com.ibm.jaggr.core.impl.cache

Class CacheManagerImpl

java.lang.Object

com.ibm.jaggr.core.impl.cache.CacheManagerImpl

All Implemented Interfaces:

ICacheManager, IConfigListener, IDependenciesListener, IShutdownListener, IOptionsListener

public class CacheManagerImpl
extends Object
implements ICacheManager, IShutdownListener, IConfigListener, IDependenciesListener, IOptionsListener

Nested Class Summary

Nested classes/interfaces inherited from interface com.ibm.jaggr.core.cache.ICacheManager

ICacheManager.CreateCompletionCallback

Constructor Summary

Constructors

Constructor and Description
CacheManagerImpl(IAggregator aggregator, long stamp) Starts up the cache.

Method Summary

Methods

Modifier and Type	Method and Description
void	clearCache() Clears the cache
void	configLoaded(IConfig config, long sequence) This method is called when the config is loaded/reloaded, after the config has been modified by any registered IConfigModifier services.
void	createCacheFileAsync(String fileNamePrefix, InputStream is, ICacheManager.CreateCompletionCallback callback) Utility method to create a cache file on an asynchronous thread.
void	createCacheFileAsync(String fileNamePrefix, Reader reader, ICacheManager.CreateCompletionCallback callback) Utility method to create a cache file on an asynchronous thread.
void	createNamedCacheFileAsync(String filename, InputStream is, ICacheManager.CreateCompletionCallback callback) Utility method to create a cache file on an asynchronous thread.
void	createNamedCacheFileAsync(String fileNamePrefix, Reader reader, ICacheManager.CreateCompletionCallback callback) Utility method to create a cache file on an asynchronous thread.
void	deleteFileDelayed(String fname) Utility method to asynchronously delete cache files after a delay period specified by IOptions.getDeleteDelay().
void	dependenciesLoaded(IDependencies deps, long sequence) This method is called when dependencies are loaded/reloaded/validated.
void	dumpCache(Writer writer, Pattern filter) Outputs the string representation of the cache to the specified writer, filtered using the specified regular expression pattern
void	externalizeCacheObjectAsync(String fileNamePrefix, Object object, ICacheManager.CreateCompletionCallback callback) Utility method to externalize an object on an asynchronous thread.
ICache	getCache() Returns the current cache object
File	getCacheDir() Returns the File object for the cache directory.
protected void	notifyInit() Notify listeners that the cache manager is initialized.
void	optionsUpdated(IOptions options, long sequence) This method is called when the options are loaded/changed.
void	serializeCache() Serializes the specified cache object to the sepecified directory.
void	shutdown(IAggregator aggregator) This method is called from within the aggregator's GenericServlet.destroy() method to notify listeners that the servlet is shutting down.

Methods inherited from class java.lang.Object

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

Constructor Detail

CacheManagerImpl

public CacheManagerImpl(IAggregator aggregator,
                long stamp)
                 throws IOException

Starts up the cache. Attempts to de-serialize a previously serialized cache from disk and starts the periodic serializer task.

Parameters:

aggregator - the aggregator instance this cache manager belongs to

stamp - a time stamp used to determine if the cache should be cleared. The cache should be cleared if the time stamp is later than the one associated with the cached resources.

Throws:

IOException

Method Detail

clearCache

public void clearCache()

Description copied from interface: ICacheManager

Clears the cache

Specified by:

clearCache in interface ICacheManager

dumpCache

public void dumpCache(Writer writer,
             Pattern filter)
               throws IOException

Description copied from interface: ICacheManager

Outputs the string representation of the cache to the specified writer, filtered using the specified regular expression pattern

Specified by:

dumpCache in interface ICacheManager

Parameters:

writer - The writer object to output to

filter - The regular expression filter, or null

Throws:

IOException

shutdown

public void shutdown(IAggregator aggregator)

Description copied from interface: IShutdownListener

This method is called from within the aggregator's GenericServlet.destroy() method to notify listeners that the servlet is shutting down.

Specified by:

shutdown in interface IShutdownListener

Parameters:

aggregator - The aggregator that is shutting down

getCacheDir

public File getCacheDir()

Description copied from interface: ICacheManager

Returns the File object for the cache directory.

Specified by:

getCacheDir in interface ICacheManager

Returns:

The cache directory

getCache

public ICache getCache()

Description copied from interface: ICacheManager

Returns the current cache object

Specified by:

getCache in interface ICacheManager

Returns:

The cache object

serializeCache

public void serializeCache()

Serializes the specified cache object to the sepecified directory. Note that we actually serialize a clone of the specified cache because some of the objects that are serialized require synchronization and we don't want to cause service threads to block while we are doing file I/O.

Specified by:

serializeCache in interface ICacheManager

createCacheFileAsync

public void createCacheFileAsync(String fileNamePrefix,
                        Reader reader,
                        ICacheManager.CreateCompletionCallback callback)

Description copied from interface: ICacheManager

Utility method to create a cache file on an asynchronous thread.

Specified by:

createCacheFileAsync in interface ICacheManager

Parameters:

fileNamePrefix - The prefix to use for the generated file name

reader - The Reader to read the file contents from

callback - The completion callback

createCacheFileAsync

public void createCacheFileAsync(String fileNamePrefix,
                        InputStream is,
                        ICacheManager.CreateCompletionCallback callback)

Description copied from interface: ICacheManager

Utility method to create a cache file on an asynchronous thread.

Specified by:

createCacheFileAsync in interface ICacheManager

Parameters:

fileNamePrefix - The prefix to use for the generated file name

is - The InputStream to read the file contents from

callback - The completion callback

externalizeCacheObjectAsync

public void externalizeCacheObjectAsync(String fileNamePrefix,
                               Object object,
                               ICacheManager.CreateCompletionCallback callback)

Description copied from interface: ICacheManager

Utility method to externalize an object on an asynchronous thread.

Specified by:

externalizeCacheObjectAsync in interface ICacheManager

Parameters:

fileNamePrefix - The prefix to use for the generated file name

object - The object to externalize

callback - The completion callback

createNamedCacheFileAsync

public void createNamedCacheFileAsync(String filename,
                             InputStream is,
                             ICacheManager.CreateCompletionCallback callback)

Description copied from interface: ICacheManager

Utility method to create a cache file on an asynchronous thread.

Specified by:

createNamedCacheFileAsync in interface ICacheManager

Parameters:

filename - The filename of the cache file. The cache file with the specified name will be created in the cache directory. The filename may not include a path component

is - The InputStream to read the file contents from

callback - The completion callback

createNamedCacheFileAsync

public void createNamedCacheFileAsync(String fileNamePrefix,
                             Reader reader,
                             ICacheManager.CreateCompletionCallback callback)

Description copied from interface: ICacheManager

Utility method to create a cache file on an asynchronous thread.

Specified by:

createNamedCacheFileAsync in interface ICacheManager

Parameters:

fileNamePrefix - The filename of the cache file. The cache file with the specified name will be created in the cache directory. The filename may not include a path component

reader - The Reader to read the file contents from

callback - The completion callback

deleteFileDelayed

public void deleteFileDelayed(String fname)

Description copied from interface: ICacheManager

Utility method to asynchronously delete cache files after a delay period specified by IOptions.getDeleteDelay(). The idea is to delay deleting the cache file long enough so that any threads which may be using the file at the time this method is called have finished with it and no longer need it. Note that the file may be deleted before the delay time has expired if the aggregator is shutdown before the delay time has expired

Specified by:

deleteFileDelayed in interface ICacheManager

Parameters:

fname - The name of the cache file to delete.

optionsUpdated

public void optionsUpdated(IOptions options,
                  long sequence)

Description copied from interface: IOptionsListener

This method is called when the options are loaded/changed.

Specified by:

optionsUpdated in interface IOptionsListener

Parameters:

options - The new options. Note that changes to the options may occur in-place, using the same IOptions object with updated values, or may result in a new object instance. This interface does not specify which approach is used by an implementation.

sequence - The sequence number. Notifications for different listener events (options, config, dependencies) that have the same cause have the same sequence number. The sequence number is incremented for subsequent event causes, but there is no guarantee about the the values for subsequent notifications other than that they will be increasing.

dependenciesLoaded

public void dependenciesLoaded(IDependencies deps,
                      long sequence)

Description copied from interface: IDependenciesListener

This method is called when dependencies are loaded/reloaded/validated. Listeners may track the value returned by IDependencies.getLastModified() to detect when the dependencies have changed.

Specified by:

dependenciesLoaded in interface IDependenciesListener

Parameters:

deps - The dependencies object. Note that changes to the dependencies may occur in-place, using the same IDependencies object with updated values, or may result in a new IDependencies object. This interface does not specify which approach is used by an implementation.

sequence - The sequence number. Notifications for different listener events (options, config, dependencies) that have the same cause have the same sequence number. Notifications resulting from servlet initialization have the sequence number 1. The sequence number is incremented for subsequent event causes, but there is no guarantee about the the values for subsequent notifications other than that they will be increasing.

configLoaded

public void configLoaded(IConfig config,
                long sequence)

Description copied from interface: IConfigListener

This method is called when the config is loaded/reloaded, after the config has been modified by any registered IConfigModifier services.

Specified by:

configLoaded in interface IConfigListener

Parameters:

config - The new config object. In order to detect and react to config changes, you can save the value returned from IConfig.toString() and compare it with the value returned in subsequent configLoaded events.

sequence - The sequence number. Notifications for different listener events (options, config, dependencies) that have the same cause have the same sequence number. Notifications resulting from servlet initialization have the sequence number 1. The sequence number is incremented for subsequent event causes, but there is no guarantee about the the values for subsequent notifications other than that they will be increasing.

notifyInit

protected void notifyInit()

Notify listeners that the cache manager is initialized.