add weather processing to 10micron stellarium

Daemons/10micron_stellarium/socket.c

@@ -0,0 +1,208 @@
+/*
+ * This file is part of the StelD project.
+ * Copyright 2021 Edward V. Emelianov <edward.emelianoff@gmail.com>.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <arpa/inet.h>
+#include <netdb.h>
+#include <pthread.h>
+#include <signal.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include "cmdlnopts.h"
+#include "socket.h"
+#include "usefull_macro.h"
+
+// max time to wait answer from server
+#define WAITANSTIME         (1.0)
+
+static int sockfd = -1; // server file descriptor
+static pthread_t sock_thread;
+static char buf[BUFSIZ]; // buffer for messages
+static int Nread; // amount of bytes in buf
+static pthread_mutex_t mutex = PTHREAD_MUTEX_INITIALIZER;
+
+static void *getmessages(_U_ void *par);
+
+/**
+ * @brief weatherserver_connect - connect to a weather server
+ * @return FALSE if failed
+ */
+int weatherserver_connect(){
+    if(sockfd > 0) return TRUE;
+    DBG("connect to %s:%d", GP->weathserver, GP->weathport);
+    char port[10];
+    snprintf(port, 10, "%d", GP->weathport);
+    struct addrinfo hints = {0}, *res, *p;
+    hints.ai_family = AF_INET;
+    hints.ai_socktype = SOCK_STREAM;
+    hints.ai_flags = AI_PASSIVE;
+    if(getaddrinfo(GP->weathserver, port, &hints, &res) != 0){
+        WARN("getaddrinfo()");
+        return FALSE;
+    }
+    // loop through all the results and connect to the first we can
+    for(p = res; p; p = p->ai_next){
+        if((sockfd = socket(p->ai_family, p->ai_socktype, p->ai_protocol)) == -1){
+            WARN("socket");
+            continue;
+        }
+        if(connect(sockfd, p->ai_addr, p->ai_addrlen) == -1){
+            WARN("connect()");
+            close(sockfd);
+            continue;
+        }
+        break; // if we get here, we have a successfull connection
+    }
+    if(!p){
+        WARNX("Can't connect to socket");
+        sockfd = -1;
+        return FALSE;
+    }
+    freeaddrinfo(res);
+    if(pthread_create(&sock_thread, NULL, getmessages, NULL)){
+        WARN("pthread_create()");
+        weatherserver_disconnect();
+        return FALSE;
+    }
+    DBG("connected, fd=%d", sockfd);
+    return TRUE;
+}
+
+void weatherserver_disconnect(){
+    if(sockfd > -1){
+        pthread_kill(sock_thread, 9);
+        pthread_join(sock_thread, NULL);
+        close(sockfd);
+    }
+    sockfd = -1;
+}
+
+/**
+ * @brief getparval - return value of parameter
+ * @param par (i)        - parameter value
+ * @param ansbuf (i)     - buffer with server answer
+ * @param val (o)        - value of parameter
+ * @return TRUE if parameter found and set `val` to its value
+ */
+int getparval(const char *par, const char *ansbuf, double *val){
+    if(!par || !ansbuf) return FALSE;
+    int ret = FALSE;
+    char *b = strdup(ansbuf);
+    char *parval = NULL, *token = strtok(b, "\n");
+    int l = strlen(par);
+    if(!token) goto rtn;
+    while(token){
+        if(strncmp(token, par, l) == 0){ // found
+            //DBG("token: '%s'", token);
+            parval = strchr(token, '=');
+            if(!parval) goto rtn;
+            ++parval; while(*parval == ' ' || *parval == '\t') ++parval;
+            //DBG("parval: '%s'", parval);
+            ret = TRUE;
+            break;
+        }
+        token = strtok(NULL, "\n");
+    }
+    if(parval && val){
+        *val = atof(parval);
+        //DBG("Set %s to %g", par, *val);
+    }
+rtn:
+    FREE(b);
+    return ret;
+}
+
+/**
+ * wait for answer from socket
+ * @return FALSE in case of error or timeout, TRUE if socket is ready
+ */
+static int canread(){
+    if(sockfd < 0) return FALSE;
+    fd_set fds;
+    struct timeval timeout;
+    int rc;
+    // wait not more than 10ms
+    timeout.tv_sec = 0;
+    timeout.tv_usec = 10000;
+    FD_ZERO(&fds);
+    FD_SET(sockfd, &fds);
+    do{
+        rc = select(sockfd+1, &fds, NULL, NULL, &timeout);
+        if(rc < 0){
+            if(errno != EINTR){
+                WARN("select()");
+                return FALSE;
+            }
+            continue;
+        }
+        break;
+    }while(1);
+    if(FD_ISSET(sockfd, &fds)) return TRUE;
+    return FALSE;
+}
+
+/**
+ * @brief getmessages - continuosly read data from server and fill buffer
+ */
+static void *getmessages(_U_ void *par){
+    write(sockfd, "get\n", 4);
+    while(sockfd > 0){
+        pthread_mutex_lock(&mutex);
+        if(Nread == 0){
+            double t0 = dtime();
+            while(dtime() - t0 < WAITANSTIME && Nread < BUFSIZ){
+                if(!canread()) continue;
+                int n = read(sockfd, buf+Nread, BUFSIZ-Nread);
+                if(n == 0) break;
+                if(n < 0){
+                    close(sockfd);
+                    sockfd = -1;
+                    return NULL;
+                }
+                Nread += n;
+            }
+            if(Nread){
+                buf[Nread] = 0;
+                //DBG("got %d: %s", Nread, buf);
+            }
+        }
+        pthread_mutex_unlock(&mutex);
+        if(Nread == 0){
+            sleep(1);
+        }
+    }
+    return NULL;
+}
+
+/**
+ * @brief getweathbuffer - read whole buffer with data and set Nread to zero
+ * @return NULL if no data or buffer (allocated here)
+ */
+char *getweathbuffer(){
+    if(!weatherserver_connect()) return NULL; // not connected & can't connect
+    char *ret = NULL;
+    pthread_mutex_lock(&mutex);
+    if(Nread){
+        ret = strdup(buf);
+        Nread = 0;
+    }
+    pthread_mutex_unlock(&mutex);
+    return ret;
+}