手撸golang 仿spring ioc/aop 之7 扫码2

手撸golang 仿spring ioc/aop 之7 扫码2

缘起

最近阅读 [Spring Boot技术内幕: 架构设计与实现原理] (朱智胜 , 2020.6)
本系列笔记拟采用golang练习之
Talk is cheap, show me the code.

Spring

Spring的主要特性：
1. 控制反转（Inversion of Control, IoC）
2. 面向容器
3. 面向切面（AspectOriented Programming, AOP）

源码gitee地址：
https://gitee.com/ioly/learning.gooop

原文链接：
https://my.oschina.net/ioly

目标

• 参考spring boot常用注解，使用golang编写“基于注解的静态代码增强器/生成器”

子目标（Day 7）

• 今天继续the hard part：struct/field/method元素的扫描

  • common/Tokens.go：添加数据类型的词法解析支持
  • scanner/IStructScanner.go: 结构体扫描器的接口及实现

common/Tokens.go

添加数据类型的词法解析支持：

• 分别解析基本类型/自定义类型/指针类型/数组类型/map类型
• 自定义类型需要注意排除'map'关键字

• 指针，数组和map类型都是复合类型，需递归解析

  package common
  
  import (
      "regexp"
      "strings"
      "sync"
  )
  
  type tTokens struct {
      cache   map[string]*regexp.Regexp
      rwmutex *sync.RWMutex
  }
  
  var Tokens = newTokensLib()
  
  func newTokensLib() *tTokens {
      it := new(tTokens)
      it.init()
      return it
  }
  
  func (me *tTokens) init() {
      me.cache = make(map[string]*regexp.Regexp)
      me.rwmutex = new(sync.RWMutex)
  }
  
  func (me *tTokens) MatchString(s string, p string) bool {
      return strings.HasPrefix(s, p)
  }
  
  func (me *tTokens) MatchRegexp(s string, p string) (bool, string) {
      me.rwmutex.RLock()
      r, ok := me.cache[p]
      me.rwmutex.RUnlock()
  
      if !ok {
          me.rwmutex.Lock()
          if r, ok = me.cache[p]; !ok {
              r, _ = regexp.Compile(p)
          }
          me.rwmutex.Unlock()
      }
  
      if r == nil {
          return false, ""
      }
  
      if !r.MatchString(s) {
          return false, ""
      }
  
      return true, r.FindString(s)
  }
  
  func (me *tTokens) MatchIdentifier(s string) (bool, string) {
      return me.MatchRegexp(s, "^[_a-zA-Z]\\w{0,99}")
  }
  
  func (me *tTokens) MatchSpaces(s string) (bool, string) {
      return me.MatchRegexp(s, "^\\s+")
  }
  
  func (me *tTokens) MatchDir(s string) (bool, string) {
      b, s := me.MatchRegexp(s, "^([a-zA-Z]\\:)?([\\\\/][^\\s/:*?<>|\\\"\\\\]+)+[\\/]?")
      if b {
          return b, s
      }
  
      b, s = me.MatchRegexp(s, "^\\\"([a-zA-Z]\\:)?([\\\\/][^/:*?<>|\\\"\\\\]+)+[\\/]?\\\"")
      if b {
          return b, s
      }
  
      b, s = me.MatchRegexp(s, "^'([a-zA-Z]\\:)?([\\\\/][^'/:*?<>|\\\"\\\\]+)+[\\/]?'")
      if b {
          return b, s
      }
  
      return false, ""
  }
  
  
  func (me *tTokens) MatchDataType(s string) (bool, string) {
      if ok,t := me.MatchBasicType(s);ok {
          return true, t
      }
  
      if ok,t := me.MatchCustomType(s);ok {
          return true, t
      }
  
      if ok,t := me.MatchPointerType(s);ok {
          return true, t
      }
  
      if ok,t := me.MatchArrayType(s);ok {
          return true, t
      }
  
      if ok,t := me.MatchMapType(s);ok {
          return true, t
      }
  
      return false, ""
  }
  
  func (me *tTokens) MatchBasicType(s string) (bool, string) {
      list := []string {
          "int",
          "string",
          "bool",
          "byte",
          "int32",
          "int64",
          "uint32",
          "uint64",
          "float32",
          "float64",
          "int8",
          "uint8",
          "int16",
          "uint16",
          "time.Time",
      }
      for _,it := range list {
          if me.MatchString(s, it) {
              return true, it
          }
      }
  
      return false, ""
  }
  
  func (me *tTokens) MatchCustomType(s string) (bool, string) {
      t := s
      b1, s1 := me.MatchRegexp(t, `^\w+\.`)
      if b1 {
          t = t[len(s1):]
      }
  
      b2, s2 := me.MatchRegexp(t, `^\w+`)
      if !b2 {
          return false, ""
      }
      if s2 == "map" {
          // map is reserved word
          return false, ""
      }
  
      return true, s1 + s2
  }
  
  func (me *tTokens) MatchPointerType(s string) (bool, string) {
      t := s
      if t[0] != '*' {
          return false,""
      }
      t = t[1:]
  
      b, s := me.MatchDataType(t)
      if !b {
          return false, ""
      }
  
      return true, "*" + s
  }
  
  func (me *tTokens) MatchArrayType(s string) (bool, string) {
      t := s
      b1, s1 := me.MatchRegexp(s, `^\[\s*\d*\s*\]\s*`)
      if !b1 {
          return false, ""
      }
      t = t[len(s1):]
  
      b2, s2 := me.MatchDataType(t)
      if !b2 {
          return false, ""
      }
      return true, s1 + s2
  }
  
  func (me *tTokens) MatchMapType(s string) (bool, string) {
      t := s
      s1 := "map"
      if !me.MatchString(t, s1) {
          return false, ""
      }
      t = t[len(s1):]
  
      b2, s2 := me.MatchRegexp(t, `^\s*\[\s*`)
      if !b2 {
          return false, ""
      }
      t = t[len(s2):]
  
      b3,s3 := me.MatchDataType(t)
      if !b3 {
          return false, ""
      }
      t = t[len(s3):]
  
      b4, s4 := me.MatchRegexp(t, `^\s*\]\s*`)
      if !b4 {
          return false, ""
      }
      t = t[len(s4):]
  
      b5, s5 := me.MatchDataType(t)
      if !b5 {
          return false, ""
      }
  
      return true, s1 + s2 + s3 + s4 + s5
  }

scanner/IStructScanner.go

结构体扫描器的接口及实现

package scanner

import (
    "errors"
    "learning/gooop/spring/autogen/common"
    "learning/gooop/spring/autogen/domain"
    "regexp"
    "strings"
)

type IStructScanner interface {
    ScanStruct(file *domain.CodeFileInfo)
}

type tStructScanner int

func (me *tStructScanner) ScanStruct(file *domain.CodeFileInfo) {
    bInStruct := false
    var stru *domain.StructInfo
    for lineNO,line := range file.CleanLines {
        if bInStruct {
            // end?
            if gStructEndRegexp.MatchString(line) {
                bInStruct = false

                me.scanMethod(stru, lineNO + 1)
                stru = nil
                continue
            }
        }

        // start?
        if gStructStartRegexp.MatchString(line) {
            bInStruct = true
            ss := gStructStartRegexp.FindAllString(line, -1)

            stru := domain.NewStructInfo()
            stru.LineNO = lineNO
            stru.CodeFile = file
            stru.Name = ss[1]
            continue
        }

        // in struct block
        ok,fname,ftype := me.scanField(line)
        if ok {
            stru.AppendField(lineNO, fname, ftype)
        }
    }
}


func (me *tStructScanner) scanField(line string) (ok bool, fldName string, fldType string) {
    if !gFieldStartRegexp.MatchString(line) {
        return false, "",""
    }

    fldName = strings.TrimSpace(gFieldStartRegexp.FindString(line))
    fldType = strings.TrimSpace(line[len(fldName):])
    return true, fldName, fldType
}


func (me *tStructScanner) scanMethod(stru *domain.StructInfo, fromLineNO int) {
    for i,max := fromLineNO, len(stru.CodeFile.CleanLines);i <= max;i++ {
        line := stru.CodeFile.CleanLines[i]
        if !gMethodStartRegex.MatchString(line) {
            continue
        }


        ss := gMethodStartRegex.FindAllString(line, -1)

        // declare
        declare := ss[0]
        offset := len(declare)

        // receiver
        receiver := ss[1]
        if receiver != stru.Name {
            continue
        }
        method := domain.NewMethodInfo()

        // name
        method.Name = ss[2]

        // method input args
        e,args := me.scanMethodArgs(method, strings.TrimSpace(line[offset:]))
        if e != nil {
            panic(e)
        }
        offset += len(args)

        // method return args
        e = me.scanReturnArgs(method, strings.TrimSpace(line[offset:]))
        if e != nil {
            panic(e)
        }

        // end scan method
        stru.AppendMethod(method)
    }
}

func (me *tStructScanner) scanMethodArgs(method *domain.MethodInfo, s string) (error, string) {
    t := s
    offset := 0
    for {
        // name
        b1, s1 := common.Tokens.MatchRegexp(t, `\w+(\s*,\s*\w+)\s+`)
        if !b1 {
            break
        }
        argNames := s1
        offset += len(s1)
        t = s[offset:]

        // data type
        b2, s2 := common.Tokens.MatchDataType(t)
        if !b2 {
            return gInvalidMethodArgs, ""
        }
        argDataType := s2
        offset += len(s2)
        t = s[offset:]

        for _,it := range strings.Split(argNames, ",") {
            method.AppendArgument(it, argDataType)
        }

        // ,\s+
        b3, s3 := common.Tokens.MatchRegexp(t, `\s*,\s*`)
        if !b3 {
            break
        }
        offset += len(s3)
        t = s[offset:]
    }

    return nil, s[0:offset]
}

func (me *tStructScanner) scanReturnArgs(method *domain.MethodInfo, s string) error {
    // todo: fixme
    panic("implements me")
}


var gStructStartRegexp = regexp.MustCompile(`^\s*type\s+(\w+)\s+struct\s+\{`)
var gStructEndRegexp = regexp.MustCompile(`^\s*}`)
var gFieldStartRegexp = regexp.MustCompile(`^\s*\w+\s+`)
var gMethodStartRegex = regexp.MustCompile(`\s*func\s+\(\s*\w+\s+\*?(\w+)\s*\)\s+(\w+)\s*\(`)
var gInvalidMethodArgs = errors.New("invalid method arguments")


var DefaultStructScanner IStructScanner = new(tStructScanner)

（未完待续）