1# Upload and Download Subsystem 2 3## Introduction 4 5The upload and download subsystem provides upload and download capabilities for applications, including creating, removing, suspending, and starting upload and download tasks, and subscribing to the task progress and result. 6 7 8## System Architecture 9 10**Figure 1** Architecture of the upload and download subsystem 11 12 13 14 15## Directory Structure 16 17The source code of the upload and download subsystem is stored in the **/base/request** directory. 18 19The directory structure is as follows: 20 21``` 22/base/request/request 23├── common # Common classes such as constants and logs 24├── figures # Architecture diagram 25├── framework # Framework layer 26│ └── js # JS APIs that are parsed to NAPIs 27│ └── native # Client implementation 28├── services # Upload and download service implementation. 29│ └── sa_profile # System service configuration files 30│ └── etc # Process configuration files 31└── test # Test cases 32``` 33 34## Repositories Involved 35 36[request_request](https://gitee.com/openharmony/request_request) 37
