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/**
* Copyright 2014 JogAmp Community. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without modification, are
* permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this list of
* conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice, this list
* of conditions and the following disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
* FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
* ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* The views and conclusions contained in the software and documentation are those of the
* authors and should not be interpreted as representing official policies, either expressed
* or implied, of JogAmp Community.
*/
package com.jogamp.common.util;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.nio.ByteBuffer;
import jogamp.common.Debug;
/**
* Versatile Bitstream implementation supporting:
*
* - Utilize I/O operations on I/O streams, buffers and arrays
* - Consider MSBfirst / LSBfirst mode
* - Linear bit R/W operations
* - Bulk R/W operations w/ endian related type conversion
* - Allow mark/reset and switching streams and input/output mode
* - Optimized operations
*
*/
public class Bitstream {
private static final boolean DEBUG = Debug.debug("Bitstream");
/** End of stream marker, {@value} or 0xFFFFFFFF */
public static final int EOS = -1;
/**
* General byte stream.
*/
public static interface ByteStream {
/** Sets the underlying stream, without {@link #close()}ing the previous one. */
void setStream(final T stream);
/** Returns the underlying stream */
T getStream();
/**
* Closing the underlying stream, implies {@link #flush()}.
*
* Implementation will null the stream references,
* hence {@link #setStream(Object)} must be called before re-using instance.
*
* @throws IOException
*/
void close() throws IOException;
/**
* Synchronizes all underlying {@link #canOutput() output stream} operations, or do nothing.
* @throws IOException
*/
void flush() throws IOException;
/** Return true if stream can handle input, i.e. {@link #read()}. */
boolean canInput();
/** Return true if stream can handle output, i.e. {@link #write(byte)} */
boolean canOutput();
/**
* Returns the byte position in the stream.
*/
long position();
/**
* Sets this stream's position.
*
* A set mark is cleared if > new position.
*
*
* Returns {@link Bitstream#EOS} is end-of-stream is reached,
* otherwise the new position.
*
*
* Known supporting implementation is {@link ByteBufferStream} and {@link ByteArrayStream}.
*
*
* @param newPosition The new positive position.
*
* @return The new set position or {@link Bitstream#EOS} if end-of-stream is reached.
*
* @throws UnsupportedOperationException if not supported, i.e. {@link ByteInputStream} or {@link ByteOutputStream}
* @throws IllegalArgumentException If the {@code newPosition} is negative
*/
long position(long newPosition) throws UnsupportedOperationException, IllegalArgumentException;
/**
* It is implementation dependent, whether backward skip giving a negative number is supported or not.
* @param n number of bytes to skip
* @return actual skipped bytes
* @throws IOException
*/
long skip(final long n) throws IOException;
/**
* Set {@code markpos} to current position, allowing the stream to be {@link #reset()}.
* @param readlimit maximum number of bytes able to read before invalidating the {@code markpos}.
* @throws UnsupportedOperationException if not supported, i.e. if stream is not an {@link #canInput() input stream}.
*/
void mark(final int readLimit) throws UnsupportedOperationException;
/**
* Reset stream position to markpos as set via {@link #mark(int)}.
*
* markpos is kept, hence {@link #reset()} can be called multiple times.
*
* @throws UnsupportedOperationException if not supported, i.e. if stream is not an {@link #canInput() input stream}.
* @throws IllegalStateException if markpos has not been set via {@link #mark(int)} or reset operation failed.
* @throws IOException if reset operation failed.
*/
void reset() throws UnsupportedOperationException, IllegalStateException, IOException;
/**
* Reads one byte from the stream.
*
* Returns {@link Bitstream#EOS} is end-of-stream is reached,
* otherwise the resulting value.
*
* @throws IOException
* @throws UnsupportedOperationException if not supported, i.e. if stream is not an {@link #canInput() input stream}.
*/
int read() throws UnsupportedOperationException, IOException;
/**
* Writes one byte, to the stream.
*
* Returns {@link Bitstream#EOS} is end-of-stream is reached,
* otherwise the written value.
*
* @throws IOException
* @throws UnsupportedOperationException if not supported, i.e. if stream is not an {@link #canOutput() output stream}.
*/
int write(final byte val) throws UnsupportedOperationException, IOException;
}
/**
* Specific {@link ByteStream byte stream}.
*
* Can handle {@link #canInput() input} and {@link #canOutput() output} operations.
*
*/
public static class ByteArrayStream implements ByteStream {
private byte[] media;
private int pos;
private int posMark;
public ByteArrayStream(final byte[] stream) {
setStream(stream);
}
@Override
public void setStream(final byte[] stream) {
media = stream;
pos = 0;
posMark = -1;
}
@Override
public byte[] getStream() { return media; }
@Override
public void close() {
media = null;
}
@Override
public void flush() {
// NOP
}
@Override
public boolean canInput() { return true; }
@Override
public boolean canOutput() { return true; }
@Override
public long position() { return pos; }
@Override
public long position(final long newPosition) throws UnsupportedOperationException, IllegalArgumentException {
if( newPosition >= media.length ) {
return Bitstream.EOS;
}
pos = (int)newPosition;
if( posMark > pos ) {
posMark = -1;
}
return pos;
}
@Override
public long skip(final long n) {
final long skip;
if( n >= 0 ) {
final int remaining = media.length - pos;
skip = Math.min(remaining, (int)n);
} else {
final int n2 = (int)n * -1;
skip = -1 * Math.min(pos, n2);
}
pos += skip;
return skip;
}
@Override
public void mark(final int readLimit) {
posMark = pos;
}
@Override
public void reset() throws IllegalStateException {
if( 0 > posMark ) {
throw new IllegalStateException("markpos not set");
}
if(DEBUG) { System.err.println("rewind: "+pos+" -> "+posMark); }
pos = posMark;
}
@Override
public int read() {
final int r;
if( media.length > pos ) {
r = 0xff & media[pos++];
} else {
r = -1; // EOS
}
if( DEBUG ) {
if( EOS != r ) {
System.err.println("u8["+(pos-1)+"] -> "+toHexBinString(true, r, 8));
} else {
System.err.println("u8["+(pos-0)+"] -> EOS");
}
}
return r;
}
@Override
public int write(final byte val) {
final int r;
if( media.length > pos ) {
media[pos++] = val;
r = 0xff & val;
} else {
r = -1; // EOS
}
if( DEBUG ) {
if( EOS != r ) {
System.err.println("u8["+(pos-1)+"] <- "+toHexBinString(true, r, 8));
} else {
System.err.println("u8["+(pos-0)+"] <- EOS");
}
}
return r;
}
}
/**
* Specific {@link ByteStream byte stream}.
*
* Can handle {@link #canInput() input} and {@link #canOutput() output} operations.
*
*/
public static class ByteBufferStream implements ByteStream {
private ByteBuffer media;
private int pos;
private int posMark;
public ByteBufferStream(final ByteBuffer stream) {
setStream(stream);
}
@Override
public void setStream(final ByteBuffer stream) {
media = stream;
pos = 0;
posMark = -1;
}
@Override
public ByteBuffer getStream() { return media; }
@Override
public void close() {
media = null;
}
@Override
public void flush() {
// NOP
}
@Override
public boolean canInput() { return true; }
@Override
public boolean canOutput() { return true; }
@Override
public long position() { return pos; }
@Override
public long position(final long newPosition) throws UnsupportedOperationException, IllegalArgumentException {
if( newPosition >= media.limit() ) {
return Bitstream.EOS;
}
media.position((int)newPosition);
pos = (int)newPosition;
if( posMark > pos ) {
posMark = -1;
}
return pos;
}
@Override
public long skip(final long n) {
final long skip;
if( n >= 0 ) {
final int remaining = media.limit() - pos;
skip = Math.min(remaining, (int)n);
} else {
final int n2 = (int)n * -1;
skip = -1 * Math.min(pos, n2);
}
pos += skip;
return skip;
}
@Override
public void mark(final int readLimit) {
posMark = pos;
}
@Override
public void reset() throws IllegalStateException {
if( 0 > posMark ) {
throw new IllegalStateException("markpos not set");
}
if(DEBUG) { System.err.println("rewind: "+pos+" -> "+posMark); }
media.position(posMark);
pos = posMark;
}
@Override
public int read() {
final int r;
if( media.limit() > pos ) {
r = 0xff & media.get(pos++);
} else {
r = -1; // EOS
}
if( DEBUG ) {
if( EOS != r ) {
System.err.println("u8["+(pos-1)+"] -> "+toHexBinString(true, r, 8));
} else {
System.err.println("u8["+(pos-0)+"] -> EOS");
}
}
return r;
}
@Override
public int write(final byte val) {
final int r;
if( media.limit() > pos ) {
media.put(pos++, val);
r = 0xff & val;
} else {
r = -1; // EOS
}
if( DEBUG ) {
if( EOS != r ) {
System.err.println("u8["+(pos-1)+"] <- "+toHexBinString(true, r, 8));
} else {
System.err.println("u8["+(pos-0)+"] <- EOS");
}
}
return r;
}
}
/**
* Specific {@link ByteStream byte stream}.
*
* Can handle {@link #canInput() input} operations only.
*
*/
public static class ByteInputStream implements ByteStream {
private BufferedInputStream media;
private long pos;
private long posMark;
public ByteInputStream(final InputStream stream) {
setStream(stream);
}
@Override
public void setStream(final InputStream stream) {
if( stream instanceof BufferedInputStream ) {
media = (BufferedInputStream) stream;
} else if( null != stream ) {
media = new BufferedInputStream(stream);
} else {
media = null;
}
pos = 0;
posMark = -1;
}
@Override
public InputStream getStream() { return media; }
@Override
public void close() throws IOException {
if( null != media ) {
media.close();
media = null;
}
}
@Override
public void flush() {
// NOP
}
@Override
public boolean canInput() { return true; }
@Override
public boolean canOutput() { return false; }
@Override
public long position() { return pos; }
@Override
public long position(final long newPosition) throws UnsupportedOperationException, IllegalArgumentException {
throw new UnsupportedOperationException("N/a for "+getClass().getCanonicalName());
}
@Override
public long skip(final long n) throws IOException {
final long skip = media.skip(n);
pos += skip;
return skip;
}
@Override
public void mark(final int readLimit) {
media.mark(readLimit);
posMark = pos;
}
@Override
public void reset() throws IllegalStateException, IOException {
if( 0 > posMark ) {
throw new IllegalStateException("markpos not set");
}
if(DEBUG) { System.err.println("rewind: "+pos+" -> "+posMark); }
media.reset();
pos = posMark;
}
@Override
public int read() throws IOException {
final int r = media.read();
if(DEBUG) {
if( EOS != r ) {
System.err.println("u8["+pos+"] -> "+toHexBinString(true, r, 8));
} else {
System.err.println("u8["+pos+"] -> EOS");
}
}
if( EOS != r ) {
pos++;
}
return r;
}
@Override
public int write(final byte val) throws UnsupportedOperationException {
throw new UnsupportedOperationException("not allowed with input stream");
}
}
/**
* Specific {@link ByteStream byte stream}.
*
* Can handle {@link #canOutput() output} operations only.
*
*/
public static class ByteOutputStream implements ByteStream {
private BufferedOutputStream media;
private long pos = 0;
public ByteOutputStream(final OutputStream stream) {
setStream(stream);
}
@Override
public void setStream(final OutputStream stream) {
if( stream instanceof BufferedOutputStream ) {
media = (BufferedOutputStream) stream;
} else if( null != stream ) {
media = new BufferedOutputStream(stream);
} else {
media = null;
}
pos = 0;
}
@Override
public void close() throws IOException {
if( null != media ) {
media.close();
media = null;
}
}
@Override
public void flush() throws IOException {
if( null != media ) {
media.flush();
}
}
@Override
public boolean canInput() { return false; }
@Override
public boolean canOutput() { return true; }
@Override
public long position() { return pos; }
@Override
public long position(final long newPosition) throws UnsupportedOperationException, IllegalArgumentException {
throw new UnsupportedOperationException("N/a for "+getClass().getCanonicalName());
}
@Override
public long skip(final long n) throws IOException {
long i = n;
while(i > 0) {
media.write(0);
i--;
}
final long skip = n-i; // should be n
pos += skip;
return skip;
}
@Override
public OutputStream getStream() { return media; }
@Override
public void mark(final int readLimit) throws UnsupportedOperationException {
throw new UnsupportedOperationException("not allowed with output stream");
}
@Override
public void reset() throws UnsupportedOperationException {
throw new UnsupportedOperationException("not allowed with output stream");
}
@Override
public int read() throws UnsupportedOperationException {
throw new UnsupportedOperationException("not allowed with output stream");
}
@Override
public int write(final byte val) throws IOException {
final int r = 0xff & val;
media.write(r);
if(DEBUG) {
System.err.println("u8["+pos+"] <- "+toHexBinString(true, r, 8));
}
pos++;
return r;
}
}
private ByteStream bytes;
/** 8-bit cache of byte stream */
private int bitBuffer;
private int bitsDataMark;
/** See {@link #getBitCount()}. */
private int bitCount;
private int bitsCountMark;
private boolean outputMode;
private boolean throwIOExceptionOnEOF;
/**
* @param stream
* @param outputMode
* @throws IllegalArgumentException if requested outputMode doesn't match stream's {@link #canInput()} and {@link #canOutput()}.
*/
public Bitstream(final ByteStream stream, final boolean outputMode) throws IllegalArgumentException {
this.bytes = stream;
this.outputMode = outputMode;
resetLocal();
validateMode();
throwIOExceptionOnEOF = false;
}
private final void resetLocal() {
bitBuffer = 0;
bitCount = 0;
bitsDataMark = 0;
bitsCountMark = -1;
}
private final void validateMode() throws IllegalArgumentException {
if( !canInput() && !canOutput() ) {
throw new IllegalArgumentException("stream can neither input nor output: "+this);
}
if( outputMode && !canOutput() ) {
throw new IllegalArgumentException("stream cannot output as requested: "+this);
}
if( !outputMode && !canInput() ) {
throw new IllegalArgumentException("stream cannot input as requested: "+this);
}
}
/**
* Enables or disables throwing an {@link IOException} in case {@link #EOS} appears.
*
* Default behavior for I/O methods is not to throw an {@link IOException}, but to return {@link #EOS}.
*
*/
public final void setThrowIOExceptionOnEOF(final boolean enable) {
throwIOExceptionOnEOF = enable;
}
/** Returns true if I/O methods throw an {@link IOException} if {@link #EOS} appears, otherwise false (default). */
public final boolean getThrowIOExceptionOnEOF() { return throwIOExceptionOnEOF; }
/**
* Sets the underlying stream, without {@link #close()}ing the previous one.
*
* If the previous stream was in {@link #canOutput() output mode},
* {@link #flush()} is being called.
*
* @throws IllegalArgumentException if requested outputMode doesn't match stream's {@link #canInput()} and {@link #canOutput()}.
* @throws IOException could be caused by {@link #flush()}.
*/
public final void setStream(final T stream, final boolean outputMode) throws IllegalArgumentException, IOException {
if( null != bytes && this.outputMode ) {
flush();
}
this.bytes.setStream(stream);
this.outputMode = outputMode;
resetLocal();
validateMode();
}
/** Returns the currently used {@link ByteStream}. */
public final ByteStream getStream() { return bytes; }
/** Returns the currently used {@link ByteStream}'s {@link ByteStream#getStream()}. */
public final T getSubStream() { return bytes.getStream(); }
/**
* Closing the underlying stream, implies {@link #flush()}.
*
* Implementation will null the stream references,
* hence {@link #setStream(Object)} must be called before re-using instance.
*
*
* If the closed stream was in {@link #canOutput() output mode},
* {@link #flush()} is being called.
*
*
* @throws IOException
*/
public final void close() throws IOException {
if( null != bytes && this.outputMode ) {
flush();
}
bytes.close();
bytes = null;
resetLocal();
}
/**
* Synchronizes all underlying {@link ByteStream#canOutput() output stream} operations, or do nothing.
*
* Method also flushes incomplete bytes to the underlying {@link ByteStream}
* and hence skips to the next byte position.
*
* @return {@link #EOS} caused by writing, otherwise zero.
* @throws IllegalStateException if not in output mode or stream closed
* @throws IOException
*/
public final int flush() throws IllegalStateException, IOException {
if( !outputMode || null == bytes ) {
throw new IllegalStateException("not in output-mode: "+this);
}
bytes.flush();
if( 0 != bitCount ) {
final int r = bytes.write((byte)bitBuffer);
bitBuffer = 0;
bitCount = 0;
if( EOS == r ) {
if( throwIOExceptionOnEOF ) {
throw new IOException("EOS "+this);
}
return EOS;
}
}
return 0;
}
/** Return true if stream can handle input, i.e. {@link #readBit(boolean)}. */
public final boolean canInput() { return null != bytes ? bytes.canInput() : false; }
/** Return true if stream can handle output, i.e. {@link #writeBit(boolean, int)}. */
public final boolean canOutput() { return null != bytes ? bytes.canOutput() : false; }
/**
* Set {@code markpos} to current position, allowing the stream to be {@link #reset()}.
* @param readlimit maximum number of bytes able to read before invalidating the {@code markpos}.
* @throws IllegalStateException if not in input mode or stream closed
*/
public final void mark(final int readLimit) throws IllegalStateException {
if( outputMode || null == bytes ) {
throw new IllegalStateException("not in input-mode: "+this);
}
bytes.mark(readLimit);
bitsDataMark = bitBuffer;
bitsCountMark = bitCount;
}
/**
* Reset stream position to markpos as set via {@link #mark(int)}.
*
* markpos is kept, hence {@link #reset()} can be called multiple times.
*
* @throws IllegalStateException if not in input mode or stream closed
* @throws IllegalStateException if markpos has not been set via {@link #mark(int)} or reset operation failed.
* @throws IOException if reset operation failed.
*/
public final void reset() throws IllegalStateException, IOException {
if( outputMode || null == bytes ) {
throw new IllegalStateException("not in input-mode: "+this);
}
if( 0 > bitsCountMark ) {
throw new IllegalStateException("markpos not set: "+this);
}
bytes.reset();
bitBuffer = bitsDataMark;
bitCount = bitsCountMark;
}
/**
* Number of remaining bits in cache to read before next byte-read (input mode)
* or number of remaining bits to be cached before next byte-write (output mode).
*
* Counting down from 7..0 7..0, starting with 0.
*
*
* In input mode, zero indicates reading a new byte and cont. w/ 7.
* In output mode, the cached byte is written when flipping over to 0.
*
*/
public final int getBitCount() { return bitCount; }
/**
* Return the last bit number read or written counting from [0..7].
* If no bit access has been performed, 7 is returned.
*
* Returned value is normalized [0..7], i.e. independent from msb or lsb read order.
*
*/
public final int getLastBitPos() { return 7 - bitCount; }
/**
* Return the next bit number to be read or write counting from [0..7].
* If no bit access has been performed, 0 is returned.
*
* Returned value is normalized [0..7], i.e. independent from msb or lsb read order.
*
*/
public final int getBitPosition() {
if( 0 == bitCount ) {
return 0;
} else {
return 8 - bitCount;
}
}
/**
* Returns the current bit buffer.
* @see #getBitCount()
*/
public final int getBitBuffer() { return bitBuffer; }
/**
* Returns the bit position in the stream.
*/
public final long position() {
// final long bytePos = bytes.position() - ( !outputMode && 0 != bitCount ? 1 : 0 );
// return ( bytePos << 3 ) + getBitPosition();
if( null == bytes ) {
return EOS;
} else if( 0 == bitCount ) {
return bytes.position() << 3;
} else {
final long bytePos = bytes.position() - ( outputMode ? 0 : 1 );
return ( bytePos << 3 ) + 8 - bitCount;
}
}
/**
* Sets this stream's bit position.
*
* A set mark is cleared.
*
*
* Returns {@link Bitstream#EOS} is end-of-stream is reached,
* otherwise the new position.
*
*
* Known supporting implementation is {@link ByteBufferStream} and {@link ByteArrayStream}.
*
*
* @param newPosition The new positive position.
*
* @return The new set position or {@link Bitstream#EOS} if end-of-stream is reached.
*
* @throws UnsupportedOperationException if not supported, i.e. {@link ByteInputStream} or {@link ByteOutputStream}
* @throws IllegalArgumentException If the {@code newPosition} is negative
* @throws IOException if read error occurs or EOS is reached and {@link #setThrowIOExceptionOnEOF(boolean)} is set to true.
* @throws IllegalStateException
*/
public final long position(final long newPosition) throws UnsupportedOperationException, IllegalArgumentException, IllegalStateException, IOException {
if( 0 > newPosition ) {
throw new IllegalArgumentException("new position not positive: "+newPosition);
}
bytes.position(0); // throws UnsupportedOperationException
resetLocal();
if( newPosition > skip(newPosition) ) {
return EOS;
}
return newPosition;
}
/**
* @param msbFirst if true incoming stream bit order is MSB to LSB, otherwise LSB to MSB.
* @return the read bit or {@link #EOS} if end-of-stream is reached.
* @throws IOException
* @throws IllegalStateException if not in input mode or stream closed
*/
public final int readBit(final boolean msbFirst) throws UnsupportedOperationException, IllegalStateException, IOException {
if( outputMode || null == bytes ) {
throw new IllegalStateException("not in input-mode: "+this);
}
if ( 0 < bitCount ) {
bitCount--;
if( msbFirst ) {
return ( bitBuffer >>> bitCount ) & 0x01;
} else {
return ( bitBuffer >>> ( 7 - bitCount ) ) & 0x01;
}
} else {
bitBuffer = bytes.read();
if( EOS == bitBuffer ) {
if( throwIOExceptionOnEOF ) {
throw new IOException("EOS "+this);
}
return EOS;
} else {
bitCount=7;
if( msbFirst ) {
return bitBuffer >>> 7;
} else {
return bitBuffer & 0x01;
}
}
}
}
/**
* @param msbFirst if true outgoing stream bit order is MSB to LSB, otherwise LSB to MSB.
* @param bit
* @return the currently written byte or {@link #EOS} if end-of-stream is reached.
* @throws IOException
* @throws IllegalStateException if not in output mode or stream closed
*/
public final int writeBit(final boolean msbFirst, final int bit) throws IllegalStateException, IOException {
if( !outputMode || null == bytes ) {
throw new IllegalStateException("not in output-mode: "+this);
}
if ( 0 < bitCount ) {
bitCount--;
if( msbFirst ) {
bitBuffer |= ( 0x01 & bit ) << bitCount;
} else {
bitBuffer |= ( 0x01 & bit ) << ( 7 - bitCount );
}
if( 0 == bitCount ) {
final int r = bytes.write((byte)bitBuffer);
if( throwIOExceptionOnEOF && EOS == r ) {
throw new IOException("EOS "+this);
}
return r;
}
} else {
bitCount = 7;
if( msbFirst ) {
bitBuffer = ( 0x01 & bit ) << 7;
} else {
bitBuffer = 0x01 & bit;
}
}
return bitBuffer;
}
/**
* It is implementation dependent, whether backward skip giving a negative number is supported or not.
*
* @param n number of bits to skip
* @return actual skipped bits
* @throws IOException if read error occurs or EOS is reached and {@link #setThrowIOExceptionOnEOF(boolean)} is set to true.
* @throws IllegalStateException if closed
*/
public long skip(final long n) throws IllegalStateException, IOException {
if( null == bytes ) {
throw new IllegalStateException("closed: "+this);
}
if( DEBUG ) {
System.err.println("Bitstream.skip.0: "+n+" - "+toStringImpl());
}
if( n > 0 ) {
if( n <= bitCount ) {
bitCount -= (int)n;
if( DEBUG ) {
System.err.println("Bitstream.skip.F_N1: "+n+" - "+toStringImpl());
}
return n;
} else { // n > bitCount
if( outputMode ) {
if( 0 < bitCount ) {
if( EOS == bytes.write((byte)bitBuffer) ) {
return 0;
}
}
bitBuffer = 0;
}
final long n2 = n - bitCount; // subtract cached bits, bitsCount is zero at this point
final long n3 = n2 >>> 3; // bytes to skip
final long n4 = bytes.skip(n3); // actual skipped bytes
final int n5 = (int) ( n2 - ( n3 << 3 ) ); // remaining skip bits == nX % 8
final long nX = ( n4 << 3 ) + n5 + bitCount; // actual skipped bits
/**
if( DEBUG ) {
System.err.println("Bitstream.skip.1: n2 "+n2+", n3 "+n3+", n4 "+n4+", n5 "+n5+", nX "+nX+" - "+toStringImpl());
} */
if( nX < n ) {
// couldn't complete skipping .. EOS .. etc
bitCount = 0;
bitBuffer = 0;
if( DEBUG ) {
System.err.println("Bitstream.skip.F_EOS: "+n+" - "+toStringImpl());
}
if( throwIOExceptionOnEOF ) {
throw new IOException("EOS "+this);
}
return nX;
}
bitCount = ( 8 - n5 ) & 7; // % 8
int notReadBits = 0;
if( !outputMode && 0 < bitCount ) {
bitBuffer = bytes.read();
if( EOS == bitBuffer ) {
notReadBits = bitCount;
bitCount = 0;
}
}
if( DEBUG ) {
System.err.println("Bitstream.skip.F_N2: "+n+", notReadBits "+notReadBits+" - "+toStringImpl());
}
return nX - notReadBits;
}
} else {
// Zero skip or backward skip
// FIXME: Backward skip n < 0
return 0;
}
}
private static final boolean useFastPathStream = true;
private static final boolean useFastPathTypes = true;
/**
* Return incoming bits as read via {@link #readBit(boolean)} LSB-first as little-endian.
*
* The incoming bit order is from low- to most-significant-bit, maintaining bit LSB-first order.
*
* @param n number of bits, maximum 31 bits
* @return the read bits from 0-n in the given order or {@link #EOS}.
* @throws IllegalStateException if not in input mode or stream closed
* @throws IllegalArgumentException if n > 31
* @throws IOException
*/
public int readBits31(final int n) throws IllegalArgumentException, IOException {
if( 31 < n ) {
throw new IllegalArgumentException("n > 31: "+n);
}
if( outputMode || null == bytes ) {
throw new IllegalStateException("not in input-mode: "+this);
}
if( 0 == n ) {
return 0;
} else {
if( !useFastPathStream ) {
// Slow path
int r = 0;
for(int i=0; i < n; i++) {
final int b = readBit(false /* msbFirst */);
if( EOS == b ) {
if( throwIOExceptionOnEOF ) {
throw new IOException("EOS "+this);
}
return EOS;
}
r |= b << i;
}
return r;
} else {
// fast path
int c = n;
final int n1 = Math.min(n, bitCount); // remaining portion
int r;
if( 0 < n1 ) {
final int m1 = ( 1 << n1 ) - 1;
final int s1 = 7 - bitCount + 1; // LSBfirst: right-shift to new bits
bitCount -= n1;
c -= n1;
// MSBfirst: r = ( m1 & ( bitBuffer >>> bitCount ) ) << c;
r = ( m1 & ( bitBuffer >>> s1 ) ); // LSBfirst
if( 0 == c ) {
return r;
}
} else {
r = 0;
}
assert( 0 == bitCount );
int s = n1; // LSBfirst: left shift for additional elements
do {
bitBuffer = bytes.read();
if( EOS == bitBuffer ) {
if( throwIOExceptionOnEOF ) {
throw new IOException("EOS "+this);
}
return EOS;
}
final int n2 = Math.min(c, 8); // full portion
final int m2 = ( 1 << n2 ) - 1;
bitCount = 8 - n2;
c -= n2;
// MSBfirst: r |= ( m2 & ( bitBuffer >>> bitCount ) ) << c;
r |= ( m2 & bitBuffer ) << s; // LSBfirst on new bits
s += n2;
} while ( 0 < c );
return r;
}
}
}
/**
* Write the given bits via {@link #writeBit(boolean, int)} LSB-first as little-endian.
*
* The outgoing bit order is from low- to most-significant-bit, maintaining bit LSB-first order.
*
* @param n number of bits, maximum 31 bits
* @param bits the bits to write
* @return the written bits or {@link #EOS}.
* @throws IllegalStateException if not in output mode or stream closed
* @throws IllegalArgumentException if n > 31
* @throws IOException
*/
public int writeBits31(final int n, final int bits) throws IllegalStateException, IllegalArgumentException, IOException {
if( 31 < n ) {
throw new IllegalArgumentException("n > 31: "+n);
}
if( !outputMode || null == bytes ) {
throw new IllegalStateException("not in output-mode: "+this);
}
if( 0 < n ) {
if( !useFastPathStream ) {
// Slow path
for(int i=0; i < n; i++) {
final int b = writeBit(false /* msbFirst */, ( bits >>> i ) & 0x1);
if( EOS == b ) {
return EOS;
}
}
} else {
// fast path
int c = n;
final int n1 = Math.min(n, bitCount); // remaining portion
if( 0 < n1 ) {
final int m1 = ( 1 << n1 ) - 1;
final int s1 = 7 - bitCount + 1; // LSBfirst: left-shift to free bit-pos
bitCount -= n1;
c -= n1;
// MSBfirst: bitBuffer |= ( m1 & ( bits >>> c ) ) << bitCount;
bitBuffer |= ( m1 & bits ) << s1 ; // LSBfirst
if( 0 == bitCount ) {
if( EOS == bytes.write((byte)bitBuffer) ) {
if( throwIOExceptionOnEOF ) {
throw new IOException("EOS "+this);
}
return EOS;
}
}
if( 0 == c ) {
return bits;
}
}
assert( 0 == bitCount );
int s = n1; // LSBfirst: left shift for additional elements
do {
final int n2 = Math.min(c, 8); // full portion
final int m2 = ( 1 << n2 ) - 1;
bitCount = 8 - n2;
c -= n2;
// MSBfirst: bitBuffer = ( m2 & ( bits >>> c ) ) << bitCount;
bitBuffer = ( m2 & ( bits >>> s ) ); // LSBfirst
s += n2;
if( 0 == bitCount ) {
if( EOS == bytes.write((byte)bitBuffer) ) {
if( throwIOExceptionOnEOF ) {
throw new IOException("EOS "+this);
}
return EOS;
}
}
} while ( 0 < c );
}
}
return bits;
}
/**
* Return incoming uint8_t as read via {@link #readBits31(int)}.
*
* In case of a int8_t 2-complement signed value, simply cast the result to byte
* after checking for {@link #EOS}.
*
* @return {@link #EOS} or the 8bit unsigned value within the lower bits.
* @throws IllegalStateException if not in input mode or stream closed
* @throws IOException
*/
public final int readUInt8() throws IllegalStateException, IOException {
if( 0 == bitCount && useFastPathTypes ) {
// fast path
if( outputMode || null == bytes ) {
throw new IllegalStateException("not in input-mode: "+this);
}
final int r = bytes.read();
if( throwIOExceptionOnEOF && EOS == r ) {
throw new IOException("EOS "+this);
}
return r;
} else {
return readBits31(8);
}
}
/**
* Write the given 8 bits via {@link #writeBits31(int, int)}.
* @return {@link #EOS} or the written 8bit value.
* @throws IllegalStateException if not in output mode or stream closed
* @throws IOException
*/
public final int writeInt8(final byte int8) throws IllegalStateException, IOException {
if( 0 == bitCount && useFastPathTypes ) {
// fast path
if( !outputMode || null == bytes ) {
throw new IllegalStateException("not in output-mode: "+this);
}
final int r = bytes.write(int8);
if( throwIOExceptionOnEOF && EOS == r ) {
throw new IOException("EOS "+this);
}
return r;
} else {
return this.writeBits31(8, int8);
}
}
/**
* Return incoming uint16_t as read via {@link #readBits31(int)} LSB-first as little-endian,
* hence bytes are swapped if bigEndian.
*
* In case of a int16_t 2-complement signed value, simply cast the result to short
* after checking for {@link #EOS}.
*
* @param bigEndian if true, swap incoming bytes to little-endian, otherwise leave them as little-endian.
* @return {@link #EOS} or the 16bit unsigned value within the lower bits.
* @throws IllegalStateException if not in input mode or stream closed
* @throws IOException
*/
public final int readUInt16(final boolean bigEndian) throws IllegalStateException, IOException {
if( 0 == bitCount && useFastPathTypes ) {
// fast path
if( outputMode || null == bytes ) {
throw new IllegalStateException("not in input-mode: "+this);
}
final int b1 = bytes.read();
final int b2 = EOS != b1 ? bytes.read() : EOS;
if( EOS == b2 ) {
if( throwIOExceptionOnEOF ) {
throw new IOException("EOS "+this);
}
return EOS;
} else if( bigEndian ) {
return b1 << 8 | b2;
} else {
return b2 << 8 | b1;
}
} else {
final int i16 = readBits31(16);
if( EOS == i16 ) {
return EOS;
} else if( bigEndian ) {
final int b1 = 0xff & ( i16 >>> 8 );
final int b2 = 0xff & i16;
return b2 << 8 | b1;
} else {
return i16;
}
}
}
/**
* Return incoming uint16_t value and swap bytes according to bigEndian.
*
* In case of a int16_t 2-complement signed value, simply cast the result to short.
*
* @param bigEndian if false, swap incoming bytes to little-endian, otherwise leave them as big-endian.
* @return the 16bit unsigned value within the lower bits.
* @throws IndexOutOfBoundsException
*/
public static final int readUInt16(final boolean bigEndian, final byte[] bytes, final int offset) throws IndexOutOfBoundsException {
checkBounds(bytes, offset, 2);
// Make sure we clear any high bits that get set in sign-extension
final int b1 = bytes[offset] & 0xff;
final int b2 = bytes[offset+1] & 0xff;
if( bigEndian ) {
return b1 << 8 | b2;
} else {
return b2 << 8 | b1;
}
}
/**
* Write the given 16 bits via {@link #writeBits31(int, int)} LSB-first as little-endian,
* hence bytes are swapped if bigEndian.
* @param bigEndian if true, swap given bytes to little-endian, otherwise leave them as little-endian.
* @return {@link #EOS} or the written 16bit value.
* @throws IllegalStateException if not in output mode or stream closed
* @throws IOException
*/
public final int writeInt16(final boolean bigEndian, final short int16) throws IllegalStateException, IOException {
if( 0 == bitCount && useFastPathTypes ) {
// fast path
if( !outputMode || null == bytes ) {
throw new IllegalStateException("not in output-mode: "+this);
}
final byte hi = (byte) ( 0xff & ( int16 >>> 8 ) );
final byte lo = (byte) ( 0xff & int16 );
final byte b1, b2;
if( bigEndian ) {
b1 = hi;
b2 = lo;
} else {
b1 = lo;
b2 = hi;
}
if( EOS != bytes.write(b1) ) {
if( EOS != bytes.write(b2) ) {
return int16;
}
}
if( throwIOExceptionOnEOF ) {
throw new IOException("EOS "+this);
}
return EOS;
} else if( bigEndian ) {
final int b1 = 0xff & ( int16 >>> 8 );
final int b2 = 0xff & int16;
return writeBits31(16, b2 << 8 | b1);
} else {
return writeBits31(16, int16);
}
}
/**
* Return incoming uint32_t as read via {@link #readBits31(int)} LSB-first as little-endian,
* hence bytes are swapped if bigEndian.
*
* In case of a int32_t 2-complement signed value, simply cast the result to int
* after checking for {@link #EOS}.
*
* @param bigEndian if true, swap incoming bytes to little-endian, otherwise leave them as little-endian.
* @return {@link #EOS} or the 32bit unsigned value within the lower bits.
* @throws IllegalStateException if not in input mode or stream closed
* @throws IOException
*/
public final long readUInt32(final boolean bigEndian) throws IllegalStateException, IOException {
if( 0 == bitCount && useFastPathTypes ) {
// fast path
if( outputMode || null == bytes ) {
throw new IllegalStateException("not in input-mode: "+this);
}
final int b1 = bytes.read();
final int b2 = EOS != b1 ? bytes.read() : EOS;
final int b3 = EOS != b2 ? bytes.read() : EOS;
final int b4 = EOS != b3 ? bytes.read() : EOS;
if( EOS == b4 ) {
if( throwIOExceptionOnEOF ) {
throw new IOException("EOS "+this);
}
return EOS;
} else if( bigEndian ) {
return 0xffffffffL & ( b1 << 24 | b2 << 16 | b3 << 8 | b4 );
} else {
return 0xffffffffL & ( b4 << 24 | b3 << 16 | b2 << 8 | b1 );
}
} else {
final int i16a = readBits31(16);
final int i16b = EOS != i16a ? readBits31(16) : EOS;
if( EOS == i16b ) {
return EOS;
} else if( bigEndian ) {
final int b1 = 0xff & ( i16b >>> 8 );
final int b2 = 0xff & i16b;
final int b3 = 0xff & ( i16a >>> 8 );
final int b4 = 0xff & i16a;
return 0xffffffffL & ( b4 << 24 | b3 << 16 | b2 << 8 | b1 );
} else {
return 0xffffffffL & ( i16b << 16 | i16a );
}
}
}
/**
* Return incoming uint32_t and swap bytes according to bigEndian.
*
* In case of a int32_t 2-complement signed value, simply cast the result to int.
*
* @param bigEndian if false, swap incoming bytes to little-endian, otherwise leave them as big-endian.
* @return the 32bit unsigned value within the lower bits.
* @throws IndexOutOfBoundsException
*/
public static final long readUInt32(final boolean bigEndian, final byte[] bytes, final int offset) throws IndexOutOfBoundsException {
checkBounds(bytes, offset, 4);
final int b1 = bytes[offset];
final int b2 = bytes[offset+1];
final int b3 = bytes[offset+2];
final int b4 = bytes[offset+3];
if( bigEndian ) {
return 0xffffffffL & ( b1 << 24 | b2 << 16 | b3 << 8 | b4 );
} else {
return 0xffffffffL & ( b4 << 24 | b3 << 16 | b2 << 8 | b1 );
}
}
/**
* Write the given 32 bits via {@link #writeBits31(int, int)} LSB-first as little-endian,
* hence bytes are swapped if bigEndian.
* @param bigEndian if true, swap given bytes to little-endian, otherwise leave them as little-endian.
* @return {@link #EOS} or the written 32bit value.
* @throws IllegalStateException if not in output mode or stream closed
* @throws IOException
*/
public final int writeInt32(final boolean bigEndian, final int int32) throws IllegalStateException, IOException {
if( 0 == bitCount && useFastPathTypes ) {
// fast path
if( !outputMode || null == bytes ) {
throw new IllegalStateException("not in output-mode: "+this);
}
final byte p1 = (byte) ( 0xff & ( int32 >>> 24 ) );
final byte p2 = (byte) ( 0xff & ( int32 >>> 16 ) );
final byte p3 = (byte) ( 0xff & ( int32 >>> 8 ) );
final byte p4 = (byte) ( 0xff & int32 );
final byte b1, b2, b3, b4;
if( bigEndian ) {
b1 = p1;
b2 = p2;
b3 = p3;
b4 = p4;
} else {
b1 = p4;
b2 = p3;
b3 = p2;
b4 = p1;
}
if( EOS != bytes.write(b1) ) {
if( EOS != bytes.write(b2) ) {
if( EOS != bytes.write(b3) ) {
if( EOS != bytes.write(b4) ) {
return int32;
}
}
}
}
if( throwIOExceptionOnEOF ) {
throw new IOException("EOS "+this);
}
return EOS;
} else if( bigEndian ) {
final int p1 = 0xff & ( int32 >>> 24 );
final int p2 = 0xff & ( int32 >>> 16 );
final int p3 = 0xff & ( int32 >>> 8 );
final int p4 = 0xff & int32 ;
if( EOS != writeBits31(16, p2 << 8 | p1) ) {
if( EOS != writeBits31(16, p4 << 8 | p3) ) {
return int32;
}
}
return EOS;
} else {
final int hi = 0x0000ffff & ( int32 >>> 16 );
final int lo = 0x0000ffff & int32 ;
if( EOS != writeBits31(16, lo) ) {
if( EOS != writeBits31(16, hi) ) {
return int32;
}
}
return EOS;
}
}
/**
* Reinterpret the given int32_t value as uint32_t,
* i.e. perform the following cast to long:
*
* final long l = 0xffffffffL & int32;
*
*/
public static final long toUInt32Long(final int int32) {
return 0xffffffffL & int32;
}
/**
* Returns the reinterpreted given int32_t value
* as uint32_t if ≤ {@link Integer#MAX_VALUE}
* as within an int storage.
* Otherwise return -1.
*/
public static final int toUInt32Int(final int int32) {
return uint32LongToInt(toUInt32Long(int32));
}
/**
* Returns the given uint32_t value long
* value as int if ≤ {@link Integer#MAX_VALUE}.
* Otherwise return -1.
*/
public static final int uint32LongToInt(final long uint32) {
if( Integer.MAX_VALUE >= uint32 ) {
return (int)uint32;
} else {
return -1;
}
}
@Override
public String toString() {
return String.format("Bitstream[%s]", toStringImpl());
}
protected String toStringImpl() {
final String mode;
final long bpos;
if( null == bytes ) {
mode = "closed";
bpos = -1;
} else {
mode = outputMode ? "output" : "input";
bpos = bytes.position();
}
return String.format("%s, pos %d [byteP %d, bitCnt %d], bitbuf %s",
mode, position(), bpos, bitCount, toHexBinString(true, bitBuffer, 8));
}
private static final String strZeroPadding= "0000000000000000000000000000000000000000000000000000000000000000"; // 64
public static String toBinString(final boolean msbFirst, final int v, final int bitCount) {
if( 0 == bitCount ) {
return "";
}
if( msbFirst ) {
final int mask = (int) ( ( 1L << bitCount ) - 1L );
final String s0 = Integer.toBinaryString( mask & v );
return strZeroPadding.substring(0, bitCount-s0.length())+s0;
} else {
final char[] c = new char[32];
for(int i=0; i sb.length ) {
throw new IndexOutOfBoundsException("Buffer of size "+sb.length+" cannot hold offset "+offset+" + remaining "+remaining);
}
}
}