org.jrobin.core
Class Header

java.lang.Object
  org.jrobin.core.Header

public class Header
extends Object

Class to represent RRD header. Header information is mainly static (once set, it cannot be changed), with the exception of last update time (this value is changed whenever RRD gets updated).

Normally, you don't need to manipulate the Header object directly - JRobin framework does it for you.

Author:

Sasa Markovic*

Method Summary

void	copyStateTo(org.jrobin.core.RrdUpdater other) Copies object's internal state to another Header object.
int	getArcCount() Returns the number of archives defined in the RRD.
int	getDsCount() Returns the number of datasources defined in the RRD.
String	getInfo()
long	getLastUpdateTime() Returns the last update time of the RRD.
org.jrobin.core.RrdAllocator	getRrdAllocator() Required to implement RrdUpdater interface.
RrdBackend	getRrdBackend() Returns the underlying storage (backend) object which actually performs all I/O operations.
String	getSignature() Returns RRD signature.
long	getStep() Returns primary RRD time step.
void	setInfo(String info)

Methods inherited from class java.lang.Object

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

Method Detail

getSignature

public String getSignature()
                    throws IOException

Returns RRD signature. Initially, the returned string will be of the form JRobin, version x.x. Note: RRD format did not change since Jrobin 1.0.0 release (and probably never will).

Returns:

RRD signature

Throws:

IOException - Thrown in case of I/O error

getInfo

public String getInfo()
               throws IOException

Throws:

IOException

setInfo

public void setInfo(String info)
             throws IOException

Throws:

IOException

getLastUpdateTime

public long getLastUpdateTime()
                       throws IOException

Returns the last update time of the RRD.

Returns:

Timestamp (Unix epoch, no milliseconds) corresponding to the last update time.

Throws:

IOException - Thrown in case of I/O error

getStep

public long getStep()
             throws IOException

Returns primary RRD time step.

Returns:

Primary time step in seconds

Throws:

IOException - Thrown in case of I/O error

getDsCount

public int getDsCount()
               throws IOException

Returns the number of datasources defined in the RRD.

Returns:

Number of datasources defined

Throws:

IOException - Thrown in case of I/O error

getArcCount

public int getArcCount()
                throws IOException

Returns the number of archives defined in the RRD.

Returns:

Number of archives defined

Throws:

IOException - Thrown in case of I/O error

copyStateTo

public void copyStateTo(org.jrobin.core.RrdUpdater other)
                 throws IOException,
                        RrdException

Copies object's internal state to another Header object.

Parameters:

other - New Header object to copy state to

Throws:

IOException - Thrown in case of I/O error

RrdException - Thrown if supplied argument is not a Header object

getRrdBackend

public RrdBackend getRrdBackend()

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

Returns:

I/O backend object

getRrdAllocator

public org.jrobin.core.RrdAllocator getRrdAllocator()

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

Returns:

Allocator object