You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
186 lines
7.3 KiB
186 lines
7.3 KiB
2 years ago
|
const instanceOfAny = (object, constructors) => constructors.some((c) => object instanceof c);
|
||
|
|
||
|
let idbProxyableTypes;
|
||
|
let cursorAdvanceMethods;
|
||
|
// This is a function to prevent it throwing up in node environments.
|
||
|
function getIdbProxyableTypes() {
|
||
|
return (idbProxyableTypes ||
|
||
|
(idbProxyableTypes = [
|
||
|
IDBDatabase,
|
||
|
IDBObjectStore,
|
||
|
IDBIndex,
|
||
|
IDBCursor,
|
||
|
IDBTransaction,
|
||
|
]));
|
||
|
}
|
||
|
// This is a function to prevent it throwing up in node environments.
|
||
|
function getCursorAdvanceMethods() {
|
||
|
return (cursorAdvanceMethods ||
|
||
|
(cursorAdvanceMethods = [
|
||
|
IDBCursor.prototype.advance,
|
||
|
IDBCursor.prototype.continue,
|
||
|
IDBCursor.prototype.continuePrimaryKey,
|
||
|
]));
|
||
|
}
|
||
|
const cursorRequestMap = new WeakMap();
|
||
|
const transactionDoneMap = new WeakMap();
|
||
|
const transactionStoreNamesMap = new WeakMap();
|
||
|
const transformCache = new WeakMap();
|
||
|
const reverseTransformCache = new WeakMap();
|
||
|
function promisifyRequest(request) {
|
||
|
const promise = new Promise((resolve, reject) => {
|
||
|
const unlisten = () => {
|
||
|
request.removeEventListener('success', success);
|
||
|
request.removeEventListener('error', error);
|
||
|
};
|
||
|
const success = () => {
|
||
|
resolve(wrap(request.result));
|
||
|
unlisten();
|
||
|
};
|
||
|
const error = () => {
|
||
|
reject(request.error);
|
||
|
unlisten();
|
||
|
};
|
||
|
request.addEventListener('success', success);
|
||
|
request.addEventListener('error', error);
|
||
|
});
|
||
|
promise
|
||
|
.then((value) => {
|
||
|
// Since cursoring reuses the IDBRequest (*sigh*), we cache it for later retrieval
|
||
|
// (see wrapFunction).
|
||
|
if (value instanceof IDBCursor) {
|
||
|
cursorRequestMap.set(value, request);
|
||
|
}
|
||
|
// Catching to avoid "Uncaught Promise exceptions"
|
||
|
})
|
||
|
.catch(() => { });
|
||
|
// This mapping exists in reverseTransformCache but doesn't doesn't exist in transformCache. This
|
||
|
// is because we create many promises from a single IDBRequest.
|
||
|
reverseTransformCache.set(promise, request);
|
||
|
return promise;
|
||
|
}
|
||
|
function cacheDonePromiseForTransaction(tx) {
|
||
|
// Early bail if we've already created a done promise for this transaction.
|
||
|
if (transactionDoneMap.has(tx))
|
||
|
return;
|
||
|
const done = new Promise((resolve, reject) => {
|
||
|
const unlisten = () => {
|
||
|
tx.removeEventListener('complete', complete);
|
||
|
tx.removeEventListener('error', error);
|
||
|
tx.removeEventListener('abort', error);
|
||
|
};
|
||
|
const complete = () => {
|
||
|
resolve();
|
||
|
unlisten();
|
||
|
};
|
||
|
const error = () => {
|
||
|
reject(tx.error || new DOMException('AbortError', 'AbortError'));
|
||
|
unlisten();
|
||
|
};
|
||
|
tx.addEventListener('complete', complete);
|
||
|
tx.addEventListener('error', error);
|
||
|
tx.addEventListener('abort', error);
|
||
|
});
|
||
|
// Cache it for later retrieval.
|
||
|
transactionDoneMap.set(tx, done);
|
||
|
}
|
||
|
let idbProxyTraps = {
|
||
|
get(target, prop, receiver) {
|
||
|
if (target instanceof IDBTransaction) {
|
||
|
// Special handling for transaction.done.
|
||
|
if (prop === 'done')
|
||
|
return transactionDoneMap.get(target);
|
||
|
// Polyfill for objectStoreNames because of Edge.
|
||
|
if (prop === 'objectStoreNames') {
|
||
|
return target.objectStoreNames || transactionStoreNamesMap.get(target);
|
||
|
}
|
||
|
// Make tx.store return the only store in the transaction, or undefined if there are many.
|
||
|
if (prop === 'store') {
|
||
|
return receiver.objectStoreNames[1]
|
||
|
? undefined
|
||
|
: receiver.objectStore(receiver.objectStoreNames[0]);
|
||
|
}
|
||
|
}
|
||
|
// Else transform whatever we get back.
|
||
|
return wrap(target[prop]);
|
||
|
},
|
||
|
set(target, prop, value) {
|
||
|
target[prop] = value;
|
||
|
return true;
|
||
|
},
|
||
|
has(target, prop) {
|
||
|
if (target instanceof IDBTransaction &&
|
||
|
(prop === 'done' || prop === 'store')) {
|
||
|
return true;
|
||
|
}
|
||
|
return prop in target;
|
||
|
},
|
||
|
};
|
||
|
function replaceTraps(callback) {
|
||
|
idbProxyTraps = callback(idbProxyTraps);
|
||
|
}
|
||
|
function wrapFunction(func) {
|
||
|
// Due to expected object equality (which is enforced by the caching in `wrap`), we
|
||
|
// only create one new func per func.
|
||
|
// Edge doesn't support objectStoreNames (booo), so we polyfill it here.
|
||
|
if (func === IDBDatabase.prototype.transaction &&
|
||
|
!('objectStoreNames' in IDBTransaction.prototype)) {
|
||
|
return function (storeNames, ...args) {
|
||
|
const tx = func.call(unwrap(this), storeNames, ...args);
|
||
|
transactionStoreNamesMap.set(tx, storeNames.sort ? storeNames.sort() : [storeNames]);
|
||
|
return wrap(tx);
|
||
|
};
|
||
|
}
|
||
|
// Cursor methods are special, as the behaviour is a little more different to standard IDB. In
|
||
|
// IDB, you advance the cursor and wait for a new 'success' on the IDBRequest that gave you the
|
||
|
// cursor. It's kinda like a promise that can resolve with many values. That doesn't make sense
|
||
|
// with real promises, so each advance methods returns a new promise for the cursor object, or
|
||
|
// undefined if the end of the cursor has been reached.
|
||
|
if (getCursorAdvanceMethods().includes(func)) {
|
||
|
return function (...args) {
|
||
|
// Calling the original function with the proxy as 'this' causes ILLEGAL INVOCATION, so we use
|
||
|
// the original object.
|
||
|
func.apply(unwrap(this), args);
|
||
|
return wrap(cursorRequestMap.get(this));
|
||
|
};
|
||
|
}
|
||
|
return function (...args) {
|
||
|
// Calling the original function with the proxy as 'this' causes ILLEGAL INVOCATION, so we use
|
||
|
// the original object.
|
||
|
return wrap(func.apply(unwrap(this), args));
|
||
|
};
|
||
|
}
|
||
|
function transformCachableValue(value) {
|
||
|
if (typeof value === 'function')
|
||
|
return wrapFunction(value);
|
||
|
// This doesn't return, it just creates a 'done' promise for the transaction,
|
||
|
// which is later returned for transaction.done (see idbObjectHandler).
|
||
|
if (value instanceof IDBTransaction)
|
||
|
cacheDonePromiseForTransaction(value);
|
||
|
if (instanceOfAny(value, getIdbProxyableTypes()))
|
||
|
return new Proxy(value, idbProxyTraps);
|
||
|
// Return the same value back if we're not going to transform it.
|
||
|
return value;
|
||
|
}
|
||
|
function wrap(value) {
|
||
|
// We sometimes generate multiple promises from a single IDBRequest (eg when cursoring), because
|
||
|
// IDB is weird and a single IDBRequest can yield many responses, so these can't be cached.
|
||
|
if (value instanceof IDBRequest)
|
||
|
return promisifyRequest(value);
|
||
|
// If we've already transformed this value before, reuse the transformed value.
|
||
|
// This is faster, but it also provides object equality.
|
||
|
if (transformCache.has(value))
|
||
|
return transformCache.get(value);
|
||
|
const newValue = transformCachableValue(value);
|
||
|
// Not all types are transformed.
|
||
|
// These may be primitive types, so they can't be WeakMap keys.
|
||
|
if (newValue !== value) {
|
||
|
transformCache.set(value, newValue);
|
||
|
reverseTransformCache.set(newValue, value);
|
||
|
}
|
||
|
return newValue;
|
||
|
}
|
||
|
const unwrap = (value) => reverseTransformCache.get(value);
|
||
|
|
||
|
export { reverseTransformCache as a, instanceOfAny as i, replaceTraps as r, unwrap as u, wrap as w };
|