Module app_builder 

Application builder for constructing DMSC applications Copyright © 2025-2026 Wenze Wei. All Rights Reserved.

This file is part of DMSC. The DMSC project belongs to the Dunimd Team.

Licensed under the Apache License, Version 2.0 (the “License”); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an “AS IS” BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

Application Builder

This module provides the application builder for constructing DMSC applications. The DMSCAppBuilder follows the builder pattern for fluent configuration, enabling developers to compose applications from various modules, configuration sources, and runtime settings in a declarative manner.

Builder Pattern

The builder pattern allows step-by-step construction of complex objects. Each method on DMSCAppBuilder configures a specific aspect of the application and returns the builder for method chaining. This results in a fluent API that is both readable and type-safe.

Module Registration

Modules are the primary extension point for DMSC applications. The builder supports multiple types of modules:

• Synchronous modules: Implement ServiceModule trait for sync operations
• Asynchronous modules: Implement AsyncServiceModule trait for async operations
• DMSC modules: Implement public DMSCModule trait (converted to async internally)
• Python modules: Modules created from Python code (with pyo3 feature)

Configuration Management

The builder supports multiple configuration sources with a defined priority order:

1. Configuration files (lowest priority): dms.yaml, dms.yml, dms.toml, dms.json
2. Custom configuration via with_config() method
3. Environment variables (highest priority)

Usage Example

use dmsc::prelude::*;

#[tokio::main]
async fn main() -> DMSCResult<()> {
    let app = DMSCAppBuilder::new()
        .with_config("config.yaml")?
        .with_module(Box::new(MySyncModule::new()))
        .with_async_module(Box::new(MyAsyncModule::new()))
        .build()?;

    app.run(|ctx| async move {
        ctx.logger().info("service", "DMSC service started")?;
        Ok(())
    }).await
}

Thread Safety

The DMSCAppBuilder is designed to be used in a single-threaded context during application construction. After calling build(), the resulting DMSCAppRuntime is safe to use across multiple threads.

Error Handling

All builder methods that can fail return DMSCResult, enabling proper error handling through the ? operator or explicit match statements.

Structs

DMSCAppBuilder

Public-facing application builder for DMSC.