Overview
This document describes the basic concepts of a bundle and how to define it in compliance with specifications.
Definition
OpenHarmony software is developed on a per-bundle basis. In terms of the operating system, all software running on OpenHarmony are bundles. Generally, bundles are classified into the following types based on their application scopes:
- Board-level bundles: device hardware-specific bundles, such as board, arch, and mcu
- System-level bundles: a set of bundles with independent features, such as the kernel, file system, and framework
- Application-level bundles: applications that provide services to users, such as wifi_iot and ip_camera
Bundles are designed for the reuse purpose. Any reusable modules can be defined as bundles. They are classified into the following types based on their forms:
- Source code
- Binary system
- Code snippet
- Distribution
Bundle Division Principles
In principle, bundles should be grouped at a fine-grained granularity as much as possible to achieve maximum reuse. The following factors are taken into account regarding bundle division:
- Independence: Bundles provide relatively independent features and can be independently compiled. Each of them is capable of providing its own APIs and services for external systems.
- Coupling: If a bundle must depend on another bundle to provide services, they can be coupled to one bundle.
- Correlation: If a group of bundles jointly implement a feature, and if other bundles never depend on them, the group of bundles can be combined into one bundle.
Bundle Dependency
A bundle dependency can be mandatory or optional.
- Mandatory dependency: If bundle A must depend on bundle B to implement a feature, that is, the APIs or services specific to bundle B must be invoked, then bundle B is defined as the mandatory dependency of bundle A.
- Optional dependency: If either bundle C or bundle D is required for bundle A to implement a feature, and if bundle C and bundle D are interchangeable, then bundle C and bundle D are defined as optional dependencies of bundle A.
