org.apache.cassandra.io.util
Class MappedFileDataInput

java.lang.Object
  java.io.InputStream
      org.apache.cassandra.io.util.MappedFileDataInput

All Implemented Interfaces:

java.io.Closeable, java.io.DataInput, FileDataInput

public class MappedFileDataInput
extends java.io.InputStream
implements FileDataInput

Constructor Summary

MappedFileDataInput(java.nio.MappedByteBuffer buffer, java.lang.String filename, long absoluteStartPosition)

MappedFileDataInput(java.nio.MappedByteBuffer buffer, java.lang.String filename, long absoluteStartPosition, int position)

Method Summary

int	bytesPastMark()
long	getAbsolutePosition()
java.lang.String	getPath()
boolean	isEOF()
void	mark()
void	mark(int ignored)
boolean	markSupported()
int	read()
boolean	readBoolean() Reads a boolean from the current position in this file.
byte	readByte() Reads an 8-bit byte from the current position in this file.
char	readChar() Reads a 16-bit character from the current position in this file.
double	readDouble() Reads a 64-bit double from the current position in this file.
float	readFloat() Reads a 32-bit float from the current position in this file.
void	readFully(byte[] buffer) Reads bytes from this file into buffer.
void	readFully(byte[] buffer, int offset, int count) Read bytes from this file into buffer starting at offset offset.
int	readInt() Reads a 32-bit integer from the current position in this file.
java.lang.String	readLine() Reads a line of text form the current position in this file.
long	readLong() Reads a 64-bit long from the current position in this file.
short	readShort() Reads a 16-bit short from the current position in this file.
int	readUnsignedByte() Reads an unsigned 8-bit byte from the current position in this file and returns it as an integer.
int	readUnsignedShort() Reads an unsigned 16-bit short from the current position in this file and returns it as an integer.
java.lang.String	readUTF() Reads a string that is encoded in modified UTF-8 from this file.
void	reset()
int	skipBytes(int n)

Methods inherited from class java.io.InputStream

available, close, read, read, skip

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.io.Closeable

close

Constructor Detail

MappedFileDataInput

public MappedFileDataInput(java.nio.MappedByteBuffer buffer,
                           java.lang.String filename,
                           long absoluteStartPosition)

MappedFileDataInput

public MappedFileDataInput(java.nio.MappedByteBuffer buffer,
                           java.lang.String filename,
                           long absoluteStartPosition,
                           int position)

Method Detail

getAbsolutePosition

public long getAbsolutePosition()

Specified by:

getAbsolutePosition in interface FileDataInput

markSupported

public boolean markSupported()

Overrides:

markSupported in class java.io.InputStream

mark

public void mark(int ignored)

Overrides:

mark in class java.io.InputStream

reset

public void reset()
           throws java.io.IOException

Specified by:

reset in interface FileDataInput

Overrides:

reset in class java.io.InputStream

Throws:

java.io.IOException

mark

public void mark()

Specified by:

mark in interface FileDataInput

bytesPastMark

public int bytesPastMark()

Specified by:

bytesPastMark in interface FileDataInput

isEOF

public boolean isEOF()
              throws java.io.IOException

Specified by:

isEOF in interface FileDataInput

Throws:

java.io.IOException

getPath

public java.lang.String getPath()

Specified by:

getPath in interface FileDataInput

read

public int read()
         throws java.io.IOException

Specified by:

read in class java.io.InputStream

Throws:

java.io.IOException

skipBytes

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

Specified by:

skipBytes in interface java.io.DataInput

Throws:

java.io.IOException

readBoolean

public final boolean readBoolean()
                          throws java.io.IOException

Reads a boolean from the current position in this file. Blocks until one byte has been read, the end of the file is reached or an exception is thrown.

Specified by:

readBoolean in interface java.io.DataInput

Returns:

the next boolean value from this file.

Throws:

java.io.EOFException - if the end of this file is detected.

java.io.IOException - if this file is closed or another I/O error occurs.

readByte

public final byte readByte()
                    throws java.io.IOException

Reads an 8-bit byte from the current position in this file. Blocks until one byte has been read, the end of the file is reached or an exception is thrown.

Specified by:

readByte in interface java.io.DataInput

Returns:

the next signed 8-bit byte value from this file.

Throws:

java.io.EOFException - if the end of this file is detected.

java.io.IOException - if this file is closed or another I/O error occurs.

readChar

public final char readChar()
                    throws java.io.IOException

Reads a 16-bit character from the current position in this file. Blocks until two bytes have been read, the end of the file is reached or an exception is thrown.

Specified by:

readChar in interface java.io.DataInput

Returns:

the next char value from this file.

Throws:

java.io.EOFException - if the end of this file is detected.

java.io.IOException - if this file is closed or another I/O error occurs.

readDouble

public final double readDouble()
                        throws java.io.IOException

Reads a 64-bit double from the current position in this file. Blocks until eight bytes have been read, the end of the file is reached or an exception is thrown.

Specified by:

readDouble in interface java.io.DataInput

Returns:

the next double value from this file.

Throws:

java.io.EOFException - if the end of this file is detected.

java.io.IOException - if this file is closed or another I/O error occurs.

readFloat

public final float readFloat()
                      throws java.io.IOException

Reads a 32-bit float from the current position in this file. Blocks until four bytes have been read, the end of the file is reached or an exception is thrown.

Specified by:

readFloat in interface java.io.DataInput

Returns:

the next float value from this file.

Throws:

java.io.EOFException - if the end of this file is detected.

java.io.IOException - if this file is closed or another I/O error occurs.

readFully

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

Reads bytes from this file into buffer. Blocks until buffer.length number of bytes have been read, the end of the file is reached or an exception is thrown.

Specified by:

readFully in interface java.io.DataInput

Parameters:

buffer - the buffer to read bytes into.

Throws:

java.io.EOFException - if the end of this file is detected.

java.io.IOException - if this file is closed or another I/O error occurs.

java.lang.NullPointerException - if buffer is null.

readFully

public final void readFully(byte[] buffer,
                            int offset,
                            int count)
                     throws java.io.IOException

Read bytes from this file into buffer starting at offset offset. This method blocks until count number of bytes have been read.

Specified by:

readFully in interface java.io.DataInput

Parameters:

buffer - the buffer to read bytes into.

offset - the initial position in buffer to store the bytes read from this file.

count - the maximum number of bytes to store in buffer.

Throws:

java.io.EOFException - if the end of this file is detected.

java.lang.IndexOutOfBoundsException - if offset < 0 or count < 0, or if offset + count is greater than the length of buffer.

java.io.IOException - if this file is closed or another I/O error occurs.

java.lang.NullPointerException - if buffer is null.

readInt

public final int readInt()
                  throws java.io.IOException

Reads a 32-bit integer from the current position in this file. Blocks until four bytes have been read, the end of the file is reached or an exception is thrown.

Specified by:

readInt in interface java.io.DataInput

Returns:

the next int value from this file.

Throws:

java.io.EOFException - if the end of this file is detected.

java.io.IOException - if this file is closed or another I/O error occurs.

readLine

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

Reads a line of text form the current position in this file. A line is represented by zero or more characters followed by '\n', '\r', "\r\n" or the end of file marker. The string does not include the line terminating sequence.

Blocks until a line terminating sequence has been read, the end of the file is reached or an exception is thrown.

Specified by:

readLine in interface java.io.DataInput

Returns:

the contents of the line or null if no characters have been read before the end of the file has been reached.

Throws:

java.io.IOException - if this file is closed or another I/O error occurs.

readLong

public final long readLong()
                    throws java.io.IOException

Reads a 64-bit long from the current position in this file. Blocks until eight bytes have been read, the end of the file is reached or an exception is thrown.

Specified by:

readLong in interface java.io.DataInput

Returns:

the next long value from this file.

Throws:

java.io.EOFException - if the end of this file is detected.

java.io.IOException - if this file is closed or another I/O error occurs.

readShort

public final short readShort()
                      throws java.io.IOException

Reads a 16-bit short from the current position in this file. Blocks until two bytes have been read, the end of the file is reached or an exception is thrown.

Specified by:

readShort in interface java.io.DataInput

Returns:

the next short value from this file.

Throws:

java.io.EOFException - if the end of this file is detected.

java.io.IOException - if this file is closed or another I/O error occurs.

readUnsignedByte

public final int readUnsignedByte()
                           throws java.io.IOException

Reads an unsigned 8-bit byte from the current position in this file and returns it as an integer. Blocks until one byte has been read, the end of the file is reached or an exception is thrown.

Specified by:

readUnsignedByte in interface java.io.DataInput

Returns:

the next unsigned byte value from this file as an int.

Throws:

java.io.EOFException - if the end of this file is detected.

java.io.IOException - if this file is closed or another I/O error occurs.

readUnsignedShort

public final int readUnsignedShort()
                            throws java.io.IOException

Reads an unsigned 16-bit short from the current position in this file and returns it as an integer. Blocks until two bytes have been read, the end of the file is reached or an exception is thrown.

Specified by:

readUnsignedShort in interface java.io.DataInput

Returns:

the next unsigned short value from this file as an int.

Throws:

java.io.EOFException - if the end of this file is detected.

java.io.IOException - if this file is closed or another I/O error occurs.

readUTF

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

Reads a string that is encoded in modified UTF-8 from this file. The number of bytes that must be read for the complete string is determined by the first two bytes read from the file. Blocks until all required bytes have been read, the end of the file is reached or an exception is thrown.

Specified by:

readUTF in interface java.io.DataInput

Returns:

the next string encoded in modified UTF-8 from this file.

Throws:

java.io.EOFException - if the end of this file is detected.

java.io.IOException - if this file is closed or another I/O error occurs.

java.io.UTFDataFormatException - if the bytes read cannot be decoded into a character string.