Split Delta-rs: Faster Compilation With Multiple Crates

The Challenge of Long Compilation Times in Delta-rs

Developing with delta-rs can be a challenging experience, primarily due to the lengthy compilation times. This issue is significantly amplified by the datafusion dependency, which is substantial in size and often impedes the compilation of other parts of the crate. When developers face long wait times during compilation, it not only slows down the development process but also impacts productivity and overall efficiency. Addressing this challenge is crucial for fostering a more streamlined and enjoyable development experience with delta-rs. The current monolithic structure of delta-rs means that even small changes can trigger recompilation of large portions of the codebase, leading to considerable delays. By breaking down delta-rs into smaller, more manageable crates, we can leverage build parallelization to reduce compilation times and improve the overall development workflow. This is particularly important for large projects where frequent builds and tests are necessary to maintain code quality and stability. Furthermore, faster compilation times translate to quicker feedback loops, allowing developers to iterate more rapidly and deliver features and bug fixes more efficiently. Therefore, optimizing compilation times is not just a matter of convenience but a critical factor in ensuring the long-term success and usability of delta-rs.

Proposed Solution: Splitting Delta-rs into Multiple Crates

To address the issue of long compilation times, the suggested solution involves dividing delta-rs into several smaller crates. This approach allows for build parallelization and helps in avoiding large-scale recompilations, which can significantly reduce the time spent waiting for builds to complete. By splitting the codebase into logical units, changes in one area are less likely to trigger recompilation in other, unrelated parts of the system. For instance, the "protocol" folder could be transformed into a deltalake-protocol crate, while the "logstore" folder could become deltalake-logstore. Similarly, functionalities related to operations and data fusion could be separated into deltalake-operations / deltalake-datafusion-operations and deltalake-datafusion crates, respectively. This modular design not only improves build times but also enhances the maintainability and scalability of the project. Each crate can be developed, tested, and deployed independently, making it easier to manage dependencies and updates. Moreover, this approach promotes code reuse, as individual crates can be utilized in other projects that require specific functionalities without the need to include the entire delta-rs library. The transition to a multi-crate architecture requires careful planning and execution, but the benefits in terms of reduced compilation times and improved development workflow make it a worthwhile endeavor. Ultimately, this restructuring will contribute to a more efficient and enjoyable experience for developers working with delta-rs.

Benefits of a Multi-Crate Architecture

The move to a multi-crate architecture offers several significant advantages for the delta-rs project. Firstly, and most importantly, it leads to substantial reductions in compilation times. By splitting the codebase into smaller, independent units, the build system can compile these crates in parallel, maximizing the utilization of available resources and minimizing overall build time. This is particularly beneficial in large projects where compilation times can become a major bottleneck. Secondly, a modular design enhances code maintainability and organization. Each crate has a clear and well-defined responsibility, making it easier to understand, modify, and test the codebase. This also reduces the likelihood of introducing bugs and simplifies the process of debugging. Thirdly, the multi-crate approach promotes code reusability. Individual crates can be used in other projects that require specific functionalities, without the need to include the entire delta-rs library. This fosters a more efficient and collaborative development environment. Furthermore, splitting delta-rs into multiple crates facilitates independent development and deployment cycles for each module. This means that updates and bug fixes can be released for specific components without affecting the stability of the entire system. This granular approach to updates allows for more frequent releases and faster response times to user feedback. The multi-crate architecture also simplifies dependency management, as each crate can declare its own dependencies, reducing the risk of dependency conflicts and versioning issues. Overall, the transition to a multi-crate architecture is a strategic investment that improves the long-term health and sustainability of the delta-rs project.

Specific Crate Divisions

To effectively split delta-rs into multiple crates, a logical division of functionalities is essential. One proposed division involves creating a deltalake-protocol crate from the existing "protocol" folder. This crate would encapsulate all the logic related to the Delta Lake protocol, including versioning, metadata management, and transaction handling. Separating the protocol-related code into its own crate allows for focused development and testing, ensuring the integrity and reliability of the core protocol functionalities. Another key division involves transforming the "logstore" folder into a deltalake-logstore crate. This crate would be responsible for managing the storage and retrieval of transaction logs, which are crucial for maintaining the consistency and durability of Delta Lake tables. By isolating the logstore implementation, developers can experiment with different storage backends and optimize performance without affecting other parts of the system. Additionally, functionalities related to data operations and data fusion can be split into deltalake-operations / deltalake-datafusion-operations and deltalake-datafusion crates, respectively. The deltalake-operations crate would handle operations such as adding, updating, and deleting data in Delta Lake tables, while the deltalake-datafusion crate would integrate with the DataFusion query engine to enable efficient data processing and analysis. This separation of concerns allows for specialized development and optimization of each component, leading to improved performance and scalability. The modular structure also makes it easier to extend and customize the functionalities of delta-rs to meet specific project requirements. By carefully dividing delta-rs into these distinct crates, we can create a more robust, maintainable, and scalable system that better serves the needs of the Delta Lake community.

Alternatives Considered

While splitting delta-rs into multiple crates is the preferred solution for addressing long compilation times, it's important to acknowledge that other alternatives have been considered, though none provide the comprehensive benefits of a modular architecture. One alternative could be optimizing the existing codebase to reduce the complexity and dependencies within delta-rs. This might involve refactoring code, removing unused dependencies, and improving the efficiency of critical algorithms. However, this approach is often time-consuming and may not yield the same level of improvement as splitting the project into multiple crates. Furthermore, it doesn't address the underlying issue of a monolithic codebase, which can still lead to long compilation times and hinder maintainability. Another alternative is to explore different build tools and configurations to optimize the compilation process. For example, using incremental compilation and caching mechanisms can help reduce the time spent recompiling unchanged code. However, these optimizations are often limited in their effectiveness and may not be sufficient to address the challenges posed by a large and complex codebase like delta-rs. Additionally, relying solely on build tool optimizations can create dependencies on specific tools and configurations, making it more difficult to build and deploy the project in different environments. In contrast, splitting delta-rs into multiple crates provides a more fundamental solution that addresses the root cause of the problem. By creating a modular architecture, we can leverage build parallelization, improve code maintainability, and enable independent development and deployment cycles. While other alternatives may offer incremental improvements, they don't provide the same level of long-term benefits as the multi-crate approach. Therefore, splitting delta-rs into multiple crates remains the most effective strategy for reducing compilation times and enhancing the overall development experience.

Prioritization and Next Steps

The prioritization of splitting delta-rs into multiple crates is considered medium, indicating that it is a beneficial enhancement that would significantly improve the development experience. While not a critical bug fix or essential feature, the reduction in compilation times and the improvements in code maintainability make this a worthwhile endeavor. The benefits of a multi-crate architecture align with the long-term goals of the project, such as enhancing scalability, fostering code reuse, and enabling more efficient development workflows. Given the medium priority, the next steps involve creating a detailed plan for the crate division, identifying the key components and their dependencies, and outlining the steps required to migrate the existing codebase. This planning phase is crucial to ensure a smooth and successful transition to the new architecture. It's also important to involve the community in the planning process, soliciting feedback and input from developers who are familiar with delta-rs and its use cases. Collaboration and open communication can help identify potential challenges and ensure that the crate division meets the needs of the community. Once the plan is finalized, the implementation phase can begin, with developers working on splitting the codebase, creating new crates, and updating dependencies. This process may involve significant refactoring and testing to ensure that the new architecture functions correctly and doesn't introduce any regressions. The transition to a multi-crate architecture is a significant undertaking, but the long-term benefits make it a valuable investment for the delta-rs project. By prioritizing this effort and following a well-defined plan, we can create a more robust, maintainable, and scalable system that better serves the needs of the Delta Lake community. For more information on Rust Crates you can check The Rust Package Registry.