44 lines
1.5 KiB
JavaScript
44 lines
1.5 KiB
JavaScript
// Copyright IBM Corp. 2016,2019. All Rights Reserved.
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// Node module: loopback-datasource-juggler
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// This file is licensed under the MIT License.
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// License text available at https://opensource.org/licenses/MIT
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'use strict';
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const assert = require('assert');
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const utils = require('../utils');
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/**
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* Asynchronously iterate all keys in the database. Similar to `.keys()` but
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* instead allows for iteration over large data sets without having to load
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* everything into memory at once.
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*
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* @param {Object} filter An optional filter object with the following
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* @param {String} filter.match Glob string to use to filter returned
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* keys (i.e. `userid.*`). All connectors are required to support `*` and
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* `?`. They may also support additional special characters that are
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* specific to the backing database.
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* @param {Object} options
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* @returns {AsyncIterator} An Object implementing `next(cb) -> Promise`
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* function that can be used to iterate all keys.
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*
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* @header KVAO.iterateKeys(filter)
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*/
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module.exports = function keyValueIterateKeys(filter, options) {
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filter = filter || {};
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options = options || {};
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assert(typeof filter === 'object', 'filter must be an object');
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assert(typeof options === 'object', 'options must be an object');
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const iter = this.getConnector().iterateKeys(this.modelName, filter, options);
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// promisify the returned iterator
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return {
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next: function(callback) {
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callback = callback || utils.createPromiseCallback();
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iter.next(callback);
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return callback.promise;
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},
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};
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};
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