rxdb
Version:
A local-first realtime NoSQL Database for JavaScript applications - https://rxdb.info/
93 lines (89 loc) • 3.52 kB
JavaScript
import { BehaviorSubject } from 'rxjs';
import { INTERNAL_CONTEXT_COLLECTION, getPrimaryKeyOfInternalDocument } from "../../rx-database-internal-store.js";
import { getPreviousVersions } from "../../rx-schema.js";
import { PROMISE_RESOLVE_FALSE, PROMISE_RESOLVE_NULL, clone, flatClone, getFromMapOrCreate, toPromise } from "../utils/index.js";
export async function getOldCollectionMeta(migrationState) {
var collectionDocKeys = getPreviousVersions(migrationState.collection.schema.jsonSchema).map(version => migrationState.collection.name + '-' + version);
var found = await migrationState.database.internalStore.findDocumentsById(collectionDocKeys.map(key => getPrimaryKeyOfInternalDocument(key, INTERNAL_CONTEXT_COLLECTION)), false);
if (found.length > 1) {
throw new Error('more than one old collection meta found');
}
return found[0];
}
/**
* runs the doc-data through all following migrationStrategies
* so it will match the newest schema.
* @throws Error if final doc does not match final schema or migrationStrategy crashes
* @return final object or null if migrationStrategy deleted it
*/
export function migrateDocumentData(collection, docSchemaVersion, docData) {
/**
* We cannot deep-clone Blob or Buffer
* so we just flat clone it here
* and attach it to the deep cloned document data.
*/
var attachmentsBefore = flatClone(docData._attachments);
var mutateableDocData = clone(docData);
var meta = mutateableDocData._meta;
delete mutateableDocData._meta;
mutateableDocData._attachments = attachmentsBefore;
var nextVersion = docSchemaVersion + 1;
// run the document through migrationStrategies
var currentPromise = Promise.resolve(mutateableDocData);
var _loop = function () {
var version = nextVersion;
currentPromise = currentPromise.then(docOrNull => runStrategyIfNotNull(collection, version, docOrNull));
nextVersion++;
};
while (nextVersion <= collection.schema.version) {
_loop();
}
return currentPromise.then(doc => {
if (doc === null) {
return PROMISE_RESOLVE_NULL;
}
doc._meta = meta;
return doc;
});
}
export function runStrategyIfNotNull(collection, version, docOrNull) {
if (docOrNull === null) {
return PROMISE_RESOLVE_NULL;
} else {
var ret = collection.migrationStrategies[version](docOrNull, collection);
var retPromise = toPromise(ret);
return retPromise;
}
}
/**
* returns true if a migration is needed
*/
export async function mustMigrate(migrationState) {
if (migrationState.collection.schema.version === 0) {
return PROMISE_RESOLVE_FALSE;
}
var oldColDoc = await getOldCollectionMeta(migrationState);
return !!oldColDoc;
}
export var MIGRATION_DEFAULT_BATCH_SIZE = 200;
export var DATA_MIGRATION_STATE_SUBJECT_BY_DATABASE = new WeakMap();
export function addMigrationStateToDatabase(migrationState) {
var allSubject = getMigrationStateByDatabase(migrationState.database);
var allList = allSubject.getValue().slice(0);
allList.push(migrationState);
allSubject.next(allList);
}
export function getMigrationStateByDatabase(database) {
return getFromMapOrCreate(DATA_MIGRATION_STATE_SUBJECT_BY_DATABASE, database, () => new BehaviorSubject([]));
}
/**
* Complete on database destroy
* so people do not have to unsubscribe
*/
export function onDatabaseDestroy(database) {
var subject = DATA_MIGRATION_STATE_SUBJECT_BY_DATABASE.get(database);
if (subject) {
subject.complete();
}
}
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