gor 引流测试中间件golang代码添加注释

package main

import (
"bufio"
"bytes"
"encoding/hex"
"fmt"
"github.com/buger/goreplay/proto"
"os"
)

// requestID -> originalToken
var originalTokens map[string][]byte

// originalToken -> replayedToken
var tokenAliases map[string][]byte

func main() {
originalTokens = make(map[string][]byte)
tokenAliases = make(map[string][]byte)

scanner := bufio.NewScanner(os.Stdin)for scanner.Scan() {    encoded := scanner.Bytes()    buf := make([]byte, len(encoded)/2)    hex.Decode(buf, encoded)    process(buf)}

}

func process(buf []byte) {
// First byte indicate payload type, possible values:
// 1 - Request
// 2 - Response
// 3 - ReplayedResponse
payloadType := buf[0]
headerSize := bytes.IndexByte(buf, '\n') + 1
header := buf[:headerSize-1]

// Header contains space separated values of: request type, request id, and request start time (or round-trip time for responses)meta := bytes.Split(header, []byte(" "))// For each request you should receive 3 payloads (request, response, replayed response) with same request idreqID := string(meta[1])payload := buf[headerSize:]Debug("Received payload:", string(buf))switch payloadType {case '1': // Request    if bytes.Equal(proto.Path(payload), []byte("/token")) {        originalTokens[reqID] = []byte{}        Debug("Found token request:", reqID)    } else {        token, vs, _ := proto.PathParam(payload, []byte("token"))//取到生产服务器的token值        if vs != -1 { // If there is GET token param            if alias, ok := tokenAliases[string(token)]; ok {  //检查要替换的token值是否存在                // Rewrite original token to alias                payload = proto.SetPathParam(payload, []byte("token"), alias)//将生产的token替换成测服的token                // Copy modified payload to our buffer                buf = append(buf[:headerSize], payload...)            }        }    }    // Emitting data back    os.Stdout.Write(encode(buf))//重写请求准备发往测试服务器case '2': // Original response    if _, ok := originalTokens[reqID]; ok {        // Token is inside response body        secureToken := proto.Body(payload) //取到生产服务器中返回的token值        originalTokens[reqID] = secureToken        Debug("Remember origial token:", string(secureToken))    }case '3': // Replayed response    if originalToken, ok := originalTokens[reqID]; ok {        delete(originalTokens, reqID)        secureToken := proto.Body(payload)        tokenAliases[string(originalToken)] = secureToken//拿到测试服务器的token值用来替换掉正服的token值        Debug("Create alias for new token token, was:", string(originalToken), "now:", string(secureToken))    }}

}

func encode(buf []byte) []byte {
dst := make([]byte, len(buf)*2+1)
hex.Encode(dst, buf)
dst[len(dst)-1] = '\n'

return dst

}

func Debug(args ...interface{}) {
fmt.Fprint(os.Stderr, "[DEBUG][TOKEN-MOD] ")
fmt.Fprintln(os.Stderr, args...)
}