53cdabb459
as fragments can be unaware of their chronological relationship, we need to check whether the events received from /messages or /context already exists, so we can later hook up the fragments.
166 lines
7 KiB
HTML
166 lines
7 KiB
HTML
<html>
|
|
<head><meta charset="utf-8"></head>
|
|
<body>
|
|
<script type="text/javascript">
|
|
function reqAsPromise(req) {
|
|
return new Promise((resolve, reject) => {
|
|
req.onsuccess = () => resolve(req);
|
|
req.onerror = (err) => reject(err);
|
|
});
|
|
}
|
|
|
|
function txnAsPromise(txn) {
|
|
return new Promise((resolve, reject) => {
|
|
txn.addEventListener("complete", resolve);
|
|
txn.addEventListener("abort", reject);
|
|
});
|
|
}
|
|
|
|
function iterateCursor(cursor, processValue) {
|
|
// TODO: does cursor already have a value here??
|
|
return new Promise((resolve, reject) => {
|
|
cursor.onerror = (event) => {
|
|
reject(new Error("Query failed: " + event.target.errorCode));
|
|
};
|
|
// collect results
|
|
cursor.onsuccess = (event) => {
|
|
const cursor = event.target.result;
|
|
if (!cursor) {
|
|
resolve(false);
|
|
return; // end of results
|
|
}
|
|
const {done, jumpTo} = processValue(cursor.value, cursor.key);
|
|
if (done) {
|
|
resolve(true);
|
|
} else {
|
|
cursor.continue(jumpTo);
|
|
}
|
|
};
|
|
});
|
|
}
|
|
|
|
/**
|
|
* Checks if a given set of keys exist.
|
|
* Calls `callback(key, found)` for each key in `keys`, in an unspecified order.
|
|
* If the callback returns true, the search is halted and callback won't be called again.
|
|
*/
|
|
async function findKeys(target, keys, backwards, callback) {
|
|
const direction = backwards ? "prev" : "next";
|
|
const compareKeys = (a, b) => backwards ? -indexedDB.cmp(a, b) : indexedDB.cmp(a, b);
|
|
const sortedKeys = keys.slice().sort(compareKeys);
|
|
console.log(sortedKeys);
|
|
const firstKey = backwards ? sortedKeys[sortedKeys.length - 1] : sortedKeys[0];
|
|
const lastKey = backwards ? sortedKeys[0] : sortedKeys[sortedKeys.length - 1];
|
|
const cursor = target.openKeyCursor(IDBKeyRange.bound(firstKey, lastKey), direction);
|
|
let i = 0;
|
|
let consumerDone = false;
|
|
await iterateCursor(cursor, (value, key) => {
|
|
// while key is larger than next key, advance and report false
|
|
while(i < sortedKeys.length && compareKeys(sortedKeys[i], key) < 0 && !consumerDone) {
|
|
console.log("before match", sortedKeys[i]);
|
|
consumerDone = callback(sortedKeys[i], false);
|
|
++i;
|
|
}
|
|
if (i < sortedKeys.length && compareKeys(sortedKeys[i], key) === 0 && !consumerDone) {
|
|
console.log("match", sortedKeys[i]);
|
|
consumerDone = callback(sortedKeys[i], true);
|
|
++i;
|
|
}
|
|
const done = consumerDone || i >= sortedKeys.length;
|
|
const jumpTo = !done && sortedKeys[i];
|
|
return {done, jumpTo};
|
|
});
|
|
// report null for keys we didn't to at the end
|
|
while (!consumerDone && i < sortedKeys.length) {
|
|
console.log("afterwards", sortedKeys[i]);
|
|
consumerDone = callback(sortedKeys[i], false);
|
|
++i;
|
|
}
|
|
}
|
|
|
|
async function findFirstOrLastOccurringEventId(target, roomId, eventIds, findLast = false) {
|
|
const keys = eventIds.map(eventId => [roomId, eventId]);
|
|
const results = new Array(keys.length);
|
|
let firstFoundEventId;
|
|
|
|
// find first result that is found and has no undefined results before it
|
|
function firstFoundAndPrecedingResolved() {
|
|
let inc = findLast ? -1 : 1;
|
|
let start = findLast ? results.length - 1 : 0;
|
|
for(let i = start; i >= 0 && i < results.length; i += inc) {
|
|
if (results[i] === undefined) {
|
|
return;
|
|
} else if(results[i] === true) {
|
|
return keys[i];
|
|
}
|
|
}
|
|
}
|
|
|
|
await findKeys(target, keys, findLast, (key, found) => {
|
|
const index = keys.indexOf(key);
|
|
results[index] = found;
|
|
firstFoundEventId = firstFoundAndPrecedingResolved();
|
|
return !!firstFoundEventId;
|
|
});
|
|
|
|
return firstFoundEventId;
|
|
}
|
|
|
|
(async () => {
|
|
let db;
|
|
let isNew = false;
|
|
// open db
|
|
{
|
|
const req = window.indexedDB.open("prototype-idb-continue-key");
|
|
req.onupgradeneeded = (ev) => {
|
|
const db = ev.target.result;
|
|
db.createObjectStore("timeline", {keyPath: ["roomId", "eventId"]});
|
|
isNew = true;
|
|
};
|
|
db = (await reqAsPromise(req)).result;
|
|
}
|
|
const roomId = "!abcdef:localhost";
|
|
if (isNew) {
|
|
const txn = db.transaction(["timeline"], "readwrite");
|
|
const store = txn.objectStore("timeline");
|
|
for (var i = 1; i <= 100; ++i) {
|
|
store.add({roomId, eventId: `$${i * 10}`});
|
|
}
|
|
await txnAsPromise(txn);
|
|
}
|
|
console.log("show all in order we get them");
|
|
{
|
|
const txn = db.transaction(["timeline"], "readonly");
|
|
const store = txn.objectStore("timeline");
|
|
const cursor = store.openKeyCursor();
|
|
await iterateCursor(cursor, (value, key) => {
|
|
console.log(key);
|
|
return {done: false};
|
|
});
|
|
}
|
|
console.log("run findKeys");
|
|
{
|
|
const txn = db.transaction(["timeline"], "readonly");
|
|
const store = txn.objectStore("timeline");
|
|
const eventIds = ["$992", "$1000", "$1010", "$991", "$500", "$990"];
|
|
// const eventIds = ["$992", "$1010"];
|
|
const keys = eventIds.map(eventId => [roomId, eventId]);
|
|
await findKeys(store, keys, false, (key, found) => {
|
|
console.log(key, found);
|
|
});
|
|
}
|
|
console.log("run findFirstOrLastOccurringEventId");
|
|
{
|
|
const txn = db.transaction(["timeline"], "readonly");
|
|
const store = txn.objectStore("timeline");
|
|
const eventIds = ["$992", "$1000", "$1010", "$991", "$500", "$990", "$123"];
|
|
const firstMatch = await findFirstOrLastOccurringEventId(store, roomId, eventIds, false);
|
|
console.log("firstMatch", firstMatch);
|
|
const lastMatch = await findFirstOrLastOccurringEventId(store, roomId, eventIds, true);
|
|
console.log("lastMatch", lastMatch);
|
|
}
|
|
})();
|
|
</script>
|
|
</body>
|
|
</html>
|