feat(storage): add maxConcurrentUploads concurrency limit

Author: kukhariev

packages/core/src/storages/config.ts

@@ -18,7 +18,8 @@ export class ConfigHandler {
     path: '/files',
     validation: {},
     maxMetadataSize: '4MB',
-    logger: logger
+    logger: logger,
+    maxConcurrentUploads: 0
   };
 
   private _config = this.set(ConfigHandler.defaults);

packages/core/src/storages/storage.ts

@@ -108,6 +108,11 @@ export interface BaseStorageOptions<T extends File> {
    * @defaultValue 'none'
    */
   logLevel?: LogLevel;
+
+  /**
+   * Limits the number of concurrent upload requests
+   */
+  maxConcurrentUploads?: number;
 }
 
 const LOCK_TIMEOUT = 300; // seconds
@@ -288,15 +293,23 @@ export abstract class BaseStorage<TFile extends File> {
 
   /**
    * Prevent upload from being accessed by multiple requests
+   * Limits the number of concurrent upload requests
    */
   async lock(key: string): Promise<string> {
+    const max = this.config.maxConcurrentUploads;
+    if (max && locker.keys().length >= max) {
+      return fail(ERRORS.TOO_MANY_UPLOADS);
+    }
     try {
       return locker.lock(key);
     } catch {
       return fail(ERRORS.FILE_LOCKED);
     }
   }
 
+  /**
+   * Unlocks a previously locked upload
+   */
   async unlock(key: string): Promise<void> {
     locker.unlock(key);
   }

packages/core/src/utils/errors.ts

@@ -24,7 +24,8 @@ export enum ERRORS {
   CHECKSUM_MISMATCH = 'ChecksumMismatch',
   UNSUPPORTED_CHECKSUM_ALGORITHM = 'UnsupportedChecksumAlgorithm',
   REQUEST_ABORTED = 'RequestAborted',
-  FILE_LOCKED = 'FileLocked'
+  FILE_LOCKED = 'FileLocked',
+  TOO_MANY_UPLOADS = 'TooManyUploads'
 }
 
 export type ErrorResponses<T extends string = string> = {
@@ -56,7 +57,8 @@ class E_ {
     UnprocessableEntity: [422, 'Validation failed'],
     UnsupportedMediaType: [415, 'Unsupported media type'],
     RequestAborted: [499, 'Request aborted'],
-    FileLocked: [423, 'File locked']
+    FileLocked: [423, 'File locked'],
+    TooManyUploads: [503, 'Too many active uploads, please try again later']
   };
 
   static _buildErrorBody = (target: typeof E_, _: string): void => {