Skip navigation links

com.tangosol.io
Class WrapperBufferInput

java.lang.Object
com.tangosol.util.Base
com.tangosol.io.WrapperBufferInput

All Implemented Interfaces:

InputStreaming, ReadBuffer.BufferInput, java.io.DataInput

public class WrapperBufferInput

extends Base

implements ReadBuffer.BufferInput

This is an imitation BufferInput implementation that provides the BufferInput interface by delegating to an object that implements the DataInput interface. Primarily, this is intended as a base class for building specific-purpose DataInput wrappers.

Author:

jh 2007.11.17

Constructor Summary

WrapperBufferInput(java.io.DataInput in)
Construct a WrapperBufferInput that will read from the specified object implementing the DataInput interface.

WrapperBufferInput(java.io.DataInput in, ReadBuffer rb)
Construct a WrapperBufferInput that will read from the specified object implementing the DataInput interface and return the optional ReadBuffer as its underlying source.

Method Summary

int	available() 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.
void	close() Close the InputStream and release any system resources associated with it.
ReadBuffer	getBuffer() Get the ReadBuffer object that this BufferInput is reading from.
java.io.DataInput	getDataInput() Obtain the underlying object providing the DataInput interface that this object is delegating to.
int	getOffset() Determine the current offset of this BufferInput within the underlying ReadBuffer.
void	mark(int cbReadLimit) Marks the current read position in the InputStream in order to support the stream to be later "rewound" (using the InputStreaming.reset() method) to the current position.
boolean	markSupported() Determine if this InputStream supports the ReadBuffer.BufferInput.mark(int) and InputStreaming.reset() methods.
int	read() Read the next byte of data from the InputStream.
int	read(byte[] ab) Read some number of bytes from the input stream and store them into the passed array ab.
int	read(byte[] ab, int of, int cb) Read up to cb bytes from the input stream and store them into the passed array ab starting at offset of.
boolean	readBoolean() Read a boolean value.
ReadBuffer	readBuffer(int cb) Read cb bytes and return them as a ReadBuffer object.
byte	readByte() Read a byte value.
char	readChar() Read a char value.
double	readDouble() Read a double value.
float	readFloat() Read a float value.
void	readFully(byte[] ab) Read ab.length bytes and store them in ab.
void	readFully(byte[] ab, int of, int cb) Read cb bytes and store them in ab starting at offset of.
int	readInt() Read an int value.
java.lang.String	readLine() Reads the next "line" of text.
long	readLong() Read a long value.
int	readPackedInt() Read an int value using a variable-length storage format as described by WriteBuffer.BufferOutput.writePackedInt(int).
long	readPackedLong() Read a long value using a variable-length storage format as described by WriteBuffer.BufferOutput.writePackedLong(long).
java.lang.String	readSafeUTF() Read a variable-length encoded UTF packed String.
short	readShort() Read a short value.
int	readUnsignedByte() Read an unsigned byte value.
int	readUnsignedShort() Read an unsigned short value.
java.lang.String	readUTF() Reads a String value.
void	reset() Rewind this stream to the position at the time the InputStreaming.mark(int) method was last called on this InputStream.
void	setOffset(int of) Specify the offset of the next byte to read from the underlying ReadBuffer.
long	skip(long cb) Skips over up to the specified number of bytes of data from this InputStream.
int	skipBytes(int cb) Skips over up to the specified number of bytes of data.

Constructor Detail

WrapperBufferInput

public WrapperBufferInput(java.io.DataInput in)

Construct a WrapperBufferInput that will read from the specified object implementing the DataInput interface.

Parameters:

in - an object implementing DataInput to read from

WrapperBufferInput

public WrapperBufferInput(java.io.DataInput in,
                          ReadBuffer rb)

Construct a WrapperBufferInput that will read from the specified object implementing the DataInput interface and return the optional ReadBuffer as its underlying source.

Parameters:

in - an object implementing DataInput to read from

rb - an optional object implementing ReadBuffer

Method Detail

read

public int read()
         throws java.io.IOException

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.

Specified by:

read in interface InputStreaming

Returns:

the next byte of data, or -1 if the end of the stream has been reached

Throws:

java.io.IOException - if an I/O error occurs

read

public int read(byte[] ab)
         throws java.io.IOException

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.

Specified by:

read in interface InputStreaming

Parameters:

ab - the array to store the bytes which are read from the stream

Returns:

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

Throws:

java.io.IOException - if an I/O error occurs

read

public int read(byte[] ab,
                int of,
                int cb)
         throws java.io.IOException

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.

Specified by:

read in interface InputStreaming

Parameters:

ab - the array to store the bytes which are read from the stream

of - the offset into the array that the read bytes will be stored

cb - the maximum number of bytes to read

Returns:

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

Throws:

java.io.IOException - if an I/O error occurs

skip

public long skip(long cb)
          throws java.io.IOException

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.

Specified by:

skip in interface InputStreaming

Parameters:

cb - the maximum number of bytes to skip over

Returns:

the actual number of bytes that were skipped over

Throws:

java.io.IOException - if an I/O error occurs

available

public int available()
              throws java.io.IOException

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.

BufferInput implementations must implement this method to return the extent of the buffer that has not yet been read; in other words, the entire un-read portion of the buffer must be available.

Specified by:

available in interface InputStreaming

Specified by:

available in interface ReadBuffer.BufferInput

Returns:

the number of bytes that can be read from this InputStream without blocking

Throws:

java.io.IOException - if an I/O error occurs

close

public void close()
           throws java.io.IOException

Close the InputStream and release any system resources associated with it.

BufferInput implementations do not pass this call down onto an underlying stream, if any.

Specified by:

close in interface InputStreaming

Specified by:

close in interface ReadBuffer.BufferInput

Throws:

java.io.IOException - if an I/O error occurs

mark

public void mark(int cbReadLimit)

Marks the current read position in the InputStream in order to support the stream to be later "rewound" (using the InputStreaming.reset() method) to the current position. The caller passes in the maximum number of bytes that it expects to read before calling the InputStreaming.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.

BufferInput implementations ignore the cbReadLimit; they must support an unlimited read limit, since they appear to the user as an input stream on top of a fully realized read buffer.

Specified by:

mark in interface InputStreaming

Specified by:

mark in interface ReadBuffer.BufferInput

Parameters:

cbReadLimit - the maximum number of bytes that caller expects the InputStream to be able to read before the mark position becomes invalid

reset

public void reset()
           throws java.io.IOException

Rewind this stream to the position at the time the InputStreaming.mark(int) method was last called on this InputStream. If the InputStream cannot fulfill this contract, it should throw an IOException.

Specified by:

reset in interface InputStreaming

Throws:

java.io.IOException - if an I/O error occurs, for example if this has not been marked or if the mark has been invalidated

markSupported

public boolean markSupported()

Determine if this InputStream supports the ReadBuffer.BufferInput.mark(int) and InputStreaming.reset() methods.

BufferInput implementations must support the ReadBuffer.BufferInput.mark(int) and InputStreaming.reset() methods, so this method always returns true.

Specified by:

markSupported in interface InputStreaming

Specified by:

markSupported in interface ReadBuffer.BufferInput

Returns:

true if this InputStream supports the mark and reset method; false otherwise

readFully

public void readFully(byte[] ab)
               throws java.io.IOException

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.

Specified by:

readFully in interface ReadBuffer.BufferInput

Specified by:

readFully in interface java.io.DataInput

Parameters:

ab - the array to store the bytes which are read from the stream

Throws:

java.io.EOFException - if the stream is exhausted before the number of bytes indicated by the array length could be read

java.io.IOException - if an I/O error occurs

readFully

public void readFully(byte[] ab,
                      int of,
                      int cb)
               throws java.io.IOException

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.

Specified by:

readFully in interface ReadBuffer.BufferInput

Specified by:

readFully in interface java.io.DataInput

Parameters:

ab - the array to store the bytes which are read from the stream

of - the offset into the array that the read bytes will be stored

cb - the maximum number of bytes to read

Throws:

java.io.EOFException - if the stream is exhausted before the number of bytes indicated by the array length could be read

java.io.IOException - if an I/O error occurs

skipBytes

public int skipBytes(int cb)
              throws java.io.IOException

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.

Specified by:

skipBytes in interface ReadBuffer.BufferInput

Specified by:

skipBytes in interface java.io.DataInput

Parameters:

cb - the maximum number of bytes to skip over

Returns:

the actual number of bytes that were skipped over

Throws:

java.io.IOException - if an I/O error occurs

readBoolean

public boolean readBoolean()
                    throws java.io.IOException

Read a boolean value.

This method is the counterpart for the DataOutput.writeBoolean(boolean) method.

Specified by:

readBoolean in interface ReadBuffer.BufferInput

Specified by:

readBoolean in interface java.io.DataInput

Returns:

either true or false

Throws:

java.io.EOFException - if the value could not be read because no more data remains to be read

java.io.IOException - if an I/O error occurs

readByte

public byte readByte()
              throws java.io.IOException

Read a byte value.

This method is the counterpart for the DataOutput.writeByte(int) method.

Specified by:

readByte in interface ReadBuffer.BufferInput

Specified by:

readByte in interface java.io.DataInput

Returns:

a byte value

Throws:

java.io.EOFException - if the value could not be read because no more data remains to be read

java.io.IOException - if an I/O error occurs

readUnsignedByte

public int readUnsignedByte()
                     throws java.io.IOException

Read an unsigned byte value.

This method is the counterpart for the DataOutput.writeByte(int) method when it is used with unsigned 8-bit values.

Specified by:

readUnsignedByte in interface ReadBuffer.BufferInput

Specified by:

readUnsignedByte in interface java.io.DataInput

Returns:

an int value in the range 0x00 to 0xFF

Throws:

java.io.EOFException - if the value could not be read because no more data remains to be read

java.io.IOException - if an I/O error occurs

readShort

public short readShort()
                throws java.io.IOException

Read a short value.

This method is the counterpart for the DataOutput.writeShort(int) method.

Specified by:

readShort in interface ReadBuffer.BufferInput

Specified by:

readShort in interface java.io.DataInput

Returns:

a short value

Throws:

java.io.EOFException - if the value could not be read because no more data remains to be read

java.io.IOException - if an I/O error occurs

readUnsignedShort

public int readUnsignedShort()
                      throws java.io.IOException

Read an unsigned short value.

This method is the counterpart for the DataOutput.writeShort(int) method when it is used with unsigned 16-bit values.

Specified by:

readUnsignedShort in interface ReadBuffer.BufferInput

Specified by:

readUnsignedShort in interface java.io.DataInput

Returns:

an int value in the range of 0x0000 to 0xFFFF

Throws:

java.io.EOFException - if the value could not be read because no more data remains to be read

java.io.IOException - if an I/O error occurs

readChar

public char readChar()
              throws java.io.IOException

Read a char value.

This method is the counterpart for the DataOutput.writeChar(int) method.

Specified by:

readChar in interface ReadBuffer.BufferInput

Specified by:

readChar in interface java.io.DataInput

Returns:

a char value

Throws:

java.io.EOFException - if the value could not be read because no more data remains to be read

java.io.IOException - if an I/O error occurs

readInt

public int readInt()
            throws java.io.IOException

Read an int value.

This method is the counterpart for the DataOutput.writeInt(int) method.

Specified by:

readInt in interface ReadBuffer.BufferInput

Specified by:

readInt in interface java.io.DataInput

Returns:

an int value

Throws:

java.io.EOFException - if the value could not be read because no more data remains to be read

java.io.IOException - if an I/O error occurs

readLong

public long readLong()
              throws java.io.IOException

Read a long value.

This method is the counterpart for the DataOutput.writeLong(long) method.

Specified by:

readLong in interface ReadBuffer.BufferInput

Specified by:

readLong in interface java.io.DataInput

Returns:

a long value

Throws:

java.io.EOFException - if the value could not be read because no more data remains to be read

java.io.IOException - if an I/O error occurs

readFloat

public float readFloat()
                throws java.io.IOException

Read a float value.

This method is the counterpart for the DataOutput.writeFloat(float) method.

Specified by:

readFloat in interface ReadBuffer.BufferInput

Specified by:

readFloat in interface java.io.DataInput

Returns:

a float value

Throws:

java.io.EOFException - if the value could not be read because no more data remains to be read

java.io.IOException - if an I/O error occurs

readDouble

public double readDouble()
                  throws java.io.IOException

Read a double value.

This method is the counterpart for the DataOutput.writeDouble(double) method.

Specified by:

readDouble in interface ReadBuffer.BufferInput

Specified by:

readDouble in interface java.io.DataInput

Returns:

a double value

Throws:

java.io.EOFException - if the value could not be read because no more data remains to be read

java.io.IOException - if an I/O error occurs

readLine

public java.lang.String readLine()
                          throws java.io.IOException

Reads the next "line" of text.

This method does not have a counterpart in the 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 (which it has been in java.io.DataInputStream).

Specified by:

readLine in interface ReadBuffer.BufferInput

Specified by:

readLine in interface java.io.DataInput

Returns:

a line of text as a String

Throws:

java.io.IOException - if an I/O error occurs.

readUTF

public java.lang.String readUTF()
                         throws java.io.IOException

Reads a String value.

This method is the counterpart for the DataOutput.writeUTF(java.lang.String) method.

Specified by:

readUTF in interface ReadBuffer.BufferInput

Specified by:

readUTF in interface java.io.DataInput

Returns:

a String value

Throws:

java.io.UTFDataFormatException - if the bytes that were read were not a valid UTF-8 encoded string

java.io.EOFException - if the value could not be read because no more data remains to be read

java.io.IOException - if an I/O error occurs

getBuffer

public ReadBuffer getBuffer()

Get the ReadBuffer object that this BufferInput is reading from.

Specified by:

getBuffer in interface ReadBuffer.BufferInput

Returns:

the underlying ReadBuffer object

readSafeUTF

public java.lang.String readSafeUTF()
                             throws java.io.IOException

Read a variable-length encoded UTF packed String. The major differences between this implementation and DataInput is that this supports null String values and is not limited to 64KB UTF-encoded values.

Specified by:

readSafeUTF in interface ReadBuffer.BufferInput

Returns:

a String value; may be null

Throws:

java.io.IOException - if an I/O error occurs

readPackedInt

public int readPackedInt()
                  throws java.io.IOException

Read an int value using a variable-length storage format as described by WriteBuffer.BufferOutput.writePackedInt(int).

Specified by:

readPackedInt in interface ReadBuffer.BufferInput

Returns:

an int value

Throws:

java.io.IOException - if an I/O error occurs

readPackedLong

public long readPackedLong()
                    throws java.io.IOException

Read a long value using a variable-length storage format as described by WriteBuffer.BufferOutput.writePackedLong(long).

Specified by:

readPackedLong in interface ReadBuffer.BufferInput

Returns:

a long value

Throws:

java.io.IOException - if an I/O error occurs

readBuffer

public ReadBuffer readBuffer(int cb)
                      throws java.io.IOException

Read cb bytes and return them as a ReadBuffer object.

Specified by:

readBuffer in interface ReadBuffer.BufferInput

Parameters:

cb - the number of bytes to read

Returns:

a ReadBuffer object composed of cb bytes read from the BufferInput

Throws:

java.io.EOFException - if the stream is exhausted before the number of bytes indicated could be read

java.io.IOException - if an I/O error occurs

getOffset

public int getOffset()

Determine the current offset of this BufferInput within the underlying ReadBuffer.

Specified by:

getOffset in interface ReadBuffer.BufferInput

Returns:

the offset of the next byte to read from the ReadBuffer

setOffset

public void setOffset(int of)

Specify the offset of the next byte to read from the underlying ReadBuffer.

Specified by:

setOffset in interface ReadBuffer.BufferInput

Parameters:

of - the offset of the next byte to read from the ReadBuffer

getDataInput

public java.io.DataInput getDataInput()

Obtain the underlying object providing the DataInput interface that this object is delegating to.

Returns:

the underlying DataInput

Skip navigation links