adding server and local reader programs

websocket_storage/readBinFile.c

@@ -0,0 +1,24 @@
+
+#include <stdio.h>
+#include <stdlib.h>
+
+struct tweetData
+{
+  int id;
+  char data[5000];
+};
+
+int main()
+{
+  struct tweetData tweet;
+  FILE *fptr;
+  fptr = fopen("tweet.bin","rb");
+  if(fptr == NULL){
+    printf("Error in opening tweet file\n");
+    return 1;
+  }
+  while(fread(&tweet,sizeof(tweet),1,fptr))
+    printf("%d\t:%s\n", tweet.id,tweet.data);
+  fclose(fptr);
+  return 0;
+}

websocket_storage/websocket_chat.c

@@ -0,0 +1,185 @@
+/*
+ * Copyright (c) 2014 Cesanta Software Limited
+ * All rights reserved
+ */
+
+#include "mongoose.h"
+
+static sig_atomic_t s_signal_received = 0;
+static const char *s_http_port = "3232";
+static struct mg_serve_http_opts s_http_server_opts;
+static char serverpass[100];
+static struct mg_connection *selfClient = NULL;
+
+struct tweetData
+{
+  int id;
+  char data[5000];
+};
+
+static void signal_handler(int sig_num) {
+  signal(sig_num, signal_handler);  // Reinstantiate signal handler
+  s_signal_received = sig_num;
+}
+
+static int is_websocket(const struct mg_connection *nc) {
+  return nc->flags & MG_F_IS_WEBSOCKET;
+}
+
+static void broadcast(struct mg_connection *nc, const struct mg_str msg) {
+  struct mg_connection *c;
+  char buf[5000];
+
+  snprintf(buf, sizeof(buf), "%.*s", (int) msg.len, msg.p);
+  printf("%s\n", buf); /* Local echo. */
+  for (c = mg_next(nc->mgr, NULL); c != NULL; c = mg_next(nc->mgr, c)) {
+    if (c == nc) continue; /* Don't send to the sender. */
+    mg_send_websocket_frame(c, WEBSOCKET_OP_TEXT, buf, strlen(buf));
+  }
+}
+
+static void unicast(struct mg_connection *nc,const struct mg_str msg) {
+  char buf[5000];
+
+  snprintf(buf, sizeof(buf), "%.*s", (int) msg.len, msg.p);
+  printf("%s\n", buf); /* Local echo. */
+  if(nc != NULL)
+    mg_send_websocket_frame(nc, WEBSOCKET_OP_TEXT, buf, strlen(buf));
+  else
+    printf("No selfClient is connected!\n");
+  
+}
+
+static void storeTweet(struct mg_connection *nc,const struct mg_str msg){
+  struct tweetData tweet;
+  snprintf(tweet.data, sizeof(tweet.data), "%.*s", (int) msg.len, msg.p);
+  FILE *fptr;
+  fptr = fopen("tweet.bin","ab");
+  if(fptr == NULL){
+    printf("Error in opening tweet file");
+    return;
+  }
+  fseek(fptr,0,SEEK_END);
+  long int filesize = ftell(fptr);
+  tweet.id = filesize/sizeof(tweet) + 1;
+  fwrite(&tweet,sizeof(tweet),1,fptr);
+  fclose(fptr);
+  //broadcast
+  struct mg_connection *c;
+  char buf[5050];
+  snprintf(buf, sizeof(buf), "{\"id\":%d,\"data\":%s}", tweet.id, tweet.data);
+  printf("%s\n", buf); /* Local echo. */
+  for (c = mg_next(nc->mgr, NULL); c != NULL; c = mg_next(nc->mgr, c)) {
+    if (c == nc) continue; /* Don't send to the sender. */
+    mg_send_websocket_frame(c, WEBSOCKET_OP_TEXT, buf, strlen(buf));
+  }
+}
+
+static void sendTweets(struct mg_connection *nc, const struct mg_str d){
+  int i, n = 0;
+  for(i=1; i < d.len; i++)
+    n = (n*10) + (d.p[i] - '0');
+  //printf("%d\n",n);
+  struct tweetData tweet;
+  char buf[5050];
+  FILE *fptr;
+  fptr = fopen("tweet.bin","rb");
+  if(fptr == NULL){
+    printf("Error in opening tweet file\n");
+    return;
+  }
+  fseek(fptr, n*sizeof(tweet), SEEK_SET);
+  while(fread(&tweet,sizeof(tweet),1,fptr)){
+    snprintf(buf, sizeof(buf), "{\"id\":%d,\"data\":%s}", tweet.id, tweet.data);
+    printf("%s\n", buf);
+    mg_send_websocket_frame(nc, WEBSOCKET_OP_TEXT, buf, strlen(buf));
+  }
+  fclose(fptr);
+}
+
+static void ev_handler(struct mg_connection *nc, int ev, void *ev_data) {
+  switch (ev) {
+    case MG_EV_WEBSOCKET_HANDSHAKE_DONE: {
+      /* New websocket connection. Tell everybody. */
+      //broadcast(nc, mg_mk_str("++ joined"));
+      break;
+    }
+    case MG_EV_WEBSOCKET_FRAME: {
+      struct websocket_message *wm = (struct websocket_message *) ev_data;
+      /* New websocket message. Tell everybody. */
+      struct mg_str d = {(char *) wm->data, wm->size};
+      if (d.p[0] == '$'){
+        char pass[100];
+        snprintf(pass, sizeof(pass), "%.*s",(int)d.len-1, &d.p[1]);
+        if(!strcmp(pass,serverpass)){
+          if(selfClient!=NULL)
+            unicast(selfClient,mg_mk_str("$Another login is encountered! Please close/refresh this window"));
+          selfClient = nc;
+          unicast(selfClient,mg_mk_str("$Access Granted!"));
+          broadcast(nc, mg_mk_str("#+"));
+        }else
+          unicast(nc,mg_mk_str("$Access Denied!"));
+      }
+      else if(d.p[0] == '#'){
+        if(selfClient == NULL)
+          unicast(nc,mg_mk_str("#-"));
+        else
+          unicast(nc,mg_mk_str("#+"));
+      }
+      else if(d.p[0] == '>'){
+        sendTweets(nc, d);
+      }
+      else if(selfClient == nc){
+        storeTweet(nc, d);
+      }
+      break;
+    }
+    case MG_EV_HTTP_REQUEST: {
+      mg_serve_http(nc, (struct http_message *) ev_data, s_http_server_opts);
+      break;
+    }
+    case MG_EV_CLOSE: {
+      /* Disconnect. Tell everybody. */
+      if (is_websocket(nc)) {
+        if(nc == selfClient){
+          selfClient = NULL;
+          broadcast(nc, mg_mk_str("#-"));
+        }  
+      }
+      break;
+    }
+  }
+}
+
+int main(int argc, char** argv) {
+
+  if(argc<=1){
+    printf("Enter server password : ");
+    scanf("%s",serverpass);
+  }
+  else
+    strcpy(serverpass,argv[1]);
+
+  struct mg_mgr mgr;
+  struct mg_connection *nc;
+
+  signal(SIGTERM, signal_handler);
+  signal(SIGINT, signal_handler);
+  setvbuf(stdout, NULL, _IOLBF, 0);
+  setvbuf(stderr, NULL, _IOLBF, 0);
+
+  mg_mgr_init(&mgr, NULL);
+
+  nc = mg_bind(&mgr, s_http_port, ev_handler);
+  mg_set_protocol_http_websocket(nc);
+  s_http_server_opts.document_root = ".";  // Serve current directory
+  s_http_server_opts.enable_directory_listing = "no";
+
+  printf("Started on port %s\n", s_http_port);
+  while (s_signal_received == 0) {
+    mg_mgr_poll(&mgr, 200);
+  }
+  mg_mgr_free(&mgr);
+
+  return 0;
+}