moleculer-api/dist/broker/batching.js

A dynamic API Gateway for MoleculerJS which updates REST endpoints and aggregated GraphQL schema, access control policy for each action calls from metadata of remote services schema without restart or deployment.

"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.BatchingPool = void 0;
const tslib_1 = require("tslib");
// tslint:disable:max-classes-per-file
const _ = tslib_1.__importStar(require("lodash"));
const dataloader_1 = tslib_1.__importDefault(require("dataloader"));
const interface_1 = require("../interface");
const defaultOptions = {
    batchingKey: (...args) => interface_1.hashObject(args, true),
    entryKey: (batchingParams) => interface_1.hashObject(batchingParams, true),
    failedEntryCheck: (entry) => !!(entry && entry.batchingError),
    entriesLimit: 100,
};
class BatchingPool {
    constructor(opts) {
        this.loaderMap = new Map();
        this.opts = _.defaultsDeep(opts || {}, defaultOptions);
    }
    getBatchingKey(...args) {
        return this.opts.batchingKey(...args);
    }
    hasBatchingHandler(key) {
        return this.loaderMap.has(key);
    }
    setBatchingHandler(key, handler) {
        const loader = new dataloader_1.default((batchingParamsList) => {
            return handler(batchingParamsList)
                .then(entries => {
                return entries.map(entry => {
                    if (this.opts.failedEntryCheck(entry)) {
                        // wrap entry as Error, ref: https://github.com/graphql/dataloader/blob/master/src/index.js#L175
                        const err = new Error("failed batching entry"); // TODO: normalize error
                        for (const [k, v] of Object.entries(entry)) {
                            // @ts-ignore
                            err[k] = v;
                        }
                        return err;
                    }
                    return entry;
                });
            });
        }, {
            batch: true,
            maxBatchSize: this.opts.entriesLimit,
            cache: true,
            cacheKeyFn: this.opts.entryKey,
        });
        this.loaderMap.set(key, loader);
    }
    batch(key, batchingParams) {
        return tslib_1.__awaiter(this, void 0, void 0, function* () {
            const loader = this.loaderMap.get(key);
            console.assert(loader, "cannot find batching handler with given key");
            return loader.load(batchingParams);
        });
    }
    clear() {
        this.loaderMap.clear();
    }
}
exports.BatchingPool = BatchingPool;
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