Package lumis.portal.page.cache

Implements the portal's page HTML cache engine. Generates the HTML for pages with cache enabled and handles requests for missing caches.

Overview

IPageCacheManager is the main entry point for this package. An instance of this interface may be obtained by calling {@link lumis.portal.manager.ManagerFactoryInternal.getPageCacheManager()}.

A generator runs in the background, generating the cache for pages outdated.

PageRenderDataChangedEvent events are observed, invalidating the corresponding caches as appropriated.

Shadow cache, when enabled, saves the generated HTML in a second-level cache. When page cache is requested but not present, the shadow cache copy is used if available.

The global configuration for the HTML cache feature is encapsulated by HtmlGenerationConfig, available in PortalContext.getHtmlGenerationConfig(). This configuration is done in the lumisportalconfig.xml file. Scoped configurations exist in PageCacheQueue, PageCacheGeneratorProfile and PageCacheGeneratorConfig.

Generator

The generator contains a pool of threads that generates the HTML for pages that have their cache outdated. The choice of the order of page generation is composed for a set of factors, including user demand, page characteristics and priority configurations.

Cache states

The following diagram shows the cache state flow while no user interference happens:

Requests for cached pages

The following activity diagram shows how requests for cached pages are processed:

Since:

4.0.0

Version:

$Revision: 12879 $ $Date: 2011-05-03 08:26:37 -0300 (Tue, 03 May 2011) $

Interface Summary

Interface	Description
IPageCacheManager	Provides page cache operations.
IPageCacheManagerSPI	Manager responsible for page cache related internal operations.
IPageCacheQueueResolver	Resolves the generation queue to be used for the cache of a web resource.

Class Summary

Class	Description
DefaultPageCacheQueueResolver	The default resolver for a cache's generation queue.
HtmlGenerationConfig	Contains configurations for the cache HTML generation.
PageCacheConfig	Stores information about the caching of a page.
PageCacheControllerHtml	Contains implementations for handling HTTP requests specific for page HTML cache scenarios.
PageCacheGeneratorProfile	Contains the configurations for cache generation.
PageCacheManager	Manager for page cache information.
PageCacheMonitorUtil	Utility class for page cache monitoring.
PageCacheObserver	Observer that clears page caches according to the notifications received.
PageCacheSSIFilter	Servlet filter responsible for replacing include start string ("<!--#include") for a customized one ("<!--LumisInclude") after the processing of the request.
PageCacheUtil	Utility class for dealing with page cache.
PCGeneratorConfig	Page cache generator configuration.

Enum Summary

Enum	Description
PageCacheMonitorUtil.Event	Enumeration of monitoring events configurations related to page cache.
PageCacheMonitorUtil.Field	Enumeration of measure types configurations related to page cache monitoring.

Exception Summary

Exception	Description
PageCacheControllerHtml.PageUnavailableException	Exception thrown when the requested page is temporarily unavailable, for example, due to timeout in the page generation.