file-management.md

# File Management

## Introduction

The file management subsystem provides a complete file management solution for OpenHarmony. It provides secure and easy-to-use file access and comprehensive file management capabilities, including:

- A sandbox to ensure the least privilege as well as application data security
- Unified management of user files and streamlined user data access and storage to ensure user data security and purity
- Access framework to allow applications to access distributed file system files and cloud files as they access local files
- Sharing of user data and system files across applications and devices
- System storage management capabilities and basic file system capabilities

**Figure 1** Architecture of the file management subsystem
![](figures/file_management_architecture.png "file management subsystem architecture")

The file management subsystem provides the file access framework, file sharing framework, and storage management framework for applications.

| Module        | Description                                                    |
| ------------ | ------------------------------------------------------------ |
| File access interface| 1. Provides complete JavaScript APIs to implement basic file access capabilities.<br>2. Provides extension APIs for local files, distributed files, and cloud files.|
| Storage management    | 1. Provides data backup and restore to support system and application data backup and cloning.<br>2. Provides space management capabilities such as application space clearing and statistics, and quota control.<br>3. Provides storage management capabilities such as mount operations, external card management, device management, and multi-user management.|
| User files    | 1.  Provides a sandbox to ensure user data security and purity.<br>2. Allows access to user data only through **mediaLibrary**.<br>3. Provides a unified file management framework.<br>4. Supports distributed and device-cloud capabilities.|
| Application files    | 1. Provides a sandbox to ensure the least privilege as well as application data security.<br>2. Supports file sharing between applications, across devices, and in groups.<br>3. Allows applications to access distributed and cloud files as they access local files.|
| Distributed capabilities  | 1. Provides basic cross-device access capabilities and supports distributed access using the same account and temporary access using different accounts.<br>2. Supports device-cloud interaction irrespective of the data locations.<br>3. Supports cross-device hopping, such as application hopping and distributed pasteboard.|
| Basic file system| 1. Supports local file systems such as ext4, Flash-Friendly File System (F2FS), Extensible File Allocation Table (exFAT), and New Technology File System (NTFS).<br>2. Supports network file systems such as the distributed file system and Network File System (NFS).<br>3. Provides tools related to file systems.|


## Repositories Involved

User file management

[filemanagement_user_file_service](https://gitee.com/openharmony/filemanagement_user_file_service)

Application file management

[filemanagement_app_file_service](https://gitee.com/openharmony/filemanagement_app_file_service)

File interfaces

[filemanagement_file_api](https://gitee.com/openharmony/filemanagement_file_api)

[distributeddatamgr_file](https://gitee.com/openharmony/distributeddatamgr_file)

Storage management

[filemanagement_storage_service](https://gitee.com/openharmony/filemanagement_storage_service)

Distributed files

 [filemanagement_dfs_service](https://gitee.com/openharmony/filemanagement_dfs_service)