This GitHub project, titled "Hobby Project: A dynamic C (Hot reloading) module-based Web Framework," details the development of a web framework written entirely in C, with a focus on dynamic module loading and hot reloading capabilities. The author's primary goal is to create a system where modifying and recompiling individual modules doesn't necessitate restarting the entire web server, thereby significantly streamlining the development workflow. This is achieved through a modular architecture where functionality is broken down into separate, dynamically linked libraries (.so files on Linux/macOS, .dll files on Windows).
The framework utilizes a central core responsible for handling incoming HTTP requests and routing them to the appropriate modules. These modules, compiled as shared libraries, can be loaded, unloaded, and reloaded at runtime without interrupting the server's operation. This dynamic loading is facilitated through the use of dlopen and related functions (or their Windows equivalents). When a module is modified and recompiled, the framework detects the change and automatically reloads the updated library, making the new code immediately active.
The project utilizes a custom configuration file, likely in a format like JSON or INI, to define routes and associate them with specific modules and their respective functions. This allows for flexible mapping of URLs to specific functionalities provided by the loaded modules.
The hot reloading mechanism likely involves some form of file system monitoring to detect changes in module files. Upon detection of a change, the framework gracefully unloads the old module, loads the newly compiled version, and updates the routing table accordingly. This process minimizes downtime and allows for continuous development and testing without restarting the server.
While the project is explicitly labelled as a hobby project, suggesting it isn't intended for production use, it explores an interesting approach to web framework design in C. The focus on modularity and dynamic reloading offers potential advantages in terms of development speed and flexibility. The implementation details provided in the repository offer insights into the challenges and considerations involved in building such a system in C, including memory management, inter-module communication, and handling potential errors during dynamic loading and unloading.
The Mozilla Developer Network (MDN) web documentation article titled "Contain – CSS Cascading Style Sheets" elaborates on the contain CSS property, a powerful tool for optimizing website performance by isolating specific elements from the rest of the document. This isolation limits the browser's calculations for layout, style, and paint, which can significantly improve rendering speed, especially in complex web applications. The contain property achieves this by declaring that an element's subtree (its descendants) are independent and their changes won't affect the layout, style, paint, or size calculations of the rest of the page, or vice-versa.
The article details the various values the contain property can accept, each offering different levels of isolation:
strict: This value provides the strongest level of containment. It encapsulates the element completely, meaning changes within the element will not trigger layout, paint, style, or size recalculations outside of it, nor will external changes affect it. It essentially treats the element as an entirely separate document.
content: This value signifies that the element's contents are independent in terms of layout, style, and paint. Changes within the contained element won't affect the layout or styling of the rest of the document, and vice-versa. Size containment, however, is not implied.
size: This value indicates that the element's dimensions are fixed and known beforehand. This allows the browser to allocate space for the element without needing to examine its descendants, which can expedite layout calculations. Crucially, size containment requires the element to have a specified size (e.g., through properties like width and height). Otherwise, it defaults to a size of 0, potentially hiding the content. This value does not isolate style, layout, or paint.
layout: This isolates the element's layout. Changes in the element's internal layout won't affect the layout of the surrounding elements, and external layout changes won't affect the contained element's internal layout.
style: This prevents style changes within the contained element from leaking out and affecting the styling of the parent document, and likewise, external style changes won't influence the element's internal styling. This particularly applies to style inheritance and counter incrementing. Note: As of the documentation's current state, style containment is still experimental and may not be fully supported by all browsers.
paint: This value ensures that the element's painting is contained within its boundaries. Any painting done within the element won't overflow outside its box, and painting from other elements won't bleed into the contained element. This is particularly useful for elements with effects like shadows or filters, preventing them from overlapping adjacent content.
The article also clarifies that multiple values can be combined, separated by spaces, to provide a composite containment effect. For example, contain: layout paint would isolate both layout and paint. Using the keyword contain: none explicitly disables containment, ensuring no isolation is applied.
Finally, the MDN documentation highlights important considerations for using the contain property effectively. It emphasizes the need for careful planning when implementing containment, especially with the size value, due to its potential to inadvertently hide content if dimensions are not explicitly defined. Overall, the article positions the contain property as a valuable tool for web developers aiming to optimize rendering performance, but it stresses the importance of understanding its nuances to avoid unexpected behavior.
The Hacker News post titled "Contain – CSS Cascading Style Sheets – MDN" linking to the MDN documentation on the CSS contain property has a moderate number of comments discussing various aspects of the property and its usage.
Several commenters highlight the performance benefits of contain. One user emphasizes how crucial this property is for optimizing web performance, particularly in complex applications. They elaborate that contain allows developers to isolate specific parts of the DOM, thereby limiting the scope of reflows and repaints, leading to smoother interactions and faster rendering times. This sentiment is echoed by another comment which points out the significant impact contain can have on improving rendering performance, especially in situations with animations or transitions.
Another thread discusses the nuances of the different values of the contain property (like size, layout, style, and paint). One user questions the practical applications of style containment, leading to a discussion about scenarios where preventing style bleed from a component is beneficial, such as in shadow DOM implementations or when dealing with third-party embedded content. The utility of size containment is also highlighted, specifically for scenarios where the size of a component is known beforehand, enabling the browser to perform layout calculations more efficiently.
One commenter expresses surprise at not having known about this property sooner, suggesting that it's underutilized within the web development community. This comment sparks further discussion about the discoverability of useful CSS properties and the challenges developers face in keeping up with the evolving web standards.
A few comments dive into specific use cases for contain. One user mentions using it to isolate a complex animation, preventing performance issues from affecting the rest of the page. Another explains how contain can be instrumental in optimizing the performance of virtualized lists, where only visible items need to be rendered.
Finally, a commenter points to the MDN documentation itself as an excellent resource for understanding the intricacies of the contain property and its various values, underscoring the value of the original link shared in the Hacker News post. The commenter highlights the detailed explanations and examples provided in the documentation, which allows for a deeper understanding of its effects and proper implementation.
Summary of Comments ( 50 )
https://news.ycombinator.com/item?id=42165759
Hacker News users discussed the practicality and novelty of a C web framework with hot reloading. Some questioned the real-world use cases and performance benefits compared to existing solutions, suggesting the project serves more as an interesting experiment than a production-ready tool. Others expressed interest in the technical implementation, particularly the hot reloading aspect, and appreciated the author's effort in exploring this concept. Several users pointed out potential issues like memory leaks and the challenges of safely reloading C code in a web server environment. The overall sentiment leans towards acknowledging the project's technical ingenuity while remaining skeptical about its broad applicability.
The Hacker News post "Hobby Project: A dynamic C (Hot reloading) module-based Web Framework" linking to the GitHub project
c-web-modulessparked a moderate discussion with a mix of curiosity, skepticism, and praise.Several commenters expressed intrigue about the project's hot reloading capabilities in C, wondering about the implementation details and its effectiveness. One user questioned how the hot reloading handles global state and potential memory leaks, a crucial aspect of dynamic module loading. Another user highlighted the project's apparent focus on simplicity, which they found appealing. This comment received further engagement, with another user agreeing about the simplicity while also noting the potential limitations due to its single-threaded nature.
The project's use of
inotifyfor monitoring file changes and triggering recompilation/reloading was also discussed, with some expressing concern about its performance implications, especially under heavy load or with a large number of modules.A few commenters drew parallels with other projects and technologies. One mentioned how this approach reminded them of Erlang's hot code swapping, highlighting the benefit of minimizing downtime during development. Another commenter discussed similar hot reloading mechanisms found in other web frameworks like Django, though acknowledging the differences in language and complexity.
Some skepticism was directed towards the practicality and potential use cases of such a framework. One commenter questioned the target audience and whether there was a significant need for a dynamic C web framework, given the prevalence of more established options.
Despite some doubts, the overall sentiment towards the project was positive, with many appreciating it as an interesting experiment and a demonstration of what's possible with C. The project author also engaged in the comments, responding to questions and providing further insights into the project's goals and design choices. They clarified that the primary motivation was personal exploration and learning rather than building a production-ready framework, emphasizing its hobbyist nature. This transparency was generally well-received by the community.