org.jlab.coda.hipo

Class FileEventIndex

java.lang.Object

org.jlab.coda.hipo.FileEventIndex

public class FileEventIndex
extends java.lang.Object

Class used to handle event indexes in the context of a file and having to change records.

Author:

gavalian

Constructor Summary

Constructors

Constructor and Description
FileEventIndex() Constructor.

Method Summary

Modifier and Type	Method and Description
void	addEventSize(int size) Adds the number of events in the next record to the index of records.
boolean	advance() Advances the current event number by one.
boolean	canAdvance() Checks to see if the event counter reached the end.
boolean	canRetreat() Checks if the event index can retreat (decrease).
void	clear() Clear the entire object.
int	getEventNumber() Gets the current event number which is set by advance(), retreat() or setEvent(int) (which also sets the record number that the event belongs to).
int	getMaxEvents() Gets the total number of events in file.
int	getRecordEventNumber() Gets the event number inside the record that corresponds to the current global event number from the file.
int	getRecordNumber() Gets the current record number which is set by setEvent(int), or by using advance() or retreat() (which set the event number to the next available or previous available respectively).
static void	main(java.lang.String[] args)
void	resetIndex() Resets the current index to 0.
boolean	retreat() Reduces current event number by one.
boolean	setEvent(int event) Set the current event to the desired position.
void	show() Prints the content of the event index array on the screen.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

FileEventIndex

public FileEventIndex()

Constructor.

Method Detail

clear

public void clear()

Clear the entire object.

resetIndex

public void resetIndex()

Resets the current index to 0. The corresponding record number is recalculated by calling setEvent() method.

addEventSize

public void addEventSize(int size)

Adds the number of events in the next record to the index of records. Internally, what is stored is the total number of events in the file up to and including the record of this entry.

Parameters:

size - number of events in the next record.

getEventNumber

public int getEventNumber()

Gets the current event number which is set by advance(), retreat() or setEvent(int) (which also sets the record number that the event belongs to).

Returns:

current event number.

getRecordNumber

public int getRecordNumber()

Gets the current record number which is set by setEvent(int), or by using advance() or retreat() (which set the event number to the next available or previous available respectively).

Returns:

current record number.

getRecordEventNumber

public int getRecordEventNumber()

Gets the event number inside the record that corresponds to the current global event number from the file.

Returns:

event offset in the record.

getMaxEvents

public int getMaxEvents()

Gets the total number of events in file.

Returns:

returns the number of events corresponding to the all records.

canAdvance

public boolean canAdvance()

Checks to see if the event counter reached the end.

Returns:

true if there are more events to advance to, false otherwise.

advance

public boolean advance()

Advances the current event number by one. If the event is not from current record, the record number will also be changed. If calling this would advance the current event number beyond its maximum limit, nothing is done.

Returns:

false if the record number is the same, and true if the record number has changed.

canRetreat

public boolean canRetreat()

Checks if the event index can retreat (decrease). Convenience function.

Returns:

true if the event index can be lowered by one.

retreat

public boolean retreat()

Reduces current event number by one. If the record number changes, it returns true.

Returns:

false if the record number is the same, and true is the record number has changed.

show

public void show()

Prints the content of the event index array on the screen.

setEvent

public boolean setEvent(int event)

Set the current event to the desired position. The current record and event offset inside of the record are updated as well.

Parameters:

event - event number in the stream, must be 0 to getMaxEvents()-1.

Returns:

true if record is different from previous one, false if it is the same.

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

main

public static void main(java.lang.String[] args)