整洁架构

Software architecture begins with the code—and so we will begin our discussion of architecture by looking at what we’ve learned about code since code was first written. 任何软件架构的实现都离不开具体的代码，所以我们对软件架构的讨论应该从第一行被写下的代码开始。 In 1938, Alan Turing laid the foundations of what was to become computer programming. He was not the first to conceive of a programmable machine, but he was the first to understand that programs were simply data. By 1945, Turing was writing real programs on real computers in code that we would recognize (if we squinted enough). Those programs used loops, branches, assignment, subroutines, stacks, and other familiar structures. Turing’s language was binary. ...

Every software system provides two different values to the stakeholders: behavior and structure. Software developers are responsible for ensuring that both those values remain high. Unfortunately, they often focus on one to the exclusion of the other. Even more unfortunately, they often focus on the lesser of the two values, leaving the software system eventually valueless. 对于每个软件系统，我们都对以通过行为和架构两个维度来休现它的实际价值。软件研发人员应该确保自己的系统在这两个维度上的实际价值都能长时间维持在很高的状态。不幸的是，他们往往只关注一个维度，而忽视了另外一个维度。更不幸的是，他们常常关注的还是错误的维度，这导致了系统的价值最终趋降为零。 BEHAVIOR 行为价值 The first value of software is its behavior. Programmers are hired to make machines behave in a way that makes or saves money for the stakeholders. We do this by helping the stakeholders develop a functional specification, or requirements document. Then we write the code that causes the stakeholder’s machines to satisfy those requirements. ...

There has been a lot of confusion about design and architecture over the years. What is design? What is architecture? What are the differences between the two? 一直以来，设计（Design）与架构（Architecture）这两个概念让大多数人十分迷惑——什么是设计？什么是架构？二者究竟有什么区别？ One of the goals of this book is to cut through all that confusion and to define, once and for all, what design and architecture are. For starters, I’ll assert that there is no difference between them. None at all. 本书的一个重要的目标就是要清晰、明确地对二者进行定义。首先我要明确地说，二者没有任何区别。一丁点区别都没有！ The word “architecture” is often used in the context of something at a high level that is divorced from the lower-level details, whereas “design” more often seems to imply structures and decisions at a lower level. But this usage is nonsensical when you look at what a real architect does. ...

My professional career as a software developer began in the 1990s, at a time when the dinosaurs of Big Architecture ruled the world. To get ahead, you had to learn about objects and components, about design patterns, and about the Unified Modeling Language (and its precursors). 我的软件工程师生涯开始于 20 世纪 90 年代，那是一个恐龙级大型架构统治世界的时代。要想在那样的时代获得一席之地，我们必须学会对象及其组件、设计模式、统一建模语言（包括其前身）的相关知识。 Projects—and boy, should we rue the day when we decided to call them that?—started with long design phases, where detailed blueprints for our systems were laid out by “senior” programmers for more “junior” programmers to follow. Which, of course, they didn’t. Ever. ...