hydrogen-web/prototypes/idb-promises-safari.html

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<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
</head>
<body>
<script type="text/javascript">
function reqAsPromise(req) {
return new Promise(function (resolve, reject) {
req.onsuccess = function() {
resolve(req.result);
};
req.onerror = function(e) {
reject(new Error("IDB request failed: " + req.error));
};
});
}
function txnAsPromise(txn) {
return new Promise(function (resolve, reject) {
txn.oncomplete = function() {
resolve(txn);
};
txn.onabort = function(e) {
reject(new Error("Transaction got aborted: " + txn.error));
};
});
}
const BrowserMutationObserver = window.MutationObserver || window.WebKitMutationObserver;
function useMutationObserver(flush) {
let iterations = 0;
const observer = new BrowserMutationObserver(flush);
const node = document.createTextNode('');
observer.observe(node, { characterData: true });
return () => {
node.data = (iterations = ++iterations % 2);
};
}
const wait = (function() {
let resolve = null;
const trigger = useMutationObserver(() => {
resolve();
});
return () => {
return new Promise(r => {
resolve = r;
trigger();
});
};
})();
var _resolve = Promise.resolve.bind(Promise);
var _then = Promise.prototype.then;
async function delay() {
return Promise.resolve();
// two consecutive macro tasks
//await new Promise(r => setImmediate(r));
// the next macro task will now be the complete event of the txn,
// so schedule another macro task to execute after that
//await new Promise(r => setImmediate(r));
//return;
// for (let i = 0; i < 1000; i+=1) {
// console.log("await...");
// await wait();
// }
let p = _resolve(0);
for (let i=0;i<10;++i) {
p = _then.call(p, x => x + 1);
}
let result = await p;
console.log("Result: "+ result + " (should be 10)");
}
class Storage {
constructor(databaseName) {
this._databaseName = databaseName;
this._database = null;
}
open() {
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(mode, storeName) {
const txn = this._database.transaction([storeName], mode);
txn.addEventListener("complete", () => {
console.info(`transaction ${mode} for ${storeName} completed`);
});
txn.addEventListener("abort", e => {
console.warn(`transaction ${mode} for ${storeName} aborted`, e.target.error);
});
return txn;
}
_createStores(db) {
db.createObjectStore("foos", {keyPath: "id"});
}
}
async function getAll(store, depth = 0) {
if (depth < 15) {
return await getAll(store, depth + 1);
}
const request = store.openCursor();
const results = [];
return await 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();
//await reqAsPromise(storage.openTxn("readwrite", "foos").objectStore("foos").clear());
for (let i = 0; i < 10; i += 1) {
storage.openTxn("readonly", "foos").objectStore("foos").get(5);
//console.log("from readtxn", await reqAsPromise(storage.openTxn("readonly", "foos").objectStore("foos").get(5)));
const txn = storage.openTxn("readwrite", "foos");
const store = txn.objectStore("foos");
console.log("writing the foos");
store.put({id: 5, name: "foo"});
store.put({id: 6, name: "bar"});
store.put({id: 7, name: "bazzz"});
await delay();
console.log("reading the foos");
console.log("5", await reqAsPromise(store.get(5)));
console.log("6", await reqAsPromise(store.get(6)));
console.log("7", await reqAsPromise(store.get(7)));
// await txnAsPromise(txn);
}
} catch(err) {
console.error(err);
};
}
main();
</script>
</body>
</html>