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/*
* Copyright (c) 2000, 2023, Oracle and/or its affiliates.
*
* Licensed under the Universal Permissive License v 1.0 as shown at
* https://oss.oracle.com/licenses/upl.
*/
package com.tangosol.io;
import com.tangosol.util.Base;
import com.tangosol.util.Binary;
import com.tangosol.util.BinaryWriteBuffer;
import com.tangosol.util.ByteSequence;
import com.tangosol.util.ExternalizableHelper;
import com.tangosol.util.HashEncoded;
import java.io.DataInputStream;
import java.io.EOFException;
import java.io.InputStream;
import java.io.IOException;
import java.io.UTFDataFormatException;
import java.util.function.BinaryOperator;
/**
* Abstract base implementation of the ReadBuffer interface.
*
* @author cp 2006.04.17
*/
public abstract class AbstractReadBuffer
extends Base
implements ReadBuffer, HashEncoded
{
/**
* {@inheritDoc}
*/
public BufferInput getBufferInput()
{
return instantiateBufferInput();
}
/**
* {@inheritDoc}
*/
public ReadBuffer getReadBuffer(int of, int cb)
{
// optimize getting the "same" buffer
if (of == 0 && cb == length())
{
return this;
}
checkBounds(of, cb);
// create a "sub" buffer
return instantiateReadBuffer(of, cb);
}
/**
* {@inheritDoc}
*/
public byte[] toByteArray()
{
return toByteArray(0, length());
}
/**
* {@inheritDoc}
*/
public byte[] toByteArray(int of, int cb)
{
checkBounds(of, cb);
byte[] ab;
if (cb == 0)
{
ab = NO_BYTES;
}
else
{
ab = new byte[cb];
copyBytes(of, of + cb, ab, 0);
}
return ab;
}
/**
* {@inheritDoc}
*/
public Binary toBinary()
{
return toBinary(0, length());
}
/**
* {@inheritDoc}
*/
public Binary toBinary(int of, int cb)
{
checkBounds(of, cb);
WriteBuffer buf = new BinaryWriteBuffer(cb, cb);
buf.write(0, this, of, cb);
return buf.toBinary();
}
/**
* {@inheritDoc}
*
* @since Coherence 3.7
*/
public ByteSequence subSequence(int ofStart, int ofEnd)
{
return getReadBuffer(ofStart, ofEnd - ofStart);
}
// ----- HashEncoded interface ------------------------------------------
/**
* {@inheritDoc}
*/
public int getEncodedHash()
{
return ExternalizableHelper.isIntDecorated(this)
? AbstractReadBuffer.readPackedInt(this, 1)
: HashEncoded.UNENCODED;
}
/**
* {@inheritDoc}
*/
public boolean equals(Object o)
{
if (o instanceof ReadBuffer)
{
ReadBuffer that = (ReadBuffer) o;
if (this == that)
{
return true;
}
int cb = this.length();
if (cb != that.length())
{
return false;
}
if (cb == 0)
{
return true;
}
int cbTempBuf = Math.min(cb, 32);
byte[] abThis = new byte[cbTempBuf];
byte[] abThat = new byte[cbTempBuf];
int of = 0;
do
{
int cbChunk = Math.min(cb, cbTempBuf);
int ofEnd = of + cbChunk;
this.copyBytes(of, ofEnd, abThis, 0);
that.copyBytes(of, ofEnd, abThat, 0);
if (!Binary.equals(abThis, 0, abThat, 0, cbChunk))
{
return false;
}
of += cbChunk;
cb -= cbChunk;
}
while (cb > 0);
return true;
}
else
{
return false;
}
}
/**
* {@inheritDoc}
*/
public Object clone()
{
// this needs to be over-ridden if a shallow clone is not acceptable
try
{
return super.clone();
}
catch (CloneNotSupportedException e)
{
throw ensureRuntimeException(e);
}
}
// ----- factory methods ------------------------------------------------
/**
* Factory method: Instantiate a ReadBuffer for a portion of this
* ReadBuffer.
*
* @param of the beginning index, inclusive
* @param cb the number of bytes to include in the resulting ReadBuffer
*
* @return a ReadBuffer that represents a portion of this ReadBuffer
*/
protected abstract ReadBuffer instantiateReadBuffer(int of, int cb);
/**
* Factory method: Instantiate a BufferInput object to read data from the
* ReadBuffer.
*
* @return a new BufferInput reading from this ReadBuffer
*/
protected abstract BufferInput instantiateBufferInput();
// ----- inner class: BufferInput implementation ------------------------
/**
* This is an implementation of the BufferInput interface that delegates
* its work back to its ReadBuffer.
*
* This implementation extends InputStream, but only so that it can be
* passed to anything that takes an InputStream.
*/
public class AbstractBufferInput
extends InputStream
implements BufferInput
{
// ----- constructors -------------------------------------------
/**
* Default constructor.
*
* @implSpec
* Initialize serial filter as it done for ObjectInputStream constructor.
*
* In Java versions prior to 17, the deserialization filter is initialized to JVM-wide ObjectInputFilter.
*
* In Java version 17 and greater, the deserialization filter is initialized to the filter returned
* by invoking {@link ExternalizableHelper#getConfigSerialFilterFactory() serial filter factory}
* with {@code null} for the current filter and the
* {@linkplain ExternalizableHelper#getConfigSerialFilter() static JVM-wide filter} for the requested filter.
*/
public AbstractBufferInput()
{
BinaryOperator factorySerialFilter = ExternalizableHelper.getConfigSerialFilterFactory();
m_oInputFilter = factorySerialFilter == null
? ExternalizableHelper.getConfigSerialFilter()
: factorySerialFilter.apply(null, ExternalizableHelper.getConfigSerialFilter());
}
// ----- InputStreaming methods ---------------------------------
/**
* {@inheritDoc}
*/
public int read()
throws IOException
{
try
{
int of = getOffset();
int b = byteAt(of) & 0xFF;
setOffsetInternal(of + 1);
return b;
}
catch (IndexOutOfBoundsException e)
{
return -1;
}
}
/**
* {@inheritDoc}
*/
public int read(byte ab[])
throws IOException
{
return read(ab, 0, ab.length);
}
/**
* {@inheritDoc}
*/
public int read(byte ab[], int of, int cb)
throws IOException
{
// validate parameters
int cbDest = ab.length;
if (of < 0 || cb < 0 || of + cb > cbDest)
{
throw new IndexOutOfBoundsException("ab.length=" + cbDest
+ ", of=" + of + ", cb=" + cb);
}
// avoid confusing "nothing requested" with "nothing remains"
if (cb == 0)
{
return 0;
}
// get the current position within the buffer
int ofIn = getOffset();
// determine the amount to read by taking the smaller of the
// requested and the remainder
int cbRead = Math.min(cb, length() - ofIn);
// check for eof
if (cbRead == 0)
{
return -1;
}
else
{
// transfer the read data to the passed byte array
int ofEnd = ofIn + cbRead;
copyBytes(ofIn, ofEnd, ab, of);
// update the read offset and return the number of bytes read
setOffsetInternal(ofEnd);
return cbRead;
}
}
/**
* {@inheritDoc}
*/
public long skip(long cb)
throws IOException
{
// scale down the requested skip into a 32-bit integer
int cbReq = (cb > Integer.MAX_VALUE ? Integer.MAX_VALUE : (int) cb);
return skipBytes(cbReq);
}
/**
* {@inheritDoc}
*/
public int available()
throws IOException
{
return length() - getOffset();
}
/**
* {@inheritDoc}
*/
public void close()
throws IOException
{
m_achBuf = null;
}
/**
* {@inheritDoc}
*/
public void mark(int cbReadLimit)
{
setMarkInternal(getOffset());
}
/**
* {@inheritDoc}
*/
public void reset()
throws IOException
{
int of = getMarkInternal();
if (of < 0)
{
throw new IOException("not marked");
}
setOffsetInternal(of);
}
/**
* {@inheritDoc}
*/
public boolean markSupported()
{
return true;
}
// ----- DataInput methods --------------------------------------
/**
* {@inheritDoc}
*/
public void readFully(byte ab[])
throws IOException
{
readFully(ab, 0, ab.length);
}
/**
* {@inheritDoc}
*/
public void readFully(byte ab[], int of, int cb)
throws IOException
{
int cbRead = read(ab, of, cb);
if (cbRead < cb)
{
throw new EOFException("requested=" + cb + ", read=" + cbRead);
}
}
/**
* {@inheritDoc}
*/
public int skipBytes(int cb)
throws IOException
{
// get the current position within the buffer and determine the
// remainder of the buffer in bytes
int of = getOffset();
int cbRem = length() - of;
// determine the amount to skip by taking the smaller of the
// requested and the remainder
int cbSkip = Math.min(cb, cbRem);
// do the skip and return the number of bytes skipped
setOffsetInternal(of + cbSkip);
return cbSkip;
}
/**
* {@inheritDoc}
*/
public boolean readBoolean()
throws IOException
{
return readByte() != 0;
}
/**
* {@inheritDoc}
*/
public byte readByte()
throws IOException
{
try
{
int of = getOffset();
byte b = byteAt(of);
setOffsetInternal(of + 1);
return b;
}
catch (IndexOutOfBoundsException e)
{
throw new EOFException(e.getMessage());
}
}
/**
* {@inheritDoc}
*/
public int readUnsignedByte()
throws IOException
{
return readByte() & 0xFF;
}
/**
* {@inheritDoc}
*/
public short readShort()
throws IOException
{
return (short) readUnsignedShort();
}
/**
* {@inheritDoc}
*/
public int readUnsignedShort()
throws IOException
{
return (readUnsignedByte() << 8) |
readUnsignedByte();
}
/**
* {@inheritDoc}
*/
public char readChar()
throws IOException
{
return (char) readUnsignedShort();
}
/**
* {@inheritDoc}
*/
public int readInt()
throws IOException
{
return (readUnsignedByte() << 24) |
(readUnsignedByte() << 16) |
(readUnsignedByte() << 8) |
readUnsignedByte();
}
/**
* {@inheritDoc}
*/
public long readLong()
throws IOException
{
return (((long) readInt()) << 32) |
(((long) readInt()) & 0xFFFFFFFFL);
}
/**
* {@inheritDoc}
*/
public float readFloat()
throws IOException
{
return Float.intBitsToFloat(readInt());
}
/**
* {@inheritDoc}
*/
public double readDouble()
throws IOException
{
return Double.longBitsToDouble(readLong());
}
/**
* {@inheritDoc}
*/
public String readLine()
throws IOException
{
// this is terribly inefficient!!!
// .. but no one should be calling this method
return new DataInputStream(this).readLine();
}
/**
* {@inheritDoc}
*/
public String readUTF()
throws IOException
{
// the format is a 2-byte unsigned length-encoded binary, with
// the binary being a UTF-encoded value
return readUTF(readUnsignedShort());
}
// ----- BufferInput methods ------------------------------------
/**
* {@inheritDoc}
*/
public ReadBuffer getBuffer()
{
return AbstractReadBuffer.this;
}
/**
* {@inheritDoc}
*/
public String readSafeUTF()
throws IOException
{
return readUTF(readPackedInt());
}
/**
* {@inheritDoc}
*/
public int readPackedInt()
throws IOException
{
int b = readUnsignedByte();
int n = b & 0x3F; // only 6 bits of data in first byte
int cBits = 6;
boolean fNeg = (b & 0x40) != 0; // seventh bit is a sign bit
while ((b & 0x80) != 0) // eighth bit is the continuation bit
{
b = readUnsignedByte();
n |= ((b & 0x7F) << cBits);
cBits += 7;
}
if (fNeg)
{
n = ~n;
}
return n;
}
/**
* {@inheritDoc}
*/
public long readPackedLong()
throws IOException
{
int b = readUnsignedByte();
long l = b & 0x3F; // only 6 bits of data in first byte
int cBits = 6;
boolean fNeg = (b & 0x40) != 0; // seventh bit is a sign bit
while ((b & 0x80) != 0) // eighth bit is the continuation bit
{
b = readUnsignedByte();
l |= (((long) (b & 0x7F)) << cBits);
cBits += 7;
}
if (fNeg)
{
l = ~l;
}
return l;
}
/**
* {@inheritDoc}
*/
public ReadBuffer readBuffer(int cb)
throws IOException
{
if (cb < 0)
{
throw new IllegalArgumentException("cb=" + cb);
}
if (cb == 0)
{
return NO_BINARY;
}
int of = getOffset();
if (skipBytes(cb) < cb)
{
throw new EOFException();
}
return getReadBuffer(of, cb);
}
/**
* {@inheritDoc}
*/
public int getOffset()
{
return m_of;
}
/**
* {@inheritDoc}
*/
public void setOffset(int of)
{
if (of < 0 || of > length())
{
throw new IndexOutOfBoundsException("of=" + of
+ ", getBuffer().length()=" + length());
}
setOffsetInternal(of);
}
@Override
public final Object getObjectInputFilter()
{
return m_oInputFilter;
}
@Override
public final synchronized void setObjectInputFilter(Object oInputFilter)
{
Object oInputFilterCurrent = m_oInputFilter;
BinaryOperator factorySerialFilter = ExternalizableHelper.getConfigSerialFilterFactory();
if (m_fInputFilterSet)
{
throw new IllegalStateException("filter can not be set more than once");
}
// delegate to factory to compute stream serial filter in Java version 17 and greater
Object oInputFilterNext = factorySerialFilter == null
? oInputFilter
: factorySerialFilter.apply(oInputFilterCurrent, oInputFilter);
if (oInputFilterCurrent != null && oInputFilterNext == null)
{
throw new IllegalStateException("filter can not be replaced by null filter");
}
m_oInputFilter = oInputFilterNext;
m_fInputFilterSet = true;
}
// ----- internal -----------------------------------------------
/**
* Update the internal stream offset.
*
* @param of the new offset
*/
protected void setOffsetInternal(int of)
{
m_of = of;
}
/**
* Adjust the internal stream offset.
*
* @param cb the number of bytes that were written
*/
protected void adjustOffsetInternal(int cb)
{
m_of += cb;
}
/**
* Obtain the offset of the stream mark.
*
* @return the offset of the mark or -1 if unmarked
*/
protected int getMarkInternal()
{
return m_ofMark;
}
/**
* Update the internal stream mark.
*
* @param of the offset of the new mark
*/
protected void setMarkInternal(int of)
{
m_ofMark = of;
}
/**
* Obtain a temp buffer used to avoid allocations when building
* Strings from UTF binary data.
*
* @param cchMax the length that the String will not exceed
*
* @return a char buffer of at least the specified length
*/
protected char[] getCharBuf(int cchMax)
{
char[] ach = m_achBuf;
if (ach == null || ach.length < cchMax)
{
m_achBuf = ach = new char[Math.max(MIN_BUF, cchMax)];
}
return ach;
}
/**
* Reads the specified-length UTF data and converts it to a String
* value.
*
* @param cb the number of bytes that the UTF data takes up in the
* stream; a value less than zero indicates a null value
*
* @return a String value; may be null if the passed length could be
* negative
*
* @exception UTFDataFormatException if the bytes that were
* read were not a valid UTF-8 encoded string
* @exception EOFException if the value could not be read because no
* more data remains to be read
* @exception IOException if an I/O error occurs
*/
protected String readUTF(int cb)
throws IOException
{
if (cb < 0)
{
return null;
}
else if (cb == 0)
{
return "";
}
int of = getOffset();
int cbBuf = length();
if (of + cb > cbBuf)
{
// pretend to have read to end-of-stream
setOffsetInternal(cbBuf);
throw new EOFException();
}
else
{
// pretend to have read to the end of the binary
setOffsetInternal(of + cb);
}
// per JDK serialization filtering doc:
// The filter is not called ... for java.lang.String instances that are encoded concretely in the stream.
return convertUTF(of, cb);
}
/**
* Convert a UTF-8 encoded section of the binary stream into a String.
*
* @param of the offset within the stream
* @param cb the length in bytes within the stream
*
* @return the String value
*
* @throws IOException if an I/O or conversion exception occurs, such
* as UTFDataFormatException
*/
protected String convertUTF(int of, int cb)
throws IOException
{
return ExternalizableHelper.convertUTF(
toByteArray(of, cb), 0, cb, getCharBuf(cb));
}
// ----- data members -------------------------------------------
/**
* Current stream offset into the containing ReadBuffer.
*/
private int m_of;
/**
* The marked position expressed as a stream offset.
*/
private int m_ofMark = -1;
/**
* A lazily instantiated temp buffer used to avoid allocations for
* building Strings from UTF binaries.
*/
private transient char[] m_achBuf;
/**
* When not null, filter to validate that an instance of a class can be deserialized from
* this {@link BufferInput}.
*/
private volatile Object m_oInputFilter;
/**
* True if the stream-specific {@link BufferInput this} {@link #getObjectInputFilter() serial filter}
* has been {@link #setObjectInputFilter(Object) set}; initially false.
*/
private volatile boolean m_fInputFilterSet = false;
}
// ----- internal -------------------------------------------------------
/**
* Check if the specified read is within bounds.
*
* @param of the absolute offset of the read operation
* @param cb the length in bytes of the read operation
*
* @throws IndexOutOfBoundsException if the specified read is not within
* bounds
*/
protected void checkBounds(int of, int cb)
{
if (of < 0 || cb < 0 || of + cb > length())
{
throw new IndexOutOfBoundsException("of=" + of + ", cb=" + cb
+ ", length()=" + length());
}
}
/**
* Read an unsigned byte value from the given {@link ByteSequence} and
* offset.
*
* This method is the counterpart for the
* {@link java.io.DataOutput#writeByte} method when it is used with
* unsigned 8-bit values.
*
* @param bin the byte sequence
* @param of the offset
*
* @return an int value in the range 0x00 to 0xFF
*/
public static int readUnsignedByte(ByteSequence bin, int of)
{
return bin.byteAt(of) & 0xFF;
}
/**
* Read an int value using a variable-length storage format as described
* by {@link WriteBuffer.BufferOutput#writePackedInt(int)} from the given
* {@link ByteSequence} and offset.
*
* @param bin the byte sequence
* @param of the offset
*
* @return an int value
*/
public static int readPackedInt(ByteSequence bin, int of)
{
int b = readUnsignedByte(bin, of++);
int n = b & 0x3F; // only 6 bits of data in first byte
int cBits = 6;
boolean fNeg = (b & 0x40) != 0; // seventh bit is a sign bit
while ((b & 0x80) != 0) // eighth bit is the continuation bit
{
b = readUnsignedByte(bin, of++);
n |= ((b & 0x7F) << cBits);
cBits += 7;
}
if (fNeg)
{
n = ~n;
}
return n;
}
/**
* Return the number of bytes that would be required to store the given int
* using the variable-length storage format as described by {@link
* WriteBuffer.BufferOutput#writePackedInt(int)}.
*
* @param n the integer that will be stored as a packed int
*
* @return the number of bytes required to store the packed int
*/
public static int sizeofPackedInt(int n)
{
if (n < 0)
{
n = ~n;
}
int cb = n == 0 ? 1 : 0;
for (int iShift = 6; n > 0; iShift = 7)
{
n >>= iShift;
cb++;
}
return cb;
}
// ----- constants ------------------------------------------------------
/**
* An empty byte array (by definition immutable).
*/
public static final byte[] NO_BYTES = new byte[0];
/**
* An empty Binary object.
*/
public static final Binary NO_BINARY = new Binary(NO_BYTES);
/**
* The minimum size of a temp buffer.
*/
static final int MIN_BUF = 64;
}