Package ucar.nc2.util.cache

Interface FileCacheable

All Known Subinterfaces:

FeatureDataset, FeatureDatasetPoint, GridDataset, RadialDatasetSweep, StationRadialDataset

All Known Implementing Classes:

AbstractRadialAdapter, CdmRemote, CFRadialAdapter, Dorade2RadialAdapter, FeatureDatasetCoverage, FeatureDatasetImpl, GridDataset, HTTPRandomAccessFile, InMemoryRandomAccessFile, MMapRandomAccessFile, NetcdfDataset, NetcdfFile, NetcdfFileSubclass, Nexrad2RadialAdapter, NidsRadialAdapter, NsslRadialAdapter, PointDatasetImpl, PointDatasetRemote, RandomAccessFile, RemoteRandomAccessFile, SimpleGeometryFeatureDataset, UF2RadialAdapter

public interface FileCacheable

Interface for files that can be stored in FileCache. Requirements: 1. hashCode() must return Object.hashCode() 2. close() must call cache.release(this) if cache is not null. 3. must be able to detect changes in underlying object, and indicate whether it has changed. THIS IS AN INTERNAL CLASS, DO NOT USE DIRECTLY.

Method Summary

Modifier and Type	Method	Description
void	close()	Close the FileCacheable, release all resources.
long	getLastModified()	Returns the time that the underlying file(s) were last modified.
String	getLocation()	The location of the FileCacheable.
void	reacquire()	Reacquire any resources like file handles Used when reactivating in cache.
void	release()	Release any system resources like file handles.
void	setFileCache(FileCacheIF fileCache)	If the FileCache is not null, FileCacheable.close() must call FileCache.release()

Method Detail

getLocation

String getLocation()

The location of the FileCacheable. This must be sufficient for FileFactory.factory() to create the FileCacheable object

Returns:

location

close

void close()
    throws IOException

Close the FileCacheable, release all resources. Must call cache.release(this) if cache is not null.

Throws:

IOException - on io error

getLastModified

long getLastModified()

Returns the time that the underlying file(s) were last modified. If they've changed since they were stored in the cache, they will be closed and reopened with FileFactory.

Returns:

a long value representing the time the file(s) were last modified or 0L if the last-modified time couldn't be determined for any reason.

setFileCache

void setFileCache(FileCacheIF fileCache)

If the FileCache is not null, FileCacheable.close() must call FileCache.release()

 public synchronized void close() throws java.io.IOException {
   if (cache != null) {
     if (cache.release(this))
       return;
   }
 
   reallyClose();
 }
 

Parameters:

fileCache - must store this, use it on close as above.

release

void release()
      throws IOException

Release any system resources like file handles. Optional, implement only if you are able to reacquire. Used when object is made inactive in cache.

Throws:

IOException

reacquire

void reacquire()
        throws IOException

Reacquire any resources like file handles Used when reactivating in cache.

Throws:

IOException