org.alfresco.repo.content.caching

Interface ContentCache

All Known Implementing Classes:

ContentCacheImpl

public interface ContentCache

A cache designed to operate on content and split between memory and disk. The binary content data itself is stored on disk but the references to those files are stored in memory.

Author:

Matt Ward

Method Summary

Modifier and Type	Method and Description
boolean	contains(String contentUrl) Check to see if the content - specified by URL - exists in the cache.
void	deleteFile(String url) Deletes the cached content file for the specified URL.
File	getCacheRoot() Returns the location where cache files will be written (cacheRoot) - implementation dependant and may be null.
ContentReader	getReader(String contentUrl) Retrieve a ContentReader for the cached content specified by URL.
ContentWriter	getWriter(String url) Retrieve a ContentWriter to write content to a cache file.
boolean	put(String contentUrl, ContentReader reader) Put an item into cache - this will populate both a disk file (with content) and the in-memory lookup table (with the URL and cache file location).
void	remove(String contentUrl) Remove a cached item from the in-memory lookup table.

Method Detail

getCacheRoot

File getCacheRoot()

Returns the location where cache files will be written (cacheRoot) - implementation dependant and may be null.

Returns:

cacheRoot

contains

boolean contains(String contentUrl)

Check to see if the content - specified by URL - exists in the cache.

Note that just because the in-memory cache has a record of the content item having been placed into the cache, it does not mean that the disk item is guaranteed to be there. The temp file clean-up process, for example, may have removed it.

Parameters:

contentUrl - String

Returns:

true if the URL exists in the in-memory cache. It may therefore be cached on disk.

getReader

ContentReader getReader(String contentUrl)

Retrieve a ContentReader for the cached content specified by URL.

Parameters:

contentUrl - String

Returns:

ContentReader

Throws:

CacheMissException - If the cache does not contain the specified content.

put

boolean put(String contentUrl,
            ContentReader reader)

Put an item into cache - this will populate both a disk file (with content) and the in-memory lookup table (with the URL and cache file location). Empty content will NOT be cached - in which case false is returned.

Parameters:

contentUrl - String

reader - ContentReader

Returns:

true if the content was cached, false otherwise.

remove

void remove(String contentUrl)

Remove a cached item from the in-memory lookup table. Implementation should not remove the actual cached content (file) - this should be left to the clean-up process or can be deleted with deleteFile(String).

Parameters:

contentUrl - String

deleteFile

void deleteFile(String url)

Deletes the cached content file for the specified URL. To remove the item from the lookup table also, use remove(String) after calling this method.

Parameters:

url - String

getWriter

ContentWriter getWriter(String url)

Retrieve a ContentWriter to write content to a cache file. Upon closing the stream a listener will add the new content file to the in-memory lookup table.

Parameters:

url - url

Returns:

ContentWriter