com.tangosol.io.pof.PofInputStream Maven / Gradle / Ivy
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/*
* Copyright (c) 2000, 2020, Oracle and/or its affiliates.
*
* Licensed under the Universal Permissive License v 1.0 as shown at
* http://oss.oracle.com/licenses/upl.
*/
package com.tangosol.io.pof;
import com.tangosol.io.InputStreaming;
import java.io.DataInput;
import java.io.EOFException;
import java.io.InputStream;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.UTFDataFormatException;
/**
* An ObjectInput implementation suitable for reading Externalizable and
* ExternalizableLite objects from a POF stream, although without support for
* schema evolution and other advanced POF features.
*
* @author cp 2006.07.29
*/
public class PofInputStream
extends InputStream
implements InputStreaming, DataInput, ObjectInput
{
// ----- constructors ---------------------------------------------------
/**
* Construct a PofInputStream that will read its information from an
* underlying {@link PofReader PofReader}.
*
* @param in the {@link PofReader PofReader} to read from
*/
public PofInputStream(PofReader in)
{
m_in = in;
}
// ----- InputStreaming interface ---------------------------------------
/**
* Read the next byte of data from the InputStream. The value byte is
* returned as an int in the range 0 to
* 255. If the end of the stream has been reached, the value
* -1 is returned.
*
* This method blocks until input data is available, the end of the stream
* is detected, or an exception is thrown.
*
* @return the next byte of data, or -1 if the end of the
* stream has been reached
*
* @exception IOException if an I/O error occurs
*/
public int read()
throws IOException
{
return m_in.readByte(nextIndex());
}
/**
* Read some number of bytes from the input stream and store them into the
* passed array ab. The number of bytes actually read is
* returned.
*
* This method blocks until input data is available, the end of the stream
* is detected, or an exception is thrown.
*
* @param ab the array to store the bytes which are read from the stream
*
* @return the number of bytes read from the stream, or -1
* if no bytes were read from the stream because the end of the
* stream had been reached
*
* @exception NullPointerException if the passed array is null
* @exception IOException if an I/O error occurs
*/
public int read(byte ab[])
throws IOException
{
byte[] abActual = m_in.readByteArray(nextIndex());
int cbActual = abActual.length;
int cb = ab.length;
if (cbActual > cb)
{
throw new IOException("read " + cbActual
+ " bytes, but buffer was only " + cb + " bytes long");
}
System.arraycopy(abActual, 0, ab, 0, cbActual);
return cbActual;
}
/**
* Read up to cb bytes from the input stream and store them
* into the passed array ab starting at offset
* of. The number of bytes actually read is returned.
*
* This method blocks until input data is available, the end of the stream
* is detected, or an exception is thrown.
*
* @param ab the array to store the bytes which are read from the stream
* @param of the offset into the array that the read bytes will be stored
* @param cb the maximum number of bytes to read
*
* @return the number of bytes read from the stream, or -1
* if no bytes were read from the stream because the end of the
* stream had been reached
*
* @exception NullPointerException if the passed array is null
* @exception IndexOutOfBoundsException if of or
* cb is negative, or of+cb is
* greater than the length of the ab
* @exception IOException if an I/O error occurs
*/
public int read(byte ab[], int of, int cb)
throws IOException
{
byte[] abActual = m_in.readByteArray(nextIndex());
int cbActual = abActual.length;
if (cbActual > cb)
{
throw new IOException("read " + cbActual
+ " bytes, but buffer was only " + cb + " bytes long");
}
System.arraycopy(abActual, 0, ab, of, cbActual);
return cbActual;
}
/**
* Skips over up to the specified number of bytes of data from this
* InputStream. The number of bytes actually skipped over may be fewer
* than the number specified to skip, and may even be zero; this can be
* caused by an end-of-file condition, but can also occur even when there
* is data remaining in the InputStream. As a result, the caller should
* check the return value from this method, which indicates the actual
* number of bytes skipped.
*
* @param cb the maximum number of bytes to skip over
*
* @return the actual number of bytes that were skipped over
*
* @exception IOException if an I/O error occurs
*/
public long skip(long cb)
throws IOException
{
byte[] abActual = m_in.readByteArray(nextIndex());
int cbActual = abActual.length;
if (cbActual > cb)
{
throw new IOException("skipped" + cbActual
+ " bytes, but request was only for " + cb + " bytes");
}
return cbActual;
}
/**
* Returns the number of bytes that can be read (or skipped over) from
* this input stream without causing a blocking I/O condition to occur.
* This method reflects the assumed implementation of various buffering
* InputStreams, which can guarantee non-blocking reads up to the extent
* of their buffers, but beyond that the read operations will have to read
* from some underlying (and potentially blocking) source.
*
* @return the number of bytes that can be read from this InputStream
* without blocking
*
* @exception IOException if an I/O error occurs
*/
public int available()
throws IOException
{
return 0;
}
/**
* Close the InputStream and release any system resources associated with
* it.
*
* @exception IOException if an I/O error occurs
*/
public void close()
throws IOException
{
}
/**
* Marks the current read position in the InputStream in order to support
* the stream to be later "rewound" (using the {@link #reset} method) to
* the current position. The caller passes in the maximum number of bytes
* that it expects to read before calling the {@link #reset} method, thus
* indicating the upper bounds of the responsibility of the stream to be
* able to buffer what it has read in order to support this functionality.
*
* @param cbReadLimit the maximum number of bytes that caller expects the
* InputStream to be able to read before the mark
* position becomes invalid
*/
public void mark(int cbReadLimit)
{
}
/**
* Rewind this stream to the position at the time the {@link #mark} method
* was last called on this InputStream. If the InputStream cannot fulfill
* this contract, it should throw an IOException.
*
* @exception IOException if an I/O error occurs, for example if this
* has not been marked or if the mark has been
* invalidated
*/
public void reset()
throws IOException
{
throw new IOException();
}
/**
* Determine if this InputStream supports the {@link #mark} and
* {@link #reset} methods.
*
* @return true if this InputStream supports the mark and
* reset method; false otherwise
*/
public boolean markSupported()
{
return false;
}
// ----- DataInput interface --------------------------------------------
/**
* Read ab.length bytes and store them in ab.
*
* This method blocks until input data is available, the end of the stream
* is detected, or an exception is thrown.
*
* @param ab the array to store the bytes which are read from the stream
*
* @exception NullPointerException if the passed array is null
* @exception EOFException if the stream is exhausted before the number
* of bytes indicated by the array length could be read
* @exception IOException if an I/O error occurs
*/
public void readFully(byte ab[])
throws IOException
{
byte[] abActual = m_in.readByteArray(nextIndex());
int cbActual = abActual.length;
int cb = ab.length;
if (cbActual != cb)
{
throw new IOException("read " + cbActual
+ " bytes, but buffer was " + cb + " bytes long");
}
System.arraycopy(abActual, 0, ab, 0, cbActual);
}
/**
* Read cb bytes and store them in ab starting
* at offset of.
*
* This method blocks until input data is available, the end of the stream
* is detected, or an exception is thrown.
*
* @param ab the array to store the bytes which are read from the stream
* @param of the offset into the array that the read bytes will be stored
* @param cb the maximum number of bytes to read
*
* @exception NullPointerException if the passed array is null
* @exception IndexOutOfBoundsException if of or
* cb is negative, or of+cb is
* greater than the length of the ab
* @exception EOFException if the stream is exhausted before the number
* of bytes indicated by the array length could be read
* @exception IOException if an I/O error occurs
*/
public void readFully(byte ab[], int of, int cb)
throws IOException
{
byte[] abActual = m_in.readByteArray(nextIndex());
int cbActual = abActual.length;
if (cbActual != cb)
{
throw new IOException("read " + cbActual
+ " bytes, but buffer was " + cb + " bytes long");
}
System.arraycopy(abActual, 0, ab, of, cbActual);
}
/**
* Skips over up to the specified number of bytes of data. The number of
* bytes actually skipped over may be fewer than the number specified to
* skip, and may even be zero; this can be caused by an end-of-file
* condition, but can also occur even when there is data remaining to
* be read. As a result, the caller should check the return value from
* this method, which indicates the actual number of bytes skipped.
*
* @param cb the maximum number of bytes to skip over
*
* @return the actual number of bytes that were skipped over
*
* @exception IOException if an I/O error occurs
*/
public int skipBytes(int cb)
throws IOException
{
return (int) skip(cb);
}
/**
* Read a boolean value.
*
* This method is the counterpart for the
* {@link java.io.DataOutput#writeBoolean} method.
*
* @return either true or false
*
* @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
*/
public boolean readBoolean()
throws IOException
{
return m_in.readBoolean(nextIndex());
}
/**
* Read a byte value.
*
* This method is the counterpart for the
* {@link java.io.DataOutput#writeByte} method.
*
* @return a byte value
*
* @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
*/
public byte readByte()
throws IOException
{
return m_in.readByte(nextIndex());
}
/**
* Read an unsigned byte value.
*
* This method is the counterpart for the
* {@link java.io.DataOutput#writeByte} method when it is used with
* unsigned 8-bit values.
*
* @return an int value in the range 0x00 to 0xFF
*
* @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
*/
public int readUnsignedByte()
throws IOException
{
return m_in.readByte(nextIndex()) & 0xFF;
}
/**
* Read a short value.
*
* This method is the counterpart for the
* {@link java.io.DataOutput#writeShort} method.
*
* @return a short value
*
* @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
*/
public short readShort()
throws IOException
{
return m_in.readShort(nextIndex());
}
/**
* Read an unsigned short value.
*
* This method is the counterpart for the
* {@link java.io.DataOutput#writeShort} method when it is used with
* unsigned 16-bit values.
*
* @return an int value in the range of 0x0000 to 0xFFFF
*
* @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
*/
public int readUnsignedShort()
throws IOException
{
return m_in.readShort(nextIndex()) & 0xFFFF;
}
/**
* Read a char value.
*
* This method is the counterpart for the
* {@link java.io.DataOutput#writeChar} method.
*
* @return a char value
*
* @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
*/
public char readChar()
throws IOException
{
return m_in.readChar(nextIndex());
}
/**
* Read an int value.
*
* This method is the counterpart for the
* {@link java.io.DataOutput#writeInt} method.
*
* @return an int value
*
* @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
*/
public int readInt()
throws IOException
{
return m_in.readInt(nextIndex());
}
/**
* Read a long value.
*
* This method is the counterpart for the
* {@link java.io.DataOutput#writeLong} method.
*
* @return a long value
*
* @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
*/
public long readLong()
throws IOException
{
return m_in.readLong(nextIndex());
}
/**
* Read a float value.
*
* This method is the counterpart for the
* {@link java.io.DataOutput#writeFloat} method.
*
* @return a float value
*
* @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
*/
public float readFloat()
throws IOException
{
return m_in.readFloat(nextIndex());
}
/**
* Read a double value.
*
* This method is the counterpart for the
* {@link java.io.DataOutput#writeDouble} method.
*
* @return a double value
*
* @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
*/
public double readDouble()
throws IOException
{
return m_in.readDouble(nextIndex());
}
/**
* Reads the next "line" of text.
*
* This method does not have a counterpart in the
* {@link java.io.DataOutput} interface. Furthermore, this method is
* defined as operating on bytes and not on characters, and thus it should
* be selected for use only after careful consideration, as if it were
* deprecated.
*
* @return a line of text as a String
* @exception IOException if an I/O error occurs.
*/
public String readLine()
throws IOException
{
throw new UnsupportedOperationException();
}
/**
* Reads a String value.
*
* This method is the counterpart for the
* {@link java.io.DataOutput#writeUTF} method.
*
* @return a String value
*
* @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
*/
public String readUTF()
throws IOException
{
return m_in.readString(nextIndex());
}
// ----- ObjectInput interface ------------------------------------------
/**
* Read and return an object.
*
* @return the object read from the stream
*
* @exception IOException if an I/O error occurs
*/
public Object readObject()
throws IOException
{
return m_in.readObject(nextIndex());
}
// ----- internal methods -----------------------------------------------
/**
* Obtain the underlying PofReader.
*
* @return the PofReader
*/
public PofReader getPofReader()
{
return m_in;
}
/**
* Determine the next property index to read from.
*
* @return the next property index to read from
*/
public int nextIndex()
{
return m_nProp++;
}
// ----- data members ---------------------------------------------------
/**
* The underlying PofReader.
*/
private PofReader m_in;
/**
* The next property index.
*/
private int m_nProp;
}