civetweb/examples/websocket/WebSockCallbacks.c

#include <assert.h>
#include <stdlib.h>
#include <time.h>
#include "WebSockCallbacks.h"

#ifdef _WIN32
#include <Windows.h>
typedef HANDLE pthread_mutex_t;
static int pthread_mutex_init(pthread_mutex_t *mutex, void *unused) {
  unused = NULL;
  *mutex = CreateMutex(NULL, FALSE, NULL);
  return *mutex == NULL ? -1 : 0;
}

static int pthread_mutex_destroy(pthread_mutex_t *mutex) {
  return CloseHandle(*mutex) == 0 ? -1 : 0;
}

static int pthread_mutex_lock(pthread_mutex_t *mutex) {
  return WaitForSingleObject(*mutex, INFINITE) == WAIT_OBJECT_0? 0 : -1;
}

static int pthread_mutex_unlock(pthread_mutex_t *mutex) {
  return ReleaseMutex(*mutex) == 0 ? -1 : 0;
}
#define mg_sleep(x) Sleep(x)
#else
#include <unistd.h>
#include <pthread.h>
#define mg_sleep(x) usleep((x) * 1000)
#endif


typedef struct tWebSockInfo {
  int webSockState;
  unsigned long initId;
  struct mg_connection *conn;
} tWebSockInfo;

static pthread_mutex_t sMutex;

#define MAX_NUM_OF_WEBSOCKS (256)
static tWebSockInfo *socketList[MAX_NUM_OF_WEBSOCKS];


void websocket_ready_handler(struct mg_connection *conn) {

  int i;
  struct mg_request_info * rq = mg_get_request_info(conn);
  tWebSockInfo * wsock = malloc(sizeof(tWebSockInfo));
  assert(wsock);
  wsock->webSockState = 0;
  rq->conn_data = wsock;

  pthread_mutex_lock(&sMutex);
  for (i=0;i<MAX_NUM_OF_WEBSOCKS;i++) {
    if (0==socketList[i]) {
      socketList[i] = wsock;
      wsock->conn = conn;
      wsock->webSockState = 1;
      break;
    }
  }
  pthread_mutex_unlock(&sMutex);
}


static void websocket_done(tWebSockInfo * wsock) { 
  int i;
  if (wsock) {
    wsock->webSockState = 99;
    for (i=0;i<MAX_NUM_OF_WEBSOCKS;i++) {
      if (wsock==socketList[i]) {
        socketList[i] = 0;
        break;
      }
    }
    free(wsock);
  }
}


int websocket_data_handler(struct mg_connection *conn, int flags, char *data, size_t data_len) {
  struct mg_request_info * rq = mg_get_request_info(conn);
  tWebSockInfo * wsock = (tWebSockInfo*)rq->conn_data;
  char msg[128];
  int i;

  pthread_mutex_lock(&sMutex);
  if (flags==136) {
    // close websock
    websocket_done(wsock);
    rq->conn_data = 0;
    pthread_mutex_unlock(&sMutex);
    return 1;
  }
  if ((data_len>=5) && (data_len<100) && (flags==129) || (flags==130)) {

    // init command
    if ((wsock->webSockState==1) && (!memcmp(data,"init ",5))) {
      char * chk;
      unsigned long gid;
      memcpy(msg,data+5,data_len-5);
      msg[data_len-5]=0;
      gid = strtoul(msg,&chk,10);
      wsock->initId = gid;
      if (gid>0 && chk!=NULL && *chk==0) {
        wsock->webSockState = 2;
      }
      pthread_mutex_unlock(&sMutex);
      return 1;
    }
        
    // chat message
    if ((wsock->webSockState==2) && (!memcmp(data,"msg ",4))) {     
      for (i=0;i<MAX_NUM_OF_WEBSOCKS;i++) {
        if (socketList[i] && (socketList[i]->webSockState==2)) {
          mg_websocket_write(socketList[i]->conn, WEBSOCKET_OPCODE_TEXT, data, data_len);
        }
      }
      pthread_mutex_unlock(&sMutex);
      return 1;
    }
  }

  // keep alive
  if ((data_len==4) && !memcmp(data,"ping",4)) {
    pthread_mutex_unlock(&sMutex);
    return 1;
  }

  pthread_mutex_unlock(&sMutex);
  return 0;
}


void connection_close_handler(struct mg_connection *conn) {   
  struct mg_request_info * rq = mg_get_request_info(conn);
  tWebSockInfo * wsock = (tWebSockInfo*)rq->conn_data;

  pthread_mutex_lock(&sMutex);
  websocket_done(wsock);
  rq->conn_data = 0;
  pthread_mutex_unlock(&sMutex);
}


static void * eventMain(void * _ignored) {
  int i;
  char msg[256];
  for (;;) {
    time_t t = time(0);
    struct tm * timestr = localtime(&t);
    sprintf(msg,"title %s",asctime(timestr));

    pthread_mutex_lock(&sMutex);
    for (i=0;i<MAX_NUM_OF_WEBSOCKS;i++) {
      if (socketList[i] && (socketList[i]->webSockState==2)) {
        mg_websocket_write(socketList[i]->conn, WEBSOCKET_OPCODE_TEXT, msg, strlen(msg));
      }
    }
    pthread_mutex_unlock(&sMutex);

    mg_sleep(1000);
  }

  return _ignored;
}


void websock_init_lib(void) {
  int ret;
  ret = pthread_mutex_init(&sMutex, 0);
  assert(ret==0);

  memset(socketList,0,sizeof(socketList));

  mg_start_thread(eventMain, 0);
}