rename 接口实现方案（已实现，选用方案二） 背景 • 方案调研 • Chubaofs • Juicefs • 方案实现 • 方案一：chubaofs • 方案二：事务方案 • 方案三：利用 KV 自带的分布式事务 • Q&A • 1. 是否需要实现跨文件系统的 rename 操作？ • 2. 在多客户端情况下，是否需要加锁来保证其原子性？ • 3. rename rename 接口，本文档是对 rename 接口实现的调研及方案设计。 rename 操作，主要操作的是 dentry，如 rename /dir1/file1 /dir2/file2，主要有 2 个步骤：（1）删除 file1 的 dentry，（2）增加 file2 的 dentry（该 dentry 的 inodeid 等同 file1 的 inode id）。关于 rename 接口的实现，主要调研了 dentry，相当于多了一个硬链接，Linux 和 POSIX 接口中表明这允许一段时间内存在，但是最终还是要原子性，所以这一步出错会导致和本地文件系统不一致的行为： 1. Linux 接口定义允许 rename 过程中某一段时间存在这样的硬链接（或者 rename 执行到一半断电也会存在） 2. 而 POSIX 接口中提到了该函数得是原子（不断电的情况下，rename 操作不能被其他操作打断，不存在中间状态）

curve文件系统元数据proto（代码接口定义，已实现） ## 1、 代码结构和代码目录 curve文件系统是相对于curve块设备比较独立的一块，在当前curve项目的目录下，增加一个一级目录curvefs，curvefs下有自己独立的proto\src\test。 ![Image](/uploads/documents/6/5/7/9/6579a4e9a6fde3e069fddf95fb76e7bd/p2_1

1.1 Introduction 11 5.1.2 Installation 13 5.1.3 Quickstart 15 5.1.4 Tutorial (WSGI) 27 5.1.5 Tutorial (ASGI) 49 5.1.6 Recipes 70 5.1.7 FAQ 81 5.2 Deployment Guide 102 5.2.1 Preamble & Framework Reference 107 5.4.1 The App Class 107 5.4.2 Request & Response 123 5.4.3 WebSocket (ASGI Only) 186 5.4.4 Cookies 199 5.4.5 Status Codes 202 5.4.6 Error Handling 206 5.4.7 Media 239 Python Module Index 365 Index 367 ### Release v3.1b3 (Installation) Falcon is a minimalist ASGI/WSGI framework for building mission-critical REST APIs and microservices, with a focus on reliability

1.1 Introduction 11 5.1.2 Installation 13 5.1.3 Quickstart 15 5.1.4 Tutorial (WSGI) 27 5.1.5 Tutorial (ASGI) 49 5.1.6 Recipes 70 5.1.7 FAQ 81 5.2 Deployment Guide 102 5.2.1 Preamble & Framework Reference 107 5.4.1 The App Class 107 5.4.2 Request & Response 123 5.4.3 WebSocket (ASGI Only) 186 5.4.4 Cookies 199 5.4.5 Status Codes 202 5.4.6 Error Handling 206 5.4.7 Media 239 Python Module Index 365 Index 367 ### Release v3.1 (Installation) Falcon is a minimalist ASGI/WSGI framework for building mission-critical REST APIs and microservices, with a focus on reliability

# 现代编程思想 接口 Hongbo Zhang ## 回顾 ## • 第六课：定义平衡二叉树 我们定义一个更一般的二叉搜索树，允许存放任意类型的数据 1. enum Tree[T] { 2. Empty 3. Node(T, Tree[T], Tree[T]) 4. } 5. 6. // 我们需要一个比较函数来比较值的大小以了解顺序 7. // 负数表示小于，0表示等于，正数表示大于 我们将这类函数称为方法 ## 接口 Trait ## • 我们通过接口定义一系列方法的实现需求 1. trait Compare { 2. compare(Self, Self) -> Int // Self代表实现该接口的类型 3. } 4. trait Default { 5. default() -> Self 6. } ## • 月兔中的接口是结构化的 ◦ 无需 无需声明为特定的接口实现方法，类型本身实现方法即可 ## 接口 Trait • 我们可以在泛型的参数上添加接口的要求 ☐ 限制参数的类型： <类型参数> ： <接口> ☐ 在函数中使用接口定义的方法： <类型参数>::<方法名> 1. fn make[T: Default]( ) -> Queue[T] { // 类型参数T应当满足Default接口

Web Framework Release v3.1 (Installation) Falcon [https://falconframework.org] is a minimalist ASGI/WSGI framework for building mission-critical REST APIs and microservices, with a focus on reliability NOW?” ## Features Falcon tries to do as little as possible while remaining highly effective. • ASGI, WSGI, and WebSocket support • Native asyncio support • No reliance on magic globals for routing and • Idiomatic HTTP error responses • Straightforward exception handling • Snappy testing with WSGI/ASGI helpers and mocks • CPython 3.5+ and PyPy 3.5+ support ## Who’s Using Falcon? Falcon is used

class QuoteResource: # The Falcon Web Framework Release v3.0 (Installation) Falcon is a minimalist WSGI library for building speedy web APIs and app backends. We like to think of Falcon as the Dieter Rams Gitter ## Features Falcon tries to do as little as possible while remaining highly effective. • ASGI, WSGI, and WebSocket support • Native asyncio support • No reliance on magic globals for routing and • Idiomatic HTTP error responses • Straightforward exception handling • Snappy testing with WSGI/ASGI helpers and mocks • CPython 3.5+ and PyPy 3.5+ support ## Who’s Using Falcon? Falcon is used

1.1 Introduction 11 5.1.2 Installation 13 5.1.3 Quickstart 15 5.1.4 Tutorial (WSGI) 27 5.1.5 Tutorial (ASGI) 49 5.1.6 Recipes 70 5.1.7 FAQ 81 5.2 Deployment Guide 102 5.2.1 Preamble & Framework Reference 107 5.4.1 The App Class 107 5.4.2 Request & Response 123 5.4.3 WebSocket (ASGI Only) 186 5.4.4 Cookies 199 5.4.5 Status Codes 202 5.4.6 Error Handling 206 5.4.7 Media 239 Python Module Index 365 Index 367 ### Release v3.1rc1 (Installation) Falcon is a minimalist ASGI/WSGI framework for building mission-critical REST APIs and microservices, with a focus on reliability

1.1 Introduction 11 5.1.2 Installation 13 5.1.3 Quickstart 15 5.1.4 Tutorial (WSGI) 27 5.1.5 Tutorial (ASGI) 49 5.1.6 Recipes 70 5.1.7 FAQ 81 5.2 Deployment Guide 102 5.2.1 Preamble & Framework Reference 107 5.4.1 The App Class 107 5.4.2 Request & Response 123 5.4.3 WebSocket (ASGI Only) 186 5.4.4 Cookies 199 5.4.5 Status Codes 202 5.4.6 Error Handling 206 5.4.7 Media 239 Python Module Index 365 Index 367 ### Release v3.1 (Installation) Falcon is a minimalist ASGI/WSGI framework for building mission-critical REST APIs and microservices, with a focus on reliability

1.1 Introduction 11 5.1.2 Installation 13 5.1.3 Quickstart 15 5.1.4 Tutorial (WSGI) 27 5.1.5 Tutorial (ASGI) 49 5.1.6 Recipes 70 5.1.7 FAQ 81 5.2 Deployment Guide 102 5.2.1 Preamble & Framework Reference 107 5.4.1 The App Class 107 5.4.2 Request & Response 123 5.4.3 WebSocket (ASGI Only) 186 5.4.4 Cookies 199 5.4.5 Status Codes 202 5.4.6 Error Handling 206 5.4.7 Media 239 Python Module Index 365 Index 367 ### Release v3.1b1 (Installation) Falcon is a minimalist ASGI/WSGI framework for building mission-critical REST APIs and microservices, with a focus on reliability