nsICacheEntryOpenCallback.idl (3549B)
1 /* This Source Code Form is subject to the terms of the Mozilla Public 2 * License, v. 2.0. If a copy of the MPL was not distributed with this 3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ 4 5 #include "nsISupports.idl" 6 7 interface nsICacheEntry; 8 9 [scriptable, uuid(1fc9fe11-c6ac-4748-94bd-8555a5a12b94)] 10 interface nsICacheEntryOpenCallback : nsISupports 11 { 12 /** 13 * State of the entry determined by onCacheEntryCheck. 14 * 15 * ENTRY_WANTED - the consumer is interested in the entry, we will pass it. 16 * RECHECK_AFTER_WRITE_FINISHED - the consumer cannot use the entry while data is 17 * still being written and wants to check it again after the current write is 18 * finished. This actually prevents concurrent read/write and is used with 19 * non-resumable HTTP responses. 20 * ENTRY_NEEDS_REVALIDATION - entry needs to be revalidated first with origin server, 21 * this means the loading channel will decide whether to use the entry content 22 * as is after it gets a positive response from the server about validity of the 23 * content ; when a new content needs to be loaded from the server, the loading 24 * channel opens a new entry with OPEN_TRUNCATE flag which dooms the one 25 * this check has been made for. 26 * ENTRY_NOT_WANTED - the consumer is not interested in the entry, we will not pass it. 27 */ 28 const unsigned long ENTRY_WANTED = 0; 29 const unsigned long RECHECK_AFTER_WRITE_FINISHED = 1; 30 const unsigned long ENTRY_NEEDS_REVALIDATION = 2; 31 const unsigned long ENTRY_NOT_WANTED = 3; 32 33 /** 34 * Callback to perform any validity checks before the entry should be used. 35 * Called before onCacheEntryAvailable callback, depending on the result it 36 * may be called more then one time. 37 * 38 * This callback is ensured to be called on the same thread on which asyncOpenURI 39 * has been called, unless nsICacheStorage.CHECK_MULTITHREADED flag has been specified. 40 * In that case this callback can be invoked on any thread, usually it is the cache I/O 41 * or cache management thread. 42 * 43 * IMPORTANT NOTE: 44 * This callback may be invoked sooner then respective asyncOpenURI call exits. 45 * 46 * @param aEntry 47 * An entry to examine. Consumer has a chance to decide whether the 48 * entry is valid or not. 49 * @return 50 * State of the entry, see the constants just above. 51 */ 52 unsigned long onCacheEntryCheck(in nsICacheEntry aEntry); 53 54 /** 55 * Callback giving actual result of asyncOpenURI. It may give consumer the cache 56 * entry or a failure result when it's not possible to open it from some reason. 57 * This callback is ensured to be called on the same thread on which asyncOpenURI 58 * has been called. 59 * 60 * IMPORTANT NOTE: 61 * This callback may be invoked sooner then respective asyncOpenURI call exits. 62 * 63 * @param aEntry 64 * The entry bound to the originally requested URI. 65 * @param aNew 66 * Whether no data so far has been stored for this entry, i.e. reading 67 * it will just fail. When aNew is true, a server request should be 68 * made and data stored to this new entry. 69 * @param aResult 70 * Result of the request. This may be a failure only when one of these 71 * issues occur: 72 * - the cache storage service could not be started due to some unexpected 73 * faulure 74 * - there is not enough disk space to create new entries 75 */ 76 void onCacheEntryAvailable(in nsICacheEntry aEntry, 77 in boolean aNew, 78 in nsresult aResult); 79 };