/* This file is part of akonadiresources. Copyright (c) 2006 Till Adam Copyright (c) 2007 Volker Krause This library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with this library; see the file COPYING.LIB. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. */ #ifndef AKONADI_RESOURCEBASE_H #define AKONADI_RESOURCEBASE_H #include "akonadi_export.h" #include #include #include #include class KJob; class Akonadi__ResourceAdaptor; class ResourceState; namespace Akonadi { class ResourceBasePrivate; /** * @short The base class for all Akonadi resources. * * This class should be used as a base class by all resource agents, * because it encapsulates large parts of the protocol between * resource agent, agent manager and the Akonadi storage. * * It provides many convenience methods to make implementing a * new Akonadi resource agent as simple as possible. * *

How to write a resource

* * The following provides an overview of what you need to do to implement * your own Akonadi resource. In the following, the term 'backend' refers * to the entity the resource connects with Akonadi, be it a single file * or a remote server. * * @todo Complete this (online/offline state management) * *
Basic %Resource Framework
* * The following is needed to create a new resource: * - A new class deriving from Akonadi::ResourceBase, implementing at least all * pure-virtual methods, see below for further details. * - call init() in your main() function. * - a .desktop file similar to the following example * \code * [Desktop Entry] * Encoding=UTF-8 * Name=My Akonadi Resource * Type=AkonadiResource * Exec=akonadi_my_resource * Icon=my-icon * * X-Akonadi-MimeTypes= * X-Akonadi-Capabilities=Resource * X-Akonadi-Identifier=akonadi_my_resource * \endcode * *
Handling PIM Items
* * To follow item changes in the backend, the following steps are necessary: * - Implement retrieveItems() to synchronize all items in the given * collection. If the backend supports incremental retrieval, * implementing support for that is recommended to improve performance. * - Convert the items provided by the backend to Akonadi items. * This typically happens either in retrieveItems() if you retrieved * the collection synchronously (not recommended for network backends) or * in the result slot of the asynchronous retrieval job. * Converting means to create Akonadi::Item objects for every retrieved * item. It's very important that every object has its remote identifier set. * - Call itemsRetrieved() or itemsRetrievedIncremental() respectively * with the item objects created above. The Akonadi storage will then be * updated automatically. Note that it is usually not necessary to manipulate * any item in the Akonadi storage manually. * * To fetch item data on demand, the method retrieveItem() needs to be * reimplemented. Fetch the requested data there and call itemRetrieved() * with the result item. * * To write local changes back to the backend, you need to re-implement * the following three methods: * - itemAdded() * - itemChanged() * - itemRemoved() * * Note that these three functions don't get the full payload of the items by default, * you need to change the item fetch scope of the change recorder to fetch the full * payload. This can be expensive with big payloads, though.
* Once you have handled changes in these methods, call changeCommitted(). * These methods are called whenever a local item related to this resource is * added, modified or deleted. They are only called if the resource is online, otherwise * all changes are recorded and replayed as soon the resource is online again. * *
Handling Collections
* * To follow collection changes in the backend, the following steps are necessary: * - Implement retrieveCollections() to retrieve collections from the backend. * If the backend supports incremental collections updates, implementing * support for that is recommended to improve performance. * - Convert the collections of the backend to Akonadi collections. * This typically happens either in retrieveCollections() if you retrieved * the collection synchronously (not recommended for network backends) or * in the result slot of the asynchronous retrieval job. * Converting means to create Akonadi::Collection objects for every retrieved * collection. It's very important that every object has its remote identifier * and its parent remote identifier set. * - Call collectionsRetrieved() or collectionsRetrievedIncremental() respectively * with the collection objects created above. The Akonadi storage will then be * updated automatically. Note that it is usually not necessary to manipulate * any collection in the Akonadi storage manually. * * * To write local collection changes back to the backend, you need to re-implement * the following three methods: * - collectionAdded() * - collectionChanged() * - collectionRemoved() * Once you have handled changes in these methods call changeCommitted(). * These methods are called whenever a local collection related to this resource is * added, modified or deleted. They are only called if the resource is online, otherwise * all changes are recorded and replayed as soon the resource is online again. * * @todo Convenience base class for collection-less resources */ // FIXME_API: API dox need to be updated for Observer approach (kevin) class AKONADI_EXPORT ResourceBase : public AgentBase { Q_OBJECT public: /** * Use this method in the main function of your resource * application to initialize your resource subclass. * This method also takes care of creating a KApplication * object and parsing command line arguments. * * @note In case the given class is also derived from AgentBase::Observer * it gets registered as its own observer (see AgentBase::Observer), e.g. * resourceInstance->registerObserver( resourceInstance ); * * @code * * class MyResource : public ResourceBase * { * ... * }; * * int main( int argc, char **argv ) * { * return ResourceBase::init( argc, argv ); * } * * @endcode * * @param argc number of arguments * @param argv string arguments */ template static int init(int argc, char **argv) { const QString id = parseArguments(argc, argv); KApplication app; T *r = new T(id); // check if T also inherits AgentBase::Observer and // if it does, automatically register it on itself Observer *observer = dynamic_cast(r); if (observer != 0) { r->registerObserver(observer); } return init(r); } /** * This method is used to set the name of the resource. */ void setName(const QString &name); /** * Returns the name of the resource. */ QString name() const; /** * Enable or disable automatic progress reporting. By default, it is enabled. * When enabled, the resource will automatically emit the signals percent() and status() * while syncing items or collections. * * The automatic progress reporting is done on a per item / per collection basis, so if a * finer granularity is desired, automatic reporting should be disabled and the subclass should * emit the percent() and status() signals itself. * * @param enabled Whether or not automatic emission of the signals is enabled. * @since 4.7 */ void setAutomaticProgressReporting(bool enabled); Q_SIGNALS: /** * This signal is emitted whenever the name of the resource has changed. * * @param name The new name of the resource. */ void nameChanged(const QString &name); /** * Emitted when a full synchronization has been completed. */ void synchronized(); /** * Emitted when a collection attributes synchronization has been completed. * * @param collectionId The identifier of the collection whose attributes got synchronized. * @since 4.6 */ void attributesSynchronized(qlonglong collectionId); /** * Emitted when a collection tree synchronization has been completed. * * @since 4.8 */ void collectionTreeSynchronized(); /** * Emitted when the item synchronization processed the current batch and is ready for a new one. * Use this to throttle the delivery to not overload Akonadi. * * Throttling can be used during item retrieval (retrieveItems(Akonadi::Collection)) in streaming mode. * To throttle only deliver itemSyncBatchSize() items, and wait for this signal, then again deliver * @param remainingBatchSize items. * * By always only providing the number of items required to process the batch, the items don't pile * up in memory and items are only provided as fast as Akonadi can process them. * * @see batchSize() * * @since 4.14 */ void retrieveNextItemSyncBatch(int remainingBatchSize); protected Q_SLOTS: /** * Retrieve the collection tree from the remote server and supply it via * collectionsRetrieved() or collectionsRetrievedIncremental(). * @see collectionsRetrieved(), collectionsRetrievedIncremental() */ virtual void retrieveCollections() = 0; /** * Retrieve the attributes of a single collection from the backend. The * collection to retrieve attributes for is provided as @p collection. * Add the attributes parts and call collectionAttributesRetrieved() * when done. * * @param collection The collection whose attributes should be retrieved. * @see collectionAttributesRetrieved() * @since 4.6 */ // KDE5: Make it pure virtual, for now can be called only by invokeMethod() // in order to simulate polymorphism void retrieveCollectionAttributes(const Akonadi::Collection &collection); /** * Retrieve all (new/changed) items in collection @p collection. * It is recommended to use incremental retrieval if the backend supports that * and provide the result by calling itemsRetrievedIncremental(). * If incremental retrieval is not possible, provide the full listing by calling * itemsRetrieved( const Item::List& ). * In any case, ensure that all items have a correctly set remote identifier * to allow synchronizing with items already existing locally. * In case you don't want to use the built-in item syncing code, store the retrieved * items manually and call itemsRetrieved() once you are done. * @param collection The collection whose items to retrieve. * @see itemsRetrieved( const Item::List& ), itemsRetrievedIncremental(), itemsRetrieved(), currentCollection(), batchSize() */ virtual void retrieveItems(const Akonadi::Collection &collection) = 0; /** * Returns the batch size used during the item sync. * * This can be used to throttle the item delivery. * * @see retrieveNextItemSyncBatch(int), retrieveItems(Akonadi::Collection) * @since 4.14 */ int itemSyncBatchSize() const; /** * Set the batch size used during the item sync. * The default is 10. * * @see retrieveNextItemSyncBatch(int) * @since 4.14 */ void setItemSyncBatchSize(int batchSize); /** * Retrieve a single item from the backend. The item to retrieve is provided as @p item. * Add the requested payload parts and call itemRetrieved() when done. * @param item The empty item whose payload should be retrieved. Use this object when delivering * the result instead of creating a new item to ensure conflict detection will work. * @param parts The item parts that should be retrieved. * @return false if there is an immediate error when retrieving the item. * @see itemRetrieved() */ virtual bool retrieveItem(const Akonadi::Item &item, const QSet &parts) = 0; /** * Abort any activity in progress in the backend. By default this method does nothing. * * @since 4.6 */ // KDE5: Make it pure virtual, for now can be called only by invokeMethod() // in order to simulate polymorphism void abortActivity(); /** * Dump resource internals, for debugging. * @since 4.9 */ // KDE5: Make it pure virtual, for now can be called only by invokeMethod() // in order to simulate polymorphism QString dumpResourceToString() const { return QString(); } protected: /** * Creates a base resource. * * @param id The instance id of the resource. */ ResourceBase(const QString &id); /** * Destroys the base resource. */ ~ResourceBase(); /** * Call this method from retrieveItem() once the result is available. * * @param item The retrieved item. */ void itemRetrieved(const Item &item); /** * Call this method from retrieveCollectionAttributes() once the result is available. * * @param collection The collection whose attributes got retrieved. * @since 4.6 */ void collectionAttributesRetrieved(const Collection &collection); /** * Resets the dirty flag of the given item and updates the remote id. * * Call whenever you have successfully written changes back to the server. * This implicitly calls changeProcessed(). * @param item The changed item. */ void changeCommitted(const Item &item); /** * Resets the dirty flag of all given items and updates remote ids. * * Call whenever you have successfully written changes back to the server. * This implicitly calls changeProcessed(). * @param items Changed items * * @since 4.11 */ void changesCommitted(const Item::List &items); /** * Resets the dirty flag of the given tag and updates the remote id. * * Call whenever you have successfully written changes back to the server. * This implicitly calls changeProcessed(). * @param tag Changed tag. * * @since 4.13 */ void changeCommitted(const Tag &tag); /** * Call whenever you have successfully handled or ignored a collection * change notification. * * This will update the remote identifier of @p collection if necessary, * as well as any other collection attributes. * This implicitly calls changeProcessed(). * @param collection The collection which changes have been handled. */ void changeCommitted(const Collection &collection); /** * Call this to supply the full folder tree retrieved from the remote server. * * @param collections A list of collections. * @see collectionsRetrievedIncremental() */ void collectionsRetrieved(const Collection::List &collections); /** * Call this to supply incrementally retrieved collections from the remote server. * * @param changedCollections Collections that have been added or changed. * @param removedCollections Collections that have been deleted. * @see collectionsRetrieved() */ void collectionsRetrievedIncremental(const Collection::List &changedCollections, const Collection::List &removedCollections); /** * Enable collection streaming, that is collections don't have to be delivered at once * as result of a retrieveCollections() call but can be delivered by multiple calls * to collectionsRetrieved() or collectionsRetrievedIncremental(). When all collections * have been retrieved, call collectionsRetrievalDone(). * @param enable @c true if collection streaming should be enabled, @c false by default */ void setCollectionStreamingEnabled(bool enable); /** * Call this method to indicate you finished synchronizing the collection tree. * * This is not needed if you use the built in syncing without collection streaming * and call collectionsRetrieved() or collectionRetrievedIncremental() instead. * If collection streaming is enabled, call this method once all collections have been delivered * using collectionsRetrieved() or collectionsRetrievedIncremental(). */ void collectionsRetrievalDone(); /** * Allows to keep locally changed collection parts during the collection sync. * * This is useful for resources to be able to provide default values during the collection * sync, while preserving eventual more up-to date values. * * Valid values are attribute types and "CONTENTMIMETYPE" for the collections content mimetypes. * * By default this is enabled for the EntityDisplayAttribute. * * @param parts A set parts for which local changes should be preserved. * @since 4.14 */ void setKeepLocalCollectionChanges(const QSet &parts); /** * Call this method to supply the full collection listing from the remote server. Items not present in the list * will be dropped from the Akonadi database. * * If the remote server supports incremental listing, it's strongly * recommended to use itemsRetrievedIncremental() instead. * @param items A list of items. * @see itemsRetrievedIncremental(). */ void itemsRetrieved(const Item::List &items); /** * Call this method when you want to use the itemsRetrieved() method * in streaming mode and indicate the amount of items that will arrive * that way. * * @warning By default this will end the item sync automatically once * sufficient items were delivered. To disable this and only make use * of the progress reporting, use setDisableAutomaticItemDeliveryDone() * * @note Use setItemStreamingEnabled( true ) + itemsRetrieved[Incremental]() * + itemsRetrieved() and avoid the automatic delivery based on the total * number of items. * * @param amount number of items that will arrive in streaming mode */ void setTotalItems(int amount); /** * Disables the automatic completion of the item sync, * based on the number of delivered items. * * This ensures that the item sync only finishes once itemsRetrieved() * is called, while still making it possible to use the automatic progress * reporting based on setTotalItems(). * * @note This needs to be called once, before the item sync started. * * @see setTotalItems(int) * @since 4.14 */ void setDisableAutomaticItemDeliveryDone(bool disable); /** * Enable item streaming. * Item streaming is disabled by default. * @param enable @c true if items are delivered in chunks rather in one big block. */ void setItemStreamingEnabled(bool enable); /** * Set transaction mode for item sync'ing. * @param mode item transaction mode * @see Akonadi::ItemSync::TransactionMode * @since 4.6 */ void setItemTransactionMode(ItemSync::TransactionMode mode); /** * Set the fetch scope applied for item synchronization. * By default, the one set on the changeRecorder() is used. However, it can make sense * to specify a specialized fetch scope for synchronization to improve performance. * The rule of thumb is to remove anything from this fetch scope that does not provide * additional information regarding whether and item has changed or not. This is primarily * relevant for backends not supporting incremental retrieval. * @param fetchScope The fetch scope to use by the internal Akonadi::ItemSync instance. * @see Akonadi::ItemSync * @since 4.6 */ void setItemSynchronizationFetchScope(const ItemFetchScope &fetchScope); /** * Call this method to supply incrementally retrieved items from the remote server. * * @param changedItems Items changed in the backend. * @param removedItems Items removed from the backend. */ void itemsRetrievedIncremental(const Item::List &changedItems, const Item::List &removedItems); /** * Call this method to indicate you finished synchronizing the current collection. * * This is not needed if you use the built in syncing without item streaming * and call itemsRetrieved() or itemsRetrievedIncremental() instead. * If item streaming is enabled, call this method once all items have been delivered * using itemsRetrieved() or itemsRetrievedIncremental(). * @see retrieveItems() */ void itemsRetrievalDone(); /** * Call this method to remove all items and collections of the resource from the * server cache. * * The method should not be used anymore * * @see invalidateCache() * @since 4.3 */ void clearCache(); /** * Call this method to invalidate all cached content in @p collection. * * The method should be used when the backend indicated that the cached content * is no longer valid. * * @param collection parent of the content to be invalidated in cache * @since 4.8 */ void invalidateCache(const Collection &collection); /** * Returns the collection that is currently synchronized. * @note Calling this method is only allowed during a collection synchronization task, that * is directly or indirectly from retrieveItems(). */ Collection currentCollection() const; /** * Returns the item that is currently retrieved. * @note Calling this method is only allowed during fetching a single item, that * is directly or indirectly from retrieveItem(). */ Item currentItem() const; /** * This method is called whenever the resource should start synchronize all data. */ void synchronize(); /** * This method is called whenever the collection with the given @p id * shall be synchronized. */ void synchronizeCollection(qint64 id); /** * This method is called whenever the collection with the given @p id * shall be synchronized. * @param recursive if true, a recursive synchronization is done */ void synchronizeCollection(qint64 id, bool recursive); /** * This method is called whenever the collection with the given @p id * shall have its attributes synchronized. * * @param id The id of the collection to synchronize * @since 4.6 */ void synchronizeCollectionAttributes(qint64 id); /** * Refetches the Collections. */ void synchronizeCollectionTree(); /** * Stops the execution of the current task and continues with the next one. */ void cancelTask(); /** * Stops the execution of the current task and continues with the next one. * Additionally an error message is emitted. * @param error additional error message to be emitted */ void cancelTask(const QString &error); /** * Stops the execution of the current task and continues with the next one. * The current task will be tried again later. * * This can be used to delay the task processing until the resource has reached a safe * state, e.g. login to a server succeeded. * * @note This does not change the order of tasks so if there is no task with higher priority * e.g. a custom task added with #Prepend the deferred task will be processed again. * * @since 4.3 */ void deferTask(); /** * Inherited from AgentBase. */ void doSetOnline(bool online); /** * Indicate the use of hierarchical remote identifiers. * * This means that it is possible to have two different items with the same * remoteId in different Collections. * * This should be called in the resource constructor as needed. * * @param enable whether to enable use of hierarchical remote identifiers * @since 4.4 */ void setHierarchicalRemoteIdentifiersEnabled(bool enable); friend class ResourceScheduler; friend class ::ResourceState; /** * Describes the scheduling priority of a task that has been queued * for execution. * * @see scheduleCustomTask * @since 4.4 */ enum SchedulePriority { Prepend, ///< The task will be executed as soon as the current task has finished. AfterChangeReplay, ///< The task is scheduled after the last ChangeReplay task in the queue Append ///< The task will be executed after all tasks currently in the queue are finished }; /** * Schedules a custom task in the internal scheduler. It will be queued with * all other tasks such as change replays and retrieval requests and eventually * executed by calling the specified method. With the priority parameter the * time of execution of the Task can be influenced. @see SchedulePriority * @param receiver The object the slot should be called on. * @param method The name of the method (and only the name, not signature, not SLOT(...) macro), * that should be called to execute this task. The method has to be a slot and take a QVariant as * argument. * @param argument A QVariant argument passed to the method specified above. Use this to pass task * parameters. * @param priority Priority of the task. Use this to influence the position in * the execution queue. * @since 4.4 */ void scheduleCustomTask(QObject *receiver, const char *method, const QVariant &argument, SchedulePriority priority = Append); /** * Indicate that the current task is finished. Use this method from the slot called via scheduleCustomTaks(). * As with all the other callbacks, make sure to either call taskDone() or cancelTask()/deferTask() on all * exit paths, otherwise the resource will hang. * @since 4.4 */ void taskDone(); /** * Dump the contents of the current ChangeReplay * @since 4.8.1 */ QString dumpNotificationListToString() const; /** * Dumps memory usage information to stdout. * For now it outputs the result of glibc's mallinfo(). * This is useful to check if your memory problems are due to poor management by glibc. * Look for a high value on fsmblks when interpreting results. * man mallinfo for more details. * @since 4.11 */ void dumpMemoryInfo() const; /** * Returns a string with memory usage information. * @see dumpMemoryInfo() * * @since 4.11 */ QString dumpMemoryInfoToString() const; /** * Dump the state of the scheduler * @since 4.8.1 */ QString dumpSchedulerToString() const; private: static QString parseArguments(int, char **); static int init(ResourceBase *r); // dbus resource interface friend class ::Akonadi__ResourceAdaptor; bool requestItemDelivery(qint64 uid, const QString &remoteId, const QString &mimeType, const QStringList &parts); QString requestItemDeliveryV2(qint64 uid, const QString &remoteId, const QString &mimeType, const QStringList &parts); private: Q_DECLARE_PRIVATE(ResourceBase) Q_PRIVATE_SLOT(d_func(), void slotAbortRequested()) Q_PRIVATE_SLOT(d_func(), void slotDeliveryDone(KJob *)) Q_PRIVATE_SLOT(d_func(), void slotCollectionSyncDone(KJob *)) Q_PRIVATE_SLOT(d_func(), void slotDeleteResourceCollection()) Q_PRIVATE_SLOT(d_func(), void slotDeleteResourceCollectionDone(KJob *)) Q_PRIVATE_SLOT(d_func(), void slotCollectionDeletionDone(KJob *)) Q_PRIVATE_SLOT(d_func(), void slotInvalidateCache(const Akonadi::Collection &)) Q_PRIVATE_SLOT(d_func(), void slotLocalListDone(KJob *)) Q_PRIVATE_SLOT(d_func(), void slotSynchronizeCollection(const Akonadi::Collection &)) Q_PRIVATE_SLOT(d_func(), void slotCollectionListDone(KJob *)) Q_PRIVATE_SLOT(d_func(), void slotSynchronizeCollectionAttributes(const Akonadi::Collection &)) Q_PRIVATE_SLOT(d_func(), void slotCollectionListForAttributesDone(KJob *)) Q_PRIVATE_SLOT(d_func(), void slotCollectionAttributesSyncDone(KJob *)) Q_PRIVATE_SLOT(d_func(), void slotItemSyncDone(KJob *)) Q_PRIVATE_SLOT(d_func(), void slotPercent(KJob *, unsigned long)) Q_PRIVATE_SLOT(d_func(), void slotDelayedEmitProgress()) Q_PRIVATE_SLOT(d_func(), void slotPrepareItemRetrieval(const Akonadi::Item &item)) Q_PRIVATE_SLOT(d_func(), void slotPrepareItemRetrievalResult(KJob *)) Q_PRIVATE_SLOT(d_func(), void changeCommittedResult(KJob *)) Q_PRIVATE_SLOT(d_func(), void slotSessionReconnected()) Q_PRIVATE_SLOT(d_func(), void slotRecursiveMoveReplay(RecursiveMover *)) Q_PRIVATE_SLOT(d_func(), void slotRecursiveMoveReplayResult(KJob *)) Q_PRIVATE_SLOT(d_func(), void slotItemRetrievalCollectionFetchDone(KJob *)); Q_PRIVATE_SLOT(d_func(), void slotAttributeRetrievalCollectionFetchDone(KJob *)); }; } #ifndef AKONADI_RESOURCE_MAIN /** * Convenience Macro for the most common main() function for Akonadi resources. */ #define AKONADI_RESOURCE_MAIN( resourceClass ) \ int main( int argc, char **argv ) \ { \ return Akonadi::ResourceBase::init( argc, argv ); \ } #endif #endif