webpack/lib/json/JsonData.js

Packs ECMAScript/CommonJs/AMD modules for the browser. Allows you to split your codebase into multiple bundles, which can be loaded on demand. Supports loaders to preprocess files, i.e. json, jsx, es7, css, less, ... and your custom stuff.

/*
	MIT License http://www.opensource.org/licenses/mit-license.php
	Author Tobias Koppers @sokra
*/

"use strict";

const { register } = require("../util/serialization");

/** @typedef {import("../serialization/ObjectMiddleware").ObjectDeserializerContext} ObjectDeserializerContext */
/** @typedef {import("../serialization/ObjectMiddleware").ObjectSerializerContext} ObjectSerializerContext */
/** @typedef {import("../util/Hash")} Hash */
/** @typedef {import("../util/fs").JsonValue} JsonValue */

class JsonData {
	/**
	 * Creates an instance of JsonData.
	 * @param {Buffer | JsonValue} data JSON data
	 */
	constructor(data) {
		/** @type {Buffer | undefined} */
		this._buffer = undefined;
		/** @type {JsonValue | undefined} */
		this._data = undefined;
		if (Buffer.isBuffer(data)) {
			this._buffer = data;
		} else {
			this._data = data;
		}
	}

	/**
	 * Returns raw JSON data.
	 * @returns {JsonValue | undefined} Raw JSON data
	 */
	get() {
		if (this._data === undefined && this._buffer !== undefined) {
			this._data = JSON.parse(this._buffer.toString());
		}
		return this._data;
	}

	/**
	 * Updates the hash with the data contributed by this instance.
	 * @param {Hash} hash hash to be updated
	 * @returns {void} the updated hash
	 */
	updateHash(hash) {
		if (this._buffer === undefined && this._data !== undefined) {
			this._buffer = Buffer.from(JSON.stringify(this._data));
		}

		if (this._buffer) hash.update(this._buffer);
	}
}

register(JsonData, "webpack/lib/json/JsonData", null, {
	/**
	 * Serializes this instance into the provided serializer context.
	 * @param {JsonData} obj JSONData object
	 * @param {ObjectSerializerContext} context context
	 */
	serialize(obj, { write }) {
		if (obj._buffer === undefined && obj._data !== undefined) {
			obj._buffer = Buffer.from(JSON.stringify(obj._data));
		}
		write(obj._buffer);
	},
	/**
	 * Restores this instance from the provided deserializer context.
	 * @param {ObjectDeserializerContext} context context
	 * @returns {JsonData} deserialized JSON data
	 */
	deserialize({ read }) {
		return new JsonData(read());
	}
});

module.exports = JsonData;