A wrapper around another input stream that performs a buffered read, where it reads more data than it needs in order to reduce the number of io operations on the input stream. More...

#include <src/main/decaf/io/BufferedInputStream.h>

Inheritance diagram for decaf::io::BufferedInputStream:

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Public Member Functions

BufferedInputStream (InputStream *stream, bool own=false)

Constructor.

BufferedInputStream (InputStream *stream, int bufferSize, bool own=false)

Constructor.

virtual ~BufferedInputStream ()

virtual int available () const

Indicates the number of bytes available.The default implementation of this methods returns 0. Classes that override this method may return the total number of bytes that are currently available for reading and others may simply return a value of one indicating that there is some data avaiable. The caller should view the result of this method as an absolute.The default implementation of this method returns zero.

Returns:: the number of bytes available on this input stream.

Exceptions:

IOException if an I/O error occurs.

virtual void close ()

Closes the InputStream freeing any resources that might have been acquired during the lifetime of this stream.The default implementation of this method does nothing.

Exceptions:

IOException if an I/O error occurs while closing the InputStream.

virtual long long skip (long long num)

Skips over and discards n bytes of data from this input stream.The skip method may, for a variety of reasons, end up skipping over some smaller number of bytes, possibly 0. This may result from any of a number of conditions; reaching end of file before n bytes have been skipped is only one possibility. The actual number of bytes skipped is returned.The skip method of InputStream creates a byte array and then repeatedly reads into it until num bytes have been read or the end of the stream has been reached. Subclasses are encouraged to provide a more efficient implementation of this method.

Parameters:

num	The number of bytes to skip.

Returns:: total bytes skipped

Exceptions:

IOException	if an I/O error occurs.
UnsupportedOperationException	if the concrete stream class does not support skipping bytes.

virtual void mark (int readLimit)

Marks the current position in the stream A subsequent call to the reset method repositions this stream at the last marked position so that subsequent reads re-read the same bytes.If a stream instance reports that marks are supported then the stream will ensure that the same bytes can be read again after the reset method is called so long the readLimit is not reached.Calling mark on a closed stream instance should have no effect.The default implementation of this method does nothing.

Parameters:

readLimit The max bytes read before marked position is invalid.

virtual void reset ()

Repositions this stream to the position at the time the mark method was last called on this input stream.If the method markSupported returns true, then: * If the method mark has not been called since the stream was created, or the number of bytes read from the stream since mark was last called is larger than the argument to mark at that last call, then an IOException might be thrown. * If such an IOException is not thrown, then the stream is reset to a state such that all the bytes read since the most recent call to mark (or since the start of the file, if mark has not been called) will be resupplied to subsequent callers of the read method, followed by any bytes that otherwise would have been the next input data as of the time of the call to reset.If the method markSupported returns false, then: * The call to reset may throw an IOException. * If an IOException is not thrown, then the stream is reset to a fixed state that depends on the particular type of the input stream and how it was created. The bytes that will be supplied to subsequent callers of the read method depend on the particular type of the input stream.The default implementation of this method throws an IOException.

Exceptions:

IOException if an I/O error occurs.

virtual bool markSupported () const

Determines if this input stream supports the mark and reset methods.Whether or not mark and reset are supported is an invariant property of a particular input stream instance.The default implementation of this method returns false.

Returns:: true if this stream instance supports marks

Protected Member Functions

virtual int doReadByte ()

virtual int doReadArrayBounded (unsigned char *buffer, int size, int offset, int length)

Detailed Description

A wrapper around another input stream that performs a buffered read, where it reads more data than it needs in order to reduce the number of io operations on the input stream.

Constructor & Destructor Documentation

decaf::io::BufferedInputStream::BufferedInputStream	(	InputStream *	stream,
		bool	own = `false`
	)

Constructor.

Parameters:

stream	The target input stream to buffer.
own	Indicates if we own the stream object, defaults to false.

decaf::io::BufferedInputStream::BufferedInputStream	(	InputStream *	stream,
		int	bufferSize,
		bool	own = `false`
	)

Constructor.

Parameters:

stream	The target input stream to buffer.
bufferSize	The size in bytes to allocate for the internal buffer.
own	Indicates if we own the stream object, defaults to false.

Exceptions:

IllegalArgumentException is the size is zero or negative.

virtual decaf::io::BufferedInputStream::~BufferedInputStream ( ) [virtual]

Member Function Documentation

virtual int decaf::io::BufferedInputStream::available ( ) const [virtual]

Indicates the number of bytes available.The default implementation of this methods returns 0. Classes that override this method may return the total number of bytes that are currently available for reading and others may simply return a value of one indicating that there is some data avaiable. The caller should view the result of this method as an absolute.The default implementation of this method returns zero.

Returns:: the number of bytes available on this input stream.

Exceptions:

IOException if an I/O error occurs.

Reimplemented from decaf::io::FilterInputStream.

virtual void decaf::io::BufferedInputStream::close ( ) [virtual]

Closes the InputStream freeing any resources that might have been acquired during the lifetime of this stream.The default implementation of this method does nothing.

Exceptions:

IOException if an I/O error occurs while closing the InputStream.

Reimplemented from decaf::io::FilterInputStream.

virtual int decaf::io::BufferedInputStream::doReadArrayBounded	(	unsigned char *	buffer,
		int	size,
		int	offset,
		int	length
	)		`[protected, virtual]`

Reimplemented from decaf::io::FilterInputStream.

virtual int decaf::io::BufferedInputStream::doReadByte ( ) [protected, virtual]

Reimplemented from decaf::io::FilterInputStream.

virtual void decaf::io::BufferedInputStream::mark ( int readLimit ) [virtual]

Marks the current position in the stream A subsequent call to the reset method repositions this stream at the last marked position so that subsequent reads re-read the same bytes.If a stream instance reports that marks are supported then the stream will ensure that the same bytes can be read again after the reset method is called so long the readLimit is not reached.Calling mark on a closed stream instance should have no effect.The default implementation of this method does nothing.

Parameters:

readLimit The max bytes read before marked position is invalid.

Reimplemented from decaf::io::FilterInputStream.

virtual bool decaf::io::BufferedInputStream::markSupported ( ) const [inline, virtual]

Determines if this input stream supports the mark and reset methods.Whether or not mark and reset are supported is an invariant property of a particular input stream instance.The default implementation of this method returns false.

Returns:: true if this stream instance supports marks

Reimplemented from decaf::io::FilterInputStream.

virtual void decaf::io::BufferedInputStream::reset ( ) [virtual]

Repositions this stream to the position at the time the mark method was last called on this input stream.If the method markSupported returns true, then: * If the method mark has not been called since the stream was created, or the number of bytes read from the stream since mark was last called is larger than the argument to mark at that last call, then an IOException might be thrown. * If such an IOException is not thrown, then the stream is reset to a state such that all the bytes read since the most recent call to mark (or since the start of the file, if mark has not been called) will be resupplied to subsequent callers of the read method, followed by any bytes that otherwise would have been the next input data as of the time of the call to reset.If the method markSupported returns false, then: * The call to reset may throw an IOException. * If an IOException is not thrown, then the stream is reset to a fixed state that depends on the particular type of the input stream and how it was created. The bytes that will be supplied to subsequent callers of the read method depend on the particular type of the input stream.The default implementation of this method throws an IOException.

Exceptions:

IOException if an I/O error occurs.

Reimplemented from decaf::io::FilterInputStream.

virtual long long decaf::io::BufferedInputStream::skip ( long long num ) [virtual]

Skips over and discards n bytes of data from this input stream.The skip method may, for a variety of reasons, end up skipping over some smaller number of bytes, possibly 0. This may result from any of a number of conditions; reaching end of file before n bytes have been skipped is only one possibility. The actual number of bytes skipped is returned.The skip method of InputStream creates a byte array and then repeatedly reads into it until num bytes have been read or the end of the stream has been reached. Subclasses are encouraged to provide a more efficient implementation of this method.

Parameters:

num	The number of bytes to skip.

Returns:: total bytes skipped

Exceptions:

IOException	if an I/O error occurs.
UnsupportedOperationException	if the concrete stream class does not support skipping bytes.

Reimplemented from decaf::io::FilterInputStream.

The documentation for this class was generated from the following file:

src/main/decaf/io/BufferedInputStream.h

decaf::io::BufferedInputStream Class Reference

Public Member Functions

Protected Member Functions

Detailed Description

Constructor & Destructor Documentation

Member Function Documentation