gecko-dev/netwerk/cache2/nsICacheStorage.idl

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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 nsIURI;
interface nsICacheEntry;
interface nsICacheEntryOpenCallback;
interface nsICacheEntryDoomCallback;
interface nsICacheStorageVisitor;
/**
* Representation of a cache storage. There can be just-in-mem,
* in-mem+on-disk, in-mem+on-disk+app-cache or just a specific
* app-cache storage.
*/
[scriptable, uuid(35d104a6-d252-4fd4-8a56-3c14657cad3b)]
interface nsICacheStorage : nsISupports
{
/**
* Placeholder for specifying "no special flags" during open.
*/
const uint32_t OPEN_NORMALLY = 0;
/**
* Rewrite any existing data when opening a URL.
*/
const uint32_t OPEN_TRUNCATE = 1 << 0;
/**
* Only open an existing entry. Don't create a new one.
*/
const uint32_t OPEN_READONLY = 1 << 1;
/**
* Use for first-paint blocking loads.
*/
const uint32_t OPEN_PRIORITY = 1 << 2;
/**
* Bypass the cache load when write is still in progress.
*/
const uint32_t OPEN_BYPASS_IF_BUSY = 1 << 3;
/**
* Perform the cache entry check (onCacheEntryCheck invocation) on any thread
* for optimal perfomance optimization. If this flag is not specified it is
* ensured that onCacheEntryCheck is called on the same thread as respective
* asyncOpen has been called.
*/
const uint32_t CHECK_MULTITHREADED = 1 << 4;
/**
* Don't automatically update any 'last used' metadata of the entry.
*/
const uint32_t OPEN_SECRETLY = 1 << 5;
/**
* Asynchronously opens a cache entry for the specified URI.
* Result is fetched asynchronously via the callback.
*
* @param aURI
* The URI to search in cache or to open for writting.
* @param aIdExtension
* Any string that will extend (distinguish) the entry. Two entries
* with the same aURI but different aIdExtension will be comletely
* different entries. If you don't know what aIdExtension should be
* leave it empty.
* @param aFlags
* OPEN_NORMALLY - open cache entry normally for read and write
* OPEN_TRUNCATE - delete any existing entry before opening it
* OPEN_READONLY - don't create an entry if there is none
* OPEN_PRIORITY - give this request a priority over others
* OPEN_BYPASS_IF_BUSY - backward compatibility only, LOAD_BYPASS_LOCAL_CACHE_IF_BUSY
* CHECK_MULTITHREADED - onCacheEntryCheck may be called on any thread, consumer
* implementation is thread-safe
* @param aCallback
* The consumer that receives the result.
* IMPORTANT: The callback may be called sooner the method returns.
*/
void asyncOpenURI(in nsIURI aURI, in ACString aIdExtension,
in uint32_t aFlags,
in nsICacheEntryOpenCallback aCallback);
/**
* Immediately opens a new and empty cache entry in the storage, any existing
* entries are immediately doomed. This is similar to the recreate() method
* on nsICacheEntry.
*
* Storage may not implement this method and throw NS_ERROR_NOT_IMPLEMENTED.
* In that case consumer must use asyncOpen with OPEN_TRUNCATE flag and get
* the new entry via a callback.
*
* @param aURI @see asyncOpenURI
* @param aIdExtension @see asyncOpenURI
*/
nsICacheEntry openTruncate(in nsIURI aURI,
in ACString aIdExtension);
/**
* Synchronously check on existance of an entry. In case of disk entries
* this uses information from the cache index. When the index data are not
* up to date or index is still building, NS_ERROR_NOT_AVAILABLE is thrown.
* The same error may throw any storage implementation that cannot determine
* entry state without blocking the caller.
*/
boolean exists(in nsIURI aURI, in ACString aIdExtension);
/**
* Asynchronously removes an entry belonging to the URI from the cache.
*/
void asyncDoomURI(in nsIURI aURI, in ACString aIdExtension,
in nsICacheEntryDoomCallback aCallback);
/**
* Asynchronously removes all cached entries under this storage.
* NOTE: Disk storage also evicts memory storage.
*/
void asyncEvictStorage(in nsICacheEntryDoomCallback aCallback);
/**
* Visits the storage and its entries.
* NOTE: Disk storage also visits memory storage.
*/
void asyncVisitStorage(in nsICacheStorageVisitor aVisitor,
in boolean aVisitEntries);
};