/* 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/. */
interface nsICacheInfoChannel : nsISupports
* Get the number of times the cache entry has been opened. This attribute is
* equivalent to nsICachingChannel.cacheToken.fetchCount.
* @throws NS_ERROR_NOT_AVAILABLE if the cache entry or the alternate data
* cache entry cannot be read.
readonly attribute int32_t cacheTokenFetchCount;
* Get expiration time from cache token. This attribute is equivalent to
readonly attribute uint32_t cacheTokenExpirationTime;
* Set/get charset of cache entry. Accessing this attribute is equivalent to
* calling nsICachingChannel.cacheToken.getMetaDataElement("charset") and
attribute ACString cacheTokenCachedCharset;
* TRUE if this channel's data is being loaded from the cache. This value
* is undefined before the channel fires its OnStartRequest notification
* and after the channel fires its OnStopRequest notification.
* The unique ID of the corresponding nsICacheEntry from which the response is
* retrieved. By comparing the returned value, we can judge whether the data
* of two distinct nsICacheInfoChannels is from the same nsICacheEntry. This
* scenario could be useful when verifying whether the alternative data from
* one nsICacheInfochannel matches the main data from another one.
* Note: NS_ERROR_NOT_AVAILABLE is thrown when a nsICacheInfoChannel has no
* valid corresponding nsICacheEntry.
* Set/get the cache key. This integer uniquely identifies the data in
* the cache for this channel.
* A cache key retrieved from a particular instance of nsICacheInfoChannel
* could be set on another instance of nsICacheInfoChannel provided the
* underlying implementations are compatible and provided the new
* channel instance was created with the same URI. The implementation of
* nsICacheInfoChannel would be expected to use the cache entry identified
* by the cache token. Depending on the value of nsIRequest::loadFlags,
* the cache entry may be validated, overwritten, or simply read.
* The cache key may be 0 indicating that the URI of the channel is
* sufficient to locate the same cache entry. Setting a 0 cache key
* is likewise valid.
attribute unsigned long cacheKey;
* Tells the channel to behave as if the LOAD_FROM_CACHE flag has been set,
* but without affecting the loads for the entire loadGroup in case of this
* channel being the default load group's channel.
attribute boolean allowStaleCacheContent;
* Calling this method instructs the channel to serve the alternative data
* if that was previously saved in the cache, otherwise it will serve the
* real data.
* Must be called before AsyncOpen.
void preferAlternativeDataType(in ACString type);
* Get the preferred alternative data type set by preferAlternativeDataType().
* This attribute stands for the desired data type instead of the type of the
* information retrieved from the network stack.
readonly attribute ACString preferredAlternativeDataType;
* Holds the type of the alternative data representation that the channel
* is returning.
* Is empty string if no alternative data representation was requested, or
* if the requested representation wasn't found in the cache.
* Can only be called during or after OnStartRequest.
readonly attribute ACString alternativeDataType;
* Opens and returns an output stream that a consumer may use to save an
* alternate representation of the data.
* Must be called after the OnStopRequest that delivered the real data.
* The consumer may choose to replace the saved alt representation.
* Opening the output stream will fail if there are any open input streams
* reading the already saved alt representation.
* @param type
* type of the alternative data representation
* @param predictedSize
* Predicted size of the data that will be written. It's used to decide
* whether the resulting entry would exceed size limit, in which case
* an error is thrown. If the size isn't known in advance, -1 should be
nsIOutputStream openAlternativeOutputStream(in ACString type, in long long predictedSize);