Header (I2P Anonymous Network - Java Documentation

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

All Implemented Interfaces:

RrdUpdater
```
public class Header
extends Object
implements RrdUpdater
```
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*

Field Summary

Fields
Modifier and Type	Field	Description
`(package private) static String`	`DEFAULT_SIGNATURE`
`(package private) static String`	`RRDTOOL_VERSION`
`(package private) static String`	`SIGNATURE`
`(package private) static int`	`SIGNATURE_LENGTH`

Constructor Summary

Constructors
Constructor Description

Header(RrdDb parentDb, DataImporter reader)

Header(RrdDb parentDb, RrdDef rrdDef)

Constructors
Constructor	Description
`Header(RrdDb parentDb, DataImporter reader)`
`Header(RrdDb parentDb, RrdDef rrdDef)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`(package private) void`	`appendXml(XmlWriter writer)`
`void`	`copyStateTo(RrdUpdater other)`	Copies object's internal state to another Header object.
`(package private) String`	`dump()`
`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.
`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.
`(package private) boolean`	`isJRobinHeader()`
`void`	`setInfo(String info)`
`void`	`setLastUpdateTime(long lastUpdateTime)`
`(package private) void`	`validateHeader()`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - SIGNATURE_LENGTH
```
static final int SIGNATURE_LENGTH
```
    See Also:
    
    Constant Field Values
  - SIGNATURE
```
static final String SIGNATURE
```
    See Also:
    
    Constant Field Values
  - DEFAULT_SIGNATURE
```
static final String DEFAULT_SIGNATURE
```
    See Also:
    
    Constant Field Values
  - RRDTOOL_VERSION
```
static final String RRDTOOL_VERSION
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - Header
```
Header(RrdDb parentDb,
       RrdDef rrdDef)
throws IOException
```
    Throws:
    
    IOException
  - Header
```
Header(RrdDb parentDb,
       DataImporter reader)
throws IOException,
       RrdException
```
    Throws:
    
    IOException
    
    RrdException
- 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
  - setLastUpdateTime
```
public void setLastUpdateTime(long lastUpdateTime)
                       throws IOException
```
    Throws:
    
    IOException
  - dump
```
String dump()
     throws IOException
```
    Throws:
    
    IOException
  - appendXml
```
void appendXml(XmlWriter writer)
        throws IOException
```
    Throws:
    
    IOException
  - copyStateTo
```
public void copyStateTo(RrdUpdater other)
                 throws IOException,
                        RrdException
```
    Copies object's internal state to another Header object.
    
    Specified by:
    
    copyStateTo in interface RrdUpdater
    
    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.
    
    Specified by:
    
    getRrdBackend in interface RrdUpdater
    
    Returns:
    
    I/O backend object
  - isJRobinHeader
```
boolean isJRobinHeader()
                throws IOException
```
    Throws:
    
    IOException
  - validateHeader
```
void validateHeader()
             throws IOException,
                    RrdException
```
    Throws:
    
    IOException
    
    RrdException
  - getRrdAllocator
```
public RrdAllocator getRrdAllocator()
```
    Required to implement RrdUpdater interface. You should never call this method directly.
    
    Specified by:
    
    getRrdAllocator in interface RrdUpdater
    
    Returns:
    
    Allocator object

Class Header

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

SIGNATURE_LENGTH

SIGNATURE

DEFAULT_SIGNATURE

RRDTOOL_VERSION

Constructor Detail

Header

Header

Method Detail

getSignature

getInfo

setInfo

getLastUpdateTime

getStep

getDsCount

getArcCount

setLastUpdateTime

dump

appendXml

copyStateTo

getRrdBackend

isJRobinHeader

validateHeader

getRrdAllocator