rxdb
Version:
A local-first realtime NoSQL Database for JavaScript applications - https://rxdb.info/
240 lines (233 loc) • 7.81 kB
JavaScript
import { Subject, distinctUntilChanged, map, merge, shareReplay, startWith, tap } from 'rxjs';
import { overwritable } from "../../overwritable.js";
import { getChangedDocumentsSince } from "../../rx-storage-helper.js";
import { RXJS_SHARE_REPLAY_DEFAULTS, getProperty, setProperty, PROMISE_RESOLVE_VOID, appendToArray, clone, randomCouchString, deepEqual } from "../utils/index.js";
import { RX_STATE_COLLECTION_SCHEMA, nextRxStateId } from "./helpers.js";
import { newRxError } from "../../rx-error.js";
import { runPluginHooks } from "../../hooks.js";
var debugId = 0;
/**
* RxDB internally used properties are
* prefixed with lodash _ to make them less
* likely to clash with actual state properties
* from the user.
*/
export var RxStateBase = /*#__PURE__*/function () {
// used for debugging
function RxStateBase(prefix, collection) {
this._id = debugId++;
this._state = {};
this._nonPersisted = [];
this._writeQueue = PROMISE_RESOLVE_VOID;
this._initDone = false;
this._instanceId = randomCouchString(RX_STATE_COLLECTION_SCHEMA.properties.sId.maxLength);
this._ownEmits$ = new Subject();
this.prefix = prefix;
this.collection = collection;
this.collection.onDestroy.push(() => this._writeQueue);
this._lastIdQuery = this.collection.findOne({
sort: [{
id: 'desc'
}]
});
// make it "hot" for better write performance
this._lastIdQuery.$.subscribe();
this.$ = merge(this._ownEmits$, this.collection.$.pipe(tap(event => {
if (this._initDone && event.operation === 'INSERT' && event.documentData.sId !== this._instanceId) {
mergeOperationsIntoState(this._state, event.documentData.ops);
}
}))).pipe(shareReplay(RXJS_SHARE_REPLAY_DEFAULTS), map(() => this._state));
// directly subscribe because of the tap() side effect
this.$.subscribe();
}
var _proto = RxStateBase.prototype;
_proto.set = async function set(path, modifier) {
this._nonPersisted.push({
path,
modifier
});
return this._triggerWrite();
}
/**
* To have deterministic writes,
* and to ensure that multiple js realms do not overwrite
* each other, the write happens with incremental ids
* that would throw conflict errors and trigger a retry.
*/;
_proto._triggerWrite = function _triggerWrite() {
this._writeQueue = this._writeQueue.then(async () => {
if (this._nonPersisted.length === 0) {
return;
}
var useWrites = [];
var done = false;
while (!done) {
var lastIdDoc = await this._lastIdQuery.exec();
appendToArray(useWrites, this._nonPersisted);
this._nonPersisted = [];
var nextId = nextRxStateId(lastIdDoc ? lastIdDoc.id : undefined);
try {
/**
* TODO instead of a deep-clone we should
* only clone the parts where we know that they
* will be changed. This would improve performance.
*/
var newState = clone(this._state);
var ops = [];
for (var index = 0; index < useWrites.length; index++) {
var writeRow = useWrites[index];
var value = getProperty(newState, writeRow.path);
var newValue = writeRow.modifier(value);
setProperty(newState, writeRow.path, newValue);
ops.push({
k: writeRow.path,
/**
* Here we have to clone the value because
* some storages like the memory storage
* make input data deep-frozen in dev-mode.
*/
v: clone(newValue)
});
}
await this.collection.insert({
id: nextId,
sId: this._instanceId,
ops
});
this._state = newState;
this._ownEmits$.next(this._state);
done = true;
} catch (err) {
if (err.code !== 'CONFLICT') {
throw err;
}
}
}
}).catch(error => {
throw newRxError('SNH', {
name: 'RxState WRITE QUEUE ERROR',
error
});
});
return this._writeQueue;
};
_proto.get = function get(path) {
if (!path) {
return overwritable.deepFreezeWhenDevMode(this._state);
}
return overwritable.deepFreezeWhenDevMode(getProperty(this._state, path));
};
_proto.get$ = function get$(path) {
return this.$.pipe(map(() => this.get(path)), startWith(this.get(path)), distinctUntilChanged(deepEqual), shareReplay(RXJS_SHARE_REPLAY_DEFAULTS));
};
_proto.get$$ = function get$$(path) {
var obs = this.get$(path);
var reactivity = this.collection.database.getReactivityFactory();
return reactivity.fromObservable(obs, this.get(path), this.collection.database);
}
/**
* Merges the state operations into a single write row
* to store space and make recreating the state from
* disc faster.
*/;
_proto._cleanup = async function _cleanup() {
var firstWrite = await this.collection.findOne({
sort: [{
id: 'asc'
}]
}).exec();
var lastWrite = await this._lastIdQuery.exec();
if (!firstWrite || !lastWrite) {
return;
}
var firstNr = parseInt(firstWrite.id, 10);
var lastNr = parseInt(lastWrite.id, 10);
if (lastNr - 5 < firstNr) {
// only run if more then 5 write rows
return;
}
// update whole state object
await this._writeQueue;
await this.set('', () => this._state);
// delete old ones
await this.collection.find({
selector: {
id: {
$lte: lastWrite.id
}
}
}).remove();
};
return RxStateBase;
}();
export async function createRxState(database, prefix) {
var collectionName = 'rx-state-' + prefix;
await database.addCollections({
[collectionName]: {
schema: RX_STATE_COLLECTION_SCHEMA
}
});
var collection = database.collections[collectionName];
var rxState = new RxStateBase(prefix, collection);
/**
* Directly get the state and put it into memory.
* This ensures we can do non-async accesses to the
* correct state.
*/
var done = false;
var checkpoint = undefined;
while (!done) {
var result = await getChangedDocumentsSince(collection.storageInstance, 1000, checkpoint);
checkpoint = result.checkpoint;
var documents = result.documents;
if (documents.length === 0) {
done = true;
} else {
for (var index = 0; index < documents.length; index++) {
var document = documents[index];
mergeOperationsIntoState(rxState._state, document.ops);
}
}
}
rxState._initDone = true;
var proxy = new Proxy(rxState, {
get(target, property) {
if (typeof property !== 'string') {
return target[property];
}
if (rxState[property]) {
var ret = rxState[property];
if (typeof ret === 'function') {
return ret.bind(rxState);
} else {
return ret;
}
}
var lastChar = property.charAt(property.length - 1);
if (property.endsWith('$$')) {
var key = property.slice(0, -2);
return rxState.get$$(key);
} else if (lastChar === '$') {
var _key = property.slice(0, -1);
return rxState.get$(_key);
} else {
return rxState.get(property);
}
},
set(target, newValue, receiver) {
throw new Error('Do not write to RxState');
}
});
runPluginHooks('createRxState', {
collection,
state: proxy
});
return proxy;
}
export function mergeOperationsIntoState(state, operations) {
for (var index = 0; index < operations.length; index++) {
var operation = operations[index];
setProperty(state, operation.k, clone(operation.v));
}
}
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