org.opencms.cache

Class CmsVfsNameBasedDiskCache

java.lang.Object

org.opencms.cache.CmsVfsNameBasedDiskCache

Direct Known Subclasses:

CmsPdfCache, CmsPdfThumbnailCache

public class CmsVfsNameBasedDiskCache
extends java.lang.Object

Implements a name based RFS file based disk cache, that handles parameter based versions of VFS files.

This RFS cache operates on file names, plus a hash code calculated from CmsResource.getDateLastModified(), CmsResource.getDateCreated() and CmsResource.getLength(). Optional parameters can be appended to this name, which will be added as a second hash code. This way a file can have multiple versions based on different parameters.

This cache is usable for resources from the online AND the offline project at the same time, because any change to a resource will result in a changed hash code. This means a resource changed in the offline project will have a new hash code compared to the online project. If the resource is identical in the online and the offline project, the generated hash codes will be the same.

Since:

6.2.0

Constructor Summary

Constructors

Constructor and Description
CmsVfsNameBasedDiskCache(java.lang.String basepath, java.lang.String foldername) Creates a new disk cache.

Method Summary

Methods

Modifier and Type	Method and Description
byte[]	getCacheContent(java.lang.String rfsName) Returns the content of the requested file in the disk cache, or null if the file is not found in the cache, or is found but outdated.
java.lang.String	getCacheName(CmsResource resource, java.lang.String parameters) Returns the RFS name to use for caching the given VFS resource with parameters in the disk cache.
java.lang.String	getRepositoryPath() Returns the absolute path of the cache repository in the RFS.
boolean	hasCacheContent(java.lang.String rfsName) Returns the the requested file is available within the cache.
void	saveCacheFile(java.lang.String rfsName, byte[] content) Saves the given file content in the disk cache.

Methods inherited from class java.lang.Object

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

Constructor Detail

CmsVfsNameBasedDiskCache

public CmsVfsNameBasedDiskCache(java.lang.String basepath,
                        java.lang.String foldername)

Creates a new disk cache.

Parameters:

basepath - the base path for the cache in the RFS

foldername - the folder name for this cache, to be used a sub-folder for the base folder

Method Detail

getCacheContent

public byte[] getCacheContent(java.lang.String rfsName)

Returns the content of the requested file in the disk cache, or null if the file is not found in the cache, or is found but outdated.

Parameters:

rfsName - the file RFS name to look up in the cache

Returns:

the content of the requested file in the disk cache, or null

getCacheName

public java.lang.String getCacheName(CmsResource resource,
                            java.lang.String parameters)

Returns the RFS name to use for caching the given VFS resource with parameters in the disk cache.

Parameters:

resource - the VFS resource to generate the cache name for

parameters - the parameters of the request to the VFS resource

Returns:

the RFS name to use for caching the given VFS resource with parameters

getRepositoryPath

public java.lang.String getRepositoryPath()

Returns the absolute path of the cache repository in the RFS.

Returns:

the absolute path of the cache repository in the RFS

hasCacheContent

public boolean hasCacheContent(java.lang.String rfsName)

Returns the the requested file is available within the cache.

Parameters:

rfsName - the file name

Returns:

true if the file is available

saveCacheFile

public void saveCacheFile(java.lang.String rfsName,
                 byte[] content)
                   throws java.io.IOException

Saves the given file content in the disk cache.

Parameters:

rfsName - the RFS name of the file to save the content in

content - the content of the file to save

Throws:

java.io.IOException - in case of disk access errors