C# Class CSJ2K.j2k.io.BufferedRandomAccessFile

This class defines a Buffered Random Access File. It implements the BinaryDataInput and BinaryDataOutput interfaces so that binary data input/output can be performed. This class is abstract since no assumption is done about the byte ordering type (little Endian, big Endian). So subclasses will have to implement methods like readShort(), writeShort(), readFloat(), ...

BufferedRandomAccessFile (BRAF for short) is a RandomAccessFile containing an extra buffer. When the BRAF is accessed, it checks if the requested part of the file is in the buffer or not. If that is the case, the read/write is done on the buffer. If not, the file is uppdated to reflect the current status of the buffer and the file is then accessed for a new buffer containing the requested byte/bit.

Inheritance: RandomAccessIO, EndianType

Show file Open project: cureos/csj2k Class Usage Examples

Protected Properties

Property	Type	Description
byteBuffer	byte[]
byteBufferChanged	bool
byte_Ordering	int
isEOFInBuffer	bool
maxByte	int
offset	int
position	int

Public Methods

Method	Description
ToString ( ) : System.String	Returns a string of information about the file
close ( ) : void	Closes the buffered random access file
flush ( ) : void	Any data that has been buffered must be written (including buffering at the bit level), and the stream should be realigned at the byte level.
length ( ) : int	Returns the current length of the stream, in bytes, taking into account any buffering.
read ( ) : byte
readByte ( ) : byte	Reads an unsigned byte of data from the stream. Prior to reading, the stream is realigned at the byte level.
readDouble ( ) : double
readFloat ( ) : float
readFully ( byte b, int off, int len ) : void	Reads up to len bytes of data from this file into an array of bytes. This method reads repeatedly from the stream until all the bytes are read. This method blocks until all the bytes are read, the end of the stream is detected, or an exception is thrown.
readInt ( ) : int
readLong ( ) : long
readShort ( ) : short
readUnsignedByte ( ) : byte
readUnsignedInt ( ) : long
readUnsignedShort ( ) : int
seek ( int off ) : void	Moves the current position to the given offset at which the next read or write occurs. The offset is measured from the beginning of the stream.
skipBytes ( int n ) : int	Skips `n` bytes from the input. Prior to skipping, the input should be realigned at the byte level.
write ( byte b ) : void	Writes a byte to the stream. Prior to writing, the stream is realigned at the byte level.
write ( byte b, int offset, int length ) : void	Writes aan array of bytes to the stream. Prior to writing, the stream is realigned at the byte level.
write ( int b ) : void	Writes a byte to the stream. Prior to writing, the stream is realigned at the byte level.
writeByte ( int v ) : void	Writes the byte value of `v` (i.e., 8 least significant bits) to the output. Prior to writing, the output should be realigned at the byte level. Signed or unsigned data can be written. To write a signed value just pass the `byte` value as an argument. To write unsigned data pass the `int` value as an argument (it will be automatically casted, and only the 8 least significant bits will be written).
writeDouble ( double param1 ) : void
writeFloat ( float param1 ) : void
writeInt ( int param1 ) : void
writeLong ( long param1 ) : void
writeShort ( int param1 ) : void

Protected Methods

Method	Description
BufferedRandomAccessFile ( IFileInfo file, System mode ) : System	Constructor. Uses the default value for the byte-buffer size (512 bytes).
BufferedRandomAccessFile ( IFileInfo file, System mode, int bufferSize ) : System	Constructor. Always needs a size for the buffer.
BufferedRandomAccessFile ( System.Stream stream, bool isReadOnly ) : System	Constructor. Uses the default value for the byte-buffer size (512 bytes).
BufferedRandomAccessFile ( System.Stream stream, bool isReadOnly, int bufferSize ) : System	Constructor. Always needs a size for the buffer.
BufferedRandomAccessFile ( System name, System mode ) : System	Constructor. Uses the default value for the byte-buffer size (512 bytes).
BufferedRandomAccessFile ( System name, System mode, int bufferSize ) : System	Constructor. Always needs a size for the buffer.
readNewBuffer ( int off ) : void	Reads a new buffer from the file. If there has been any changes made since the buffer was read, the buffer is first written to the file.

Method Details

BufferedRandomAccessFile() protected method

Constructor. Uses the default value for the byte-buffer size (512 bytes).

If an I/O error ocurred. /// ///

protected BufferedRandomAccessFile ( IFileInfo file, System mode ) : System
file	IFileInfo	The file associated with the buffer /// ///
mode	System	"r" for read, "rw" or "rw+" for read and write mode /// ("rw+" opens the file for update whereas "rw" removes /// it before. So the 2 modes are different only if the /// file already exists). /// ///
return	System

BufferedRandomAccessFile() protected method

Constructor. Always needs a size for the buffer.

If an I/O error ocurred. /// ///

protected BufferedRandomAccessFile ( IFileInfo file, System mode, int bufferSize ) : System
file	IFileInfo	The file associated with the buffer /// ///
mode	System	"r" for read, "rw" or "rw+" for read and write mode ("rw+" /// opens the file for update whereas "rw" removes it /// before. So the 2 modes are different only if the file /// already exists). /// ///
bufferSize	int	The number of bytes to buffer /// ///
return	System

BufferedRandomAccessFile() protected method

Constructor. Uses the default value for the byte-buffer size (512 bytes).

If an I/O error ocurred. /// ///

protected BufferedRandomAccessFile ( System.Stream stream, bool isReadOnly ) : System
stream	System.Stream	The stream associated with the buffer /// ///
isReadOnly	bool	Indicates whether file is read-only or not.
return	System

BufferedRandomAccessFile() protected method

Constructor. Always needs a size for the buffer.

If an I/O error ocurred. /// ///

protected BufferedRandomAccessFile ( System.Stream stream, bool isReadOnly, int bufferSize ) : System
stream	System.Stream	The stream associated with the buffer /// ///
isReadOnly	bool	Indicates whether file is read-only or not.
bufferSize	int	The number of bytes to buffer /// ///
return	System

BufferedRandomAccessFile() protected method

Constructor. Uses the default value for the byte-buffer size (512 bytes).

If an I/O error ocurred. /// ///

protected BufferedRandomAccessFile ( System name, System mode ) : System
name	System	The name of the file associated with the buffer /// ///
mode	System	"r" for read, "rw" or "rw+" for read and write mode /// ("rw+" opens the file for update whereas "rw" removes /// it before. So the 2 modes are different only if the /// file already exists). /// ///
return	System

BufferedRandomAccessFile() protected method

Constructor. Always needs a size for the buffer.

If an I/O error ocurred. /// ///

protected BufferedRandomAccessFile ( System name, System mode, int bufferSize ) : System
name	System	The name of the file associated with the buffer /// ///
mode	System	"r" for read, "rw" or "rw+" for read and write mode /// ("rw+" opens the file for update whereas "rw" removes /// it before. So the 2 modes are different only if the /// file already exists). /// ///
bufferSize	int	The number of bytes to buffer /// ///
return	System

ToString() public method

Returns a string of information about the file

public ToString ( ) : System.String
return	System.String

close() public method

Closes the buffered random access file

If an I/O error ocurred. /// ///

public close ( ) : void
return	void

flush() public method

Any data that has been buffered must be written (including buffering at the bit level), and the stream should be realigned at the byte level.

If an I/O error ocurred. /// ///

public flush ( ) : void
return	void

length() public method

Returns the current length of the stream, in bytes, taking into account any buffering.

If an I/O error ocurred. /// ///

public length ( ) : int
return	int

read() public method

public read ( ) : byte
return	byte

readByte() public method

Reads an unsigned byte of data from the stream. Prior to reading, the stream is realigned at the byte level.

If an I/O error ocurred. /// /// If the end of file was reached /// ///

public readByte ( ) : byte
return	byte

readDouble() public abstract method

public abstract readDouble ( ) : double
return	double

readFloat() public abstract method

public abstract readFloat ( ) : float
return	float

readFully() public method

Reads up to len bytes of data from this file into an array of bytes. This method reads repeatedly from the stream until all the bytes are read. This method blocks until all the bytes are read, the end of the stream is detected, or an exception is thrown.

If the end-of file was reached before /// getting all the necessary data. /// /// If an I/O error ocurred. /// ///

public readFully ( byte b, int off, int len ) : void
b	byte	The buffer into which the data is to be read. It must be long /// enough. /// ///
off	int	The index in 'b' where to place the first byte read. /// ///
len	int	The number of bytes to read. /// ///
return	void

readInt() public abstract method

public abstract readInt ( ) : int
return	int

readLong() public abstract method

public abstract readLong ( ) : long
return	long

readNewBuffer() protected method

Reads a new buffer from the file. If there has been any changes made since the buffer was read, the buffer is first written to the file.

If an I/O error ocurred. /// ///

protected readNewBuffer ( int off ) : void
off	int	The offset where to move to. /// ///
return	void

readShort() public abstract method

public abstract readShort ( ) : short
return	short

readUnsignedByte() public method

public readUnsignedByte ( ) : byte
return	byte

readUnsignedInt() public abstract method

public abstract readUnsignedInt ( ) : long
return	long

readUnsignedShort() public abstract method

public abstract readUnsignedShort ( ) : int
return	int

seek() public method

Moves the current position to the given offset at which the next read or write occurs. The offset is measured from the beginning of the stream.

If in read-only and seeking beyond EOF. /// /// If an I/O error ocurred. /// ///

public seek ( int off ) : void
off	int	The offset where to move to. /// ///
return	void

skipBytes() public method

Skips n bytes from the input. Prior to skipping, the input should be realigned at the byte level.

If the end-of file was reached before /// all the bytes could be skipped. /// /// If an I/O error ocurred. /// ///

public skipBytes ( int n ) : int
n	int	The number of bytes to skip /// ///
return	int

write() public method

Writes a byte to the stream. Prior to writing, the stream is realigned at the byte level.

If an I/O error ocurred. /// ///

public write ( byte b ) : void
b	byte	The byte to write. /// ///
return	void

write() public method

Writes aan array of bytes to the stream. Prior to writing, the stream is realigned at the byte level.

If an I/O error ocurred. /// ///

public write ( byte b, int offset, int length ) : void
b	byte	The array of bytes to write. /// ///
offset	int	The first byte in b to write /// ///
length	int	The number of bytes from b to write /// ///
return	void

write() public method

Writes a byte to the stream. Prior to writing, the stream is realigned at the byte level.

If an I/O error ocurred. /// ///

public write ( int b ) : void
b	int	The byte to write. The lower 8 bits of `b` are /// written. /// ///
return	void

writeByte() public method

Writes the byte value of v (i.e., 8 least significant bits) to the output. Prior to writing, the output should be realigned at the byte level.

Signed or unsigned data can be written. To write a signed value just pass the byte value as an argument. To write unsigned data pass the int value as an argument (it will be automatically casted, and only the 8 least significant bits will be written).

If an I/O error ocurred. /// ///

public writeByte ( int v ) : void
v	int	The value to write to the output /// ///
return	void

writeDouble() public abstract method

public abstract writeDouble ( double param1 ) : void
param1	double
return	void

writeFloat() public abstract method

public abstract writeFloat ( float param1 ) : void
param1	float
return	void

writeInt() public abstract method

public abstract writeInt ( int param1 ) : void
param1	int
return	void

writeLong() public abstract method

public abstract writeLong ( long param1 ) : void
param1	long
return	void

writeShort() public abstract method

public abstract writeShort ( int param1 ) : void
param1	int
return	void

Property Details

byteBuffer protected property

Buffer of bytes containing the part of the file that is currently being accessed

protected byte[] byteBuffer
return	byte[]

byteBufferChanged protected property

Boolean keeping track of whether the byte buffer has been changed since it was read.

protected bool byteBufferChanged
return	bool

byte_Ordering protected property

protected int byte_Ordering
return	int

isEOFInBuffer protected property

Whether the end of the file is in the current buffer or not

protected bool isEOFInBuffer
return	bool

maxByte protected property

The maximum number of bytes that can be read from the buffer

protected int maxByte
return	int

offset protected property

The current offset of the buffer (which will differ from the offset of the file)

protected int offset
return	int

position protected property

The current position in the byte-buffer

protected int position
return	int