initial implementation of firmware cache

manifest.json

@@ -34,7 +34,8 @@
         {"usbDevices": [
             {"vendorId": 1155, "productId": 57105}
         ]},
-        "webview"
+        "webview",
+        "unlimitedStorage"
     ],
     "sockets": {
         "tcp": {

package.json

@@ -36,6 +36,7 @@
   "dependencies": {
     "i18next": "^10.3.0",
     "i18next-xhr-backend": "^1.5.1",
+    "lru_map": "^0.3.3",
     "marked": "^0.3.12"
   },
   "devDependencies": {

src/js/FirmwareCache.js

@@ -0,0 +1,183 @@
+'use strict';
+
+/**
+ * Caching of previously downloaded firmwares and release descriptions
+ * 
+ * Depends on LRUMap for which the docs can be found here:
+ * https://github.com/rsms/js-lru
+ */
+
+/**
+ * @typedef {object} Descriptor Release descriptor object
+ * @property {string} releaseUrl
+ * @property {string} name
+ * @property {string} version
+ * @property {string} url
+ * @property {string} file
+ * @property {string} target
+ * @property {string} date
+ * @property {string} notes
+ * @property {string} status
+ * @see buildBoardOptions() in {@link release_checker.js}
+ */
+
+/**
+ * @typedef {object} CacheItem
+ * @property {Descriptor} release
+ * @property {string} [hexdata]
+ */
+
+ /**
+  * Manages caching of downloaded firmware files
+  */
+let FirmwareCache = (function() {
+
+    let MetadataStorage = (function() {
+        let CACHEKEY = "firmware-cache-metadata";
+
+        /**
+         * @param {Array} data LRU key-value pairs
+         */
+        function persist(data) {
+            let obj = {};
+            obj[CACHEKEY] = data;
+            chrome.storage.local.set(obj);
+        }
+
+        /**
+         * @param {Function} callback 
+         */
+        function load(callback) {
+            chrome.storage.local.get(CACHEKEY, obj => {
+                let entries = typeof obj === "object" && obj.hasOwnProperty(CACHEKEY) 
+                    ? obj[CACHEKEY]
+                    : [];
+                callback(entries);
+            });
+        }
+
+        return {
+            persist: persist,
+            load: load,
+        };
+    })();
+
+    let metadataCache = new LRUMap(100);
+    let metadataLoaded = false;
+
+    metadataCache.shift = function() {
+        // remove hexdata for oldest release
+        let oldest = LRUMap.prototype.shift.call(this);
+        if (oldest !== undefined) {
+            /** @type {CacheItem} */
+            let cached = oldest[1];
+            let hexdataKey = withHexdataPrefix(keyOf(cached.release));
+            chrome.storage.local.remove(hexdataKey, 
+                () => console.debug("Hex data removed: " + hexdataKey));
+        }
+        return oldest;
+    };
+
+    /**
+     * @param {Descriptor} release 
+     * @returns {string} A key used for caching the metadata for a release
+     */
+    function keyOf(release) {
+        return release.file;
+    }
+
+    /**
+     * @param {string} key 
+     * @returns {string} A key for storing the hex data for a release
+     */
+    function withHexdataPrefix(key) {
+        return "hex:" + key;
+    }
+
+    /**
+     * @param {Descriptor} release
+     * @returns {boolean}
+     */
+    function has(release) {
+        if (!metadataLoaded) {
+            console.warn("Cache not yet loaded");
+            return false;
+        }
+        return metadataCache.has(keyOf(release));
+    }
+
+    /**
+     * @param {Descriptor} release
+     * @param {string} hexdata
+     */
+    function put(release, hexdata) {
+        if (!metadataLoaded) {
+            console.warn("Cache not yet loaded");
+            return;
+        }
+        if (has(release)) {
+            console.debug("Firmware is already cached: " + keyOf(release));
+            return;
+        }
+        let key = keyOf(release);
+        let hexdataKey = withHexdataPrefix(key);
+        metadataCache.set(key, {
+            release: release,
+        });
+        MetadataStorage.persist(metadataCache.toJSON());
+        let obj = {};
+        obj[hexdataKey] = hexdata;
+        chrome.storage.local.set(obj);
+    }
+
+    /**
+     * @param {Descriptor} release
+     * @param {Function} callback
+     * @returns {(CacheItem|undefined)}
+     */
+    function get(release, callback) {
+        if (!metadataLoaded) {
+            console.warn("Cache not yet loaded");
+            return undefined;
+        }
+        let key = keyOf(release);
+        /** @type {CacheItem} */
+        let cached = metadataCache.get(key);
+        if (cached !== undefined) {
+            let hexdataKey = withHexdataPrefix(key);
+            chrome.storage.local.get(hexdataKey, function(obj) {
+                cached.hexdata = typeof obj === "object" && obj.hasOwnProperty(hexdataKey) 
+                    ? obj[hexdataKey]
+                    : null;
+                callback(cached);
+            });
+        }
+        return cached;
+    }
+
+    /**
+     * @param {Array} entries 
+     */
+    function onEntriesLoaded(entries) {
+        let pairs = [];
+        for (let entry of entries) {
+            pairs.push([entry.key, entry.value]);
+        }
+        metadataCache.assign(pairs);
+        metadataLoaded = true;
+        console.info("Firmware cache loaded; number of entries: " + entries.length);
+    }
+
+    return {
+        has: has,
+        put: put,
+        get: get,
+        load: () => {
+            MetadataStorage.load(onEntriesLoaded);
+        },
+        flush: () => {
+            MetadataStorage.persist(metadataCache.toJSON());
+            metadataCache.clear();
+        },
+    };
+})();

src/js/tabs/firmware_flasher.js

@@ -17,6 +17,8 @@ TABS.firmware_flasher.initialize = function (callback) {
         parsed_hex = false; // parsed raw hex in array format
 
     $('#content').load("./tabs/firmware_flasher.html", function () {
+        FirmwareCache.load();
+
         function parse_hex(str, callback) {
             // parsing hex in different thread
             var worker = new Worker('./js/workers/hex_parser.js');
@@ -30,6 +32,54 @@ TABS.firmware_flasher.initialize = function (callback) {
             worker.postMessage(str);
         }
 
+        function process_hex(data, summary) {
+            intel_hex = data;
+
+            parse_hex(intel_hex, function (data) {
+                parsed_hex = data;
+
+                if (parsed_hex) {
+                    if (!FirmwareCache.has(summary)) {
+                        FirmwareCache.put(summary, intel_hex);
+                        console.info("Release put to cache: " + summary.file);
+                    }
+
+                    var url;
+
+                    $('span.progressLabel').html('<a class="save_firmware" href="#" title="Save Firmware">Loaded Online Firmware: (' + parsed_hex.bytes_total + ' bytes)</a>');
+
+                    $('a.flash_firmware').removeClass('disabled');
+
+                    $('div.release_info .target').text(summary.target);
+                    $('div.release_info .name').text(summary.version).prop('href', summary.releaseUrl);
+                    $('div.release_info .date').text(summary.date);
+                    $('div.release_info .status').text(summary.status);
+                    $('div.release_info .file').text(summary.file).prop('href', summary.url);
+
+                    var formattedNotes = summary.notes.replace(/#(\d+)/g, '[#$1](https://github.com/betaflight/betaflight/pull/$1)');
+                    formattedNotes = marked(formattedNotes);
+                    $('div.release_info .notes').html(formattedNotes);
+                    $('div.release_info .notes').find('a').each(function() {
+                        $(this).attr('target', '_blank');
+                    });
+
+                    $('div.release_info').slideDown();
+
+                } else {
+                    $('span.progressLabel').text(i18n.getMessage('firmwareFlasherHexCorrupted'));
+                }
+            });
+        }
+
+        function onLoadSuccess(data, summary) {
+            summary = typeof summary === "object" 
+                ? summary 
+                : $('select[name="firmware_version"] option:selected').data('summary');
+            process_hex(data, summary);
+            $("a.load_remote_file").removeClass('disabled');
+            $("a.load_remote_file").text(i18n.getMessage('firmwareFlasherButtonLoadOnline'));
+        };
+    
         function buildBoardOptions(releaseData) {
             if (!releaseData) {
                 $('select[name="board"]').empty().append('<option value="0">Offline</option>');
@@ -226,7 +276,15 @@ TABS.firmware_flasher.initialize = function (callback) {
         $('select[name="firmware_version"]').change(function(evt){
             $('div.release_info').slideUp();
             $('a.flash_firmware').addClass('disabled');
-            if (evt.target.value=="0") {
+            let release = $("option:selected", evt.target).data("summary");
+            let isCached = FirmwareCache.has(release);
+            if (evt.target.value=="0" || isCached) {
+                if (isCached) {
+                    FirmwareCache.get(release, cached => {
+                        console.info("Release found in cache: " + release.file);
+                        onLoadSuccess(cached.hexdata, release);
+                    });
+                }
                 $("a.load_remote_file").addClass('disabled');
             }
             else {
@@ -241,40 +299,6 @@ TABS.firmware_flasher.initialize = function (callback) {
                 return;
             }
 
-            function process_hex(data, summary) {
-                intel_hex = data;
-
-                parse_hex(intel_hex, function (data) {
-                    parsed_hex = data;
-
-                    if (parsed_hex) {
-                        var url;
-
-                        $('span.progressLabel').html('<a class="save_firmware" href="#" title="Save Firmware">Loaded Online Firmware: (' + parsed_hex.bytes_total + ' bytes)</a>');
-
-                        $('a.flash_firmware').removeClass('disabled');
-
-                        $('div.release_info .target').text(summary.target);
-                        $('div.release_info .name').text(summary.version).prop('href', summary.releaseUrl);
-                        $('div.release_info .date').text(summary.date);
-                        $('div.release_info .status').text(summary.status);
-                        $('div.release_info .file').text(summary.file).prop('href', summary.url);
-
-                        var formattedNotes = summary.notes.replace(/#(\d+)/g, '[#$1](https://github.com/betaflight/betaflight/pull/$1)');
-                        formattedNotes = marked(formattedNotes);
-                        $('div.release_info .notes').html(formattedNotes);
-                        $('div.release_info .notes').find('a').each(function() {
-                            $(this).attr('target', '_blank');
-                        });
-
-                        $('div.release_info').slideDown();
-
-                    } else {
-                        $('span.progressLabel').text(i18n.getMessage('firmwareFlasherHexCorrupted'));
-                    }
-                });
-            }
-
             function failed_to_load() {
                 $('span.progressLabel').text(i18n.getMessage('firmwareFlasherFailedToLoadOnlineFirmware'));
                 $('a.flash_firmware').addClass('disabled');
@@ -286,11 +310,7 @@ TABS.firmware_flasher.initialize = function (callback) {
             if (summary) { // undefined while list is loading or while running offline
                 $("a.load_remote_file").text(i18n.getMessage('firmwareFlasherButtonDownloading'));
                 $("a.load_remote_file").addClass('disabled');
-                $.get(summary.url, function (data) {
+                $.get(summary.url, onLoadSuccess).fail(failed_to_load);
-                    process_hex(data, summary);
-                    $("a.load_remote_file").removeClass('disabled');
-                    $("a.load_remote_file").text(i18n.getMessage('firmwareFlasherButtonLoadOnline'));
-                }).fail(failed_to_load);
             } else {
                 $('span.progressLabel').text(i18n.getMessage('firmwareFlasherFailedToLoadOnlineFirmware'));
             }
@@ -507,6 +527,7 @@ TABS.firmware_flasher.initialize = function (callback) {
 
 TABS.firmware_flasher.cleanup = function (callback) {
     PortHandler.flush_callbacks();
+    FirmwareCache.flush();
 
     // unbind "global" events
     $(document).unbind('keypress');

src/main.html

@@ -35,6 +35,7 @@
     <link type="text/css" rel="stylesheet" href="./css/dropdown-lists/css/style_lists.css" media="all"/>
     <link type="text/css" rel="stylesheet" href="./js/libraries/switchery/switchery.css" media="all"/>
     <link rel="stylesheet" type="text/css" href="./js/libraries/jbox/jBox.css"/>
+    <script type="text/javascript" src="./node_modules/lru_map/lru.js"></script>
     <script type="text/javascript" src="./node_modules/i18next/i18next.js"></script>
     <script type="text/javascript" src="./node_modules/i18next-xhr-backend/i18nextXHRBackend.js"></script>
     <script type="text/javascript" src="./node_modules/marked/marked.min.js"></script>
@@ -96,6 +97,7 @@
     <script type="text/javascript" src="./js/tabs/cli.js"></script>
     <script type="text/javascript" src="./js/tabs/logging.js"></script>
     <script type="text/javascript" src="./js/tabs/onboard_logging.js"></script>
+    <script type="text/javascript" src="./js/FirmwareCache.js"></script>
     <script type="text/javascript" src="./js/tabs/firmware_flasher.js"></script>
     <script type="text/javascript" src="./js/tabs/failsafe.js"></script>
     <script type="text/javascript" src="./js/LogoManager.js"></script>