prototype using await to see if it makes any difference

...to the es5 one in gnome web. Alas, it does not, and I can't recreate the failure mode I see in the app when awaiting opening txns.
2020-09-25 16:55:02 +02:00 · 2020-09-25 16:55:02 +02:00 · c68bafde54
commit c68bafde54
parent 76381fbca1
1 changed files with 112 additions and 0 deletions
--- a/prototypes/idb-promises-es6.html
+++ b/prototypes/idb-promises-es6.html
@ -0,0 +1,112 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <meta charset="utf-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1">
+</head>
+<body>
+    <script type="text/javascript" src="promifill.js"></script>
+    <!-- <script src="https://cdn.jsdelivr.net/npm/promise-polyfill@8/dist/polyfill.min.js"></script> -->
+    <script type="text/javascript">
+        //window.Promise = Promifill;
+        function reqAsPromise(req) {
+            return new Promise(function (resolve, reject) {
+                req.onsuccess = function() {
+                    resolve(req);
+                    Promise.flushQueue && Promise.flushQueue();
+                };
+                req.onerror = function(e) {
+                    reject(new Error("IDB request failed: " + e.target.error.message));
+                    Promise.flushQueue && Promise.flushQueue();
+                };
+            });
+        }
+
+        function Storage(databaseName) {
+            this._databaseName = databaseName;
+            this._database = null;
+        }
+
+        Storage.prototype = {
+            open: function() {
+                const req = window.indexedDB.open(this._databaseName);
+                const self = this;
+                req.onupgradeneeded = function(ev) {
+                    const db = ev.target.result;
+                    const oldVersion = ev.oldVersion;
+                    self._createStores(db, oldVersion);
+                }; 
+                return reqAsPromise(req).then(function() {
+                    self._database = req.result;
+                });
+            },
+            openTxn: function(mode, storeName) {
+                const txn = this._database.transaction([storeName], mode);
+                const store = txn.objectStore(storeName);
+                return Promise.resolve(store);
+            },
+            _createStores: function(db) {
+                db.createObjectStore("foos", {keyPath: ["id"]});
+            }
+        };
+
+        function getAll(store) {
+            const request = store.openCursor();
+            const results = [];
+            return new Promise(function(resolve, reject) {
+                request.onsuccess = function(event) {
+                    const cursor = event.target.result;
+                    if(cursor) {
+                        results.push(cursor.value);
+                        cursor.continue();
+                    } else {
+                        resolve(results);
+                        Promise.flushQueue && Promise.flushQueue();
+                    }
+                };
+                request.onerror = function(e) {
+                    reject(new Error("IDB request failed: " + e.target.error.message));
+                    Promise.flushQueue && Promise.flushQueue();
+                };
+            });
+        }
+
+        async function main() {
+            try {
+                let storage = new Storage("idb-promises");
+                await storage.open();
+                const store = await storage.openTxn("readwrite", "foos");
+                store.clear();
+                store.add({id: 5, name: "foo"});
+                store.add({id: 6, name: "bar"});
+                console.log("all1", await getAll(store));
+                store.add({id: 7, name: "bazzz"});
+                console.log("all2", await getAll(store));
+            } catch(err) {
+                console.error(err.message + ": " + err.stack);
+            };
+        }
+        main();
+
+
+        /*
+        
+        we basically want something like this for IE11/Win7:
+            
+            return new Promise(function (resolve, reject) {
+                req.onsuccess = function() {
+                    resolve(req);
+                    Promise?.flushQueue();
+                };
+                req.onerror = function(e) {
+                    reject(new Error("IDB request failed: " + e.target.error.message));
+                    Promise?.flushQueue();
+                };
+            });
+
+        we don't have this problem on platforms with a native promise implementation, so we can just have our own (forked) promise polyfill? 
+         */
+    </script>
+</body>
+</html>
+