c版观察者模式

2014-08-23 星期六 20:55:28

见代码

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#include <stdio.h> #include <string.h> #include <stdlib.h> #include <unistd.h> #include <sys/ioctl.h> #include <sys/time.h>   typedef void (*pUpadte)(int);   // 订阅者回调 typedef struct _observer_t {     int id;     pUpadte update; }observer_t;   // 订阅者链表,可以直接用linux list //简单点的话,就用array[id],其实负载多了也不好 typedef struct _observer_list_t  {      observer_t *observer;     struct _observer_list_t *next; }observer_list_t;   // 发布者 typedef struct _subject_t {     int data;     observer_list_t *observer_list; }subject_t;     //update void update0(int data) {     printf("line %03d, %s recv data(%d)\n", __LINE__, __func__, data); }   void update1(int data) {     printf("line %03d, %s recv data(%d)\n", __LINE__, __func__, data); }   void update2(int data) {     printf("line %03d, %s recv data(%d)\n", __LINE__, __func__, data); }   void update3(int data) {     printf("line %03d, %s recv data(%d)\n", __LINE__, __func__, data); }     int myid = 0; void initobserver(observer_t *observer, pUpadte update) {     observer->id = myid++;     observer->update = update; }   observer_list_t* make_observer_list(observer_t *observer) {     observer_list_t *observer_list = NULL;     if ( !(observer_list = (observer_list_t *)malloc(sizeof(observer_list_t))) )     {         printf("line %d, %s, err\n", __LINE__, __func__);         return NULL;     }           if ( !(observer_list->observer = (observer_t *)malloc(sizeof(observer_t))) )     {         printf("line %d, %s, err\n", __LINE__, __func__);         return NULL;     }       //printf("line %d, %s, observer->id(%d)\n", __LINE__, __func__, observer->id);       observer_list->observer = observer;     observer_list->next = NULL;               return observer_list; }     /*在头插入*/ void insert_at_front(observer_list_t **pphead, observer_list_t *pnode) {     pnode ->next=*pphead;     *pphead=pnode; }   /*在尾插入*/  void insert_at_rear0(observer_list_t **ppfirst, observer_list_t* pnode) {     observer_list_t *t_observer_list = *ppfirst;       if(*ppfirst == NULL)     {         *ppfirst = pnode;         printf("line %d, %s, node 0\n", __LINE__, __func__);     }     else     {         while(t_observer_list->next)         {             t_observer_list = t_observer_list->next;             printf("line %d, %s\n", __LINE__, __func__);         }                   t_observer_list->next = pnode;     } }    void insert_at_rear1(observer_list_t **ppfirst, observer_list_t* pnode) {     while(*ppfirst)     {         ppfirst = &(*ppfirst)->next;         printf("line %d, %s\n", __LINE__, __func__);     }     *ppfirst = pnode; }   #define insert_at_rear  insert_at_rear1   // 加入订阅者链表  int attach2subject0(subject_t *subject, observer_t *observer) {     // 将observer加入subject中的observer链表     //assert(subject);     observer_list_t *pnode = make_observer_list(observer);           insert_at_rear(&subject->observer_list, pnode);     return 0; }   //global,first_observer_list给外部调用 observer_list_t *first_observer_list = NULL;   // 加入订阅者链表  int attach2subject1(subject_t *subject, observer_t *observer) {     // 将observer加入subject中的observer链表     //assert(subject);           observer_list_t **ppobserver_list;     ppobserver_list = &first_observer_list;           observer_list_t *pnode = make_observer_list(observer);       while(*ppobserver_list)     {         ppobserver_list = &(*ppobserver_list)->next;     }     *ppobserver_list = pnode;       subject->observer_list = first_observer_list;           return 0; }   #define attach2subject  attach2subject0   void dump_observer_list0(observer_list_t *pnode) { #if 0     while(first_observer_list)     {         if(first_observer_list->observer)         {             printf("line %d, %s, id(%d)\n", __LINE__, __func__, first_observer_list->observer->id);         }         first_observer_list = first_observer_list->next;     }   #else   //not change first_observer_list     int cnt = 0;     pnode = first_observer_list;     while(pnode)     {         if( (pnode->observer) && (pnode->observer->update) )         {             ++cnt;             printf("line %d, %s, id(%d)\n", __LINE__, __func__, pnode->observer->id);         }         pnode = pnode->next;     }       printf("line %03d, %s, dump %d observer\n", __LINE__, __func__, cnt);         #endif }   void dump_observer_list1(observer_list_t *pnode) {       int cnt = 0;     while(pnode)     {         if( (pnode->observer) && (pnode->observer->update) )         {             ++cnt;             printf("line %d, %s, id(%d)\n", __LINE__, __func__, pnode->observer->id);         }         pnode = pnode->next;     }       printf("line %03d, %s, dump %d observer\n", __LINE__, __func__, cnt); }   #define dump_observer_list  dump_observer_list0   int free_observer_list(observer_list_t *pnode) {     if(pnode)     {         free(pnode);     } }   void    clr_observer_list(observer_list_t *pnode) {     free_observer_list(pnode);     pnode->observer = NULL;     pnode = NULL; }   // 从订阅者链表删除  int detach4subject0(subject_t *subject, observer_t *observer) {     //assert(subject);     if(!observer)     {         return -1;     }           printf("\nline %03d, %s, pre to del id(%d)\n", __LINE__, __func__, observer->id);       observer_list_t *pcurr, *pprev;     observer_list_t **ppfirst;       ppfirst = &subject->observer_list;     first_observer_list = *ppfirst; #if 1     for (pcurr=*ppfirst; pcurr; pprev=pcurr, pcurr=pcurr->next)     {         //first         if(observer == (*ppfirst)->observer)         {             if((*ppfirst)->next)             {                 printf("line %03d, %s, id(%d)\n", __LINE__, __func__, (*ppfirst)->observer->id);                  printf("line %03d, %s, id(%d)\n", __LINE__, __func__, subject->observer_list->observer->id);                                     ppfirst = &(*ppfirst)->next;                 //free_observer_list(pcurr);                   printf("line %03d, %s, id(%d)\n", __LINE__, __func__, (*ppfirst)->observer->id);                 //printf("line %03d, %s, id(%d)\n", __LINE__, __func__, subject->observer_list->next->observer->id);             }             else    //仅有1个node             {                 printf("line %d, %s, only one node\n", __LINE__, __func__);                 //free_observer_list(*ppfirst);                 //free_observer_list(pcurr);                   /*不置为null,subject->observer_list为野指针,                    在notify2observer()仍旧会调用update                 */                 //*ppfirst = NULL;             }               clr_observer_list(pcurr);             printf("line %d, %s, return\n", __LINE__, __func__);                               return 0;         }           else if (observer == pcurr->observer)         {             printf("line %d, %s, return\n", __LINE__, __func__);             pprev->next = pcurr->next;               clr_observer_list(pcurr);             return 0;         }     } #endif       printf("line %d, %s, has deled or not exist\n", __LINE__, __func__);     return -2; }   int detach4subject1(subject_t *subject, observer_t *observer) {     //assert(subject);           observer_list_t **ppobserver_list;     ppobserver_list = &first_observer_list;       while(subject)     {       }       return 0; } #define detach4subject  detach4subject0   // 修改被观察数据  int setdata(subject_t *subject, int value)  {      subject->data = value;  }   // 通知观察者  void notify2observer(subject_t *subject)  {     if(!subject->observer_list)     {         printf("\nline %03d, %s, observer_list NULL\n", __LINE__, __func__);         return;     }     printf("\nline %03d, %s\n", __LINE__, __func__);       int cnt = 0;     observer_list_t *p_observer_list_t = subject->observer_list;           while(p_observer_list_t)     {               if(      (p_observer_list_t->observer)            && (p_observer_list_t->observer->update)           )         {             ++cnt;             p_observer_list_t->observer->update(subject->data);                printf("line %03d, %s\n", __LINE__, __func__);         }         p_observer_list_t = p_observer_list_t->next;         printf("line %03d, %s\n", __LINE__, __func__);     }           if(cnt)     {         printf("line %03d, %s, has %d observer\n", __LINE__, __func__, cnt);     }     else     {         printf("line %03d, %s, has NOT observer\n", __LINE__, __func__);     } }   // 初始化主题对象  void initsubject(subject_t *subject) { #if 0     observer_t *p_observer;     observer_list_t *p_observer_list;       p_observer = (observer_t *)malloc(sizeof(observer_t));     p_observer_list = (observer_list_t *)malloc(sizeof(observer_list_t));     p_observer_list->observer = p_observer; #else     observer_t t_observer;     observer_list_t t_observer_list;     t_observer_list.observer = &t_observer;   #endif       //assert(subject);     memset(subject, 0, sizeof(subject_t));   #if 0     if(!subject)     {         subject = (subject_t *)malloc(sizeof(subject_t));     } #endif     //make_observer_list     //subject->observer_list = (observer_list_t *)malloc(sizeof(observer_list_t));     //subject->observer_list->observer = (observer_t *)malloc(sizeof(observer_t)); }   //subject_t   subject; int main(int argc, const char *agrc[])  {     observer_t observer0;     observer_t observer1;     observer_t observer2;     observer_t observer3;     subject_t   subject;       // 初始化订阅者     initobserver(&observer0, update0);     initobserver(&observer1, update1);     initobserver(&observer2, update2);     initobserver(&observer3, update3);       // 初始化发布者      initsubject(&subject);       // 订阅者关联发布者     attach2subject(&subject, &observer0);     attach2subject(&subject, &observer1);     attach2subject(&subject, &observer2);     attach2subject(&subject, &observer3);       printf("\nline %03d, %s, notify date\n", __LINE__, __func__);       // 修改状态，并通知观察者      setdata(&subject, 1);     notify2observer(&subject);       printf("\nline %03d, %s, refresh date\n", __LINE__, __func__);           setdata(&subject, 2);     notify2observer(&subject);       dump_observer_list(subject.observer_list);       detach4subject(&subject, &observer1);     dump_observer_list(subject.observer_list);       //setdata(&subject, 3);     //notify2observer(&subject);           //return 0;           detach4subject(&subject, &observer2);     detach4subject(&subject, &observer3);     detach4subject(&subject, &observer0);       setdata(&subject, 4);     notify2observer(&subject);           dump_observer_list(subject.observer_list);       return 0; }

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