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apps/app/src/features/page-bulk-export/server/service/page-bulk-export-job-cron/index.ts

@@ -43,6 +43,10 @@ export interface IPageBulkExportJobCronService {
   getTmpOutputDir(pageBulkExportJob: PageBulkExportJobDocument): string;
 }
 
+/**
+ * Manages cronjob which proceeds PageBulkExportJobs in progress.
+ * If PageBulkExportJob finishes the current step, the next step will be started on the next cron execution.
+ */
 class PageBulkExportJobCronService extends CronService implements IPageBulkExportJobCronService {
 
   crowi: any;
@@ -64,6 +68,8 @@ class PageBulkExportJobCronService extends CronService implements IPageBulkExpor
 
   userModel: mongoose.Model<IUser>;
 
+  // Keep track of the stream executed for PageBulkExportJob to destroy it on job failure.
+  // The key is the id of a PageBulkExportJob.
   private streamInExecutionMemo: {
     [key: string]: Readable;
   } = {};
@@ -101,21 +107,31 @@ class PageBulkExportJobCronService extends CronService implements IPageBulkExpor
   }
 
   /**
-   * Get the stream in execution of a job.
+   * Get the stream in execution for a job.
    * A getter method that includes "undefined" in the return type
    */
   getStreamInExecution(jobId: ObjectIdLike): Readable | undefined {
     return this.streamInExecutionMemo[jobId.toString()];
   }
 
+  /**
+   * Set the stream in execution for a job
+   */
   setStreamInExecution(jobId: ObjectIdLike, stream: Readable) {
     this.streamInExecutionMemo[jobId.toString()] = stream;
   }
 
+  /**
+   * Remove the stream in execution for a job
+   */
   removeStreamInExecution(jobId: ObjectIdLike) {
     delete this.streamInExecutionMemo[jobId.toString()];
   }
 
+  /**
+   * Proceed the page bulk export job if the next step is executable
+   * @param pageBulkExportJob PageBulkExportJob in progress
+   */
   async proceedBulkExportJob(pageBulkExportJob: PageBulkExportJobDocument) {
     if (pageBulkExportJob.restartFlag) {
       await this.cleanUpExportJobResources(pageBulkExportJob, true);
@@ -125,6 +141,7 @@ class PageBulkExportJobCronService extends CronService implements IPageBulkExpor
       await pageBulkExportJob.save();
     }
 
+    // return if job is still the same status as the previous cron exec
     if (pageBulkExportJob.status === pageBulkExportJob.statusOnPreviousCronExec) {
       return;
     }
@@ -151,6 +168,11 @@ class PageBulkExportJobCronService extends CronService implements IPageBulkExpor
     }
   }
 
+  /**
+   * Handle errors that occurred inside a stream pipeline
+   * @param err error
+   * @param pageBulkExportJob PageBulkExportJob executed in the pipeline
+   */
   async handlePipelineError(err: Error | null, pageBulkExportJob: PageBulkExportJobDocument) {
     if (err == null) return;