Bind+Berkerley DB实现Transactional mode 动态更新(3)

 

四．程序设计与实现（以下是以c来实现的）

1．  需求:

据以上来看，由于数据库只有API,不支持sql,也没server概念，数据库的维护管理全由程序来完成，其基本模块为：

A：添加

B：查找

C：删除

D：同步                                                    

2．  细节（子模块）

 从上面我们知道要实现上面的功能，其子模块有：

A：复制ID的获得

   通过取得dns_xfr中的zone+a space+host遍历dns_data的值，复制ID初值为1(为SOA的),其后相同的zone，复制ID++;

B：reverse zone

  也就是把zone反向存储.

C：分离字符串判断是否为SOA记录，如果是则repid=1,否则repid++;

D：把整数转化为字符串函数

E：字符串分离与连接函数

F：命令行getop获取参数函数

H：btree和hash表要实现一Key多值，必须支持key值的复制，而且要提高查找的速度的话，还要支持数据的排序，默认为字典顺序，实现更好的算法则以自定义的callback函数来实现。

3．  程序实现

#include

#include

#define dlz_data "dns_data"

#define dlz_zone "dns_zone"

#define dlz_xfr "dns_xfr"

#define dlz_client "dns_client"

……………………………………………….

void Usage(void)

char *soa(char *str);

int bdbhpt_open(DBTYPE db_type, DB **db_out, const char *db_name, int flags);

int bdbhpt_create(void);

void put_data(char *db_name, char *input_key, char *input_data);

void bdbhpt_close(void);

void bdbhpt_find(void );

void bdbhpt_dele();

void bdbhpt_add(void);

static char * bdbhpt_strrev (char *str);

int get_last_repid(void);

int IntToStr(int num, char *buffer);

…………………………………………………………

int main(int argc, char *argv[])

{

    char ch;

    int ret; 

    opterr = 0;

    while ((ch = getopt(argc, argv, "c:f:h:i:j:m:z:adsn")) != -1)

    {

        switch (ch)

        {

                case 'a':             

                              operation = add;

                              break;

                case 'd':

           operation = dele;    

            break;

       case 's':

                              operation = list;

                              break;

                case 'n':

                              key_val =1;

                              operation = add;

                              break;

       case 'z':

    zone = optarg;

           break;

       case 'h':

           host = optarg;

           break;

       case 'c':

           c_zone = optarg;

           break;

       case 'i':

           c_ip = optarg;

           break;

       case 'j':

           a_data = optarg;

           break;

       case 'm':

           db_envdir = optarg;

           break;

       case 'f':

           db_file = optarg;

           break;   

        case '?':

        default:

            printf("please use -H\n");

            Usage();

        }

      }

  if (argc < 2)

       {

        fprintf(stderr, "Both a Berkeley DB environment and file must be specified\n");          

  }

 

switch(operation)

{

        case list:

          bdbhpt_find();

               break;

        case dele:

               bdbhpt_dele();

               break;

        case add:

               bdbhpt_add();

               break;

        default:

               fprintf(stderr, "\nNo operation was selected. "\

                      "Select an operation (s d a f)\n");

               break;

}

}