目錄
1.LARS-DNS-MYSQL環境搭建
2.LARSDNS-系統整體模塊的簡單說明
3.Lars-Dns-功能說明
4.Lars-Dns-數據表的創建
5.Lars-Dns-整體功能說明
6.Lars-DnsV0.1-Route類的單例實現
7.Lars-DnsV0.1-Route類的鏈接數據庫方法實現
8.Lars-DnsV0.1-定義存放RouteData關系的map數據結構
9.課前回顧
10.Lars-DnsV0.1-將Route數據加載map中
11.Lars-Dns的proto協議定義
12.Lars-DnsV0.1-實現獲取route信息功能
13.Lars-DnsV0.1-獲取route hosts信息測試
14.Lars-DnsV0.1-總結
1.LARS-DNS-MYSQL環境搭建
四、Lars-DNS Service開發
## **1) 簡介**
?????????負責接收各agent對某modid、cmdid的請求并返回該modid、cmdid下的所有節點,即為agent提供獲取路由服務
### 1.1 架構

### **1.2 網絡模塊**
?????DnsService服務模型采用了one loop per thread TCP服務器,主要是基于Lars-Reactor:
-?主線程Accepter負責接收連接(agent端連接)
-?Thread loop們負責處理連接的請求、回復;(agent端發送查詢請求,期望獲取結果)
2.LARSDNS-系統整體模塊的簡單說明
### **1.3 雙map模型**?
?????DnsServer使用兩個map存儲路由數據(key =?`modid<<32 + cmdid`?, value = set of?`ip<<32 + port`)
-?一個`RouterDataMap_A`:主數據,查詢請求在此map執行
-?另一個`RouterDataMap_B`:后臺線程周期性重加載路由到此map,作為最新數據替換掉上一個map
這兩個map分別由指針`data_pointer`與`temp_pointer`指向.
?
3.Lars-Dns-功能說明
### 1.4 Backend Thread守護線程
**dns service還有個業務線程:**?
1、負責周期性(default:1s)檢查`RouteVersion`表版本號,如有變化,說明`RouteData`有變更,則重加載`RouteData`表內容;然后將`RouteChange`表中被變更的`modid`取出,根據訂閱列表查出`modid`被哪些連接訂閱后,向所有工作線程發送任務:要求訂閱這些`modid`的連接推送`modid`路由到agent
2、此外,還負責周期性(default:8s)重加載`RouteData`表內容
**PS:重加載`RouteData`表內容的細節**
重加載`RouteData`表內容到`temp_pointer`指向的`RouterDataMap_B`,而后上寫鎖,交換指針`data_pointer`與`temp_pointer`的地址,于是完成了路由數據更新
4.Lars-Dns-數據表的創建
### **主業務**
1.?服務啟動時,`RouteData`表被加載到`data_pointer`指向的`RouterDataMap_A`中,?`temp_pointer`指向的`RouterDataMap_B`為空
??????????2.?服務啟動后,agent發來Query for 請求某`modid/cmdid`,到其所在Thread Loop上,上讀鎖查詢`data_pointer`指向的`RouterDataMap_A`,返回查詢結果;
??????????3.?如果此`modid/cmdid`不存在,則把`agent ip+port`+`moid/cmdid`發送到Backend thread loop1的隊列,讓其記錄到ClientMap
后臺線程Backend thread每隔10s清空`temp_pointer`指向的`RouterDataMap_B`,再加載`RouteData`表內容到`temp_pointer`指向的`RouterDataMap_B`,加載成功后交換指針`data_pointer`與`temp_pointer`指針內容,于是完成了路由數據的更新.
5.Lars-Dns-整體功能說明
## **2) 數據庫創建**
*?表`RouteData`: 保存了所有mod路由信息.
| 字段???????| 數據類型?????????| 是否可以為空 | 主鍵 | 默認 | 附加???| 說明?????????|
| ---------- | ---------------- | ------------ | ---- | ---- | ------ | ------------ |
| id?????????| int(10) unsigned | No???????????| 是???| NULL | 自增長 | 該條數據ID???|
| modid??????| int(10) unsigned | No???????????|??????| NULL |????????| 模塊ID???????|
| cmdid??????| int(10) unsigned | No???????????|??????| NULL |????????| 指令ID???????|
| serverip???| int(10) unsigned | No???????????|??????| NULL |????????| 服務器IP地址 |
| serverport | int(10) unsigned | No???????????|??????| NULL |????????| 服務器端口???|
*?表`RouteVersion`: 當前`RouteData`路由版本號,每次管理端修改某mod的路由,`RouteVersion`表中的版本號都被更新為當前時間戳
| 字段????| 數據類型?????????| 是否可以為空 | 主鍵 | 默認 | 附加???|
| ------- | ---------------- | ------------ | ---- | ---- | ------ |
| id??????| int(10) unsigned | No???????????| 是???| NULL | 自增長 |
| version | int(10) unsigned | No???????????|??????| NULL |????????|
*?表`RouteChange`: 每次管理端修改某mod的路由,會記錄本次對哪個mod進行修改(增、刪、改),以便指示最新的`RouteData`路由有哪些mod變更了。
| 字段????| 數據類型????????????| 是否可以為空 | 主鍵 | 默認 | 附加???|
| ------- | ------------------- | ------------ | ---- | ---- | ------ |
| id??????| int(10) unsigned????| No???????????| 是???| NULL | 自增長 |
| modid???| int(10) unsigned????| No???????????|??????| NULL |????????|
| cmdid???| int(10) unsigned????| No???????????|??????| NULL |????????|
| version | bigint(20) unsigned | No???????????|??????| NULL |????????|
相關創建表格的sql語句如下`lars_dns.sql`
```sql
DROP DATABASE if exists lars_dns;
CREATE DATABASE lars_dns;
USE lars_dns;
DROP TABLE IF EXISTS `RouteData`;
CREATE TABLE `RouteData` (
????`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
????`modid` int(10) unsigned NOT NULL,
????`cmdid` int(10) unsigned NOT NULL,
????`serverip` int(10) unsigned NOT NULL,
????`serverport` int(10) unsigned NOT NULL,
????PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=116064 DEFAULT CHARSET=utf8;
DROP TABLE IF EXISTS `RouteVersion`;
CREATE TABLE RouteVersion (
????`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
????`version` int(10) unsigned NOT NULL,
????PRIMARY KEY (`id`)
);
INSERT INTO RouteVersion(version) VALUES(0);
DROP TABLE IF EXISTS `RouteChange`;
CREATE TABLE RouteChange (
????`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
????`modid` int(10) unsigned NOT NULL,
????`cmdid` int(10) unsigned NOT NULL,
????`version` bigint(20) unsigned NOT NULL,
????PRIMARY KEY (`id`)
);
```
?????????我們創建一個基礎目錄`Lars/base`來存放一些公共的工具和資源.
cd到`Lars/base`, 我們`mkdir sql`, 然后將`lars_dns.sql`拷貝到`sql/`文件夾下。
然后執行創建表格
```sql
$mysql -u root -p
Enter password:?
Welcome to the MySQL monitor.??Commands end with ; or \g.
Your MySQL connection id is 18
Server version: 5.7.27-0ubuntu0.18.04.1 (Ubuntu)
Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> \. lars_dns.sql
Query OK, 0 rows affected, 1 warning (0.01 sec)
Query OK, 1 row affected (0.00 sec)
Database changed
Query OK, 0 rows affected, 1 warning (0.00 sec)
Query OK, 0 rows affected (0.08 sec)
Query OK, 0 rows affected, 1 warning (0.01 sec)
Query OK, 0 rows affected (0.06 sec)
Query OK, 1 row affected (0.01 sec)
Query OK, 0 rows affected, 1 warning (0.01 sec)
Query OK, 0 rows affected (0.13 sec)
```
6.Lars-DnsV0.1-Route類的單例實現
## 3) dns serivce模塊目錄構建
### 3.1 集成lars_reactor模塊
?????????首先我們給dns模塊創建一個項目文件夾,與`lars_reactor`并列,在`Lars/`下創建
```bash
$mkdir Lars/lars_dns
```
在`lars_dns`中,我們可以先創建基本的項目必須文件夾和文件,目錄結構如下
```bash
lars_dns/
????├── bin/
????├── conf/
????│?? └── lars_dns.conf
????├── include/
????├── Makefile
????└── src/
????????└── dns_service.cpp
```
> conf/lars_dns.conf
```ini
[reactor]
maxConn = 1024
threadNum = 5
ip = 127.0.0.1
port = 7778
```
> src/dns_service.cpp
```c
#include "lars_reactor.h"
int main(int argc, char **argv)
{
????event_loop loop;
????//加載配置文件
????config_file::setPath("conf/lars_dns.conf");
????std::string ip = config_file::instance()->GetString("reactor", "ip", "0.0.0.0");
????short port = config_file::instance()->GetNumber("reactor", "port", 7778);
????//創建tcp服務器
????tcp_server *server = new tcp_server(&loop, ip.c_str(), port);
????//注冊路由業務
????
????//開始事件監聽????
????printf("lars dns service ....\n");
????loop.event_process();
????return 0;
}
```
> Makefile
```makefile
TARGET= bin/lars_dns
CXX=g++
CFLAGS=-g -O2 -Wall -Wno-deprecated
BASE=../base
BASE_H=$(BASE)/include
LARS_REACTOR=../lars_reactor
LARS_REACTOR_H =$(LARS_REACTOR)/include
LARS_REACTOR_LIB=$(LARS_REACTOR)/lib??-llreactor
OTHER_LIB = -lpthread
SRC= ./src
INC= -I./include -I$(BASE_H) -I$(LARS_REACTOR_H)
LIB= -L$(LARS_REACTOR_LIB) $(OTHER_LIB)
OBJS = $(addsuffix .o, $(basename $(wildcard $(SRC)/*.cpp)))
$(TARGET): $(OBJS)
????????mkdir -p bin
????????$(CXX) $(CFLAGS) -o $(TARGET) $(OBJS) $(INC) $(LIB)
%.o: %.cpp
????????$(CXX) $(CFLAGS) -c -o $@ $< $(INC)?
.PHONY: clean
clean:
????????-rm -f src/*.o $(TARGET)
```
這里主要注意一下`Makefile`的編寫,我們需要連接libreactor庫還有libpthread庫等,還有一些頭文件的文件目錄不要寫錯。
接下來進行make,我們會在`bin/`得到dns的可執行程序,并且可以成功運行.
7.Lars-DnsV0.1-Route類的鏈接數據庫方法實現
### 3.2 集成mysql模塊
?????????我們需要使用libmysqlclient開發者第三方庫,當然可以從mysql官方網站下載與你當前mysql版本匹配的so或者a文件,這里我們提供一個已經編譯好的libmysqlclient.a和對應的頭文件,代碼參見:
<https://github.com/aceld/Lars/tree/master/base/mysql-connector-c>
?????????我們把`mysql-connector-c`文件夾放在了`Lars/base/`下,作為公共包使用。
?????????接下來我們要重新修改一下`Makefile`
> Lars/lars_dns/Makefile
```makefile
TARGET= bin/lars_dns
CXX=g++
CFLAGS=-g -O2 -Wall -Wno-deprecated
BASE=../base
BASE_H=$(BASE)/include
LARS_REACTOR=../lars_reactor
LARS_REACTOR_H =$(LARS_REACTOR)/include
LARS_REACTOR_LIB=$(LARS_REACTOR)/lib??-llreactor
MYSQL=$(BASE)/mysql-connector-c
MYSQL_H=$(MYSQL)/include
MYSQL_LIB=$(MYSQL)/lib/libmysqlclient.a
OTHER_LIB = -lpthread -ldl
SRC= ./src
INC= -I./include -I$(BASE_H) -I$(LARS_REACTOR_H) -I$(MYSQL_H)
LIB= $(MYSQL_LIB) -L$(LARS_REACTOR_LIB) $(OTHER_LIB)?
OBJS = $(addsuffix .o, $(basename $(wildcard $(SRC)/*.cpp)))
$(TARGET): $(OBJS)
????????mkdir -p bin
????????$(CXX) $(CFLAGS) -o $(TARGET) $(OBJS) $(INC) $(LIB)
%.o: %.cpp
????????$(CXX) $(CFLAGS) -c -o $@ $< $(INC)?
.PHONY: clean
clean:
????????-rm -f src/*.o $(TARGET)
```
?????????加上mysqlclient庫的關聯。注意,libmysqlclient.a依賴libdl庫, 所以我們在 OTHER_LIB變量中加上`-ldl`, 然后我們嘗試使用mysql庫的接口。
> dns_service.cpp
```c
#include "lars_reactor.h"
#include "mysql.h"
int main(int argc, char **argv)
{
????event_loop loop;
????//加載配置文件
????config_file::setPath("conf/lars_dns.conf");
????std::string ip = config_file::instance()->GetString("reactor", "ip", "0.0.0.0");
????short port = config_file::instance()->GetNumber("reactor", "port", 7778);
????//創建tcp服務器
????tcp_server *server = new tcp_server(&loop, ip.c_str(), port);
????//注冊路由業務
????
????//測試mysql接口
????MYSQL dbconn;
????mysql_init(&dbconn);
????//開始事件監聽????
????printf("lars dns service ....\n");
????loop.event_process();
????return 0;
}
```
8.Lars-DnsV0.1-定義存放RouteData關系的map數據結構
首先我們將Route類設計成單例,我們創建頭文件和cpp文件.
> lars_dns/include/dns_route.h
```c
#pragma once
class Route
{
public:
????//創建單例的方法
????static void init() {
????????_instance = new Route();?
????}
????static Route *instance() {
????????//保證init方法在這個進程執行中,只執行一次
????????pthread_once(&_once, init);
????????return _instance;
????}
????
private:
????//構造函數私有化
????Route();
????Route(const Route&);
????const Route& operator=(const Route&);
????//單例
????static Route* _instance;
????//單例鎖
????static pthread_once_t _once;
????/* ---- 屬性 ---- */
????//...
};
```
> lars_dns/src/dns_route.cpp
```c
#include "dns_route.h"
//單例對象
Route * Route::_instance = NULL;
//用于保證創建單例的init方法只執行一次的鎖
pthread_once_t Route::_once = PTHREAD_ONCE_INIT;
```
9.課前回顧
### 4.2 Route中的map數據類型定義
?????????**這里的Route并非reactor中的router,這里的Route我們是把`modid/cmdid`與需要管理的遠程服務器的`serverip/serverport`的一條對應關系叫一個`Route`。**
?????????我們用map來存儲這些關系,其中key是modid/cmdid的一個二進制偏移量處理,而map的value是一個set集合,因為一個modid/cmdid可能對應多個host主機的ip和端口。具體的表現數據結構形式如下。
?????????
?????????接下來,我們來定義一個相關代碼:
> lars_dns/include/dns_route.h
```c
#pragma once
#include <pthread.h>
#include <ext/hash_map>
#include <ext/hash_set>
#include "mysql.h"
using __gnu_cxx::hash_map;
using __gnu_cxx::hash_set;
//定義用來保存modID/cmdID與host的IP/host的port的對應的關系 數據類型??
typedef hash_map< uint64_t, hash_set<uint64_t> > route_map;
typedef hash_map< uint64_t, hash_set<uint64_t> >::iterator route_map_it;
//定義用來保存host的IP/host的port的的集合 數據類型
typedef hash_set<uint64_t> host_set;
typedef hash_set<uint64_t>::iterator host_set_it;
class Route
{
public:
????//創建單例的方法
????static void init() {
????????_instance = new Route();?
????}
????static Route *instance() {
????????//保證init方法在這個進程執行中,只執行一次
????????pthread_once(&_once, init);
????????return _instance;
????}
????
private:
????//構造函數私有化
????Route();
????Route(const Route&);
????const Route& operator=(const Route&);
????//單例
????static Route* _instance;
????//單例鎖
????static pthread_once_t _once;
????/* ---- 屬性 ---- */
????//數據庫
????MYSQL _db_conn;??//mysql鏈接??
????char _sql[1000]; //sql語句
????//modid/cmdid---ip/port 對應的route關系map
????route_map *_data_pointer; //指向RouterDataMap_A 當前的關系map
????route_map *_temp_pointer; //指向RouterDataMap_B 臨時的關系map
????pthread_rwlock_t _map_lock;
};
```
10.Lars-DnsV0.1-將Route數據加載map中
### 4.3 Route初始化
> lars_dns/src/dns_route.cpp
```c
#include <string>
#include <stdlib.h>
#include <unistd.h>
#include "lars_reactor.h"
#include "dns_route.h"
#include "string.h"
using namespace std;
//單例對象
Route * Route::_instance = NULL;
//用于保證創建單例的init方法只執行一次的鎖
pthread_once_t Route::_once = PTHREAD_ONCE_INIT;
Route::Route()
{
????//1 初始化鎖
????pthread_rwlock_init(&_map_lock, NULL);
????//2 初始化map
????_data_pointer = new route_map();//RouterDataMap_A
????_temp_pointer = new route_map();//RouterDataMap_B
????//3 鏈接數據庫
????this->connect_db();
????//4 查詢數據庫,創建_data_pointer 與 _temp_pointer 兩個map
????this->build_maps();
}
void Route::connect_db()?
{
????// --- mysql數據庫配置---
????string db_host = config_file::instance()->GetString("mysql", "db_host", "127.0.0.1");
????short db_port = config_file::instance()->GetNumber("mysql", "db_port", 3306);
????string db_user = config_file::instance()->GetString("mysql", "db_user", "root");
????string db_passwd = config_file::instance()->GetString("mysql", "db_passwd", "aceld");
????string db_name = config_file::instance()->GetString("mysql", "db_name", "lars_dns");
????mysql_init(&_db_conn);
????//超時斷開
????mysql_options(&_db_conn, MYSQL_OPT_CONNECT_TIMEOUT, "30");
????//設置mysql鏈接斷開后自動重連
????my_bool reconnect = 1;?
????mysql_options(&_db_conn, MYSQL_OPT_RECONNECT, &reconnect);
????if (!mysql_real_connect(&_db_conn, db_host.c_str(), db_user.c_str(), db_passwd.c_str(), db_name.c_str(), db_port, NULL, 0)) {
????????fprintf(stderr, "Failed to connect mysql\n");
????????exit(1);
????}
}
void Route::build_maps()
{
????int ret = 0;
????snprintf(_sql, 1000, "SELECT * FROM RouteData;");
????ret = mysql_real_query(&_db_conn, _sql, strlen(_sql));
????if ( ret != 0) {
????????fprintf(stderr, "failed to find any data, error %s\n", mysql_error(&_db_conn));
????????exit(1);
????}
????//得到結果集
????MYSQL_RES *result = mysql_store_result(&_db_conn);
????
????//得到行數
????long line_num = mysql_num_rows(result);
????MYSQL_ROW row;
????for (long i = 0; i < line_num; i++) {
????????row = mysql_fetch_row(result);
????????int modID = atoi(row[1]);
????????int cmdID = atoi(row[2]);
????????unsigned ip = atoi(row[3]);
????????int port = atoi(row[4]);
????????//組裝map的key,有modID/cmdID組合
????????uint64_t key = ((uint64_t)modID << 32) + cmdID;
????????uint64_t value = ((uint64_t)ip << 32) + port;
????????printf("modID = %d, cmdID = %d, ip = %lu, port = %d\n", modID, cmdID, ip, port);
????????//插入到RouterDataMap_A中
????????(*_data_pointer)[key].insert(value);
????}
????mysql_free_result(result);
}
```
11.Lars-Dns的proto協議定義
### 4.4 測試Route的構造及map加載-V0.1
完成lars dns-service V0.1版本測試
我們在`Lars/base/sql`加入幾個簡單插入數據的sql語句,方便數據庫里有一些測試數據,我們之后應該會提供一個web管理端來操作數據庫。
> Lars/base/sql/dns_route_insert.sql
```sql
USE lars_dns;
INSERT INTO RouteData(modid, cmdid, serverip, serverport) VALUES(1, 1, 3232235953, 7777);
INSERT INTO RouteData(modid, cmdid, serverip, serverport) VALUES(1, 2, 3232235954, 7776);
INSERT INTO RouteData(modid, cmdid, serverip, serverport) VALUES(1, 2, 3232235955, 7778);
INSERT INTO RouteData(modid, cmdid, serverip, serverport) VALUES(1, 2, 3232235956, 7779);
UPDATE RouteVersion SET version = UNIX_TIMESTAMP(NOW()) WHERE id = 1;
```
> Lars/base/sql/dns_route_drop.sql
```sql
USE lars_dns;
DELETE FROM RouteData;
UPDATE RouteVersion SET version = UNIX_TIMESTAMP(NOW()) WHERE id = 1;
```
?????????先將測試數據導入數據庫。然后回到`lars_dns`下編譯。執行
```bash
$./bin/lars_dns?
msg_router init...
create 0 thread
create 1 thread
create 2 thread
create 3 thread
create 4 thread
modID = 1, cmdID = 1, ip = 3232235953, port = 7777
modID = 1, cmdID = 2, ip = 3232235954, port = 7776
modID = 1, cmdID = 2, ip = 3232235955, port = 7778
modID = 1, cmdID = 2, ip = 3232235956, port = 7779
lars dns service ....
```
12.Lars-DnsV0.1-實現獲取route信息功能
## 5) 獲取Route信息
### 5.1 proto協議定義
?????????獲取Route信息,根據之前的架構圖,可以看出來應該是Agent來獲取,這里我們并沒有實現Agent,所以用一個其他簡單的客戶端來完成單元測試。但是無論用什么,總需要一個傳遞數據,需要一定的消息協議,lars-dns也需要設置不同纖細的分發消息路由機制,所以我們需要先定義一些proto協議。
?????????在`Lars/base`下創建`proto/`文件夾.
> Lars/base/proto/lars.proto
```protobuf
syntax = "proto3";
package lars;
/* Lars系統的消息ID */
enum MessageId {
????ID_UNKNOW????????????????= 0;??//proto3 enum第一個屬性必須是0,用來占位
????ID_GetRouteRequest???????= 1;??//向DNS請求Route對應的關系的消息ID
????ID_GetRouteResponse??????= 2;??//DNS回復的Route信息的消息ID
}
//一個管理的主機的信息
message HostInfo {
????int32 ip = 1;
????int32 port = 2;
}
//請求lars-dns route信息的消息內容
message GetRouteRequest {
????int32 modid = 1;?
????int32 cmdid = 2;
}
//lars-dns 回復的route信息消息內容
message GetRouteResponse {
????int32 modid = 1;????
????int32 cmdid = 2;
????repeated HostInfo host = 3;
}
```
?????????然后我們將proto文件編譯成對應的C++文件, 我們還是提供一個腳本
> Lars/base/proto/build.sh
```bash
#!/bin/bash
# proto編譯
protoc --cpp_out=. ./*.proto
# 將全部的cc 文件 變成 cpp文件
oldsuffix="cc"
newsuffix="cpp"
dir=$(eval pwd)
for file in $(ls $dir | grep .${oldsuffix})
do
????name=$(ls ${file} | cut -d. -f1,2)
????mv $file ${name}.${newsuffix}
done
echo "build proto file successd!"
```
?????????因為protoc會自動生成cc后綴的文件,為了方便我們Makefile的編譯,所以將cc文件改成cpp的。
13.Lars-DnsV0.1-獲取route hosts信息測試
### 5.2 proto編譯環境集成
?????????現在我們將`lars-dns`的Makefile加入針對proto文件的編譯
> Lars/lars_dns/Makefile
```makefile
TARGET= bin/lars_dns
CXX=g++
CFLAGS=-g -O2 -Wall -Wno-deprecated
BASE=../base
BASE_H=$(BASE)/include
PROTO = $(BASE)/proto
PROTO_H = $(BASE)/proto
LARS_REACTOR=../lars_reactor
LARS_REACTOR_H =$(LARS_REACTOR)/include
LARS_REACTOR_LIB=$(LARS_REACTOR)/lib??-llreactor
MYSQL=$(BASE)/mysql-connector-c
MYSQL_H=$(MYSQL)/include
MYSQL_LIB=$(MYSQL)/lib/libmysqlclient.a
OTHER_LIB = -lpthread -ldl -lprotobuf
SRC= ./src
INC= -I./include -I$(BASE_H) -I$(LARS_REACTOR_H) -I$(MYSQL_H) -I$(PROTO_H)
LIB= $(MYSQL_LIB) -L$(LARS_REACTOR_LIB) $(OTHER_LIB)?
OBJS = $(addsuffix .o, $(basename $(wildcard $(SRC)/*.cpp)))
OBJS += $(PROTO)/lars.pb.o
$(TARGET): $(OBJS)
????????mkdir -p bin
????????$(CXX) $(CFLAGS) -o $(TARGET) $(OBJS) $(INC) $(LIB)
%.o: %.cpp
????????$(CXX) $(CFLAGS) -c -o $@ $< $(INC)?
.PHONY: clean
clean:
????????-rm -f src/*.o $(TARGET)
```
?????????添加了兩個部分一個`OBJS`增添一個`lars.pb.o`的依賴,然后再`OTHER_LIB`增加`-lprotobuf`動態庫的連接。
14.Lars-DnsV0.1-總結
### 5.3 實現Route獲取
?????????接下來我們來實現針對`ID_GetRouteRequest`消息指令的業務處理.
> lars_dns/src/dns_service.cpp
```c
#include "lars_reactor.h"
#include "dns_route.h"
#include "lars.pb.h"
void get_route(const char *data, uint32_t len, int msgid, net_connection *net_conn, void *user_data)
{
????//1. 解析proto文件
????lars::GetRouteRequest req;
????req.ParseFromArray(data, len);
?????
????//2. 得到modid 和 cmdid
????int modid, cmdid;
????modid = req.modid();
????cmdid = req.cmdid();
????
????//3. 根據modid/cmdid 獲取 host信息
????host_set hosts = Route::instance()->get_hosts(modid, cmdid);
????//4. 將數據打包成protobuf
????lars::GetRouteResponse rsp;
????rsp.set_modid(modid);
????rsp.set_cmdid(cmdid);
????
????for (host_set_it it = hosts.begin(); it != hosts.end(); it ++) {
????????uint64_t ip_port = *it;
????????lars::HostInfo host;
????????host.set_ip((uint32_t)(ip_port >> 32));
????????host.set_port((int)(ip_port));
????????rsp.add_host()->CopyFrom(host);
????}
????
????//5. 發送給客戶端
????std::string responseString;
????rsp.SerializeToString(&responseString);
????net_conn->send_message(responseString.c_str(), responseString.size(), lars::ID_GetRouteResponse)????;
}
int main(int argc, char **argv)
{
????event_loop loop;
????//加載配置文件
????config_file::setPath("conf/lars_dns.conf");
????std::string ip = config_file::instance()->GetString("reactor", "ip", "0.0.0.0");
????short port = config_file::instance()->GetNumber("reactor", "port", 7778);
????//創建tcp服務器
????tcp_server *server = new tcp_server(&loop, ip.c_str(), port);
????//注冊路由業務
????server->add_msg_router(lars::ID_GetRouteRequest, get_route);
????//開始事件監聽????
????printf("lars dns service ....\n");
????loop.event_process();
????return 0;
}
```
?????????需要給`Route`類,實現一個get_host()方法,來針對modid/cmdid取出對應的value
> lars_dns/src/dns_route.cpp
```c
//獲取modid/cmdid對應的host信息
host_set Route::get_hosts(int modid, int cmdid)
{
????host_set hosts;?????
????//組裝key
????uint64_t key = ((uint64_t)modid << 32) + cmdid;
????pthread_rwlock_rdlock(&_map_lock);
????route_map_it it = _data_pointer->find(key);
????if (it != _data_pointer->end()) {
????????//找到對應的ip + port對
????????hosts = it->second;
????}
????pthread_rwlock_unlock(&_map_lock);
????return hosts;
}
```