/**
* Requests a RrdDb reference for the given RRD file definition object.<p>
* <ul>
* <li>If the file with the path specified in the RrdDef object is already open,
* the method blocks until the file is closed.
* <li>If the file is not already open and the number of already open RRD files is less than
* {@link #INITIAL_CAPACITY}, a new RRD file will be created and a its RrdDb reference will be returned.
* If the file is not already open and the number of already open RRD files is equal to
* {@link #INITIAL_CAPACITY}, the method blocks until some RRD file is closed.
* </ul>
*
* @param rrdDef Definition of the RRD file to be created
* @return Reference to the newly created RRD file
* @ Thrown in case of I/O error
*/
public RrdDb requestRrdDb(RrdDef rrdDef)
{
lock (sync)
{
String canonicalPath = Util.getCanonicalPath(rrdDef.getPath());
while (rrdMap.ContainsKey(canonicalPath) || rrdMap.Count >= capacity)
{
Thread.Sleep(10);
}
RrdDb rrdDb = new RrdDb(rrdDef);
rrdMap.Add(canonicalPath, new RrdEntry(rrdDb));
return(rrdDb);
}
}
/**
* Constructor used to create new RRD object from the definition object but with a storage
* (backend) different from default.
*
* <p>Rrd4n uses <i>factories</i> to create RRD backend objecs. There are three different
* backend factories supplied with Rrd4n, and each factory has its unique name:</p>
* <p/>
* <ul>
* <li><b>FILE</b>: backends created from this factory will store RRD data to files by using
* java.io.* classes and methods
* <li><b>NIO</b>: backends created from this factory will store RRD data to files by using
* java.nio.* classes and methods
* <li><b>MEMORY</b>: backends created from this factory will store RRD data in memory. This might
* be useful in runtime environments which prohibit disk utilization, or for storing temporary,
* non-critical data (it gets lost as soon as JVM exits).
* </ul>
* <p/>
* <p>For example, to create RRD in memory, use the following code</p>
* <pre>
* RrdBackendFactory factory = RrdBackendFactory.getFactory("MEMORY");
* RrdDb rrdDb = new RrdDb(rrdDef, factory);
* rrdDb.close();
* </pre>
* <p/>
* <p>New RRD file structure is specified with an object of class
* {@link RrdDef <b>RrdDef</b>}. The underlying RRD storage is created as soon
* as the constructor returns.</p>
*
* @param rrdDef RRD definition object
* @param factory The factory which will be used to create storage for this RRD
* @Thrown in case of I/O error
* @see RrdBackendFactory
*/
public RrdDb(RrdDef rrdDef, RrdBackendFactory factory)
{
if (!rrdDef.hasDatasources())
{
throw new ArgumentException("No RRD Datasource specified. At least one is needed.");
}
if (!rrdDef.hasArchives())
{
throw new ArgumentException("No RRD archive specified. At least one is needed.");
}
String path = rrdDef.getPath();
backend = factory.open(path, false);
try
{
backend.setLength(rrdDef.getEstimatedSize());
// create header
header = new Header(this, rrdDef);
// create Datasources
DsDef[] dsDefs = rrdDef.getDsDefs();
Datasources = new Datasource[dsDefs.Length];
for (int i = 0; i < dsDefs.Length; i++)
{
Datasources[i] = new Datasource(this, dsDefs[i]);
}
// create archives
ArcDef[] arcDefs = rrdDef.getArcDefs();
archives = new Archive[arcDefs.Length];
for (int i = 0; i < arcDefs.Length; i++)
{
archives[i] = new Archive(this, arcDefs[i]);
}
}
catch (IOException e)
{
backend.close();
throw;
}
}
/**
* Requests a RrdDb reference for the given RRD file definition object.<p>
* <ul>
* <li>If the file with the path specified in the RrdDef object is already open,
* the method blocks until the file is closed.
* <li>If the file is not already open and the number of already open RRD files is less than
* {@link #INITIAL_CAPACITY}, a new RRD file will be created and a its RrdDb reference will be returned.
* If the file is not already open and the number of already open RRD files is equal to
* {@link #INITIAL_CAPACITY}, the method blocks until some RRD file is closed.
* </ul>
*
* @param rrdDef Definition of the RRD file to be created
* @return Reference to the newly created RRD file
* @ Thrown in case of I/O error
*/
public RrdDb requestRrdDb(RrdDef rrdDef)
{
lock (sync)
{
String canonicalPath = Util.getCanonicalPath(rrdDef.getPath());
while (rrdMap.ContainsKey(canonicalPath) || rrdMap.Count >= capacity)
{
Thread.Sleep(10);
}
RrdDb rrdDb = new RrdDb(rrdDef);
rrdMap.Add(canonicalPath, new RrdEntry(rrdDb));
return rrdDb;
}
}
/**
* Constructor used to create new RRD object from the definition object but with a storage
* (backend) different from default.
*
* <p>Rrd4n uses <i>factories</i> to create RRD backend objecs. There are three different
* backend factories supplied with Rrd4n, and each factory has its unique name:</p>
* <p/>
* <ul>
* <li><b>FILE</b>: backends created from this factory will store RRD data to files by using
* java.io.* classes and methods
* <li><b>NIO</b>: backends created from this factory will store RRD data to files by using
* java.nio.* classes and methods
* <li><b>MEMORY</b>: backends created from this factory will store RRD data in memory. This might
* be useful in runtime environments which prohibit disk utilization, or for storing temporary,
* non-critical data (it gets lost as soon as JVM exits).
* </ul>
* <p/>
* <p>For example, to create RRD in memory, use the following code</p>
* <pre>
* RrdBackendFactory factory = RrdBackendFactory.getFactory("MEMORY");
* RrdDb rrdDb = new RrdDb(rrdDef, factory);
* rrdDb.close();
* </pre>
* <p/>
* <p>New RRD file structure is specified with an object of class
* {@link RrdDef <b>RrdDef</b>}. The underlying RRD storage is created as soon
* as the constructor returns.</p>
*
* @param rrdDef RRD definition object
* @param factory The factory which will be used to create storage for this RRD
* @Thrown in case of I/O error
* @see RrdBackendFactory
*/
public RrdDb(RrdDef rrdDef, RrdBackendFactory factory)
{
if (!rrdDef.hasDatasources())
{
throw new ArgumentException("No RRD Datasource specified. At least one is needed.");
}
if (!rrdDef.hasArchives())
{
throw new ArgumentException("No RRD archive specified. At least one is needed.");
}
String path = rrdDef.getPath();
backend = factory.open(path, false);
try
{
backend.setLength(rrdDef.getEstimatedSize());
// create header
header = new Header(this, rrdDef);
// create Datasources
DsDef[] dsDefs = rrdDef.getDsDefs();
Datasources = new Datasource[dsDefs.Length];
for (int i = 0; i < dsDefs.Length; i++)
{
Datasources[i] = new Datasource(this, dsDefs[i]);
}
// create archives
ArcDef[] arcDefs = rrdDef.getArcDefs();
archives = new Archive[arcDefs.Length];
for (int i = 0; i < arcDefs.Length; i++)
{
archives[i] = new Archive(this, arcDefs[i]);
}
}
catch (IOException e)
{
backend.close();
throw;
}
}