amis-rpc-design/node_modules/image-size/dist/index.js

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2023-10-07 19:42:30 +08:00
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.types = exports.setConcurrency = exports.disableTypes = exports.disableFS = exports.imageSize = void 0;
const fs = require("fs");
const path = require("path");
const queue_1 = require("queue");
const types_1 = require("./types");
const detector_1 = require("./detector");
// Maximum buffer size, with a default of 512 kilobytes.
// TO-DO: make this adaptive based on the initial signature of the image
const MaxBufferSize = 512 * 1024;
// This queue is for async `fs` operations, to avoid reaching file-descriptor limits
const queue = new queue_1.default({ concurrency: 100, autostart: true });
const globalOptions = {
disabledFS: false,
disabledTypes: []
};
/**
* Return size information based on a buffer
*
* @param {Buffer} buffer
* @param {String} filepath
* @returns {Object}
*/
function lookup(buffer, filepath) {
// detect the file type.. don't rely on the extension
const type = (0, detector_1.detector)(buffer);
if (typeof type !== 'undefined') {
if (globalOptions.disabledTypes.indexOf(type) > -1) {
throw new TypeError('disabled file type: ' + type);
}
// find an appropriate handler for this file type
if (type in types_1.typeHandlers) {
const size = types_1.typeHandlers[type].calculate(buffer, filepath);
if (size !== undefined) {
size.type = type;
return size;
}
}
}
// throw up, if we don't understand the file
throw new TypeError('unsupported file type: ' + type + ' (file: ' + filepath + ')');
}
/**
* Reads a file into a buffer.
* @param {String} filepath
* @returns {Promise<Buffer>}
*/
async function asyncFileToBuffer(filepath) {
const handle = await fs.promises.open(filepath, 'r');
try {
const { size } = await handle.stat();
if (size <= 0) {
throw new Error('Empty file');
}
const bufferSize = Math.min(size, MaxBufferSize);
const buffer = Buffer.alloc(bufferSize);
await handle.read(buffer, 0, bufferSize, 0);
return buffer;
}
finally {
await handle.close();
}
}
/**
* Synchronously reads a file into a buffer, blocking the nodejs process.
*
* @param {String} filepath
* @returns {Buffer}
*/
function syncFileToBuffer(filepath) {
// read from the file, synchronously
const descriptor = fs.openSync(filepath, 'r');
try {
const { size } = fs.fstatSync(descriptor);
if (size <= 0) {
throw new Error('Empty file');
}
const bufferSize = Math.min(size, MaxBufferSize);
const buffer = Buffer.alloc(bufferSize);
fs.readSync(descriptor, buffer, 0, bufferSize, 0);
return buffer;
}
finally {
fs.closeSync(descriptor);
}
}
// eslint-disable-next-line @typescript-eslint/no-use-before-define
module.exports = exports = imageSize; // backwards compatibility
exports.default = imageSize;
/**
* @param {Buffer|string} input - buffer or relative/absolute path of the image file
* @param {Function=} [callback] - optional function for async detection
*/
function imageSize(input, callback) {
// Handle buffer input
if (Buffer.isBuffer(input)) {
return lookup(input);
}
// input should be a string at this point
if (typeof input !== 'string' || globalOptions.disabledFS) {
throw new TypeError('invalid invocation. input should be a Buffer');
}
// resolve the file path
const filepath = path.resolve(input);
if (typeof callback === 'function') {
queue.push(() => asyncFileToBuffer(filepath)
.then((buffer) => process.nextTick(callback, null, lookup(buffer, filepath)))
.catch(callback));
}
else {
const buffer = syncFileToBuffer(filepath);
return lookup(buffer, filepath);
}
}
exports.imageSize = imageSize;
const disableFS = (v) => { globalOptions.disabledFS = v; };
exports.disableFS = disableFS;
const disableTypes = (types) => { globalOptions.disabledTypes = types; };
exports.disableTypes = disableTypes;
const setConcurrency = (c) => { queue.concurrency = c; };
exports.setConcurrency = setConcurrency;
exports.types = Object.keys(types_1.typeHandlers);