codimd/lib/imageRouter/filesystem.js

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'use strict'
const crypto = require('crypto')
const fs = require('fs')
const URL = require('url').URL
const path = require('path')
const config = require('../config')
const logger = require('../logger')
/**
* generate a random filename for uploaded image
*/
function randomFilename () {
const buf = crypto.randomBytes(16)
return `upload_${buf.toString('hex')}`
}
/**
* pick a filename not exist in filesystem
* maximum attempt 5 times
*/
function pickFilename (defaultFilename) {
let retryCounter = 5
let filename = defaultFilename
const extname = path.extname(defaultFilename)
while (retryCounter-- > 0) {
if (fs.existsSync(path.join(config.uploadsPath, filename))) {
filename = `${randomFilename()}${extname}`
continue
}
return filename
}
throw new Error('file exists.')
}
exports.uploadImage = function (imagePath, callback) {
if (!imagePath || typeof imagePath !== 'string') {
callback(new Error('Image path is missing or wrong'), null)
return
}
if (!callback || typeof callback !== 'function') {
logger.error('Callback has to be a function')
return
}
let filename = path.basename(imagePath)
try {
filename = pickFilename(path.basename(imagePath))
} catch (e) {
return callback(e, null)
}
try {
fs.copyFileSync(imagePath, path.join(config.uploadsPath, filename))
} catch (e) {
return callback(e, null)
}
let url
try {
url = (new URL(filename, config.serverURL + '/uploads/')).href
} catch (e) {
url = config.serverURL + '/uploads/' + filename
}
callback(null, url)
}