[mkcal] Add a new storage observer signal on DB update

The existing storageModified() signal is emitted whenever
the ".changed" file is touched. Restrict its emission
only if some change has been done to the database content
from an external process. Currently emit it also if a
change is done in process to any notebook.

Add a new signal storageUpdated() that is emitted on any
modification of the database component parts (addition,
modification of deletion) to be in part with the associated
mCalendar.

rpm/mkcal-qt5.spec

@@ -1,7 +1,7 @@
 Name:       mkcal-qt5
 
-Summary:    Extended KDE kcal calendar library port for Maemo
-Version:    0.5.45
+Summary:    SQlite storage backend for KCalendarCore
+Version:    0.5.58
 Release:    1
 License:    LGPLv2+
 URL:        https://github.com/sailfishos/mkcal
@@ -20,7 +20,7 @@ BuildRequires:  pkgconfig(timed-qt5) >= 2.88
 BuildRequires:  pkgconfig(QmfClient)
 
 %description
-Extended KDE kcal calendar library port for Maemo
+Extends KDE calendar core library and provides an SQlite backend.
 
 
 %package devel

src/extendedstorage.cpp

@@ -317,6 +317,17 @@ void ExtendedStorageObserver::storageFinished(ExtendedStorage *storage,
     Q_UNUSED(info);
 }
 
+void ExtendedStorageObserver::storageUpdated(ExtendedStorage *storage,
+                                             const KCalendarCore::Incidence::List &added,
+                                             const KCalendarCore::Incidence::List &modified,
+                                             const KCalendarCore::Incidence::List &deleted)
+{
+    Q_UNUSED(storage);
+    Q_UNUSED(added);
+    Q_UNUSED(modified);
+    Q_UNUSED(deleted);
+}
+
 void ExtendedStorage::registerObserver(ExtendedStorageObserver *observer)
 {
     if (!d->mObservers.contains(observer)) {
@@ -363,6 +374,15 @@ void ExtendedStorage::setFinished(bool error, const QString &info)
     }
 }
 
+void ExtendedStorage::setUpdated(const KCalendarCore::Incidence::List &added,
+                                 const KCalendarCore::Incidence::List &modified,
+                                 const KCalendarCore::Incidence::List &deleted)
+{
+    foreach (ExtendedStorageObserver *observer, d->mObservers) {
+        observer->storageUpdated(this, added, modified, deleted);
+    }
+}
+
 bool ExtendedStorage::addNotebook(const Notebook::Ptr &nb)
 {
     if (nb->uid().length() < 7) {

src/extendedstorage.h

@@ -674,6 +674,9 @@ class MKCAL_EXPORT ExtendedStorage
     void setModified(const QString &info);
     void setProgress(const QString &info);
     void setFinished(bool error, const QString &info);
+    void setUpdated(const KCalendarCore::Incidence::List &added,
+                    const KCalendarCore::Incidence::List &modified,
+                    const KCalendarCore::Incidence::List &deleted);
 
     // These alarm methods are used to communicate with an external
     // daemon, like timed, to bind Incidence::Alarm with the system notification.

src/extendedstorageobserver.h

@@ -32,6 +32,7 @@
 #define MKCAL_STORAGEOBSERVER_H
 
 #include <QString>
+#include <KCalendarCore/Incidence>
 
 
 namespace mKCal {
@@ -51,7 +52,11 @@ class MKCAL_EXPORT ExtendedStorageObserver //krazy:exclude=dpointer
     virtual ~ExtendedStorageObserver() {};
 
     /**
-       Notify the Observer that a Storage has been modified.
+       Notify the Observer that a Storage has been modified by an external
+       process. There is no information about what has been changed.
+
+       See also storageUpdated() for a notification of modifications done
+       in-process.
 
        @param storage is a pointer to the ExtendedStorage object that
        is being observed.
@@ -79,6 +84,26 @@ class MKCAL_EXPORT ExtendedStorageObserver //krazy:exclude=dpointer
        @param info textual information
     */
     virtual void storageFinished(ExtendedStorage *storage, bool error, const QString &info);
+
+    /**
+       Notify the Observer that a Storage has been updated to reflect the
+       content of the associated calendar. This notification is delivered
+       because of local changes done in-process by a call to
+       ExtendedStorage::save() for instance.
+
+       See also storageModified() for a notification for modifications
+       done to the database by an external process.
+
+       @param storage is a pointer to the ExtendedStorage object that
+       is being observed.
+       @param added is a list of newly added incidences in the storage
+       @param modified is a list of updated incidences in the storage
+       @param deleted is a list of deleted incidences from the storage
+    */
+    virtual void storageUpdated(ExtendedStorage *storage,
+                                const KCalendarCore::Incidence::List &added,
+                                const KCalendarCore::Incidence::List &modified,
+                                const KCalendarCore::Incidence::List &deleted);
 };
 
 };

src/sqliteformat.cpp

@@ -54,6 +54,8 @@ class mKCal::SqliteFormat::Private
     }
     ~Private()
     {
+        sqlite3_finalize(mSelectMetadata);
+        sqlite3_finalize(mUpdateMetadata);
         sqlite3_finalize(mSelectCalProps);
         sqlite3_finalize(mInsertCalProps);
         sqlite3_finalize(mSelectIncProperties);
@@ -84,6 +86,9 @@ class mKCal::SqliteFormat::Private
     sqlite3 *mDatabase;
 
     // Cache for various queries.
+    sqlite3_stmt *mSelectMetadata = nullptr;
+    sqlite3_stmt *mUpdateMetadata = nullptr;
+
     sqlite3_stmt *mSelectCalProps = nullptr;
     sqlite3_stmt *mInsertCalProps = nullptr;
 
@@ -116,6 +121,7 @@ class mKCal::SqliteFormat::Private
 
     sqlite3_stmt *mMarkDeletedIncidences = nullptr;
 
+    bool updateMetadata(int transactionId);
     bool selectCustomproperties(Incidence::Ptr &incidence, int rowid);
     int selectRowId(Incidence::Ptr incidence);
     bool selectRecursives(Incidence::Ptr &incidence, int rowid);
@@ -153,6 +159,66 @@ SqliteFormat::~SqliteFormat()
     delete d;
 }
 
+bool SqliteFormat::selectMetadata(int *id)
+{
+    int rv = 0;
+
+    if (!id)
+        return false;
+    if (!d->mSelectMetadata) {
+        const char *query = SELECT_METADATA;
+        int qsize = sizeof(SELECT_METADATA);
+        SL3_prepare_v2(d->mDatabase, query, qsize, &d->mSelectMetadata, NULL);
+    }
+    SL3_step(d->mSelectMetadata);
+    *id = (rv == SQLITE_ROW) ? sqlite3_column_int(d->mSelectMetadata, 0) : -1;
+    SL3_reset(d->mSelectMetadata);
+
+    return true;
+
+error:
+    qCWarning(lcMkcal) << "Sqlite error:" << sqlite3_errmsg(d->mDatabase);
+    return false;
+}
+
+bool SqliteFormat::incrementTransactionId(int *id)
+{
+    int savedId;
+
+    if (id)
+        *id = -1;
+    if (!selectMetadata(&savedId))
+        return false;
+    savedId += 1;
+
+    if (!d->updateMetadata(savedId))
+        return false;
+    if (id)
+        *id = savedId;
+    return true;
+}
+
+bool SqliteFormat::Private::updateMetadata(int transactionId)
+{
+    int rv = 0;
+    int index = 1;
+
+    if (!mUpdateMetadata) {
+        const char *qupdate = UPDATE_METADATA;
+        int qsize = sizeof(UPDATE_METADATA);
+        SL3_prepare_v2(mDatabase, qupdate, qsize, &mUpdateMetadata, NULL);
+    }
+    SL3_reset(mUpdateMetadata);
+    SL3_bind_int64(mUpdateMetadata, index, transactionId);
+    SL3_step(mUpdateMetadata);
+
+    return true;
+
+error:
+    qCWarning(lcMkcal) << "Sqlite error:" << sqlite3_errmsg(mDatabase);
+    return false;
+}
+
 bool SqliteFormat::modifyCalendars(const Notebook::Ptr &notebook,
                                    DBOperation dbop, sqlite3_stmt *stmt)
 {

src/sqliteformat.h

@@ -121,6 +121,9 @@ class MKCAL_EXPORT SqliteFormat
     */
     KCalendarCore::Person::List selectContacts();
 
+    bool selectMetadata(int *id);
+    bool incrementTransactionId(int *id);
+
 private:
     //@cond PRIVATE
     Q_DISABLE_COPY(SqliteFormat)