/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at
http://mozilla.org/MPL/2.0/. */
#include "nsICacheInfoChannel.idl"
interface nsIFile;
/**
* A channel may optionally implement this interface to allow clients
* to affect its behavior with respect to how it uses the cache service.
*
* This interface provides:
* 1) Support for "stream as file" semantics (for JAR and plugins).
* 2) Support for "pinning" cached data in the cache (for printing and save-as).
* 3) Support for uniquely identifying cached data in cases when the URL
* is insufficient (e.g., HTTP form submission).
*/
[scriptable, builtinclass, uuid(dd1d6122-5ecf-4fe4-8f0f-995e7ab3121a)]
interface nsICachingChannel : nsICacheInfoChannel
{
/**
* Set/get the cache token... uniquely identifies the data in the cache.
* Holding a reference to this token prevents the cached data from being
* removed.
*
* A cache token retrieved from a particular instance of nsICachingChannel
* could be set on another instance of nsICachingChannel provided the
* underlying implementations are compatible. The implementation of
* nsICachingChannel would be expected to only read from the cache entry
* identified by the cache token and not try to validate it.
*
* The cache token can be QI'd to a nsICacheEntryInfo if more detail
* about the cache entry is needed (e.g., expiration time).
*/
attribute nsISupports cacheToken;
/**
* Instructs the channel to only store the metadata of the entry, and not
* the content. When reading an existing entry, this automatically sets
* LOAD_ONLY_IF_MODIFIED flag.
* Must be called before asyncOpen().
*/
attribute boolean cacheOnlyMetadata;
/**
* Tells the channel to use the pinning storage.
*/
attribute boolean pin;
/**
* Overrides cache validation for a time specified in seconds.
*
* @param aSecondsToTheFuture
*
*/
void forceCacheEntryValidFor(in unsigned long aSecondsToTheFuture);
/**************************************************************************
* Caching channel specific load flags:
*/
/**
* This load flag inhibits fetching from the net. An error of
* NS_ERROR_DOCUMENT_NOT_CACHED will be sent to the listener's
* onStopRequest if network IO is necessary to complete the request.
*
* This flag can be used to find out whether fetching this URL would
* cause validation of the cache entry via the network.
*
* Combining this flag with LOAD_BYPASS_LOCAL_CACHE will cause all
* loads to fail.
*/
const unsigned long LOAD_NO_NETWORK_IO = 1 << 26;
/**
* This load flag causes the local cache to be skipped when fetching a
* request. Unlike LOAD_BYPASS_CACHE, it does not force an end-to-end load
* (i.e., it does not affect proxy caches).
*/
const unsigned long LOAD_BYPASS_LOCAL_CACHE = 1 << 28;
/**
* This load flag causes the local cache to be skipped if the request
* would otherwise block waiting to access the cache.
*/
const unsigned long LOAD_BYPASS_LOCAL_CACHE_IF_BUSY = 1 << 29;
/**
* This load flag inhibits fetching from the net if the data in the cache
* has been evicted. An error of NS_ERROR_DOCUMENT_NOT_CACHED will be sent
* to the listener's onStopRequest in this case. This flag is set
* automatically when the application is offline.
*/
const unsigned long LOAD_ONLY_FROM_CACHE = 1 << 30;
/**
* This load flag controls what happens when a document would be loaded
* from the cache to satisfy a call to AsyncOpen. If this attribute is
* set to TRUE, then the document will not be loaded from the cache. A
* stream listener can check nsICachingChannel::isFromCache to determine
* if the AsyncOpen will actually result in data being streamed.
*
* If this flag has been set, and the request can be satisfied via the
* cache, then the OnDataAvailable events will be skipped. The listener
* will only see OnStartRequest followed by OnStopRequest.
*/
const unsigned long LOAD_ONLY_IF_MODIFIED = 1 << 31;
};
