Package org.rrd4j.core

Class RobinArray

java.lang.Object

org.rrd4j.core.RobinArray

All Implemented Interfaces:

Robin, RrdUpdater<Robin>

class RobinArray
extends Object
implements Robin

Class to represent archive values for a single datasource. Robin class is the heart of the so-called "round robin database" concept. Basically, each Robin object is a fixed length array of double values. Each double value represents consolidated, archived value for the specific timestamp. When the underlying array of double values gets completely filled, new values will replace the oldest ones.

Robin object does not hold values in memory - such object could be quite large. Instead of it, Robin reads them from the backend I/O only when necessary.

Author:

Sasa Markovic

Constructor Summary

Constructors

Constructor	Description
RobinArray(Archive parentArc, int rows, boolean shouldInitialize)

Method Summary

Modifier and Type	Method	Description
void	bulkStore(double newValue, int bulkCount)	bulkStore.
void	copyStateTo(Robin robin)	copyStateTo.
String	dump()	dump.
void	filterValues(double minValue, double maxValue)	Filters values stored in this archive based on the given boundary.
Archive	getParent()	getParent.
RrdAllocator	getRrdAllocator()	getRrdAllocator.
RrdBackend	getRrdBackend()	getRrdBackend.
int	getSize()	getSize.
double	getValue(int index)	Returns the i-th value from the Robin archive.
double[]	getValues()	Getter for the field values.
double[]	getValues(int index, int count)	getValues.
void	setValue(int index, double value)	Sets the i-th value in the Robin archive.
void	setValues(double newValue)	(Re)sets all values in this archive to the same value.
void	setValues(double... newValues)	Updates archived values in bulk.
void	store(double newValue)	store.
void	update(double[] newValues)	update.

Methods inherited from class java.lang.Object

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

Constructor Detail

RobinArray

RobinArray(Archive parentArc,
           int rows,
           boolean shouldInitialize)
    throws IOException

Throws:

IOException

Method Detail

getValues

public double[] getValues()
                   throws IOException

Getter for the field values.

Specified by:

getValues in interface Robin

Returns:

an array of double.

Throws:

IOException - if any.

store

public void store(double newValue)
           throws IOException

store.

Specified by:

store in interface Robin

Parameters:

newValue - a double.

Throws:

IOException - if any.

bulkStore

public void bulkStore(double newValue,
                      int bulkCount)
               throws IOException

bulkStore.

Specified by:

bulkStore in interface Robin

Parameters:

newValue - a double.

bulkCount - a int.

Throws:

IOException - if any.

update

public void update(double[] newValues)
            throws IOException

update.

Specified by:

update in interface Robin

Parameters:

newValues - an array of double.

Throws:

IOException - if any.

setValues

public void setValues(double... newValues)
               throws IOException

Updates archived values in bulk.

Specified by:

setValues in interface Robin

Parameters:

newValues - Array of double values to be stored in the archive

Throws:

IOException - Thrown in case of I/O error

setValues

public void setValues(double newValue)
               throws IOException

(Re)sets all values in this archive to the same value.

Specified by:

setValues in interface Robin

Parameters:

newValue - New value

Throws:

IOException - Thrown in case of I/O error

dump

public String dump()
            throws IOException

dump.

Specified by:

dump in interface Robin

Returns:

a String object.

Throws:

IOException - if any.

getValue

public double getValue(int index)
                throws IOException

Returns the i-th value from the Robin archive.

Specified by:

getValue in interface Robin

Parameters:

index - Value index

Returns:

Value stored in the i-th position (the oldest value has zero index)

Throws:

IOException - Thrown in case of I/O specific error.

setValue

public void setValue(int index,
                     double value)
              throws IOException

Sets the i-th value in the Robin archive.

Specified by:

setValue in interface Robin

Parameters:

index - index in the archive (the oldest value has zero index)

value - value to be stored

Throws:

IOException - Thrown in case of I/O specific error.

getValues

public double[] getValues(int index,
                          int count)
                   throws IOException

getValues.

Specified by:

getValues in interface Robin

Parameters:

index - a int.

count - a int.

Returns:

an array of double.

Throws:

IOException - if any.

getParent

public Archive getParent()

getParent.

Specified by:

getParent in interface Robin

Returns:

a Archive object.

getSize

public int getSize()

getSize.

Specified by:

getSize in interface Robin

Returns:

a int.

copyStateTo

public void copyStateTo(Robin robin)
                 throws IOException

copyStateTo.

Copies object's internal state to another Robin object.

Specified by:

copyStateTo in interface Robin

Specified by:

copyStateTo in interface RrdUpdater<Robin>

Parameters:

robin - a RrdUpdater object.

Throws:

IOException - if any.

filterValues

public void filterValues(double minValue,
                         double maxValue)
                  throws IOException

Filters values stored in this archive based on the given boundary. Archived values found to be outside of [minValue, maxValue] interval (inclusive) will be silently replaced with NaN.

Specified by:

filterValues in interface Robin

Parameters:

minValue - lower boundary

maxValue - upper boundary

Throws:

IOException - Thrown in case of I/O error

getRrdBackend

public RrdBackend getRrdBackend()

getRrdBackend.

Specified by:

getRrdBackend in interface Robin

Specified by:

getRrdBackend in interface RrdUpdater<Robin>

Returns:

a RrdBackend object.

getRrdAllocator

public RrdAllocator getRrdAllocator()

getRrdAllocator.

Specified by:

getRrdAllocator in interface Robin

Specified by:

getRrdAllocator in interface RrdUpdater<Robin>

Returns:

a RrdAllocator object.