document-server-integration/web/documentserver-example/nodejs/helpers/wopi/lockManager.js

/**
 *
 * (c) Copyright Ascensio System SIA 2023
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */

const lockDict = {};

// get the lock object of the specified file
const getLockObject = function getLockObject(filePath) {
  return lockDict[filePath];
};

// clear the lock timeout
const clearLockTimeout = function clearLockTimeout(lockObject) {
  if (lockObject && lockObject.timeout) {
    clearTimeout(lockObject.timeout);
  }
};

// get the lock value of the specified file
const getLockValue = function getLockValue(filePath) {
  const lock = getLockObject(filePath); // get the lock object of the specified file
  if (lock) return lock.value; // if it exists, get the lock value from it
  return '';
};

// check if the specified file path has lock or not
const hasLock = function hasLock(filePath) {
  return !!getLockObject(filePath);
};

// allow for file editing
const unlock = function unlock(filePath) {
  const lock = getLockObject(filePath); // get the lock of the specified file
  clearLockTimeout(lock); // clear its timeout
  delete lockDict[filePath]; // delete the lock
};

// lock file editing
const lock = function lock(filePath, lockValue) {
  const oldLock = getLockObject(filePath); // get the old lock of the specified file
  clearLockTimeout(oldLock); // clear its timeout

  // create a new lock object
  lockDict[filePath] = {
    value: lockValue,
    timeout: setTimeout(unlock, 1000 * 60 * 30, filePath), // set lock for 30 minutes
  };
};

module.exports = {
  hasLock,
  getLock: getLockValue,
  lock,
  unlock,
};