Matrix: continue from cache instead of initial sync everytime. Mainly improves pantalaimon sync speed

3 files changed, 195 insertions, 221 deletions

diff --git a/src/QuickMedia.cpp b/src/QuickMedia.cpp
index 2c40580..0e9f152 100644
--- a/src/QuickMedia.cpp
+++ b/src/QuickMedia.cpp
@@ -39,6 +39,7 @@
 #include "../include/Downloader.hpp"
 #include "../include/Storage.hpp"
 #include "../include/AsyncImageLoader.hpp"
+#include "../plugins/utils/UniqueProcess.hpp"
 #include <mglpp/system/FloatRect.hpp>
 #include "../include/gui/Button.hpp"
 #include "../external/hash-library/sha256.h"
@@ -407,7 +408,7 @@ namespace QuickMedia {
         video_max_height = 0;
         std::vector<Tab> tabs;
         const char *url = nullptr;
-        std::string program_path = dirname(argv[0]);
+        std::string program_path = Path(argv[0]).parent().data;
         std::string instance;
         std::string download_filename;
         bool no_dialog = false;
@@ -633,7 +634,7 @@ namespace QuickMedia {
                     chat_login_page();
                 }
                 after_matrix_login_page();
-                return exit_code;
+                goto done;
             }
 
             page_loop(tabs, start_tab_index);
@@ -650,6 +651,10 @@ namespace QuickMedia {
             }
         }
 
+        done:
+        if(plugin_name && strcmp(plugin_name, "matrix") == 0)
+            remove_quickmedia_instance_lock(get_cache_dir().join("matrix").data.c_str(), "matrix");
+
         return exit_code;
     }
 
@@ -1327,7 +1332,7 @@ namespace QuickMedia {
                 page_stack.push(current_page);
                 current_page = PageType::IMAGE_BOARD_THREAD;
                 image_board_thread_page(thread_page.get(), body.get());
-                exit(0);
+                exit(exit_code);
             } else {
                 auto boards_page = std::make_unique<FourchanBoardsPage>(this, resources_root);
                 FourchanBoardsPage *boards_page_ptr = boards_page.get();
@@ -1424,10 +1429,22 @@ namespace QuickMedia {
             tabs.push_back(Tab{create_body(false, true), std::make_unique<LbrySearchPage>(this), create_search_bar("Search...", 500)});
         } else if(strcmp(plugin_name, "matrix") == 0) {
             assert(!matrix);
+
             if(create_directory_recursive(get_cache_dir().join("matrix").join("events")) != 0) {
                 show_notification("QuickMedia", "Failed to create events cache directory", Urgency::CRITICAL);
                 abort();
             }
+
+            if(is_quickmedia_instance_already_running(get_cache_dir().join("matrix").data.c_str(), "matrix")) {
+                show_notification("QuickMedia", "Only one instance of matrix can be run. Change $XDG_CACHE_HOME if you want to run multiple instances", Urgency::CRITICAL);
+                exit(exit_code);
+            }
+
+            if(!set_quickmedia_instance_unique(get_cache_dir().join("matrix").data.c_str(), "matrix")) {
+                show_notification("QuickMedia", "Failed to set quickmedia process as unique", Urgency::CRITICAL);
+                exit(exit_code);
+            }
+
             matrix = new Matrix();
         } else {
             assert(false);
@@ -7872,63 +7889,6 @@ namespace QuickMedia {
                     tabs[selected_tab].body->on_bottom_reached();
             }
 
-            if(matrix_chat_page->should_clear_data) {
-                matrix_chat_page->should_clear_data = false;
-
-                std::string err_msg;
-                while(!matrix->is_initial_sync_finished()) {
-                    std::this_thread::sleep_for(std::chrono::milliseconds(10));
-                    if(matrix->did_initial_sync_fail(err_msg)) {
-                        matrix_chat_page->set_current_room(nullptr, nullptr, nullptr);
-                        fetch_messages_future.cancel();
-                        cleanup_tasks();
-                        tabs.clear();
-                        unreferenced_events.clear();
-                        unresolved_reactions.clear();
-                        all_messages.clear();
-                        show_notification("QuickMedia", "Initial matrix sync failed, error: " + err_msg, Urgency::CRITICAL);
-                        matrix->logout();
-                        delete matrix;
-                        matrix = new Matrix();
-                        current_page = PageType::CHAT_LOGIN;
-                        chat_login_page();
-                        after_matrix_login_page();
-                        window.close();
-                        goto chat_page_end;
-                    }
-                }
-                
-                //all_messages.clear();
-
-                tabs[MESSAGES_TAB_INDEX].body->clear_items();
-
-                Messages all_messages_new;
-                matrix->get_all_synced_room_messages(current_room, all_messages_new);
-                for(auto &message : all_messages_new) {
-                    fetched_messages_set.insert(message->event_id);
-                }
-                all_messages.insert(all_messages.end(), all_messages_new.begin(), all_messages_new.end());
-                //me = matrix->get_me(current_room);
-                filter_provisional_messages(all_messages_new);
-                add_new_messages_to_current_room(all_messages_new);
-                modify_related_messages_in_current_room(all_messages_new);
-                unresolved_reactions.clear();
-                after_token.clear();
-                before_token.clear(),
-                fetched_enough_messages_top = false;
-                fetched_enough_messages_bottom = false;
-                fetch_messages_future.cancel();
-                process_reactions(all_messages_new);
-                if(current_room->initial_prev_messages_fetch) {
-                    current_room->initial_prev_messages_fetch = false;
-                    tabs[MESSAGES_TAB_INDEX].body->select_last_item();
-                }
-
-                std::vector<std::string> pinned_events;
-                matrix->get_all_pinned_events(current_room, pinned_events);
-                process_pinned_events(std::move(pinned_events));
-            }
-
             if(go_to_previous_page) {
                 go_to_previous_page = false;
                 goto chat_page_end;
diff --git a/src/plugins/Matrix.cpp b/src/plugins/Matrix.cpp
index 0d93bd0..11eca06 100644
--- a/src/plugins/Matrix.cpp
+++ b/src/plugins/Matrix.cpp
@@ -17,6 +17,7 @@
 #include <rapidjson/filewritestream.h>
 #include <fcntl.h>
 #include <unistd.h>
+#include <fstream>
 #include <malloc.h>
 #include "../../include/QuickMedia.hpp"
 #include <HtmlParser.h>
@@ -38,7 +39,6 @@ namespace QuickMedia {
     // then we cant see room message preview. TODO: Fix this somehow.
     // TODO: What about state events in initial sync in timeline? such as user display name change.
     static const char* INITIAL_FILTER = "{\"presence\":{\"limit\":0,\"types\":[\"\"]},\"account_data\":{\"types\":[\"qm.emoji\",\"m.direct\"]},\"room\":{\"state\":{\"not_types\":[\"m.room.related_groups\",\"m.room.power_levels\",\"m.room.join_rules\",\"m.room.history_visibility\",\"m.room.canonical_alias\",\"m.space.child\"],\"lazy_load_members\":true},\"timeline\":{\"types\":[\"m.room.message\"],\"limit\":1,\"lazy_load_members\":true},\"ephemeral\":{\"limit\":0,\"types\":[\"\"],\"lazy_load_members\":true},\"account_data\":{\"limit\":1,\"types\":[\"m.fully_read\",\"m.tag\",\"qm.last_read_message_timestamp\"],\"lazy_load_members\":true}}}";
-    static const char* ADDITIONAL_MESSAGES_FILTER = "{\"presence\":{\"types\":[\"\"]},\"account_data\":{\"limit\":0,\"types\":[\"\"]},\"room\":{\"state\":{\"not_types\":[\"m.room.related_groups\",\"m.room.power_levels\",\"m.room.join_rules\",\"m.room.history_visibility\",\"m.room.canonical_alias\",\"m.space.child\"],\"lazy_load_members\":true},\"timeline\":{\"limit\":20,\"lazy_load_members\":true},\"ephemeral\":{\"limit\":0,\"types\":[\"\"],\"lazy_load_members\":true},\"account_data\":{\"limit\":0,\"types\":[\"\"],\"lazy_load_members\":true}}}";
     static const char* CONTINUE_FILTER = "{\"presence\":{\"limit\":0,\"types\":[\"\"]},\"account_data\":{\"types\":[\"qm.emoji\",\"m.direct\"]},\"room\":{\"state\":{\"not_types\":[\"m.room.related_groups\",\"m.room.power_levels\",\"m.room.join_rules\",\"m.room.history_visibility\",\"m.room.canonical_alias\",\"m.space.child\"],\"lazy_load_members\":true},\"timeline\":{\"lazy_load_members\":true},\"ephemeral\":{\"limit\":0,\"types\":[\"\"],\"lazy_load_members\":true},\"account_data\":{\"types\":[\"m.fully_read\",\"m.tag\",\"qm.last_read_message_timestamp\"],\"lazy_load_members\":true}}}";
 
     static bool is_gpg_installed = false;
@@ -802,15 +802,6 @@ namespace QuickMedia {
             body->set_selected_item(found_item_index, false);
     }
 
-    void MatrixQuickMedia::clear_data() {
-        //room_body_item_by_room.clear();
-        //pending_room_messages.clear();
-        //rooms_page->clear_data();
-        //room_tags_page->clear_data();
-        invites_page->clear_data();
-        //unread_notifications.clear();
-    }
-
     static std::shared_ptr<Message> get_last_message_by_timestamp(const Messages &messages) {
         if(messages.empty())
             return nullptr;
@@ -1038,12 +1029,6 @@ namespace QuickMedia {
         body->select_first_item();
     }
 
-    void MatrixRoomsPage::clear_data() {
-        body->clear_items();
-        if(current_chat_page)
-            current_chat_page->should_clear_data = true;
-    }
-
     PluginResult MatrixRoomTagsPage::submit(const SubmitArgs &args, std::vector<Tab> &result_tabs) {
         auto body = create_body(true);
         Body *body_ptr = body.get();
@@ -1131,13 +1116,6 @@ namespace QuickMedia {
         current_rooms_page = rooms_page;
     }
 
-    void MatrixRoomTagsPage::clear_data() {
-        tag_body_items_by_name.clear();
-        body->clear_items();
-        if(current_rooms_page)
-            current_rooms_page->clear_data();
-    }
-
     MatrixInvitesPage::MatrixInvitesPage(Program *program, Matrix *matrix, Body *body) : Page(program), matrix(matrix), body(body) {
 
     }
@@ -1198,12 +1176,6 @@ namespace QuickMedia {
         }
     }
 
-    void MatrixInvitesPage::clear_data() {
-        body->clear_items();
-        prev_invite_count = 0;
-        title = "Invites (0)";
-    }
-
     PluginResult MatrixSettingsPage::submit(const SubmitArgs &args, std::vector<Tab> &result_tabs) {
         if(args.url == "join") {
             result_tabs.push_back(Tab{create_body(), std::make_unique<MatrixRoomInputPage>(program, matrix), create_search_bar("Enter room id...", SEARCH_DELAY_FILTER)});
@@ -1677,44 +1649,6 @@ namespace QuickMedia {
         "M_MISSING_PARAM"
     };
 
-    static void remove_empty_fields_in_sync_rooms_response(rapidjson::Value &rooms_json) {
-        for(const char *member_name : {"join", "invite", "leave"}) {
-            auto join_it = rooms_json.FindMember(member_name);
-            if(join_it != rooms_json.MemberEnd() && join_it->value.IsObject() && join_it->value.MemberCount() == 0)
-                rooms_json.RemoveMember(join_it);
-        }
-    }
-
-    static void remove_empty_fields_in_sync_account_data_response(rapidjson::Value &account_data_json) {
-        for(const char *member_name : {"events"}) {
-            auto join_it = account_data_json.FindMember(member_name);
-            if(join_it != account_data_json.MemberEnd() && join_it->value.IsObject() && join_it->value.MemberCount() == 0)
-                account_data_json.RemoveMember(join_it);
-        }
-    }
-
-    static void remove_unused_sync_data_fields(rapidjson::Value &json_root) {
-        for(auto it = json_root.MemberBegin(); it != json_root.MemberEnd();) {
-            if(strcmp(it->name.GetString(), "account_data") == 0 && it->value.IsObject()) {
-                remove_empty_fields_in_sync_account_data_response(it->value);
-                if(it->value.MemberCount() == 0)
-                    it = json_root.RemoveMember(it);
-                else
-                    ++it;
-            } else if(strcmp(it->name.GetString(), "rooms") == 0 && it->value.IsObject()) {
-                // TODO: Call this, but dont remove our read marker (needed for notifications on mentions for example). Or maybe we can get it from "account_data"?
-                //remove_ephemeral_field_in_sync_rooms_response(rooms_it->value);
-                remove_empty_fields_in_sync_rooms_response(it->value);
-                if(it->value.MemberCount() == 0)
-                    it = json_root.RemoveMember(it);
-                else
-                    ++it;
-            } else {
-                it = json_root.EraseMember(it);
-            }
-        }
-    }
-
     bool Matrix::start_sync(MatrixDelegate *delegate, bool &cached) {
         cached = true;
         if(sync_running)
@@ -1741,21 +1675,32 @@ namespace QuickMedia {
         load_custom_emoji_from_cache();
 
         sync_thread = std::thread([this, matrix_cache_dir]() {
+            FILE *sync_cache_file;
+            const rapidjson::Value *next_batch_json = nullptr;
             sync_is_cache = true;
-            FILE *sync_cache_file = fopen(matrix_cache_dir.data.c_str(), "rb");
-            if(sync_cache_file) {
+
+            std::ifstream sync_cache_file_stream;
+            sync_cache_file_stream.open(matrix_cache_dir.data.c_str(), std::ifstream::in | std::ifstream::binary);
+            if(sync_cache_file_stream.good()) {
                 rapidjson::Document doc;
-                char read_buffer[8192];
-                rapidjson::FileReadStream is(sync_cache_file, read_buffer, sizeof(read_buffer));
-                while(true) {
-                    rapidjson::ParseResult parse_result = doc.ParseStream<rapidjson::kParseStopWhenDoneFlag>(is);
+                std::string line;
+                while(std::getline(sync_cache_file_stream, line)) {
+                    rapidjson::ParseResult parse_result = doc.Parse<rapidjson::kParseStopWhenDoneFlag>(line.c_str(), line.size());
                     if(parse_result.IsError())
-                        break;
-                    if(parse_sync_response(doc, false, false) != PluginResult::OK)
+                        continue; // This should NEVER happen. Do initial sync if it does and remove cache? :( TODO
+
+                    if(parse_sync_response(doc, false) != PluginResult::OK)
                         fprintf(stderr, "Failed to parse cached sync response\n");
+
+                    next_batch_json = &GetMember(doc, "next_batch");
+                    if(next_batch_json->IsString()) {
+                        set_next_batch(next_batch_json->GetString());
+                        //fprintf(stderr, "Matrix: next batch: %s\n", next_batch.c_str());
+                    }
                 }
-                fclose(sync_cache_file);
+                malloc_trim(0);
             }
+            sync_cache_file_stream.close();
             sync_is_cache = false;
 
             load_qm_read_markers_from_account_data(); // TODO: Remove when https://github.com/matrix-org/synapse/issues/14444 is fixed, if ever.
@@ -1777,16 +1722,22 @@ namespace QuickMedia {
             else
                 filter = FILTER;
 #endif
-            std::string filter_encoded = url_param_encode(INITIAL_FILTER);
-
             std::vector<CommandArg> additional_args = {
                 { "-H", "Authorization: Bearer " + access_token },
                 { "-m", "35" }
             };
 
-            const rapidjson::Value *next_batch_json;
+            next_batch_json = nullptr;
             PluginResult result;
-            bool initial_sync = true;
+            bool initial_sync = next_batch.empty();
+            bool first_sync = true;
+
+            std::string filter_encoded;
+            if(initial_sync)
+                filter_encoded = url_param_encode(INITIAL_FILTER);
+            else
+                filter_encoded = url_param_encode(CONTINUE_FILTER);
+
             while(sync_running) {
                 char url[2048];
                 if(next_batch.empty())
@@ -1821,10 +1772,7 @@ namespace QuickMedia {
                     }
                 }
 
-                if(next_batch.empty())
-                    clear_sync_cache_for_new_sync();
-
-                result = parse_sync_response(json_root, false, initial_sync);
+                result = parse_sync_response(json_root, initial_sync);
                 if(result != PluginResult::OK) {
                     fprintf(stderr, "Failed to parse sync response\n");
                     initial_sync = false;
@@ -1842,7 +1790,10 @@ namespace QuickMedia {
                     goto sync_end;
                 }
 
-                if(initial_sync) {
+                if(first_sync) {
+                    first_sync = false;
+                    filter_encoded = url_param_encode(CONTINUE_FILTER);
+
                     notification_thread = std::thread([this]() {
                         get_previous_notifications([this](const MatrixNotification &notification) {
                             if(notification.read)
@@ -1853,39 +1804,8 @@ namespace QuickMedia {
                                 delegate->add_unread_notification(std::move(notification));
                             });
                         });
-
                         finished_fetching_notifications = true;
-
-                        {
-                            std::vector<CommandArg> additional_args = {
-                                { "-H", "Authorization: Bearer " + access_token },
-                                { "-m", "35" }
-                            };
-
-                            char url[1024];
-                            std::string filter_encoded = url_param_encode(ADDITIONAL_MESSAGES_FILTER);
-                            snprintf(url, sizeof(url), "%s/_matrix/client/r0/sync?filter=%s&timeout=0", homeserver.c_str(), filter_encoded.c_str());
-
-                            rapidjson::Document json_root;
-                            std::string err_msg;
-                            DownloadResult download_result = download_json(json_root, url, additional_args, true, &err_msg);
-                            if(download_result != DownloadResult::OK) {
-                                fprintf(stderr, "/sync for additional messages failed\n");
-                                return;
-                            }
-
-                            // TODO: Test?
-                            //if(next_batch.empty())
-                            //    clear_sync_cache_for_new_sync();
-
-                            additional_messages_queue.pop_wait();
-                            parse_sync_response(json_root, true, false);
-                        }
                     });
-
-                    filter_encoded = url_param_encode(CONTINUE_FILTER);
-                    additional_messages_queue.push(true);
-                    malloc_trim(0);
                 }
 
 #if 0
@@ -1895,16 +1815,25 @@ namespace QuickMedia {
                 }
 #endif
 
-                // TODO: Circulate file
+                // TODO: Use a NoSQL database.
+                // TODO: Remove very old cache.
+                // TODO: Find a way to remove this? this makes sync work like other clients but we dont want that!
+                //       If the last sync was long ago then it has to sync ALL messages again. Maybe check if sync file
+                //       is XX days old and then ignore it?
                 sync_cache_file = fopen(matrix_cache_dir.data.c_str(), initial_sync ? "wb" : "ab");
                 initial_sync = false;
                 if(sync_cache_file) {
                     if(json_root.IsObject()) {
-                        char buffer[4096];
-                        rapidjson::FileWriteStream file_write_stream(sync_cache_file, buffer, sizeof(buffer));
-                        rapidjson::Writer<rapidjson::FileWriteStream> writer(file_write_stream);
-                        remove_unused_sync_data_fields(json_root);
+                        rapidjson::StringBuffer buffer;
+                        rapidjson::Writer<rapidjson::StringBuffer> writer(buffer);
                         json_root.Accept(writer);
+
+                        std::string json_data(buffer.GetString(), buffer.GetSize());
+                        string_replace_all(json_data, '\n', ' ');
+                        json_data += '\n';
+
+                        fwrite(json_data.data(), 1, json_data.size(), sync_cache_file);
+                        malloc_trim(0);
                     }
                     fclose(sync_cache_file);
                 }
@@ -1925,13 +1854,6 @@ namespace QuickMedia {
             program_kill_in_thread(sync_thread.get_id());
             sync_thread.join();
         }
-
-        if(sync_additional_messages_thread.joinable()) {
-            program_kill_in_thread(sync_additional_messages_thread.get_id());
-            additional_messages_queue.close();
-            sync_additional_messages_thread.join();
-            additional_messages_queue.restart();
-        }
         
         if(notification_thread.joinable()) {
             program_kill_in_thread(notification_thread.get_id());
@@ -2113,12 +2035,12 @@ namespace QuickMedia {
         }
     }
 
-    PluginResult Matrix::parse_sync_response(const rapidjson::Document &root, bool is_additional_messages_sync, bool initial_sync) {
+    PluginResult Matrix::parse_sync_response(const rapidjson::Document &root, bool initial_sync) {
         if(!root.IsObject())
             return PluginResult::ERR;
 
         const rapidjson::Value &rooms_json = GetMember(root, "rooms");
-        parse_sync_room_data(rooms_json, is_additional_messages_sync, initial_sync);
+        parse_sync_room_data(rooms_json, initial_sync);
 
         const rapidjson::Value &account_data_json = GetMember(root, "account_data");
         parse_sync_account_data(account_data_json);
@@ -2300,7 +2222,7 @@ namespace QuickMedia {
         return PluginResult::OK;
     }
 
-    PluginResult Matrix::parse_sync_room_data(const rapidjson::Value &rooms_json, bool is_additional_messages_sync, bool initial_sync) {
+    PluginResult Matrix::parse_sync_room_data(const rapidjson::Value &rooms_json, bool initial_sync) {
         if(!rooms_json.IsObject())
             return PluginResult::OK;
 
@@ -2342,16 +2264,9 @@ namespace QuickMedia {
 
                 const rapidjson::Value &timeline_json = GetMember(it.value, "timeline");
                 if(timeline_json.IsObject()) {
-                    if(is_additional_messages_sync) {
-                        // This may be non-existent if this is the first event in the room
-                        const rapidjson::Value &prev_batch_json = GetMember(timeline_json, "prev_batch");
-                        if(prev_batch_json.IsString())
-                            room->set_prev_batch(prev_batch_json.GetString());
-                    }
-
                     bool has_unread_notifications = false;
                     const rapidjson::Value &unread_notification_json = GetMember(it.value, "unread_notifications");
-                    if(unread_notification_json.IsObject() && !is_additional_messages_sync && !sync_is_cache) {
+                    if(unread_notification_json.IsObject() && !sync_is_cache) {
                         const rapidjson::Value &highlight_count_json = GetMember(unread_notification_json, "highlight_count");
                         if(highlight_count_json.IsInt64() && (highlight_count_json.GetInt64() > 0 || initial_sync)) {
                             room->unread_notification_count = highlight_count_json.GetInt64();
@@ -2368,7 +2283,7 @@ namespace QuickMedia {
                     if(account_data_json.IsObject()) {
                         const rapidjson::Value &events_json = GetMember(account_data_json, "events");
                         auto me = get_me(room);
-                        events_set_user_read_marker(events_json, room, me, is_additional_messages_sync);
+                        events_set_user_read_marker(events_json, room, me);
                     }
 
                     if(is_new_room)
@@ -2381,7 +2296,7 @@ namespace QuickMedia {
                     if(account_data_json.IsObject()) {
                         const rapidjson::Value &events_json = GetMember(account_data_json, "events");
                         auto me = get_me(room);
-                        events_set_user_read_marker(events_json, room, me, is_additional_messages_sync);
+                        events_set_user_read_marker(events_json, room, me);
                     }
 
                     if(is_new_room)
@@ -2410,13 +2325,11 @@ namespace QuickMedia {
             }
         }
 
-        if(!is_additional_messages_sync) {
-            const rapidjson::Value &leave_json = GetMember(rooms_json, "leave");
-            remove_rooms(leave_json);
+        const rapidjson::Value &leave_json = GetMember(rooms_json, "leave");
+        remove_rooms(leave_json);
 
-            const rapidjson::Value &invite_json = GetMember(rooms_json, "invite");
-            add_invites(invite_json);
-        }
+        const rapidjson::Value &invite_json = GetMember(rooms_json, "invite");
+        add_invites(invite_json);
 
         if(initial_sync) {
             std::lock_guard<std::recursive_mutex> lock(room_data_mutex);
@@ -2549,7 +2462,7 @@ namespace QuickMedia {
         return user_info;
     }
 
-    void Matrix::events_set_user_read_marker(const rapidjson::Value &events_json, RoomData *room_data, std::shared_ptr<UserInfo> &me, bool is_additional_messages_sync) {
+    void Matrix::events_set_user_read_marker(const rapidjson::Value &events_json, RoomData *room_data, std::shared_ptr<UserInfo> &me) {
         assert(me); // TODO: Remove read marker from user and set it for the room instead. We need that in the matrix pages also
         if(!events_json.IsArray() || !me)
             return;
@@ -2571,7 +2484,7 @@ namespace QuickMedia {
                 if(!event_id_json.IsString())
                     continue;
                 
-                if(!sync_is_cache && !is_additional_messages_sync)
+                if(!sync_is_cache)
                     room_data->set_user_read_marker(me, std::string(event_id_json.GetString(), event_id_json.GetStringLength()));
             } else if(strcmp(type_json.GetString(), "qm.last_read_message_timestamp") == 0) { // TODO: Remove qm.last_read_message_timestamp in room level eventually when everybody has data in global level
                 const rapidjson::Value &content_json = GetMember(event_json, "content");
@@ -5887,18 +5800,6 @@ namespace QuickMedia {
         return next_notifications_token;
     }
 
-    void Matrix::clear_sync_cache_for_new_sync() {
-        std::lock_guard<std::recursive_mutex> room_data_lock(room_data_mutex);
-        std::lock_guard<std::mutex> invites_lock(invite_mutex);
-        for(auto &room : rooms) {
-            room->clear_data();
-        }
-        // We intentionally dont clear |rooms| here because we want the objects inside it to still be valid. TODO: Clear |rooms| here
-        //room_data_by_id.clear();
-        invites.clear();
-        ui_thread_tasks.push([this]{ delegate->clear_data(); });
-    }
-
     std::shared_ptr<UserInfo> Matrix::get_user_by_id(RoomData *room, const std::string &user_id, bool *is_new_user, bool create_if_not_found) {
         auto user = room->get_user_by_id(user_id);
         if(user) {
diff --git a/src/plugins/utils/UniqueProcess.cpp b/src/plugins/utils/UniqueProcess.cpp
new file mode 100644
index 0000000..76b9cb1
--- /dev/null
+++ b/src/plugins/utils/UniqueProcess.cpp
@@ -0,0 +1,113 @@
+#include "../../../plugins/utils/UniqueProcess.hpp"
+#include <stdio.h>
+#include <string.h>
+#include <limits.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdlib.h>
+
+namespace QuickMedia {
+    static bool is_process_running_program(pid_t pid, const char *program_name) {
+        char filepath[256];
+        snprintf(filepath, sizeof(filepath), "/proc/%ld/cmdline", (long)pid);
+
+        int fd = open(filepath, O_RDONLY);
+        if(fd == -1)
+            return false;
+        
+        char buffer[PATH_MAX + 1];
+        ssize_t bytes_read = read(fd, buffer, sizeof(buffer) - 1);
+        if(bytes_read == -1) {
+            close(fd);
+            return false;
+        }
+        buffer[bytes_read] = '\0';
+
+        char resolved_path[PATH_MAX + 1];
+        if(!realpath(buffer, resolved_path)) {
+            close(fd);
+            return false;
+        }
+        bytes_read = strlen(resolved_path);
+        resolved_path[bytes_read] = '\0';
+
+        const char *end = resolved_path + bytes_read;
+        const char *start = (const char*)memrchr(resolved_path, '/', bytes_read);
+        if(start)
+            start += 1;
+        else
+            start = buffer;
+
+        const size_t cmd_arg0_len = end - start;
+        const size_t program_name_len = strlen(program_name);
+        bool running = (cmd_arg0_len == program_name_len && memcmp(start, program_name, program_name_len) == 0);
+        close(fd);
+        return running;
+    }
+
+    bool is_quickmedia_instance_already_running(const char *pid_file_dir, const char *plugin_name) {
+        char pid_file[PATH_MAX];
+        snprintf(pid_file, sizeof(pid_file), "%s/quickmedia.%s.pid", pid_file_dir, plugin_name);
+
+        char buffer[256];
+        int fd = open(pid_file, O_RDONLY);
+        if(fd == -1)
+            return false;
+
+        ssize_t bytes_read = read(fd, buffer, sizeof(buffer) - 1);
+        if(bytes_read < 0) {
+            perror("failed to read quickmedia pid file");
+            close(fd);
+            return false;
+        }
+        buffer[bytes_read] = '\0';
+        close(fd);
+
+        bool running = false;
+        long pid = 0;
+        if(sscanf(buffer, "%ld", &pid) == 1) {
+            if(is_process_running_program(pid, "quickmedia")) {
+                fprintf(stderr, "Error: quickmedia %s is already running\n", plugin_name);
+                running = true;
+            }
+        } else {
+            fprintf(stderr, "Warning: quickmedia pid file is in incorrect format, it's possible that its corrupt. Replacing file and continuing...\n");
+            running = false;
+        }
+
+        if(!running)
+            unlink(pid_file);
+
+        return running;
+    }
+
+    bool set_quickmedia_instance_unique(const char *pid_file_dir, const char *plugin_name) {
+        char pid_file[PATH_MAX];
+        snprintf(pid_file, sizeof(pid_file), "%s/quickmedia.%s.pid", pid_file_dir, plugin_name);
+
+        int fd = open(pid_file, O_WRONLY|O_CREAT|O_TRUNC, 0777);
+        if(fd == -1) {
+            perror("failed to create quickmedia pid file");
+            return false;
+        }
+
+        bool success = true;
+        char buffer[256];
+        const int buffer_size = snprintf(buffer, sizeof(buffer), "%ld", (long)getpid());
+        if(write(fd, buffer, buffer_size) == -1) {
+            perror("failed to write quickmedia pid file");
+            success = false;
+        }
+
+        close(fd);
+        if(!success)
+            unlink(pid_file);
+        return success;
+    }
+
+    void remove_quickmedia_instance_lock(const char *pid_file_dir, const char *plugin_name) {
+        char pid_file[PATH_MAX];
+        snprintf(pid_file, sizeof(pid_file), "%s/quickmedia.%s.pid", pid_file_dir, plugin_name);
+        unlink(pid_file);
+    }
+}
\ No newline at end of file