Save state cache per-room

Closes #257.

5 files changed, 70 insertions, 49 deletions

diff --git a/lib/connection.cpp b/lib/connection.cpp
index 8a451a79..099d6a4e 100644
--- a/lib/connection.cpp
+++ b/lib/connection.cpp
@@ -1058,41 +1058,55 @@ void Connection::setHomeserver(const QUrl& url)
     emit homeserverChanged(homeserver());
 }
 
-void Connection::saveState(const QUrl &toFile) const
+void Connection::saveRoomState(Room* r) const
 {
+    Q_ASSERT(r);
     if (!d->cacheState)
         return;
 
-    QElapsedTimer et; et.start();
+    QFile outRoomFile { stateCachePath() % SyncData::fileNameForRoom(r->id()) };
+    if (outRoomFile.open(QFile::WriteOnly))
+    {
+        QJsonDocument json { r->toJson() };
+        auto data = d->cacheToBinary ? json.toBinaryData()
+                                     : json.toJson(QJsonDocument::Compact);
+        outRoomFile.write(data.data(), data.size());
+    } else {
+        qCWarning(MAIN) << "Error opening" << outRoomFile.fileName()
+                        << ":" << outRoomFile.errorString();
+    }
+}
 
-    QFileInfo stateFile {
-        toFile.isEmpty() ? stateCachePath() : toFile.toLocalFile()
-    };
-    if (!stateFile.dir().exists())
-        stateFile.dir().mkpath(".");
+void Connection::saveState() const
+{
+    if (!d->cacheState)
+        return;
 
-    QFile outfile { stateFile.absoluteFilePath() };
-    if (!outfile.open(QFile::WriteOnly))
+    QElapsedTimer et; et.start();
+
+    QFile outFile { stateCachePath() % "state.json" };
+    if (!outFile.open(QFile::WriteOnly))
     {
-        qCWarning(MAIN) << "Error opening" << stateFile.absoluteFilePath()
-                        << ":" << outfile.errorString();
+        qCWarning(MAIN) << "Error opening" << outFile.fileName()
+                        << ":" << outFile.errorString();
         qCWarning(MAIN) << "Caching the rooms state disabled";
         d->cacheState = false;
         return;
     }
 
-    QJsonObject rootObj;
+    QJsonObject rootObj {
+        { QStringLiteral("cache_version"), QJsonObject {
+            { QStringLiteral("major"), SyncData::cacheVersion().first },
+            { QStringLiteral("minor"), SyncData::cacheVersion().second }
+    }}};
     {
         QJsonObject rooms;
         QJsonObject inviteRooms;
         for (const auto* i : roomMap()) // Pass on rooms in Leave state
         {
-            // TODO: instead of adding the room JSON add a file name and save
-            // the JSON to that file.
-            if (i->joinState() == JoinState::Invite)
-                inviteRooms.insert(i->id(), i->toJson());
-            else
-                rooms.insert(i->id(), i->toJson());
+            auto& targetArray = i->joinState() == JoinState::Invite
+                                ? inviteRooms : rooms;
+            targetArray.insert(i->id(), QJsonObject());
             QElapsedTimer et1; et1.start();
             QCoreApplication::processEvents();
             if (et1.elapsed() > 1)
@@ -1120,29 +1134,23 @@ void Connection::saveState(const QUrl &toFile) const
             QJsonObject {{ QStringLiteral("events"), accountDataEvents }});
     }
 
-    QJsonObject versionObj;
-    versionObj.insert("major", SyncData::cacheVersion().first);
-    versionObj.insert("minor", SyncData::cacheVersion().second);
-    rootObj.insert("cache_version", versionObj);
-
     QJsonDocument json { rootObj };
     auto data = d->cacheToBinary ? json.toBinaryData() :
                                    json.toJson(QJsonDocument::Compact);
     qCDebug(PROFILER) << "Cache for" << userId() << "generated in" << et;
 
-    outfile.write(data.data(), data.size());
-    qCDebug(MAIN) << "State cache saved to" << outfile.fileName();
+    outFile.write(data.data(), data.size());
+    qCDebug(MAIN) << "State cache saved to" << outFile.fileName();
 }
 
-void Connection::loadState(const QUrl &fromFile)
+void Connection::loadState()
 {
     if (!d->cacheState)
         return;
 
     QElapsedTimer et; et.start();
 
-    SyncData sync {
-        fromFile.isEmpty() ? stateCachePath() : fromFile.toLocalFile() };
+    SyncData sync { stateCachePath() % "state.json" };
     if (sync.nextBatch().isEmpty()) // No token means no cache by definition
         return;
 
@@ -1162,8 +1170,7 @@ QString Connection::stateCachePath() const
 {
     auto safeUserId = userId();
     safeUserId.replace(':', '_');
-    return QStandardPaths::writableLocation(QStandardPaths::CacheLocation)
-            % '/' % safeUserId % "_state.json";
+    return cacheLocation(safeUserId);
 }
 
 bool Connection::cacheState() const
diff --git a/lib/connection.h b/lib/connection.h
index 20dade76..20a1f47e 100644
--- a/lib/connection.h
+++ b/lib/connection.h
@@ -280,7 +280,7 @@ namespace QMatrixClient
              * to be QML-friendly. Empty parameter means using a path
              * defined by stateCachePath().
              */
-            Q_INVOKABLE void loadState(const QUrl &fromFile = {});
+            Q_INVOKABLE void loadState();
             /**
              * This method saves the current state of rooms (but not messages
              * in them) to a local cache file, so that it could be loaded by
@@ -290,7 +290,10 @@ namespace QMatrixClient
              * QML-friendly. Empty parameter means using a path defined by
              * stateCachePath().
              */
-            Q_INVOKABLE void saveState(const QUrl &toFile = {}) const;
+            Q_INVOKABLE void saveState() const;
+
+            /// This method saves the current state of a single room.
+            void saveRoomState(Room* r) const;
 
             /**
              * The default path to store the cached room state, defined as
diff --git a/lib/room.cpp b/lib/room.cpp
index 55923ed8..2d958dca 100644
--- a/lib/room.cpp
+++ b/lib/room.cpp
@@ -1170,7 +1170,10 @@ void Room::updateData(SyncRoomData&& data)
         emit notificationCountChanged(this);
     }
     if (roomChanges != Change::NoChange)
+    {
         emit changed(roomChanges);
+        connection()->saveRoomState(this);
+    }
 }
 
 QString Room::Private::sendEvent(RoomEventPtr&& event)
diff --git a/lib/syncdata.cpp b/lib/syncdata.cpp
index f0d55fd6..d141a7cc 100644
--- a/lib/syncdata.cpp
+++ b/lib/syncdata.cpp
@@ -21,6 +21,7 @@
 #include "events/eventloader.h"
 
 #include <QtCore/QFile>
+#include <QtCore/QFileInfo>
 
 using namespace QMatrixClient;
 
@@ -69,7 +70,17 @@ SyncRoomData::SyncRoomData(const QString& roomId_, JoinState joinState_,
 
 SyncData::SyncData(const QString& cacheFileName)
 {
-    parseJson(loadJson(cacheFileName));
+    QFileInfo cacheFileInfo { cacheFileName };
+    auto json = loadJson(cacheFileName);
+    auto requiredVersion = std::get<0>(cacheVersion());
+    auto actualVersion = json.value("cache_version").toObject()
+                             .value("major").toInt();
+    if (actualVersion == requiredVersion)
+        parseJson(json, cacheFileInfo.absolutePath() + '/');
+    else
+        qCWarning(MAIN)
+            << "Major version of the cache file is" << actualVersion << "but"
+            << requiredVersion << "is required; discarding the cache";
 }
 
 SyncDataList&& SyncData::takeRoomData()
@@ -77,6 +88,12 @@ SyncDataList&& SyncData::takeRoomData()
     return move(roomData);
 }
 
+QString SyncData::fileNameForRoom(QString roomId)
+{
+    roomId.replace(':', '_');
+    return roomId + ".json";
+}
+
 Events&& SyncData::takePresenceData()
 {
     return std::move(presenceData);
@@ -115,22 +132,11 @@ QJsonObject SyncData::loadJson(const QString& fileName)
     {
         qCWarning(MAIN) << "State cache in" << fileName
                         << "is broken or empty, discarding";
-        return {};
-    }
-    auto requiredVersion = std::get<0>(cacheVersion());
-    auto actualVersion = json.value("cache_version").toObject()
-                             .value("major").toInt();
-    if (actualVersion < requiredVersion)
-    {
-        qCWarning(MAIN)
-            << "Major version of the cache file is" << actualVersion << "but"
-            << requiredVersion << "is required; discarding the cache";
-        return {};
     }
     return json;
 }
 
-void SyncData::parseJson(const QJsonObject& json)
+void SyncData::parseJson(const QJsonObject& json, const QString& baseDir)
 {
     QElapsedTimer et; et.start();
 
@@ -150,8 +156,9 @@ void SyncData::parseJson(const QJsonObject& json)
         roomData.reserve(static_cast<size_t>(rs.size()));
         for(auto roomIt = rs.begin(); roomIt != rs.end(); ++roomIt)
         {
-            auto roomJson = roomIt->isString() ? loadJson(roomIt->toString())
-                                               : roomIt->toObject();
+            auto roomJson = roomIt->isString()
+                            ? loadJson(baseDir + fileNameForRoom(roomIt.key()))
+                            : roomIt->toObject();
             if (roomJson.isEmpty())
             {
                 unresolvedRoomIds.push_back(roomIt.key());
diff --git a/lib/syncdata.h b/lib/syncdata.h
index d8007db9..aa8948bc 100644
--- a/lib/syncdata.h
+++ b/lib/syncdata.h
@@ -59,7 +59,7 @@ namespace QMatrixClient {
              * \return the list of rooms with missing cache files; always
              *         empty when parsing response from /sync
              */
-            void parseJson(const QJsonObject& json);
+            void parseJson(const QJsonObject& json, const QString& baseDir = {});
 
             Events&& takePresenceData();
             Events&& takeAccountData();
@@ -70,7 +70,8 @@ namespace QMatrixClient {
 
             QStringList unresolvedRooms() const { return unresolvedRoomIds; }
 
-            static std::pair<int, int> cacheVersion() { return { 8, 0 }; }
+            static std::pair<int, int> cacheVersion() { return { 9, 0 }; }
+            static QString fileNameForRoom(QString roomId);
 
         private:
             QString nextBatch_;