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/* 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 "nsISupports.idl"
interface nsICacheEntry;
[scriptable, uuid(1fc9fe11-c6ac-4748-94bd-8555a5a12b94)]
interface nsICacheEntryOpenCallback : nsISupports
{
/**
* State of the entry determined by onCacheEntryCheck.
*
* ENTRY_WANTED - the consumer is interested in the entry, we will pass it.
* RECHECK_AFTER_WRITE_FINISHED - the consumer cannot use the entry while data is
* still being written and wants to check it again after the current write is
* finished. This actually prevents concurrent read/write and is used with
* non-resumable HTTP responses.
* ENTRY_NEEDS_REVALIDATION - entry needs to be revalidated first with origin server,
* this means the loading channel will decide whether to use the entry content
* as is after it gets a positive response from the server about validity of the
* content ; when a new content needs to be loaded from the server, the loading
* channel opens a new entry with OPEN_TRUNCATE flag which dooms the one
* this check has been made for.
* ENTRY_NOT_WANTED - the consumer is not interested in the entry, we will not pass it.
*/
const unsigned long ENTRY_WANTED = 0;
const unsigned long RECHECK_AFTER_WRITE_FINISHED = 1;
const unsigned long ENTRY_NEEDS_REVALIDATION = 2;
const unsigned long ENTRY_NOT_WANTED = 3;
/**
* Callback to perform any validity checks before the entry should be used.
* Called before onCacheEntryAvailable callback, depending on the result it
* may be called more then one time.
*
* This callback is ensured to be called on the same thread on which asyncOpenURI
* has been called, unless nsICacheStorage.CHECK_MULTITHREADED flag has been specified.
* In that case this callback can be invoked on any thread, usually it is the cache I/O
* or cache management thread.
*
* IMPORTANT NOTE:
* This callback may be invoked sooner then respective asyncOpenURI call exits.
*
* @param aEntry
* An entry to examine. Consumer has a chance to decide whether the
* entry is valid or not.
* @return
* State of the entry, see the constants just above.
*/
unsigned long onCacheEntryCheck(in nsICacheEntry aEntry);
/**
* Callback giving actual result of asyncOpenURI. It may give consumer the cache
* entry or a failure result when it's not possible to open it from some reason.
* This callback is ensured to be called on the same thread on which asyncOpenURI
* has been called.
*
* IMPORTANT NOTE:
* This callback may be invoked sooner then respective asyncOpenURI call exits.
*
* @param aEntry
* The entry bound to the originally requested URI.
* @param aNew
* Whether no data so far has been stored for this entry, i.e. reading
* it will just fail. When aNew is true, a server request should be
* made and data stored to this new entry.
* @param aResult
* Result of the request. This may be a failure only when one of these
* issues occur:
* - the cache storage service could not be started due to some unexpected
* faulure
* - there is not enough disk space to create new entries
*/
void onCacheEntryAvailable(in nsICacheEntry aEntry,
in boolean aNew,
in nsresult aResult);
};
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