Public Member Functions | Public Attributes

nsICacheEntryDescriptor Interface Reference

import "nsICacheEntryDescriptor.idl";

Inheritance diagram for nsICacheEntryDescriptor:
Collaboration diagram for nsICacheEntryDescriptor:

List of all members.

Public Member Functions

void setExpirationTime (in PRUint32 expirationTime)
 Set the time at which the cache entry should be considered invalid (in seconds since the Epoch).
void setDataSize (in unsigned long size)
 Set the cache entry data size.
nsIInputStream openInputStream (in unsigned long offset)
 Open blocking input stream to cache data.
nsIOutputStream openOutputStream (in unsigned long offset)
 Open blocking output stream to cache data.
void doom ()
 Doom the cache entry this descriptor references in order to slate it for removal.
void doomAndFailPendingRequests (in nsresult status)
void markValid ()
 A writer must validate this cache object before any readers are given a descriptor to the object.
void close ()
 Explicitly close the descriptor (optional).
string getMetaDataElement (in string key)
 Methods for accessing meta data.
void setMetaDataElement (in string key, in string value)
void visitMetaData (in nsICacheMetaDataVisitor visitor)
 Visitor will be called with key/value pair for each meta data element.

Public Attributes

attribute nsISupports cacheElement
 Get/set the cache data element.
readonly attribute
nsCacheAccessMode 
accessGranted
 Get the access granted to this descriptor.
attribute nsCacheStoragePolicy storagePolicy
 Get/set the storage policy of the cache entry.
readonly attribute nsIFile file
 Get the disk file associated with the cache entry.
attribute nsISupports securityInfo
 Get/set security info on the cache entry for this descriptor.

Member Function Documentation

void nsICacheEntryDescriptor::close (  ) 

Explicitly close the descriptor (optional).

void nsICacheEntryDescriptor::doom (  ) 

Doom the cache entry this descriptor references in order to slate it for removal.

Once doomed a cache entry cannot be undoomed.

A descriptor with WRITE access can doom the cache entry and choose to fail pending requests. This means that pending requests will not get a cache descriptor. This is meant as a tool for clients that wish to instruct pending requests to skip the cache.

void nsICacheEntryDescriptor::doomAndFailPendingRequests ( in nsresult  status  ) 
string nsICacheEntryDescriptor::getMetaDataElement ( in string  key  ) 

Methods for accessing meta data.

Meta data is a table of key/value string pairs. The strings do not have to conform to any particular charset, but they must be null terminated.

void nsICacheEntryDescriptor::markValid (  ) 

A writer must validate this cache object before any readers are given a descriptor to the object.

nsIInputStream nsICacheEntryDescriptor::openInputStream ( in unsigned long  offset  ) 

Open blocking input stream to cache data.

This will fail if the cache entry IS NOT stream based. Use the stream transport service to asynchronously read this stream on a background thread. The returned stream MAY implement nsISeekableStream.

Parameters:
offset read starting from this offset into the cached data. an offset beyond the end of the stream has undefined consequences.
Returns:
blocking, unbuffered input stream.
nsIOutputStream nsICacheEntryDescriptor::openOutputStream ( in unsigned long  offset  ) 

Open blocking output stream to cache data.

This will fail if the cache entry IS NOT stream based. Use the stream transport service to asynchronously write to this stream on a background thread. The returned stream MAY implement nsISeekableStream.

If opening an output stream to existing cached data, the data will be truncated to the specified offset.

Parameters:
offset write starting from this offset into the cached data. an offset beyond the end of the stream has undefined consequences.
Returns:
blocking, unbuffered output stream.
void nsICacheEntryDescriptor::setDataSize ( in unsigned long  size  ) 

Set the cache entry data size.

This will fail if the cache entry IS stream based.

void nsICacheEntryDescriptor::setExpirationTime ( in PRUint32  expirationTime  ) 

Set the time at which the cache entry should be considered invalid (in seconds since the Epoch).

void nsICacheEntryDescriptor::setMetaDataElement ( in string  key,
in string  value 
)
void nsICacheEntryDescriptor::visitMetaData ( in nsICacheMetaDataVisitor  visitor  ) 

Visitor will be called with key/value pair for each meta data element.


Member Data Documentation

Get the access granted to this descriptor.

See nsICache.idl for the definitions of the access modes and a thorough description of their corresponding meanings.

Get/set the cache data element.

This will fail if the cache entry IS stream based. The cache entry holds a strong reference to this object. The object will be released when the cache entry is destroyed.

Get the disk file associated with the cache entry.

Get/set security info on the cache entry for this descriptor.

This fails if the storage policy is not STORE_IN_MEMORY.

Get/set the storage policy of the cache entry.

See nsICache.idl for the definitions of the storage policies.


The documentation for this interface was generated from the following file: