may assume responsibility for saving and restoring the
 * state of the supertype's public, protected, and (if accessible)
 * package fields.  The subtype may assume this responsibility only if
 * the class it extends has an accessible no-arg constructor to
 * initialize the class's state.  It is an error to declare a class
 * Serializable if this is not the case.  The error will be detected at
 * runtime. <p>
 *
 * During deserialization, the fields of non-serializable classes will
 * be initialized using the public or protected no-arg constructor of
 * the class.  A no-arg constructor must be accessible to the subclass
 * that is serializable.  The fields of serializable subclasses will
 * be restored from the stream. <p>
 *
 * When traversing a graph, an object may be encountered that does not
 * support the Serializable interface. In this case the
 * NotSerializableException will be thrown and will identify the class
 * of the non-serializable object. <p>
 *
 * Classes that require special handling during the serialization and
 * deserialization process must implement special methods with these exact
 * signatures:
 *
 * <PRE>
 * private void writeObject(java.io.ObjectOutputStream out)
 *     throws IOException
 * private void readObject(java.io.ObjectInputStream in)
 *     throws IOException, ClassNotFoundException;
 * private void readObjectNoData()
 *     throws ObjectStreamException;
 * </PRE>
 *
 * <p>The writeObject method is responsible for writing the state of the
 * object for its particular class so that the corresponding
 * readObject method can restore it.  The default mechanism for saving
 * the Object's fields can be invoked by calling
 * out.defaultWriteObject. The method does not need to concern
 * itself with the state belonging to its superclasses or subclasses.
 * State is saved by writing the individual fields to the
 * ObjectOutputStream using the writeObject method or by using the
 * methods for primitive data types supported by DataOutput.
 *
 * <p>The readObject method is responsible for reading from the stream and
 * restoring the classes fields. It may call in.defaultReadObject to invoke
 * the default mechanism for restoring the object's non-static and
 * non-transient fields.  The defaultReadObject method uses information in
 * the stream to assign the fields of the object saved in the stream with the
 * correspondingly named fields in the current object.  This handles the case
 * when the class has evolved to add new fields. The method does not need to
 * concern itself with the state belonging to its superclasses or subclasses.
 * State is restored by reading data from the ObjectInputStream for
 * the individual fields and making assignments to the appropriate fields
 * of the object. Reading primitive data types is supported by DataInput.
 *
 * <p>The readObjectNoData method is responsible for initializing the state of
 * the object for its particular class in the event that the serialization
 * stream does not list the given class as a superclass of the object being
 * deserialized.  This may occur in cases where the receiving party uses a
 * different version of the deserialized instance's class than the sending
 * party, and the receiver's version extends classes that are not extended by
 * the sender's version.  This may also occur if the serialization stream has
 * been tampered; hence, readObjectNoData is useful for initializing
 * deserialized objects properly despite a "hostile" or incomplete source
 * stream.
 *
 * <p>Serializable classes that need to designate an alternative object to be
 * used when writing an object to the stream should implement this
 * special method with the exact signature:
 *
 * <PRE>
 * ANY-ACCESS-MODIFIER Object writeReplace() throws ObjectStreamException;
 * </PRE><p>
 *
 * This writeReplace method is invoked by serialization if the method
 * exists and it would be accessible from a method defined within the
 * class of the object being serialized. Thus, the method can have private,
 * protected and package-private access. Subclass access to this method
 * follows java accessibility rules. <p>
 *
 * Classes that need to designate a replacement when an instance of it
 * is read from the stream should implement this special method with the
 * exact signature.
 *
 * <PRE>
 * ANY-ACCESS-MODIFIER Object readResolve() throws ObjectStreamException;
 * </PRE><p>
 *
 * This readResolve method follows the same invocation rules and
 * accessibility rules as writeReplace.<p>
 *
 * The serialization runtime associates with each serializable class a version
 * number, called a serialVersionUID, which is used during deserialization to
 * verify that the sender and receiver of a serialized object have loaded
 * classes for that object that are compatible with respect to serialization.
 * If the receiver has loaded a class for the object that has a different
 * serialVersionUID than that of the corresponding sender's class, then
 * deserialization will result in an {@link InvalidClassException}.  A
 * serializable class can declare its own serialVersionUID explicitly by
 * declaring a field named <code>"serialVersionUID"</code> that must be static,
 * final, and of type <code>long</code>:
 *
 * <PRE>
 * ANY-ACCESS-MODIFIER static final long serialVersionUID = 42L;
 * </PRE>
 *
 * If a serializable class does not explicitly declare a serialVersionUID, then
 * the serialization runtime will calculate a default serialVersionUID value
 * for that class based on various aspects of the class, as described in the
 * Java(TM) Object Serialization Specification.  However, it is <em>strongly
 * recommended</em> that all serializable classes explicitly declare
 * serialVersionUID values, since the default serialVersionUID computation is
 * highly sensitive to class details that may vary depending on compiler
 * implementations, and can thus result in unexpected
 * <code>InvalidClassException</code>s during deserialization.  Therefore, to
 * guarantee a consistent serialVersionUID value across different java compiler
 * implementations, a serializable class must declare an explicit
 * serialVersionUID value.  It is also strongly advised that explicit
 * serialVersionUID declarations use the <code>private</code> modifier where
 * possible, since such declarations apply only to the immediately declaring
 * class--serialVersionUID fields are not useful as inherited members. Array
 * classes cannot declare an explicit serialVersionUID, so they always have
 * the default computed value, but the requirement for matching
 * serialVersionUID values is waived for array classes.
 *
 */
interface Serializable {

}

/**
 * This abstract class is the superclass of all classes representing
 * an input stream of bytes.
 *
 * <p> Applications that need to define a subclass of <code>InputStream</code>
 * must always provide a method that returns the next byte of input.
 *
 * @author  Arthur van Hoff
 * @see     java.io.BufferedInputStream
 * @see     java.io.ByteArrayInputStream
 * @see     java.io.DataInputStream
 * @see     java.io.FilterInputStream
 * @see     java.io.InputStream#read()
 * @see     java.io.OutputStream
 * @see     java.io.PushbackInputStream
 * @since   JDK1.0
 */
abstract class InputStream : Closeable {

    // MAX_SKIP_BUFFER_SIZE is used to determine the maximum buffer size to
    // use when skipping.
    private enum int MAX_SKIP_BUFFER_SIZE = 2048;

    /**
     * Reads the next byte of data from the input stream. The value byte is
     * returned as an <code>int</code> in the range <code>0</code> to
     * <code>255</code>. If no byte is available because the end of the stream
     * has been reached, the value <code>-1</code> is returned. This method
     * blocks until input data is available, the end of the stream is detected,
     * or an exception is thrown.
     *
     * <p> A subclass must provide an implementation of this method.
     *
     * @return     the next byte of data, or <code>-1</code> if the end of the
     *             stream is reached.
     * @exception  IOException  if an I/O error occurs.
     */
    abstract int read();

    /**
     * Reads some number of bytes from the input stream and stores them into
     * the buffer array <code>b</code>. The number of bytes actually read is
     * returned as an integer.  This method blocks until input data is
     * available, end of file is detected, or an exception is thrown.
     *
     * <p> If the length of <code>b</code> is zero, then no bytes are read and
     * <code>0</code> is returned; otherwise, there is an attempt to read at
     * least one byte. If no byte is available because the stream is at the
     * end of the file, the value <code>-1</code> is returned; otherwise, at
     * least one byte is read and stored into <code>b</code>.
     *
     * <p> The first byte read is stored into element <code>b[0]</code>, the
     * next one into <code>b[1]</code>, and so on. The number of bytes read is,
     * at most, equal to the length of <code>b</code>. Let <i>k</i> be the
     * number of bytes actually read; these bytes will be stored in elements
     * <code>b[0]</code> through <code>b[</code><i>k</i><code>-1]</code>,
     * leaving elements <code>b[</code><i>k</i><code>]</code> through
     * <code>b[b.length-1]</code> unaffected.
     *
     * <p> The <code>read(b)</code> method for class <code>InputStream</code>
     * has the same effect as: <pre><code> read(b, 0, b.length) </code></pre>
     *
     * @param      b   the buffer into which the data is read.
     * @return     the total number of bytes read into the buffer, or
     *             <code>-1</code> if there is no more data because the end of
     *             the stream has been reached.
     * @exception  IOException  If the first byte cannot be read for any reason
     * other than the end of the file, if the input stream has been closed, or
     * if some other I/O error occurs.
     * @exception  NullPointerException  if <code>b</code> is <code>null</code>.
     * @see        java.io.InputStream#read(byte[], int, int)
     */
    int read(byte[] b) {
        return read(b, 0, cast(int)b.length);
    }

    /**
     * Reads up to <code>len</code> bytes of data from the input stream into
     * an array of bytes.  An attempt is made to read as many as
     * <code>len</code> bytes, but a smaller number may be read.
     * The number of bytes actually read is returned as an integer.
     *
     * <p> This method blocks until input data is available, end of file is
     * detected, or an exception is thrown.
     *
     * <p> If <code>len</code> is zero, then no bytes are read and
     * <code>0</code> is returned; otherwise, there is an attempt to read at
     * least one byte. If no byte is available because the stream is at end of
     * file, the value <code>-1</code> is returned; otherwise, at least one
     * byte is read and stored into <code>b</code>.
     *
     * <p> The first byte read is stored into element <code>b[off]</code>, the
     * next one into <code>b[off+1]</code>, and so on. The number of bytes read
     * is, at most, equal to <code>len</code>. Let <i>k</i> be the number of
     * bytes actually read; these bytes will be stored in elements
     * <code>b[off]</code> through <code>b[off+</code><i>k</i><code>-1]</code>,
     * leaving elements <code>b[off+</code><i>k</i><code>]</code> through
     * <code>b[off+len-1]</code> unaffected.
     *
     * <p> In every case, elements <code>b[0]</code> through
     * <code>b[off]</code> and elements <code>b[off+len]</code> through
     * <code>b[b.length-1]</code> are unaffected.
     *
     * <p> The <code>read(b,</code> <code>off,</code> <code>len)</code> method
     * for class <code>InputStream</code> simply calls the method
     * <code>read()</code> repeatedly. If the first such call results in an
     * <code>IOException</code>, that exception is returned from the call to
     * the <code>read(b,</code> <code>off,</code> <code>len)</code> method.  If
     * any subsequent call to <code>read()</code> results in a
     * <code>IOException</code>, the exception is caught and treated as if it
     * were end of file; the bytes read up to that point are stored into
     * <code>b</code> and the number of bytes read before the exception
     * occurred is returned. The default implementation of this method blocks
     * until the requested amount of input data <code>len</code> has been read,
     * end of file is detected, or an exception is thrown. Subclasses are encouraged
     * to provide a more efficient implementation of this method.
     *
     * @param      b     the buffer into which the data is read.
     * @param      off   the start offset in array <code>b</code>
     *                   at which the data is written.
     * @param      len   the maximum number of bytes to read.
     * @return     the total number of bytes read into the buffer, or
     *             <code>-1</code> if there is no more data because the end of
     *             the stream has been reached.
     * @exception  IOException If the first byte cannot be read for any reason
     * other than end of file, or if the input stream has been closed, or if
     * some other I/O error occurs.
     * @exception  NullPointerException If <code>b</code> is <code>null</code>.
     * @exception  IndexOutOfBoundsException If <code>off</code> is negative,
     * <code>len</code> is negative, or <code>len</code> is greater than
     * <code>b.length - off</code>
     * @see        java.io.InputStream#read()
     */
    int read(byte[] b, int off, int len) {
        if (b is null) {
            throw new NullPointerException("");
        } else if (off < 0 || len < 0 || len > b.length - off) {
            throw new IndexOutOfBoundsException("");
        } else if (len == 0) {
            return 0;
        }

        int c = read();
        if (c == -1) {
            return -1;
        }
        b[off] = cast(byte)c;

        int i = 1;
        try {
            for (; i < len ; i++) {
                c = read();
                if (c == -1) {
                    break;
                }
                b[off + i] = cast(byte)c;
            }
        } catch (IOException ee) {
        }
        return i;
    }

    /**
     * Skips over and discards <code>n</code> bytes of data from this input
     * stream. The <code>skip</code> method may, for a variety of reasons, end
     * up skipping over some smaller number of bytes, possibly <code>0</code>.
     * This may result from any of a number of conditions; reaching end of file
     * before <code>n</code> bytes have been skipped is only one possibility.
     * The actual number of bytes skipped is returned. If {@code n} is
     * negative, the {@code skip} method for class {@code InputStream} always
     * returns 0, and no bytes are skipped. Subclasses may handle the negative
     * value differently.
     *
     * <p> The <code>skip</code> method of this class creates a
     * byte array and then repeatedly reads into it until <code>n</code> bytes
     * have been read or the end of the stream has been reached. Subclasses are
     * encouraged to provide a more efficient implementation of this method.
     * For instance, the implementation may depend on the ability to seek.
     *
     * @param      n   the number of bytes to be skipped.
     * @return     the actual number of bytes skipped.
     * @exception  IOException  if the stream does not support seek,
     *                          or if some other I/O error occurs.
     */
    long skip(long n) {
        long remaining = n;
        int nr;

        if (n <= 0) {
            return 0;
        }

        int size = cast(int)min(MAX_SKIP_BUFFER_SIZE, remaining);
        byte[] skipBuffer = new byte[size];
        while (remaining > 0) {
            nr = read(skipBuffer, 0, cast(int)min(size, remaining));
            if (nr < 0) {
                break;
            }
            remaining -= nr;
        }

        return n - remaining;
    }

    /**
     * Returns an estimate of the number of bytes that can be read (or
     * skipped over) from this input stream without blocking by the next
     * invocation of a method for this input stream. The next invocation
     * might be the same thread or another thread.  A single read or skip of this
     * many bytes will not block, but may read or skip fewer bytes.
     *
     * <p> Note that while some implementations of {@code InputStream} will return
     * the total number of bytes in the stream, many will not.  It is
     * never correct to use the return value of this method to allocate
     * a buffer intended to hold all data in this stream.
     *
     * <p> A subclass' implementation of this method may choose to throw an
     * {@link IOException} if this input stream has been closed by
     * invoking the {@link #close()} method.
     *
     * <p> The {@code available} method for class {@code InputStream} always
     * returns {@code 0}.
     *
     * <p> This method should be overridden by subclasses.
     *
     * @return     an estimate of the number of bytes that can be read (or skipped
     *             over) from this input stream without blocking or {@code 0} when
     *             it reaches the end of the input stream.
     * @exception  IOException if an I/O error occurs.
     */
    int available() { // @trusted nothrow 
        return 0;
    }

    /**
     * Closes this input stream and releases any system resources associated
     * with the stream.
     *
     * <p> The <code>close</code> method of <code>InputStream</code> does
     * nothing.
     *
     * @exception  IOException  if an I/O error occurs.
     */
    void close() {}

    /**
     * Marks the current position in this input stream. A subsequent call to
     * the <code>reset</code> method repositions this stream at the last marked
     * position so that subsequent reads re-read the same bytes.
     *
     * <p> The <code>readlimit</code> arguments tells this input stream to
     * allow that many bytes to be read before the mark position gets
     * invalidated.
     *
     * <p> The general contract of <code>mark</code> is that, if the method
     * <code>markSupported</code> returns <code>true</code>, the stream somehow
     * remembers all the bytes read after the call to <code>mark</code> and
     * stands ready to supply those same bytes again if and whenever the method
     * <code>reset</code> is called.  However, the stream is not required to
     * remember any data at all if more than <code>readlimit</code> bytes are
     * read from the stream before <code>reset</code> is called.
     *
     * <p> Marking a closed stream should not have any effect on the stream.
     *
     * <p> The <code>mark</code> method of <code>InputStream</code> does
     * nothing.
     *
     * @param   readlimit   the maximum limit of bytes that can be read before
     *                      the mark position becomes invalid.
     * @see     java.io.InputStream#reset()
     */
    void mark(int readlimit) {}

    /**
     * Repositions this stream to the position at the time the
     * <code>mark</code> method was last called on this input stream.
     *
     * <p> The general contract of <code>reset</code> is:
     *
     * <ul>
     * <li> If the method <code>markSupported</code> returns
     * <code>true</code>, then:
     *
     *     <ul><li> If the method <code>mark</code> has not been called since
     *     the stream was created, or the number of bytes read from the stream
     *     since <code>mark</code> was last called is larger than the argument
     *     to <code>mark</code> at that last call, then an
     *     <code>IOException</code> might be thrown.
     *
     *     <li> If such an <code>IOException</code> is not thrown, then the
     *     stream is reset to a state such that all the bytes read since the
     *     most recent call to <code>mark</code> (or since the start of the
     *     file, if <code>mark</code> has not been called) will be resupplied
     *     to subsequent callers of the <code>read</code> method, followed by
     *     any bytes that otherwise would have been the next input data as of
     *     the time of the call to <code>reset</code>. </ul>
     *
     * <li> If the method <code>markSupported</code> returns
     * <code>false</code>, then:
     *
     *     <ul><li> The call to <code>reset</code> may throw an
     *     <code>IOException</code>.
     *
     *     <li> If an <code>IOException</code> is not thrown, then the stream
     *     is reset to a fixed state that depends on the particular type of the
     *     input stream and how it was created. The bytes that will be supplied
     *     to subsequent callers of the <code>read</code> method depend on the
     *     particular type of the input stream. </ul></ul>
     *
     * <p>The method <code>reset</code> for class <code>InputStream</code>
     * does nothing except throw an <code>IOException</code>.
     *
     * @exception  IOException  if this stream has not been marked or if the
     *               mark has been invalidated.
     * @see     java.io.InputStream#mark(int)
     * @see     java.io.IOException
     */
    void reset() {
        throw new IOException("mark/reset not supported");
    }

    /**
     * Tests if this input stream supports the <code>mark</code> and
     * <code>reset</code> methods. Whether or not <code>mark</code> and
     * <code>reset</code> are supported is an invariant property of a
     * particular input stream instance. The <code>markSupported</code> method
     * of <code>InputStream</code> returns <code>false</code>.
     *
     * @return  <code>true</code> if this stream instance supports the mark
     *          and reset methods; <code>false</code> otherwise.
     * @see     java.io.InputStream#mark(int)
     * @see     java.io.InputStream#reset()
     */
    bool markSupported() {
        return false;
    }

}


/**
 * This abstract class is the superclass of all classes representing
 * an output stream of bytes. An output stream accepts output bytes
 * and sends them to some sink.
 * <p>
 * Applications that need to define a subclass of
 * <code>OutputStream</code> must always provide at least a method
 * that writes one byte of output.
 *
 * @author  Arthur van Hoff
 * @see     java.io.BufferedOutputStream
 * @see     java.io.ByteArrayOutputStream
 * @see     java.io.DataOutputStream
 * @see     java.io.FilterOutputStream
 * @see     java.io.InputStream
 * @see     java.io.OutputStream#write(int)
 * @since   JDK1.0
 */
abstract class OutputStream : Closeable  { // implements  Flushable
    /**
     * Writes the specified byte to this output stream. The general
     * contract for <code>write</code> is that one byte is written
     * to the output stream. The byte to be written is the eight
     * low-order bits of the argument <code>b</code>. The 24
     * high-order bits of <code>b</code> are ignored.
     * <p>
     * Subclasses of <code>OutputStream</code> must provide an
     * implementation for this method.
     *
     * @param      b   the <code>byte</code>.
     * @exception  IOException  if an I/O error occurs. In particular,
     *             an <code>IOException</code> may be thrown if the
     *             output stream has been closed.
     */
    abstract void write(int b) ;

    void write(string b) {
        write(cast(byte[])b, 0, cast(int)b.length);
    }

    /**
     * Writes <code>b.length</code> bytes from the specified byte array
     * to this output stream. The general contract for <code>write(b)</code>
     * is that it should have exactly the same effect as the call
     * <code>write(b, 0, b.length)</code>.
     *
     * @param      b   the data.
     * @exception  IOException  if an I/O error occurs.
     * @see        java.io.OutputStream#write(byte[], int, int)
     */
    void write(byte[] b)  {
        write(b, 0, cast(int)b.length);
    }

    /**
     * Writes <code>len</code> bytes from the specified byte array
     * starting at offset <code>off</code> to this output stream.
     * The general contract for <code>write(b, off, len)</code> is that
     * some of the bytes in the array <code>b</code> are written to the
     * output stream in order; element <code>b[off]</code> is the first
     * byte written and <code>b[off+len-1]</code> is the last byte written
     * by this operation.
     * <p>
     * The <code>write</code> method of <code>OutputStream</code> calls
     * the write method of one argument on each of the bytes to be
     * written out. Subclasses are encouraged to override this method and
     * provide a more efficient implementation.
     * <p>
     * If <code>b</code> is <code>null</code>, a
     * <code>NullPointerException</code> is thrown.
     * <p>
     * If <code>off</code> is negative, or <code>len</code> is negative, or
     * <code>off+len</code> is greater than the length of the array
     * <code>b</code>, then an <tt>IndexOutOfBoundsException</tt> is thrown.
     *
     * @param      b     the data.
     * @param      off   the start offset in the data.
     * @param      len   the number of bytes to write.
     * @exception  IOException  if an I/O error occurs. In particular,
     *             an <code>IOException</code> is thrown if the output
     *             stream is closed.
     */
    void write(byte[] b, int off, int len) {
        int bufferSize = cast(int)b.length;
        if (b is null) {
            throw new NullPointerException("");
        } else if ((off < 0) || (off > bufferSize) || (len < 0) ||
                   ((off + len) > bufferSize) || ((off + len) < 0)) {
            import std.format;
            string msg = format("buffer error, size: %d, offset: %d, length: %d",
                bufferSize, off, len);
            throw new IndexOutOfBoundsException(msg);
        } else if (len == 0) {
            return;
        }
        for (int i = 0 ; i < len ; i++) {
            write(b[off + i]);
        }
    }

    /**
     * Flushes this output stream and forces any buffered output bytes
     * to be written out. The general contract of <code>flush</code> is
     * that calling it is an indication that, if any bytes previously
     * written have been buffered by the implementation of the output
     * stream, such bytes should immediately be written to their
     * intended destination.
     * <p>
     * If the intended destination of this stream is an abstraction provided by
     * the underlying operating system, for example a file, then flushing the
     * stream guarantees only that bytes previously written to the stream are
     * passed to the operating system for writing; it does not guarantee that
     * they are actually written to a physical device such as a disk drive.
     * <p>
     * The <code>flush</code> method of <code>OutputStream</code> does nothing.
     *
     * @exception  IOException  if an I/O error occurs.
     */
    void flush()  {
    }

    /**
     * Closes this output stream and releases any system resources
     * associated with this stream. The general contract of <code>close</code>
     * is that it closes the output stream. A closed stream cannot perform
     * output operations and cannot be reopened.
     * <p>
     * The <code>close</code> method of <code>OutputStream</code> does nothing.
     *
     * @exception  IOException  if an I/O error occurs.
     */
    void close()  {
    }

}

/**
 * IO Utilities. Provides stream handling utilities in singleton Threadpool
 * implementation accessed by static members.
 */
// class IO {

// 	enum string CRLF = "\015\012";

// 	enum byte[] CRLF_BYTES = [ '\015', '\012' ];

// 	enum int bufferSize = 64 * 1024;

//     /**
// 	 * Closes an arbitrary closable, and logs exceptions at ignore level
// 	 *
// 	 * @param closeable
// 	 *            the closeable to close
// 	 */
// 	static void close(Closeable closeable) {
// 		try {
// 			if (closeable !is null)
// 				closeable.close();
// 		} catch (IOException ignore) {
// 		}
// 	}
// }


interface BufferReaderHandler {
	void readBuffer(ByteBuffer buf, CountingCallback countingCallback, long count);
}