Package lumis.portal.page.cache

Implements the portal's page HTML cache engine.

See:
Description

Interface Summary

IPageCacheManager

Provides page cache operations.

Class Summary

HtmlGenerationConfig	Contains configurations for the cache HTML generation.
PageCacheAwareHttpServletResponse	A HttpServletResponse wrapper that is aware of page cache and perform the necessary url conversions.
PageCacheConfig	Stores information about the caching of a page.
PageCacheControllerHtml	Contains implementations for handling HTTP requests specific for page HTML cache scenarios.
PageCacheGeneratorStarter	Starts and stops the page cache generators.
PageCacheManager	Manager for page cache information.
PageCacheManager.HttpAccessResult	Structure used to hold the result of PageCacheManager.doHttpAccess(URL, String).
PageCacheObserver	Observer that clears page caches according to the notifications received.

Enum Summary

IPageCacheManager.GenerationOutcome

Indicates the outcome of a page generation.

Exception Summary

PageCacheControllerHtml.PageUnavailableException

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

Package lumis.portal.page.cache Description

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 ManagerFactory.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A generator runs in the background, generating the cache for pages outdated.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 configuration for the HTML cache feature is encapsulated by HtmlGenerationConfig, available in PortalContext.getHtmlGenerationConfig(). This configuration is done in the lumisportalconfig.xml file. Refer to HtmlGenerationConfig for more configuration details.

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The generator contains a pool of threads that generates the HTML for pages that have their cache outdated.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