public class

RobinArray

extends Object
implements Robin
java.lang.Object
   ↳ org.rrd4j.core.RobinArray

Class Overview

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.

Summary

Public Methods
void bulkStore(double newValue, int bulkCount)
void copyStateTo(RrdUpdater other)
Copies object's internal state to another Robin object.
String dump()
void filterValues(double minValue, double maxValue)
Filters values stored in this archive based on the given boundary.
Archive getParent()
Returns the Archive object to which this Robin object belongs.
RrdAllocator getRrdAllocator()
Required to implement RrdUpdater interface.
RrdBackend getRrdBackend()
Returns the underlying storage (backend) object which actually performs all I/O operations.
int getSize()
Returns the size of the underlying array of archived values.
double getValue(int index)
Returns the i-th value from the Robin archive.
double[] getValues()
Fetches all archived values.
double[] getValues(int index, int count)
void setValue(int index, double value)
Sets the i-th value in the Robin archive.
void setValues(double... newValues)
Updates archived values in bulk.
void setValues(double newValue)
(Re)sets all values in this archive to the same value.
void store(double newValue)
void update(double[] newValues)
[Expand]
Inherited Methods
From class java.lang.Object
From interface org.rrd4j.core.Robin

Public Methods

public void bulkStore (double newValue, int bulkCount)

Throws
IOException

public void copyStateTo (RrdUpdater other)

Copies object's internal state to another Robin object.

Parameters
other New Robin object to copy state to
Throws
IOException

public String dump ()

Throws
IOException

public void filterValues (double minValue, double maxValue)

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.

Parameters
minValue lower boundary
maxValue upper boundary
Throws
IOException

public Archive getParent ()

Returns the Archive object to which this Robin object belongs.

Returns
  • Parent Archive object

public RrdAllocator getRrdAllocator ()

Required to implement RrdUpdater interface. You should never call this method directly.

Returns
  • Allocator object

public RrdBackend getRrdBackend ()

Returns the underlying storage (backend) object which actually performs all I/O operations.

Returns
  • I/O backend object

public int getSize ()

Returns the size of the underlying array of archived values.

Returns
  • Number of stored values

public double getValue (int index)

Returns the i-th value from the Robin archive.

Parameters
index Value index
Returns
  • Value stored in the i-th position (the oldest value has zero index)
Throws
IOException

public double[] getValues ()

Fetches all archived values.

Returns
  • Array of double archive values, starting from the oldest one.
Throws
IOException

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

Throws
IOException

public void setValue (int index, double value)

Sets the i-th value in the Robin archive.

Parameters
index index in the archive (the oldest value has zero index)
value value to be stored
Throws
IOException

public void setValues (double... newValues)

Updates archived values in bulk.

Parameters
newValues Array of double values to be stored in the archive
Throws
IOException

public void setValues (double newValue)

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

Parameters
newValue New value
Throws
IOException

public void store (double newValue)

Throws
IOException

public void update (double[] newValues)

Throws
IOException