org.opencms.flex
Class CmsFlexCache

java.lang.Object
  org.opencms.flex.CmsFlexCache

All Implemented Interfaces:

I_CmsEventListener

public class CmsFlexCache
extends java.lang.Object
implements I_CmsEventListener

This class implements the FlexCache.

The data structure used is a two-level hashtable. This is optimized for the structure of the keys that are used to describe the caching behaviour of the entries. The first hash-level is calculated from the resource name, i.e. the name of the resource as it is referred to in the VFS of OpenCms. The second hash-level is calculated from the cache-key of the resource, which also is a String representing the specifc variation of the cached entry.

A suffix [online] or [offline] is appended to te resource name to distinguish between the online and offline projects of OpenCms. Also, for support of JSP based workplace pages, a suffix [workplace] is appended. The same cached workplace pages are used both in the online and all offline projects.

Entries in the first level of the cache are of type CmsFlexCacheVariation, which is a sub-class of CmsFlexCache. This class is a simple data type that contains of a Map of CmsFlexCacheEntries, with variations - Strings as keys.

Here's a short summary of used terms:

• key: A combination of a resource name and a variation. The data structure used is CmsFlexCacheKey.
• resource: A String with the resource name and an appended [online] of [offline] suffix.
• variation: A String describing a variation of a cached entry in the CmsFlexCache language.
• entry: A CmsFlexCacheEntry data structure which is describes a cached OpenCms resource. For every entry a key is saved which contains the resource name and the variation.

Cache clearing is handled using events. The cache is fully flushed if an event I_CmsEventListener.EVENT_PUBLISH_PROJECT or I_CmsEventListener.EVENT_CLEAR_CACHES is caught.

Since:

6.0.0

Version:

$Revision: 1.63 $

Author:

Alexander Kandzior, Thomas Weckert

See Also:

CmsFlexCacheKey, CmsFlexCacheEntry, CmsLruCache, I_CmsLruCacheObject

Nested Class Summary

static class

CmsFlexCache.CmsFlexCacheVariation A simple data container class for the FlexCache variations.

Field Summary

static java.lang.String	CACHE_OFFLINESUFFIX Suffix to append to online cache entries.
static java.lang.String	CACHE_ONLINESUFFIX Suffix to append to online cache entries.
static int	CLEAR_ALL Trigger for clearcache event: Clear complete cache.
static int	CLEAR_ENTRIES Trigger for clearcache event: Clear only entries.
static int	CLEAR_OFFLINE_ALL Trigger for clearcache event: Clear complete offine cache.
static int	CLEAR_OFFLINE_ENTRIES Trigger for clearcache event: Clear only offline entries.
static int	CLEAR_ONLINE_ALL Trigger for clearcache event: Clear complete online cache.
static int	CLEAR_ONLINE_ENTRIES Trigger for clearcache event: Clear only online entries.
static int	INITIAL_CAPACITY_CACHE Initial cache size, this should be a power of 2 because of the Java collections implementation.
static int	INITIAL_CAPACITY_VARIATIONS Initial size for variation lists, should be a power of 2.
protected CmsLruCache	m_variationCache The LRU cache to organize the cached entries.
static java.lang.String	REPOSITORY_OFFLINE Offline repository constant.
static java.lang.String	REPOSITORY_ONLINE Online repository constant.

Fields inherited from interface org.opencms.main.I_CmsEventListener

EVENT_BEFORE_PUBLISH_PROJECT, EVENT_CLEAR_CACHES, EVENT_CLEAR_OFFLINE_CACHES, EVENT_CLEAR_ONLINE_CACHES, EVENT_CLEAR_PRINCIPAL_CACHES, EVENT_FLEX_CACHE_CLEAR, EVENT_FLEX_PURGE_JSP_REPOSITORY, EVENT_FULLSTATIC_EXPORT, EVENT_GROUP_MODIFIED, EVENT_LOGIN_USER, EVENT_OU_MODIFIED, EVENT_PROJECT_MODIFIED, EVENT_PROPERTY_DEFINITION_CREATED, EVENT_PROPERTY_DEFINITION_MODIFIED, EVENT_PROPERTY_MODIFIED, EVENT_PUBLISH_PROJECT, EVENT_REBUILD_SEARCHINDEXES, EVENT_RESOURCE_AND_PROPERTIES_MODIFIED, EVENT_RESOURCE_COPIED, EVENT_RESOURCE_CREATED, EVENT_RESOURCE_DELETED, EVENT_RESOURCE_MODIFIED, EVENT_RESOURCE_MOVED, EVENT_RESOURCES_AND_PROPERTIES_MODIFIED, EVENT_RESOURCES_MODIFIED, EVENT_UPDATE_EXPORTS, EVENT_USER_MODIFIED, KEY_CHANGE, KEY_DBCONTEXT, KEY_GROUP_ID, KEY_GROUP_NAME, KEY_INDEX_NAMES, KEY_OU_ID, KEY_OU_NAME, KEY_PROJECTID, KEY_PUBLISHID, KEY_PUBLISHLIST, KEY_REPORT, KEY_RESOURCE, KEY_RESOURCES, KEY_USER_ACTION, KEY_USER_ID, KEY_USER_NAME, LISTENERS_FOR_ALL_EVENTS, VALUE_GROUP_MODIFIED_ACTION_CREATE, VALUE_GROUP_MODIFIED_ACTION_DELETE, VALUE_GROUP_MODIFIED_ACTION_WRITE, VALUE_OU_MODIFIED_ACTION_CREATE, VALUE_OU_MODIFIED_ACTION_DELETE, VALUE_USER_MODIFIED_ACTION_ADD_USER_TO_GROUP, VALUE_USER_MODIFIED_ACTION_CREATE_USER, VALUE_USER_MODIFIED_ACTION_DELETE_USER, VALUE_USER_MODIFIED_ACTION_REMOVE_USER_FROM_GROUP, VALUE_USER_MODIFIED_ACTION_RESET_PASSWORD, VALUE_USER_MODIFIED_ACTION_SET_OU, VALUE_USER_MODIFIED_ACTION_WRITE_USER

Constructor Summary

CmsFlexCache(CmsFlexCacheConfiguration configuration)
Constructor for class CmsFlexCache.

Method Summary

boolean	cacheOffline() Indicates if offline project resources are cached.
void	cmsEvent(CmsEvent event) Implements the CmsEvent interface, the FlexCache uses the events to clear itself in case a project is published.
CmsFlexCacheKey	getCachedKey(java.lang.String key, CmsObject cms) Returns the CmsFlexCacheKey data structure for a given key (i.e. resource name).
java.util.Set	getCachedResources(CmsObject cms) Returns a set of all cached resource names.
java.util.Set	getCachedVariations(java.lang.String key, CmsObject cms) Returns all variations in the cache for a given resource name.
CmsLruCache	getEntryLruCache() Returns the LRU cache where the CacheEntries are cached.
boolean	isEnabled() Indicates if the cache is enabled (i.e. actually caching entries) or not.
int	keySize() Returns the total number of cached resource keys.
int	size() Returns the total number of entries in the cache.

Methods inherited from class java.lang.Object

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

Field Detail

CACHE_OFFLINESUFFIX

public static final java.lang.String CACHE_OFFLINESUFFIX

Suffix to append to online cache entries.

See Also:

Constant Field Values

CACHE_ONLINESUFFIX

public static final java.lang.String CACHE_ONLINESUFFIX

Suffix to append to online cache entries.

See Also:

Constant Field Values

CLEAR_ALL

public static final int CLEAR_ALL

Trigger for clearcache event: Clear complete cache.

See Also:

Constant Field Values

CLEAR_ENTRIES

public static final int CLEAR_ENTRIES

Trigger for clearcache event: Clear only entries.

See Also:

Constant Field Values

CLEAR_OFFLINE_ALL

public static final int CLEAR_OFFLINE_ALL

Trigger for clearcache event: Clear complete offine cache.

See Also:

Constant Field Values

CLEAR_OFFLINE_ENTRIES

public static final int CLEAR_OFFLINE_ENTRIES

Trigger for clearcache event: Clear only offline entries.

See Also:

Constant Field Values

CLEAR_ONLINE_ALL

public static final int CLEAR_ONLINE_ALL

Trigger for clearcache event: Clear complete online cache.

See Also:

Constant Field Values

CLEAR_ONLINE_ENTRIES

public static final int CLEAR_ONLINE_ENTRIES

Trigger for clearcache event: Clear only online entries.

See Also:

Constant Field Values

INITIAL_CAPACITY_CACHE

public static final int INITIAL_CAPACITY_CACHE

Initial cache size, this should be a power of 2 because of the Java collections implementation.

See Also:

Constant Field Values

INITIAL_CAPACITY_VARIATIONS

public static final int INITIAL_CAPACITY_VARIATIONS

Initial size for variation lists, should be a power of 2.

See Also:

Constant Field Values

REPOSITORY_OFFLINE

public static final java.lang.String REPOSITORY_OFFLINE

Offline repository constant.

See Also:

Constant Field Values

REPOSITORY_ONLINE

public static final java.lang.String REPOSITORY_ONLINE

Online repository constant.

See Also:

Constant Field Values

m_variationCache

protected CmsLruCache m_variationCache

The LRU cache to organize the cached entries.

Constructor Detail

CmsFlexCache

public CmsFlexCache(CmsFlexCacheConfiguration configuration)

Constructor for class CmsFlexCache.

The parameter "enabled" is used to control if the cache is actually on or off. Even if you don't need the cache, you still have to create an instance of it with enabled=false. This is because you need some of the FlexCache data structures for JSP inclusion buffering.

Parameters:

configuration - the flex cache configuration

Method Detail

cacheOffline

public boolean cacheOffline()

Indicates if offline project resources are cached.

Returns:

true if offline projects are cached, false if not

cmsEvent

public void cmsEvent(CmsEvent event)

Implements the CmsEvent interface, the FlexCache uses the events to clear itself in case a project is published.

Specified by:

cmsEvent in interface I_CmsEventListener

Parameters:

event - CmsEvent that has occurred

getCachedKey

public CmsFlexCacheKey getCachedKey(java.lang.String key,
                                    CmsObject cms)

Returns the CmsFlexCacheKey data structure for a given key (i.e. resource name).

Useful if you want to show the cache key for a resources, like on the FlexCache administration page.

Only users with administrator permissions are allowed to perform this operation.

Parameters:

key - the resource name for which to look up the variation for

cms - the CmsObject used for user authorization

Returns:

the CmsFlexCacheKey data structure found for the resource

getCachedResources

public java.util.Set getCachedResources(CmsObject cms)

Returns a set of all cached resource names. Usefull if you want to show a list of all cached resources, like on the FlexCache administration page.

Only users with administrator permissions are allowed to perform this operation.

Parameters:

cms - the CmsObject used for user authorization

Returns:

a Set of cached resource names (which are of type String)

getCachedVariations

public java.util.Set getCachedVariations(java.lang.String key,
                                         CmsObject cms)

Returns all variations in the cache for a given resource name. The variations are of type String.

Usefull if you want to show a list of all cached entry - variations, like on the FlexCache administration page.

Only users with administrator permissions are allowed to perform this operation.

Parameters:

key - the resource name for which to look up the variations for

cms - the CmsObject used for user authorization

Returns:

a Set of cached variations (which are of type String)

getEntryLruCache

public CmsLruCache getEntryLruCache()

Returns the LRU cache where the CacheEntries are cached.

Returns:

the LRU cache where the CacheEntries are cached

isEnabled

public boolean isEnabled()

Indicates if the cache is enabled (i.e. actually caching entries) or not.

Returns:

true if the cache is enabled, false if not

keySize

public int keySize()

Returns the total number of cached resource keys.

Returns:

the number of resource keys in the cache

size

public int size()

Returns the total number of entries in the cache.

Returns:

the number of entries in the cache