85 lines
2.2 KiB
TypeScript
85 lines
2.2 KiB
TypeScript
// Copyright 2018-2020 Signal Messenger, LLC
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// SPDX-License-Identifier: AGPL-3.0-only
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import { readFileSync, writeFileSync, unlinkSync } from 'fs';
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import { get, set } from 'lodash';
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const ENCODING = 'utf8';
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type InternalConfigType = Record<string, unknown>;
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export type ConfigType = {
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set: (keyPath: string, value: unknown) => void;
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get: (keyPath: string) => unknown;
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remove: () => void;
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// Test-only
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_getCachedValue: () => InternalConfigType | undefined;
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};
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export function start(
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name: string,
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targetPath: string,
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options?: { allowMalformedOnStartup?: boolean }
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): ConfigType {
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let cachedValue: InternalConfigType | undefined;
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let incomingJson: string | undefined;
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try {
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incomingJson = readFileSync(targetPath, ENCODING);
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cachedValue = incomingJson ? JSON.parse(incomingJson) : undefined;
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console.log(`config/get: Successfully read ${name} config file`);
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if (!cachedValue) {
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console.log(
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`config/get: ${name} config value was falsy, cache is now empty object`
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);
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cachedValue = Object.create(null);
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}
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} catch (error) {
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if (!options?.allowMalformedOnStartup && error.code !== 'ENOENT') {
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throw error;
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}
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if (incomingJson) {
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console.log(
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`config/get: ${name} config file was malformed, starting afresh`
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);
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} else {
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console.log(
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`config/get: Did not find ${name} config file (or it was empty), cache is now empty object`
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);
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}
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cachedValue = Object.create(null);
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}
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function ourGet(keyPath: string): unknown {
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return get(cachedValue, keyPath);
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}
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function ourSet(keyPath: string, value: unknown): void {
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if (!cachedValue) {
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throw new Error('ourSet: no cachedValue!');
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}
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set(cachedValue, keyPath, value);
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console.log(`config/set: Saving ${name} config to disk`);
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const outgoingJson = JSON.stringify(cachedValue, null, ' ');
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writeFileSync(targetPath, outgoingJson, ENCODING);
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}
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function remove(): void {
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console.log(`config/remove: Deleting ${name} config from disk`);
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unlinkSync(targetPath);
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cachedValue = Object.create(null);
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}
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return {
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set: ourSet,
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get: ourGet,
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remove,
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_getCachedValue: () => cachedValue,
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};
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}
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