phash-js/src/magickApi.js

Perceptual image hashing in the browser without using HTML canvas

'use strict'
var __importDefault =
  (this && this.__importDefault) ||
  function (mod) {
    return mod && mod.__esModule ? mod : { default: mod }
  }
Object.defineProperty(exports, '__esModule', { value: true })
const stacktrace_js_1 = __importDefault(require('stacktrace-js'))
/**
 * {@link call} shortcut that only returns the output files.
 */
async function Call(inputFiles, command) {
  const result = await call(inputFiles, command)
  for (let outputFile of result.outputFiles) {
    outputFile.blob = new Blob([outputFile.buffer])
  }
  return result.outputFiles
}
exports.Call = Call
/**
 * Low level execution function. All the other functions like [execute](https://github.com/KnicKnic/WASM-ImageMagick/tree/master/apidocs#execute)
 * ends up calling this one. It accept only one command and only in the form of array of strings.
 */
function call(inputFiles, command) {
  const request = {
    files: inputFiles,
    args: command,
    requestNumber: magickWorkerPromisesKey
  }
  // let transfer = [];
  // for (let file of request.files) {
  //   if(file.content instanceof ArrayBuffer)
  //   {
  //     transfer.push(file.content)
  //   }
  //   else{
  //     transfer.push(file.content.buffer)
  //   }
  // }
  const promise = CreatePromiseEvent()
  magickWorkerPromises[magickWorkerPromisesKey] = promise
  magickWorker.postMessage(request) //,transfer)
  magickWorkerPromisesKey++
  return promise
}
exports.call = call
function CreatePromiseEvent() {
  let resolver
  let rejecter
  const emptyPromise = new Promise((resolve, reject) => {
    resolver = resolve
    rejecter = reject
  })
  emptyPromise.resolve = resolver
  emptyPromise.reject = rejecter
  return emptyPromise
}
exports.CreatePromiseEvent = CreatePromiseEvent
function ChangeUrl(url, fileName) {
  let splitUrl = url.split('/')
  splitUrl[splitUrl.length - 1] = fileName
  return splitUrl.join('/')
}
function GetCurrentUrlDifferentFilename(currentUrl, fileName) {
  return ChangeUrl(currentUrl, fileName)
}
let currentJavascriptURL = './magickApi.js'
// // instead of doing the sane code of being able to just use import.meta.url
// // (Edge doesn't work) (safari mobile, chrome, opera, firefox all do)
// //
// // I will use stacktrace-js library to get the current file name
// //
// try {
//   // @ts-ignore
//   let packageUrl = import.meta.url;
//   currentJavascriptURL = packageUrl;
// } catch (error) {
//   // eat
// }
function GenerateStackAndGetPathAtDepth(depth) {
  try {
    let stacktrace$$1 = stacktrace_js_1.default.getSync()
    let filePath = stacktrace$$1[depth].fileName
    // if the stack trace code doesn't return a path separator
    if (filePath !== undefined && filePath.indexOf('/') === -1 && filePath.indexOf('\\') === -1) {
      return undefined
    }
    return filePath
  } catch (error) {
    return undefined
  }
}
function GetCurrentFileURLHelper3() {
  // 3rd call site didn't work, so I made this complicated maze of helpers..
  // Pulling the filename from the 3rd call site of the stacktrace to get the full path
  // to the module. The first index is inconsistent across browsers and does not return
  // the full path in Safari and results in the worker failing to resolve.
  // I am preferring to do depth 0 first, as that will ensure people that do minification still works
  let filePath = GenerateStackAndGetPathAtDepth(0)
  if (filePath === undefined) {
    filePath = GenerateStackAndGetPathAtDepth(2)
  }
  // if the stack trace code messes up
  if (filePath === undefined) {
    filePath = './magickApi.js'
  }
  return filePath
}
function GetCurrentFileURLHelper2() {
  return GetCurrentFileURLHelper3()
}
function GetCurrentFileURLHelper1() {
  return GetCurrentFileURLHelper2()
}
function GetCurrentFileURL() {
  return GetCurrentFileURLHelper1()
}
currentJavascriptURL = GetCurrentFileURL()
const magickWorkerUrl = GetCurrentUrlDifferentFilename(currentJavascriptURL, 'magick.js')
function GenerateMagickWorkerText(magickUrl) {
  // generates code for the following
  // var magickJsCurrentPath = 'magickUrl';
  // importScripts(magickJsCurrentPath);
  return "var magickJsCurrentPath = '" + magickUrl + "';\n" + 'importScripts(magickJsCurrentPath);'
}
let magickWorker
if (currentJavascriptURL.startsWith('http')) {
  // if worker is in a different domain fetch it, and run it
  magickWorker = new Worker(
    window.URL.createObjectURL(new Blob([GenerateMagickWorkerText(magickWorkerUrl)]))
  )
} else {
  // TODO: commit changes
  magickWorker = new Worker(window.location.origin + '/magick.js')
}
const magickWorkerPromises = {}
let magickWorkerPromisesKey = 1
// handle responses as they stream in after being outputFiles by image magick
magickWorker.onmessage = e => {
  const response = e.data
  const promise = magickWorkerPromises[response.requestNumber]
  delete magickWorkerPromises[response.requestNumber]
  const result = {
    outputFiles: response.outputFiles,
    stdout: response.stdout,
    stderr: response.stderr,
    exitCode: response.exitCode || 0
  }
  promise.resolve(result)
}