From 7093c38978e86b462071e120f1dbd0414aab3eb6 Mon Sep 17 00:00:00 2001
From: 0scar <qgt268@alumni.ku.dk>
Date: Tue, 11 Feb 2025 08:57:17 +0100
Subject: Remove clib/gnu time functions

---
 status.c | 95 ++++++++++++++++++++++++++++++++++++++++++++++------------------
 1 file changed, 69 insertions(+), 26 deletions(-)

diff --git a/status.c b/status.c
index 260ea6b..6bdcbc7 100644
--- a/status.c
+++ b/status.c
@@ -30,8 +30,8 @@ typedef void (*element_function)(char*);
 /* Data structures */
 struct element {
   const element_function f;
-  const struct timeval fire_interval;
-  struct timeval fire_previous;
+  const struct timespec fire_interval;
+  struct timespec fire_previous;
   char buf[ELEMENT_STRBUF_SZ];
 };
 
@@ -82,15 +82,17 @@ static char* battery_level_icon[] = {
   "", /* "\uf578" */
 };
 
+// Converts milliseconds to nanoseconds
+#define MSEC(msec) (msec * 1000 * 1000)
 static struct element statusbar[] = {
   /* Add status elements here */
-  /*{element_function, {seconds, microseconds}, {0}, {0}},*/
+  /*{element_function, {seconds, nanoseconds}, {0}, {0}},*/
 
   {get_net_link_status,     {15, 0}, {0}, {0}},
   {get_battery0_status,     {60, 0}, {0}, {0}},
   {get_battery1_status,     {60, 0}, {0}, {0}},
   { get_all_bat_status,     {60, 0}, {0}, {0}},
-  {               date, {7, 500000}, {0}, {0}},
+  {               date,   {7, MSEC(500)}, {0}, {0}},
 };
 
 struct interface_status interfaces[8]; // surely noone has more than 8 interfaces.
@@ -226,8 +228,7 @@ get_essid(char* if_name, char* dst) {
     dst[0] = '\0';
   }
 
-    close(sock);
-
+  close(sock);
 }
 
 void
@@ -243,10 +244,11 @@ get_net_link_status(char* buf) {
   }
 
   for (struct ifaddrs* ifa = if_addr; ifa != NULL; ifa = ifa->ifa_next) {
-    int i = 0;
+    size_t i         = 0;
     const char* name = ifa->ifa_name;
 
-    while (i < c && strcmp(name, interfaces[i].name)) i++;
+    while (i < c && strcmp(name, interfaces[i].name))
+      i++;
 
     //if (i != c) {
     //printf("found %s in %d\n", name, i);
@@ -286,7 +288,7 @@ get_net_link_status(char* buf) {
     struct interface_status s; // = &status[c];
     memset(&s, 0, sizeof(struct interface_status));
 
-        s = interfaces[i];
+    s = interfaces[i];
 
     if (ifa->ifa_addr != NULL) {
       const int family = ifa->ifa_addr->sa_family;
@@ -326,12 +328,11 @@ get_net_link_status(char* buf) {
     }
 
     memcpy(&interfaces[i], &s, sizeof(struct interface_status));
-
   }
   freeifaddrs(if_addr);
 
   memset(buf, 0, ELEMENT_STRBUF_SZ);
-  for (int i = 0; i < c; i++) {
+  for (size_t i = 0; i < c; i++) {
     // int i = 0; {
     struct interface_status* s = &interfaces[i];
     // Write the status string to the output buffer
@@ -372,30 +373,69 @@ get_net_link_status(char* buf) {
   }
 }
 
+static struct timespec
+time_add(struct timespec a, struct timespec b) {
+  struct timespec dst;
+  dst.tv_sec  = a.tv_sec + b.tv_sec;
+  dst.tv_nsec = a.tv_nsec + b.tv_nsec;
+
+  /* larger than 1 second in μsec */
+  if (dst.tv_nsec >= 1000000) {
+    dst.tv_nsec -= 1000000 * 1000;
+    dst.tv_sec++;
+  }
+
+  return dst;
+}
+
+/* Assume that time_t and time64_t are signed (they are on my machine) */
+static struct timespec
+time_sub(struct timespec a, struct timespec b) {
+  struct timespec dst;
+
+  dst.tv_sec  = a.tv_sec + b.tv_sec;
+  dst.tv_nsec = a.tv_nsec + b.tv_nsec;
+
+  if (dst.tv_nsec < 0) {
+    dst.tv_nsec += 1000000 * 1000;
+    dst.tv_sec--;
+  }
+
+  return dst;
+}
+
+static bool
+time_lt(struct timespec a, struct timespec b) {
+  if (a.tv_sec == b.tv_sec) {
+    return a.tv_nsec < b.tv_nsec;
+  }
+
+  return a.tv_sec < b.tv_sec;
+}
+
 int
 main(void) {
   const int num_elems = sizeof(statusbar) / sizeof(statusbar[0]);
-  struct timeval now;
-  const struct timeval one_minute = {60, 0};
+  struct timespec now;
+  const struct timespec one_minute = {60, 0};
 
   memset(interfaces, 0, sizeof(struct interface_status[8]));
 
   while (true) {
-    gettimeofday(&now, NULL);
+    clock_gettime(CLOCK_REALTIME, &now);
     unsigned i;
 
     /* Stall updating for at most 1 minute */
-    struct timeval next_update;
-    timeradd(&now, &one_minute, &next_update);
+    struct timespec next_update = {0};
+    now                         = time_add(one_minute, next_update);
 
     for (i = 0; i < num_elems; i++) {
-      struct timeval next_fire;
-      timeradd(&statusbar[i].fire_previous, &statusbar[i].fire_interval,
-               &next_fire);
+      struct timespec next_fire = {0};
+      statusbar[i].fire_previous = time_add(statusbar[i].fire_interval, next_fire);
 
-      if (timercmp(&next_fire, &now, >)) {
+      if (time_lt(now, next_fire)) {
         /* Check if this is the next to-be-updated element */
-        if (timercmp(&next_fire, &next_update, <)) {
+        if (time_lt(next_fire, next_update)) {
           next_update = next_fire;
         }
         continue;
@@ -407,9 +447,9 @@ main(void) {
       statusbar[i].fire_previous = now;
 
       /* Check if this element needs to be refreshed next, again */
-      timeradd(&statusbar[i].fire_previous, &statusbar[i].fire_interval,
-               &next_fire);
-      if (timercmp(&next_fire, &next_update, <)) {
+      statusbar[i].fire_previous = time_add(statusbar[i].fire_interval, next_fire);
+
+      if (time_lt(next_fire, next_update)) {
         next_update = next_fire;
       }
 
@@ -436,8 +476,11 @@ main(void) {
     puts(buf);
     fflush(stdout);
 
-    timersub(&next_update, &now, &next_update);
-    usleep(next_update.tv_sec * 1000 * 1000 + next_update.tv_usec);
+    next_update = time_sub(now, next_update);
+
+    /* Replace NULL to get "remaining time", in case we got
+     * interrupted / signaled */
+    nanosleep(&next_update, NULL);
   }
 
   return 0;
-- 
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