org.terrier.compression.bit

Class BitFileInMemoryLarge

java.lang.Object

org.terrier.compression.bit.BitFileInMemoryLarge

All Implemented Interfaces:

Closeable, AutoCloseable, BitInSeekable

public class BitFileInMemoryLarge
extends Object
implements BitInSeekable

Allows access to bit compressed files that are loaded entirely into memory. Implements a BitInSeekable that uses RandomDataInputMemory as a backing store. Can handle data files larger than those handled by BitFileInMemory (whose limit is Integer.MAX_VALUE).

Since:

3.0

Author:

Craig Macdonald

Constructor Summary

Constructors

Constructor and Description
BitFileInMemoryLarge(RandomDataInputMemory _rdim) constructor
BitFileInMemoryLarge(String filename) load compressed file into memory

Method Summary

Methods

Modifier and Type	Method and Description
void	close()
BitIn	readReset(long startByteOffset, byte startBitOffset) Reads from the file from a specific offset.
BitIn	readReset(long startByteOffset, byte startBitOffset, long endByteOffset, byte endBitOffset) Reads from the file a specific number of bytes and after this call, a sequence of read calls may follow.

Methods inherited from class java.lang.Object

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

Constructor Detail

BitFileInMemoryLarge

public BitFileInMemoryLarge(RandomDataInputMemory _rdim)
                     throws IOException

constructor

Parameters:

_rdim -

Throws:

IOException

BitFileInMemoryLarge

public BitFileInMemoryLarge(String filename)
                     throws IOException

load compressed file into memory

Parameters:

filename -

Throws:

IOException

Method Detail

readReset

public BitIn readReset(long startByteOffset,
              byte startBitOffset,
              long endByteOffset,
              byte endBitOffset)
                throws IOException

Reads from the file a specific number of bytes and after this call, a sequence of read calls may follow. The offsets given as arguments are inclusive. For example, if we call this method with arguments 0, 2, 1, 7, it will read in a buffer the contents of the underlying file from the third bit of the first byte to the last bit of the second byte.

Specified by:

readReset in interface BitInSeekable

Parameters:

startByteOffset - the starting byte to read from

startBitOffset - the bit offset in the starting byte

endByteOffset - the ending byte

endBitOffset - the bit offset in the ending byte. This bit is the last bit of this entry.

Returns:

Returns the BitIn object to use to read that data

Throws:

IOException

readReset

public BitIn readReset(long startByteOffset,
              byte startBitOffset)
                throws IOException

Reads from the file from a specific offset. After this call, a sequence of read calls may follow.

Specified by:

readReset in interface BitInSeekable

Parameters:

startByteOffset - the starting byte to read from

startBitOffset - the bit offset in the starting byte

Returns:

Returns the BitIn object to use to read that data

Throws:

IOException

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException