/* 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" #include "nsIVariant.idl" interface nsIKeyValueDatabaseCallback; interface nsIKeyValueEnumeratorCallback; interface nsIKeyValuePairCallback; interface nsIKeyValueVariantCallback; interface nsIKeyValueVoidCallback; interface nsIKeyValuePair; /** * The nsIKeyValue* interfaces provide a simple, asynchronous API to a key/value * storage engine. Basic put/get/has/delete operations are supported, as is * enumeration of key/value pairs and the use of multiple named databases within * a single storage file. Operations have ACID semantics. * * This API does not (yet) support transactions, so it will not be appropriate * for all use cases. Extension of this API to support transactions is tracked * by bug 1499238. * * The kvstore.jsm module wraps this API in a more idiomatic, Promise-based * JS API that supports async/await. In most cases, you're better off using * that API from JS rather than using this one directly. Bug 1512319 tracks * native support for Promise in Rust-implemented XPCOM methods. */ /** * The key/value service. Enables retrieval of handles to key/value databases. */ [scriptable, builtinclass, rust_sync, uuid(46c893dd-4c14-4de0-b33d-a1be18c6d062)] interface nsIKeyValueService : nsISupports { /** * Get a handle to an existing database or a newly-created one * at the specified path and with the given name. * * The service supports multiple named databases at the same path * (i.e. within the same storage file), so you can call this method * multiple times with the same path and different names to retrieve * multiple databases stored in the same location on disk. */ void getOrCreate( in nsIKeyValueDatabaseCallback callback, in AUTF8String path, in AUTF8String name); }; /** * A key/value database. * * All methods are asynchronous and take a callback as their first argument. * The types of the callbacks vary, but they can all be implemented in JS * via an object literal with the relevant methods. */ [scriptable, builtinclass, rust_sync, uuid(c449398e-174c-425b-8195-da6aa0ccd9a5)] interface nsIKeyValueDatabase : nsISupports { /** * Write the specified key/value pair to the database. */ void put( in nsIKeyValueVoidCallback callback, in AUTF8String key, in nsIVariant value); /** * Write multiple key/value pairs to the database. * * It supports two types of write: * * Put a key/value pair into the database. It takes a nsIKeyValuePair * where its key and value follow the same types as the put() method. * * Delete a key/value pair from database. It takes a nsIkeyValuePair * where its value property must be null or undefined. * * This features the "all-or-nothing" semantics, i.e. if any error occurs * during the call, it will rollback the previous writes and terminate the * call. In addition, writeMany should be more efficient than calling "put" * or "delete" for every single key/value pair since it does all the writes * in a single transaction. * * Note: * * If there are multiple values with the same key in the specified * pairs, only the last value will be stored in the database. * * Deleting a key that is not in the database will be silently ignored. * * If the same key gets put and deleted for multiple times, the final * state of that key is subject to the ordering of the put(s) and delete(s). */ void writeMany( in nsIKeyValueVoidCallback callback, in Array pairs); /** * Retrieve the value of the specified key from the database. * * If the key/value pair doesn't exist in the database, and you specify * a default value, then the default value will be returned. Otherwise, * the callback's resolve() method will be called with a variant * of type VTYPE_EMPTY, which translates to the JS `null` value. */ void get( in nsIKeyValueVariantCallback callback, in AUTF8String key, [optional] in nsIVariant defaultValue); /** * Determine whether or not the key exists in the database. */ void has( in nsIKeyValueVariantCallback callback, in AUTF8String key); /** * Remove the key/value pair with the given key from the database. * * If the given key doesn't exist in the database, this operation doesn't * fail; or rather, it fails silently, calling the resolve() method * of its callback rather than reject(). If you want to know whether * or not a key exists when deleting it, call the has() method first. */ void delete( in nsIKeyValueVoidCallback callback, in AUTF8String key); /** * Clear all the key/value pairs from the database. */ void clear(in nsIKeyValueVoidCallback callback); /** * Enumerate key/value pairs, starting with the first key equal to * or greater than the "from" key (inclusive) and ending with the last key * less than the "to" key (exclusive) sorted lexicographically. * * If either key is omitted, the range extends to the first and/or last key * in the database. */ void enumerate( in nsIKeyValueEnumeratorCallback callback, [optional] in AUTF8String fromKey, [optional] in AUTF8String toKey); }; /** * A key/value pair. Returned by nsIKeyValueEnumerator.getNext(). */ [scriptable, uuid(bc37b06a-23b5-4b32-8281-4b8479601c7e)] interface nsIKeyValuePair : nsISupports { readonly attribute AUTF8String key; readonly attribute nsIVariant value; }; /** * An enumerator of key/value pairs. Although its methods are similar * to those of nsISimpleEnumerator, this interface's getNext() method returns * an nsIKeyValuePair rather than an nsISupports, so consumers don't need * to QI it to that interface; but this interface doesn't implement the JS * iteration protocol (because the Rust-XPCOM bindings don't yet support it), * which is another reason why you should use the kvstore.jsm module from JS * instead of accessing this API directly. */ [scriptable, builtinclass, rust_sync, uuid(b9ba7116-b7ff-4717-9a28-a08e6879b199)] interface nsIKeyValueEnumerator : nsISupports { bool hasMoreElements(); nsIKeyValuePair getNext(); }; /** * A callback for the nsIKeyValueService.getOrCreate() method. * * The result is an nsIKeyValueDatabase. */ [scriptable, uuid(2becc1f8-2d80-4b63-92a8-24ee8f79ee45)] interface nsIKeyValueDatabaseCallback : nsISupports { void resolve(in nsIKeyValueDatabase database); void reject(in AUTF8String message); }; /** * A callback for the nsIKeyValueDatabase.enumerate() method. * * The result is an nsIKeyValueEnumerator. */ [scriptable, uuid(b7ea2183-880b-4424-ab24-5aa1555b775d)] interface nsIKeyValueEnumeratorCallback : nsISupports { void resolve(in nsIKeyValueEnumerator enumerator); void reject(in AUTF8String message); }; /** * A callback for the nsIKeyValueEnumerator.getNext() method. * * The result is the next key/value pair, expressed as separate key and value * parameters. */ [scriptable, uuid(50f65485-ec1e-4307-812b-b8a15e1f382e)] interface nsIKeyValuePairCallback : nsISupports { void resolve(in nsIKeyValuePair pair); void reject(in AUTF8String message); }; /** * A callback for the nsIKeyValueDatabase.has() and .get() methods. * * The result is an nsIVariant, which is always a boolean for the has() method * and can be any supported data type for the get() method. */ [scriptable, uuid(174ebfa1-74ea-42a7-aa90-85bbaf1da4bf)] interface nsIKeyValueVariantCallback : nsISupports { void resolve(in nsIVariant result); void reject(in AUTF8String message); }; /** * A callback for the nsIKeyValueDatabase.put() and .delete() methods. * * There is no result, but the resolve() method is still called when those * async operations complete, to notify consumers of completion. */ [scriptable, uuid(0c17497a-ccf8-451a-838d-9dfa7f846379)] interface nsIKeyValueVoidCallback : nsISupports { void resolve(); void reject(in AUTF8String message); };