Chapter 1 Views and Quality Objectives of Software Construction

1.1 Multi-dimensional software views

1.By phases: build-time views

• idea?requirement?design?code?installable/executable package

(1)Build-time,moment,and code-level view

functions classes methods interfaces etc

• Lexical-based semi-structured source code
• Syntax-oriented program structure: Abstract Syntax Tree (AST)

• Semantics-oriented program structure: use UML

(2)Build-time, period, and code-level view

changes /Code churn

• Code churn: line added/modified/deleted from a file from one version to another

  Like the Push

(3)Build time, moment, and component-level view

files/directories/packages/libraries

• Library

• • stored in disk files , can be reused
  • an extension
  • a library function can be viewed as an extension to the standard language
  • From OS/SDK/third-party sources/self

• 开发者总是在自己的程序中加入已经编好的库

• Linking with a library

  • 需要告诉IDE和JVM在哪里寻找这些库
  • Static Linking
    • 库被拷贝进入代码整体，执行的时候无需提供库文件
    • 发生在构造过程
  • Dynamic Linking
    • 在build阶段只做标记
    • 运行时按标记装载库至内存
    • 必须把所有动态库都复制给用户
    • 更新版本时不一定需要更新原始文件

(4)Build-time, period, and component-level view

• Version Control System

  

  2.Runtime Views

  Code-level /Component-level /Moment view /Period view

• Executable Programs
• • Native Machine Code
  • Full Program Interpretation
  • Interpreted Byte Codes
  • Java Virtual Machine

(5)Run-time, moment, and code-level view

• Snapshot diagram
• Fine-grained states of a program
• Memory dump

(6)Run-time, period and code-level view

• Sequence diagram
• Execution tracing

(7)Run-time, component and component-level view

• Deployment diagram

(8)Run-time, period and component-level view