Project Configuration

Relevant source files

• .gitignore
• Cargo.toml

This document covers the configuration files and settings that control the development environment, build process, and distribution of the flatten_objects crate. It focuses on the static configuration files that define project metadata, dependencies, and development workflows.

For information about the actual build and testing processes, see Building and Testing. For details about the codebase structure and implementation, see Implementation Details.

Package Configuration

The primary configuration for the flatten_objects crate is defined in Cargo.toml, which contains all package metadata, dependency specifications, and publication settings.

Package Metadata

The crate is configured as a library package with the following key attributes:

The package description clearly identifies its purpose: "A container that stores numbered objects. Each object can be assigned with a unique ID." This aligns with the crate's role as a specialized data structure for resource-constrained environments.

Project Configuration Structure

flowchart TD
subgraph subGraph3["Dependency Specification"]
    Bitmaps["bitmaps = { version = 3.2, default-features = false }"]
end
subgraph subGraph2["Package Metadata"]
    Name["name = flatten_objects"]
    Version["version = 0.2.3"]
    Edition["edition = 2024"]
    Authors["authors"]
    License["license"]
    Links["repository, homepage, docs"]
end
subgraph subGraph1["Cargo.toml Sections"]
    Package["[package]"]
    Dependencies["[dependencies]"]
end
subgraph subGraph0["Project Root"]
    CargoToml["Cargo.toml"]
    GitIgnore[".gitignore"]
    SrcDir["src/"]
    TargetDir["target/ (ignored)"]
end

CargoToml --> Dependencies
CargoToml --> Package
Dependencies --> Bitmaps
GitIgnore --> TargetDir
Package --> Authors
Package --> Edition
Package --> License
Package --> Links
Package --> Name
Package --> Version

Sources: Cargo.toml(L1 - L17) 

Licensing and Legal Configuration

The crate uses a triple-license configuration to maximize compatibility across different ecosystems:

license = "GPL-3.0-or-later OR Apache-2.0 OR MulanPSL-2.0"

This licensing strategy accommodates:

• GPL-3.0-or-later: Copyleft compatibility for GPL projects
• Apache-2.0: Permissive licensing for commercial use
• MulanPSL-2.0: Chinese legal framework compliance

Sources: Cargo.toml(L7) 

Repository and Documentation Links

The configuration establishes the project's presence in the Rust ecosystem:

Sources: Cargo.toml(L8 - L10) 

Dependency Management

The crate maintains a minimal dependency footprint with only one external dependency, reflecting its design for resource-constrained environments.

External Dependencies

Dependency Configuration Analysis

flowchart TD
subgraph subGraph2["Standard Library"]
    CoreOnly["core only"]
    NoStdLib["no std library"]
    NoAlloc["no alloc"]
end
subgraph subGraph1["External Dependencies"]
    BitmapsCrate["bitmaps crate"]
    BitmapsVersion["version = 3.2"]
    BitmapsConfig["default-features = false"]
end
subgraph subGraph0["flatten_objects Crate"]
    MainCrate["flatten_objects"]
    NoStdEnv["no_std environment"]
end

BitmapsCrate --> BitmapsConfig
BitmapsCrate --> BitmapsVersion
MainCrate --> BitmapsCrate
MainCrate --> NoStdEnv
NoStdEnv --> CoreOnly
NoStdEnv --> NoAlloc
NoStdEnv --> NoStdLib

The single dependency is carefully configured:

bitmaps = { version = "3.2", default-features = false }

Key aspects of this dependency configuration:

• Version constraint: 3.2 provides stable bitmap operations
• Feature configuration: default-features = false ensures no_std compatibility
• Minimal footprint: Only includes essential bitmap functionality

Sources: Cargo.toml(L15 - L16) 

No Standard Library Dependencies

The crate is designed for no_std environments, which means:

• No implicit dependency on the Rust standard library
• Only uses core library functionality
• Compatible with embedded and kernel environments
• Suitable for ArceOS integration

This configuration is reflected in the package categories: ["no-std", "data-structures"].

Sources: Cargo.toml(L12) 

Development Environment Configuration

Version Control Configuration

The .gitignore file defines which files and directories are excluded from version control:

Version Control Exclusions

flowchart TD
subgraph subGraph3["Tracked Files"]
    SourceCode["src/"]
    CargoToml["Cargo.toml"]
    ReadMe["README.md"]
end
subgraph subGraph2["Ignored Files"]
    DSStore[".DS_Store"]
    CargoLock["Cargo.lock"]
end
subgraph subGraph1["Ignored Directories"]
    Target["/target"]
    VSCode["/.vscode"]
end
subgraph subGraph0["Version Control"]
    GitRepo["Git Repository"]
    GitIgnore[".gitignore"]
end

GitIgnore --> CargoLock
GitIgnore --> DSStore
GitIgnore --> Target
GitIgnore --> VSCode
GitRepo --> CargoToml
GitRepo --> ReadMe
GitRepo --> SourceCode

The exclusion of Cargo.lock is significant because this is a library crate, not an application. Library crates typically don't commit their lock files to allow downstream users flexibility in dependency resolution.

Sources: .gitignore(L1 - L4) 

Editor Configuration

The .gitignore configuration shows consideration for multiple development environments:

• VS Code: Excludes .vscode/ directory for editor settings
• macOS: Excludes .DS_Store system files
• Cross-platform: Standard Rust build artifact exclusions

This configuration supports a diverse development team working across different platforms and editors.

Sources: .gitignore(L2 - L3) 

Publication and Distribution Settings

Crates.io Configuration

The package is configured for publication to the official Rust package registry with appropriate metadata for discoverability:

keywords = ["arceos", "data-structures"]
categories = ["no-std", "data-structures"]

Distribution Categories and Keywords

flowchart TD
subgraph subGraph4["Target Audience"]
    EmbeddedDevs["Embedded Developers"]
    KernelDevs["Kernel Developers"]
    ArceOSUsers["ArceOS Users"]
end
subgraph subGraph3["Category Tags"]
    NoStd["no-std"]
    DataStructuresCategory["data-structures"]
end
subgraph subGraph2["Keyword Tags"]
    ArceOS["arceos"]
    DataStructures["data-structures"]
end
subgraph subGraph1["Package Classification"]
    Keywords["keywords"]
    Categories["categories"]
end
subgraph subGraph0["Crates.io Registry"]
    CratesIo["crates.io"]
    SearchIndex["Search Index"]
end

ArceOS --> ArceOSUsers
Categories --> DataStructuresCategory
Categories --> NoStd
CratesIo --> SearchIndex
DataStructures --> KernelDevs
Keywords --> ArceOS
Keywords --> DataStructures
NoStd --> EmbeddedDevs
SearchIndex --> Categories
SearchIndex --> Keywords

These classifications help users discover the crate when searching for:

• ArceOS-related components
• Data structure libraries
• no_std compatible crates

Sources: Cargo.toml(L11 - L12) 

Documentation Configuration

The crate leverages automatic documentation generation through docs.rs:

• Documentation URL: https://docs.rs/flatten_objects
• Automatic builds on crate publication
• API documentation generated from source code comments

This configuration ensures that comprehensive documentation is available to users without requiring separate hosting infrastructure.

Sources: Cargo.toml(L10)