org.egothor.core.memory

Class MemoryIList

java.lang.Object

org.egothor.core.memory.MemoryIList

All Implemented Interfaces:

AutoCloseable, IListItem, IListReader, IListWriter, Proximities

public class MemoryIList
extends Object
implements IListReader, IListWriter, Proximities

The MemoryIList class is an inverted list stored to memory.

Author:

Leo Galambos

Method Summary

Modifier and Type	Method and Description
void	append(long new_uid, IListItem item) Append a new inverted list item.
void	close() Close the reader.
void	closeProx() Close this list and release resources.
long	getPostings() Return the number of items in the inverted list this object reads (including removed ones).
String	getTerm() Return the term that owns this inverted list.
int	leftProx() Return the number of items in the proximity list which were not read yet.
boolean	next() Move to the next item in the inverted list.
Proximities	openProx() Return an access object to the proximity list.
int	readProx() Read this object's inverted list.
int	readProx(int[] prox, int offset, int len) Read an inverted list of length greater than 1.
boolean	skipTo(long uid) Skips (forward) in the inverted list to the first item with an ID greater than or equal to the given uid identification.
long	uid() Identification of the document.
int	weight() Calculated vector value.

Methods inherited from class java.lang.Object

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

Method Detail

append

public void append(long new_uid,
                   IListItem item)
            throws IOException

Description copied from interface: IListWriter

Append a new inverted list item. It must be stored with the new identification in this list.

Specified by:

append in interface IListWriter

Parameters:

new_uid - The new item identification.

item - The inverted list item.

Throws:

IOException

close

public void close()

Description copied from interface: IListReader

Close the reader.

Specified by:

close in interface AutoCloseable

Specified by:

close in interface IListReader

Specified by:

close in interface IListWriter

getPostings

public long getPostings()

Description copied from interface: IListReader

Return the number of items in the inverted list this object reads (including removed ones).

Specified by:

getPostings in interface IListReader

Returns:

the number of items

getTerm

public String getTerm()

Description copied from interface: IListReader

Return the term that owns this inverted list.

Specified by:

getTerm in interface IListReader

Returns:

the term

next

public boolean next()

Description copied from interface: IListReader

Move to the next item in the inverted list.

Specified by:

next in interface IListReader

Returns:

true if the next item exists

skipTo

public boolean skipTo(long uid)

Description copied from interface: IListReader

Skips (forward) in the inverted list to the first item with an ID greater than or equal to the given uid identification.

Specified by:

skipTo in interface IListReader

Parameters:

uid - the item to skip to

Returns:

true if the next item exists

uid

public long uid()

Description copied from interface: IListItem

Identification of the document. If this value is lower than 0, then this item ought to be supposed to be invalid.

Specified by:

uid in interface IListItem

Returns:

weight

public int weight()

Description copied from interface: IListItem

Calculated vector value.

Specified by:

weight in interface IListItem

Returns:

openProx

public Proximities openProx()

Description copied from interface: IListItem

Return an access object to the proximity list.

Specified by:

openProx in interface IListItem

Returns:

a Proximities object

closeProx

public void closeProx()

Description copied from interface: Proximities

Close this list and release resources.

Specified by:

closeProx in interface Proximities

leftProx

public int leftProx()

Description copied from interface: Proximities

Return the number of items in the proximity list which were not read yet.

Specified by:

leftProx in interface Proximities

Returns:

the number of items

readProx

public int readProx()
             throws IOException

Description copied from interface: Proximities

Read this object's inverted list.

Specified by:

readProx in interface Proximities

Returns:

the position of the item read

Throws:

IOException

readProx

public int readProx(int[] prox,
                    int offset,
                    int len)
             throws IOException

Description copied from interface: Proximities

Read an inverted list of length greater than 1. The list will be read in blocks of the specified size.

Specified by:

readProx in interface Proximities

Parameters:

prox - the buffer

offset - first cell to fill

len - how many cell are read

Returns:

how many cells were read

Throws:

IOException