https://yun7211.github.io/tags/%E6%A8%A1%E5%9D%97%E5%8C%96/Recent content in 模块化 on Yun 的个人博客Hugo -- gohugo.iozh-cnMon, 18 May 2026 10:40:00 +0800https://yun7211.github.io/c-language/module-interface/module-interface-design/Mon, 18 May 2026 10:40:00 +0800https://yun7211.github.io/c-language/module-interface/module-interface-design/<h2 id="模块边界">模块边界 </h2><p>C 项目变大以后，真正难维护的往往不是语法，而是模块边界。好的模块接口应该让调用方知道能做什么，不需要知道内部怎么做。</p> <p>常见做法是把结构体定义隐藏在 <code>.c</code> 文件里，只在头文件暴露不透明类型。</p> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-c" data-lang="c"><span class="line"><span class="cl"><span class="k">struct</span> <span class="n">logger</span><span class="p">;</span> </span></span><span class="line"><span class="cl"> </span></span><span class="line"><span class="cl"><span class="k">struct</span> <span class="n">logger</span> <span class="o">*</span><span class="nf">logger_create</span><span class="p">(</span><span class="k">const</span> <span class="kt">char</span> <span class="o">*</span><span class="n">path</span><span class="p">);</span> </span></span><span class="line"><span class="cl"><span class="kt">void</span> <span class="nf">logger_destroy</span><span class="p">(</span><span class="k">struct</span> <span class="n">logger</span> <span class="o">*</span><span class="n">log</span><span class="p">);</span> </span></span><span class="line"><span class="cl"><span class="kt">int</span> <span class="nf">logger_write</span><span class="p">(</span><span class="k">struct</span> <span class="n">logger</span> <span class="o">*</span><span class="n">log</span><span class="p">,</span> <span class="k">const</span> <span class="kt">char</span> <span class="o">*</span><span class="n">message</span><span class="p">);</span> </span></span></code></pre></div><p>调用方不能直接访问内部字段，模块就有空间调整实现。</p> <h2 id="资源成对管理">资源成对管理 </h2><p>创建和销毁函数要成对出现，命名保持一致。这样调用方一眼能看出资源生命周期。</p> <div class="highlight"><pre tabindex="0" class="chroma"><code class="language-txt" data-lang="txt"><span class="line"><span class="cl">init/deinit </span></span><span class="line"><span class="cl">create/destroy </span></span><span class="line"><span class="cl">open/close </span></span><span class="line"><span class="cl">alloc/free </span></span></code></pre></div><p>不要让调用方猜一个对象应该用 <code>free</code>、<code>close</code> 还是自定义函数释放。</p> <h2 id="错误处理">错误处理 </h2><p>C 语言没有异常，接口必须明确错误返回。常见方式是返回 <code>0</code> 表示成功，负数或非零表示错误。</p> <p>更重要的是：失败时资源状态要可预测。函数要么完全成功，要么保持原状态，不能留下半初始化对象。</p> <h2 id="减少全局状态">减少全局状态 </h2><p>全局变量会让测试、并发和复用都变困难。能通过上下文对象传递的状态，就尽量放进上下文对象。</p> <h2 id="小结">小结 </h2><p>C 模块接口的目标是降低调用方心智负担。接口越稳定、语义越明确，后续维护成本越低。</p>