RrdFileBackendFactory

java.lang.Object

org.rrd4j.core.RrdBackendFactory

org.rrd4j.core.RrdFileBackendFactory

All Implemented Interfaces:: Closeable, AutoCloseable

Direct Known Subclasses:: RrdNioBackendFactory, RrdRandomAccessFileBackendFactory

public abstract class RrdFileBackendFactoryextends RrdBackendFactory

An abstract backend factory which is used to store RRD data to ordinary files on the disk.

Every backend factory storing RRD data as ordinary files should inherit from it, some check are done in the code for instanceof.

Field Summary
Fields inherited from class RrdBackendFactory
cachingAllowed, DEFAULTFACTORY, name, scheme, validateHeader
Modifier and Type
Field
Description
protected final boolean
cachingAllowed
Whether this factory's backends may cache data in memory.
static final String
DEFAULTFACTORY
Default backend factory name.
protected final String
name
Storage name this factory reports to RrdDb.
protected final String
scheme
URI scheme this factory's storage URIs start with.
protected final boolean
validateHeader
Whether opened files must carry the RRD header.
Constructor Summary
Constructors
Constructor
Description
RrdFileBackendFactory()
Constructor for subclasses that build a backend storing RRD data in ordinary files.
Method Summary
All Methods
Modifier and Type
Method
Description
boolean
canStore(URI uri)
Tests whether this factory recognises a storage URI.
protected boolean
exists(String path)
Determines if a storage with the given path already exists.
URI
getCanonicalUri(URI uri)
Ensure that an URI is returned in a non-ambiguous way.
String
getPath(URI uri)
Extract the local path from an URI.
URI
getUri(String path)
Transform an path in a valid URI for this backend.
Methods inherited from class RrdBackendFactory
addActiveFactories, buildGenericUri, checkClosing, close, exists, findFactory, getActiveFactories, getBackend, getBackend, getDefaultFactory, getName, getRootUri, getScheme, open, resolve, setActiveFactories, shouldValidateHeader, shouldValidateHeader
Modifier and Type
Method
Description
static void
addActiveFactories(RrdBackendFactory... newFactories)
/** Add factories to the list of active factories, i.e.
static URI
buildGenericUri(String rrdpath)
Try to detect an URI from a path.
void
checkClosing()
Check that all phantom reference are indeed safely closed.
void
close()
A generic close handle, default implementation does nothing.
protected boolean
exists(URI uri)
Determines if a storage with the given URI already exists.
static RrdBackendFactory
findFactory(URI uri)
For a given URI, try to find a factory that can manage it in the list of active factories.
static java.util.stream.Stream<RrdBackendFactory>
getActiveFactories()
Return the current active factories as a stream.
(package private) RrdBackend
getBackend(RrdDb rrdDb, String path, boolean readOnly)
Creates RrdBackend object for the given storage path.
(package private) RrdBackend
getBackend(RrdDb rrdDb, URI uri, boolean readOnly)
Creates RrdBackend object for the given storage path.
static RrdBackendFactory
getDefaultFactory()
/** /** Returns the default backend factory.
String
getName()
Returns the name (primary ID) for the factory.
protected URI
getRootUri()
Builds the root URI for this factory's scheme.
String
getScheme()
The URI scheme that selects this backend, used to build every RRD URI the factory hands out.
protected abstract RrdBackend
open(String path, boolean readOnly)
Opens the backend serving a storage path.
protected URI
resolve(URI rootUri, URI uri, boolean relative)
Try to match an URI against a root URI using a few rules: scheme must match if they are given.
static void
setActiveFactories(RrdBackendFactory... newFactories)
Set the list of active factories, i.e.
protected boolean
shouldValidateHeader(String path)
Determines if the header should be validated.
protected boolean
shouldValidateHeader(URI uri)
Determines if the header should be validated.
Methods inherited from class Object
clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details
- RrdFileBackendFactory
  public RrdFileBackendFactory()
  Constructor for subclasses that build a backend storing RRD data in ordinary files.
Method Details
- exists
  protected boolean exists(String path)
  Determines if a storage with the given path already exists.
  Method to determine if a file with the given path already exists.
  Specified by:
  exists in class RrdBackendFactory
  Parameters:
  path - File system path to probe for.
  Returns:
  true if a storage already exists at the given path
- canStore
  public boolean canStore(URI uri)
  Tests whether this factory recognises a storage URI.
  Overrides:
  canStore in class RrdBackendFactory
  Parameters:
  uri - the candidate storage URI to test against this factory
  Returns:
  false unless a subclass overrides this to recognise its own URIs
- getCanonicalUri
  public URI getCanonicalUri(URI uri)
  Description copied from class: RrdBackendFactory
  Ensure that an URI is returned in a non-ambiguous way.
  Overrides:
  getCanonicalUri in class RrdBackendFactory
  Parameters:
  uri - a valid URI for this backend.
  Returns:
  the canonized URI.
- getUri
  public URI getUri(String path)
  Description copied from class: RrdBackendFactory
  Transform an path in a valid URI for this backend.
  Overrides:
  getUri in class RrdBackendFactory
  Parameters:
  path - a path local to the current backend.
  Returns:
  an URI that the current backend can handle.
- getPath
  public String getPath(URI uri)
  Description copied from class: RrdBackendFactory
  Extract the local path from an URI.
  Overrides:
  getPath in class RrdBackendFactory
  Parameters:
  uri - The URI to parse.
  Returns:
  the local path from the URI.

Field Summary

Fields inherited from class RrdBackendFactory

Constructor Summary

Method Summary

Methods inherited from class RrdBackendFactory

Methods inherited from class Object

Constructor Details

Method Details

exists

canStore

getCanonicalUri

getUri

getPath