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.
 *
 */

let lockDict = {};

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

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

// get the lock value of the specified file
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
function hasLock(filePath) {
    return !!getLockObject(filePath);
}

// lock file editing
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
    }
}

// allow for file editing
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
}

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