idb-keyval
Version:
A super-simple-small keyval store built on top of IndexedDB
210 lines (207 loc) • 7.1 kB
JavaScript
;
function promisifyRequest(request) {
return new Promise((resolve, reject) => {
// @ts-ignore - file size hacks
request.oncomplete = request.onsuccess = () => resolve(request.result);
// @ts-ignore - file size hacks
request.onabort = request.onerror = () => reject(request.error);
});
}
function createStore(dbName, storeName) {
let dbp;
const getDB = () => {
if (dbp)
return dbp;
const request = indexedDB.open(dbName);
request.onupgradeneeded = () => request.result.createObjectStore(storeName);
dbp = promisifyRequest(request);
dbp.then((db) => {
// It seems like Safari sometimes likes to just close the connection.
// It's supposed to fire this event when that happens. Let's hope it does!
db.onclose = () => (dbp = undefined);
}, () => { });
return dbp;
};
return (txMode, callback) => getDB().then((db) => callback(db.transaction(storeName, txMode).objectStore(storeName)));
}
let defaultGetStoreFunc;
function defaultGetStore() {
if (!defaultGetStoreFunc) {
defaultGetStoreFunc = createStore('keyval-store', 'keyval');
}
return defaultGetStoreFunc;
}
/**
* Get a value by its key.
*
* @param key
* @param customStore Method to get a custom store. Use with caution (see the docs).
*/
function get(key, customStore = defaultGetStore()) {
return customStore('readonly', (store) => promisifyRequest(store.get(key)));
}
/**
* Set a value with a key.
*
* @param key
* @param value
* @param customStore Method to get a custom store. Use with caution (see the docs).
*/
function set(key, value, customStore = defaultGetStore()) {
return customStore('readwrite', (store) => {
store.put(value, key);
return promisifyRequest(store.transaction);
});
}
/**
* Set multiple values at once. This is faster than calling set() multiple times.
* It's also atomic – if one of the pairs can't be added, none will be added.
*
* @param entries Array of entries, where each entry is an array of `[key, value]`.
* @param customStore Method to get a custom store. Use with caution (see the docs).
*/
function setMany(entries, customStore = defaultGetStore()) {
return customStore('readwrite', (store) => {
entries.forEach((entry) => store.put(entry[1], entry[0]));
return promisifyRequest(store.transaction);
});
}
/**
* Get multiple values by their keys
*
* @param keys
* @param customStore Method to get a custom store. Use with caution (see the docs).
*/
function getMany(keys, customStore = defaultGetStore()) {
return customStore('readonly', (store) => Promise.all(keys.map((key) => promisifyRequest(store.get(key)))));
}
/**
* Update a value. This lets you see the old value and update it as an atomic operation.
*
* @param key
* @param updater A callback that takes the old value and returns a new value.
* @param customStore Method to get a custom store. Use with caution (see the docs).
*/
function update(key, updater, customStore = defaultGetStore()) {
return customStore('readwrite', (store) =>
// Need to create the promise manually.
// If I try to chain promises, the transaction closes in browsers
// that use a promise polyfill (IE10/11).
new Promise((resolve, reject) => {
store.get(key).onsuccess = function () {
try {
store.put(updater(this.result), key);
resolve(promisifyRequest(store.transaction));
}
catch (err) {
reject(err);
}
};
}));
}
/**
* Delete a particular key from the store.
*
* @param key
* @param customStore Method to get a custom store. Use with caution (see the docs).
*/
function del(key, customStore = defaultGetStore()) {
return customStore('readwrite', (store) => {
store.delete(key);
return promisifyRequest(store.transaction);
});
}
/**
* Delete multiple keys at once.
*
* @param keys List of keys to delete.
* @param customStore Method to get a custom store. Use with caution (see the docs).
*/
function delMany(keys, customStore = defaultGetStore()) {
return customStore('readwrite', (store) => {
keys.forEach((key) => store.delete(key));
return promisifyRequest(store.transaction);
});
}
/**
* Clear all values in the store.
*
* @param customStore Method to get a custom store. Use with caution (see the docs).
*/
function clear(customStore = defaultGetStore()) {
return customStore('readwrite', (store) => {
store.clear();
return promisifyRequest(store.transaction);
});
}
function eachCursor(store, callback) {
store.openCursor().onsuccess = function () {
if (!this.result)
return;
callback(this.result);
this.result.continue();
};
return promisifyRequest(store.transaction);
}
/**
* Get all keys in the store.
*
* @param customStore Method to get a custom store. Use with caution (see the docs).
*/
function keys(customStore = defaultGetStore()) {
return customStore('readonly', (store) => {
// Fast path for modern browsers
if (store.getAllKeys) {
return promisifyRequest(store.getAllKeys());
}
const items = [];
return eachCursor(store, (cursor) => items.push(cursor.key)).then(() => items);
});
}
/**
* Get all values in the store.
*
* @param customStore Method to get a custom store. Use with caution (see the docs).
*/
function values(customStore = defaultGetStore()) {
return customStore('readonly', (store) => {
// Fast path for modern browsers
if (store.getAll) {
return promisifyRequest(store.getAll());
}
const items = [];
return eachCursor(store, (cursor) => items.push(cursor.value)).then(() => items);
});
}
/**
* Get all entries in the store. Each entry is an array of `[key, value]`.
*
* @param customStore Method to get a custom store. Use with caution (see the docs).
*/
function entries(customStore = defaultGetStore()) {
return customStore('readonly', (store) => {
// Fast path for modern browsers
// (although, hopefully we'll get a simpler path some day)
if (store.getAll && store.getAllKeys) {
return Promise.all([
promisifyRequest(store.getAllKeys()),
promisifyRequest(store.getAll()),
]).then(([keys, values]) => keys.map((key, i) => [key, values[i]]));
}
const items = [];
return customStore('readonly', (store) => eachCursor(store, (cursor) => items.push([cursor.key, cursor.value])).then(() => items));
});
}
exports.clear = clear;
exports.createStore = createStore;
exports.del = del;
exports.delMany = delMany;
exports.entries = entries;
exports.get = get;
exports.getMany = getMany;
exports.keys = keys;
exports.promisifyRequest = promisifyRequest;
exports.set = set;
exports.setMany = setMany;
exports.update = update;
exports.values = values;