Implement library caching

src/c/jellyPod.c

@@ -191,6 +191,8 @@ static void to_pkjs_move_back() {
 	}
 }
 
+////////////////////// MENU LAYER CALLBACKS //////////////////////
+
 static uint16_t menu_get_num_rows(MenuLayer *menu_layer, uint16_t section_index, void *context) {
 	switch (s_current_menu_scope) {
 	case NAV_SCOPE_MAIN:
@@ -256,6 +258,8 @@ static void menu_click_config_provider(void *context) {
 	window_single_click_subscribe(BUTTON_ID_BACK, menu_back_click_handler);
 }
 
+////////////////////// UI //////////////////////
+
 static void divider_layer_update_proc(Layer *layer, GContext *ctx) {
 	graphics_context_set_fill_color(ctx, GColorBlack);
 	graphics_fill_rect(ctx, layer_get_bounds(layer), 0, GCornerNone);
@@ -296,6 +300,8 @@ static void main_window_unload() {
 	menu_layer_destroy(s_menu_layer);
 }
 
+////////////////////// SETUP //////////////////////
+
 static void init() {
 	// initialize pkjs
 	app_message_register_inbox_received(inbox_received_handler);

src/pkjs/index.js

@@ -12,10 +12,69 @@ var NavScope = Object.freeze({
 });
 
 var cfg = JSON.parse(localStorage.getItem('clay-settings'));
+var currentArtist = null;
+
+////////////////////// LIBRARY CACHE //////////////////////
+
+var LIBRARY_CACHE_KEY = 'library-cache';
 var lookupMap = new Map();
 var jfIdToSeqIdMap = new Map();
 var allJfIds = [];
-var currentArtist = null;
+
+function saveLibraryCache() {
+    function encodeValue(value) {
+        if (value instanceof Map) {
+            const entries = [];
+            for (const [k, v] of value.entries()) {
+                entries.push([k, encodeValue(v)]);
+            }
+            return { __type: 'Map', entries: entries };
+        }
+        if (Array.isArray(value)) {
+            return value.map(encodeValue);
+        }
+        return value;
+    }
+
+    try {
+        localStorage.setItem(LIBRARY_CACHE_KEY, JSON.stringify({
+            lookupMap: encodeValue(lookupMap),
+            jfIdToSeqIdMap: encodeValue(jfIdToSeqIdMap),
+            allJfIds: allJfIds
+        }));
+    } catch (err) {
+        console.log('failed to save library cache: ' + err);
+    }
+}
+
+function loadLibraryCache() {
+    function decodeValue(value) {
+        if (value && typeof value === 'object' && value.__type === 'Map') {
+            const map = new Map();
+            for (const [k, v] of value.entries) {
+                map.set(k, decodeValue(v));
+            }
+            return map;
+        }
+        if (Array.isArray(value)) {
+            return value.map(decodeValue);
+        }
+        return value;
+    }
+
+    const raw = localStorage.getItem(LIBRARY_CACHE_KEY);
+    if (!raw) { return; }
+    try {
+        const cache = JSON.parse(raw);
+        lookupMap = decodeValue(cache.lookupMap);
+        jfIdToSeqIdMap = decodeValue(cache.jfIdToSeqIdMap);
+        allJfIds = cache.allJfIds || [];
+    } catch (err) {
+        console.log('failed to load library cache: ' + err);
+    }
+}
+
+////////////////////// SYNC //////////////////////
 
 function toggleReadyState(ready) {
     const readyDict = {};
@@ -50,7 +109,9 @@ function syncLibrary() {
                 let lastAlbumInfo = { AlbumArtist: "", AlbumName: ""};
                 //let lastAlbumInfo = { AlbumArtist: "", AlbumName: "", AlbumYear: 0 }; // TODO FUTURE USE
                 let currentSeqId = 0;
-                allJfIds = [] // ensure blank
+                allJfIds = [];
+                lookupMap = new Map();
+                jfIdToSeqIdMap = new Map();
                 for (const track of libObj.Items) {
                     if (!track.Name) continue;
 
@@ -94,12 +155,15 @@ function syncLibrary() {
                 }
 
                 //console.log(JSON.stringify(lookupMap, (k, v) => v instanceof Map ? Object.fromEntries(v) : v));
+                saveLibraryCache();
                 toggleReadyState(true);
             });
         });
     }
 }
 
+////////////////////// EVENT HANDLING //////////////////////
+
 Pebble.addEventListener('showConfiguration', function () {
     Pebble.openURL(clay.generateUrl());
 });
@@ -119,6 +183,7 @@ Pebble.addEventListener('webviewclosed', function(e) {
 });
 
 Pebble.addEventListener("ready", function () {
+    loadLibraryCache();
     toggleReadyState(true);
 });
 
@@ -183,6 +248,8 @@ Pebble.addEventListener("appmessage", function (dict) {
     }
 });
 
+////////////////////// JELLYFIN API //////////////////////
+
 function reportAPIFailure() {
     console.log("API FAILURE");
 }