From a13750209b3836a4a6a16a7ba881625f397f160f Mon Sep 17 00:00:00 2001
From: Albert Cervin <albert@acervin.com>
Date: Thu, 7 Mar 2024 20:19:26 +0100
Subject: Implement timers properly

The timers shown with `M-x timers` are now actual timings.
---
 src/dged/timers.c | 95 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 95 insertions(+)
 create mode 100644 src/dged/timers.c

(limited to 'src/dged/timers.c')

diff --git a/src/dged/timers.c b/src/dged/timers.c
new file mode 100644
index 0000000..37ac367
--- /dev/null
+++ b/src/dged/timers.c
@@ -0,0 +1,95 @@
+#include "timers.h"
+#include "hash.h"
+#include "hashmap.h"
+
+#include <stdbool.h>
+#include <string.h>
+#include <time.h>
+
+#define NUM_FRAME_SAMPLES 16
+
+struct timer {
+  char name[32];
+  uint64_t samples[NUM_FRAME_SAMPLES];
+  struct timespec started_at;
+};
+
+HASHMAP_ENTRY_TYPE(timer_entry, struct timer);
+
+static struct timers {
+  uint32_t frame_index;
+  HASHMAP(struct timer_entry) timers;
+} g_timers;
+
+void timers_init() {
+  HASHMAP_INIT(&g_timers.timers, 32, hash_name);
+  g_timers.frame_index = 0;
+}
+
+void timers_destroy() { HASHMAP_DESTROY(&g_timers.timers); }
+
+void timers_start_frame() {
+  HASHMAP_FOR_EACH(&g_timers.timers, struct timer_entry * entry) {
+    struct timer *timer = &entry->value;
+    timer->samples[g_timers.frame_index] = 0;
+  }
+}
+
+void timers_end_frame() {
+  g_timers.frame_index = (g_timers.frame_index + 1) % NUM_FRAME_SAMPLES;
+}
+
+struct timer *timer_start(const char *name) {
+  HASHMAP_GET(&g_timers.timers, struct timer_entry, name, struct timer * t);
+  if (t == NULL) {
+    HASHMAP_APPEND(&g_timers.timers, struct timer_entry, name,
+                   struct timer_entry * tnew);
+    struct timer *new_timer = &tnew->value;
+
+    size_t namelen = strlen(name);
+    namelen = namelen >= 32 ? 31 : namelen;
+    memcpy(new_timer->name, name, namelen);
+    new_timer->name[namelen] = '\0';
+
+    memset(new_timer->samples, 0, sizeof(uint64_t) * NUM_FRAME_SAMPLES);
+
+    t = new_timer;
+  }
+
+  clock_gettime(CLOCK_MONOTONIC, &t->started_at);
+  return t;
+}
+
+void timer_stop(struct timer *timer) {
+  struct timespec end;
+  clock_gettime(CLOCK_MONOTONIC, &end);
+  uint64_t elapsed = ((uint64_t)end.tv_sec * 1e9 + (uint64_t)end.tv_nsec) -
+                     ((uint64_t)timer->started_at.tv_sec * 1e9 +
+                      (uint64_t)timer->started_at.tv_nsec);
+
+  timer->samples[g_timers.frame_index] += elapsed;
+}
+
+struct timer *timer_get(const char *name) {
+  HASHMAP_GET(&g_timers.timers, struct timer_entry, name, struct timer * t);
+  return t;
+}
+
+float timer_average(const struct timer *timer) {
+  uint64_t sum = 0;
+  for (uint32_t samplei = 0; samplei < NUM_FRAME_SAMPLES; ++samplei) {
+    sum += timer->samples[samplei];
+  }
+
+  return (float)sum / NUM_FRAME_SAMPLES;
+  return 0.f;
+}
+
+const char *timer_name(const struct timer *timer) { return timer->name; }
+
+void timers_for_each(timer_callback callback, void *userdata) {
+  HASHMAP_FOR_EACH(&g_timers.timers, struct timer_entry * entry) {
+    const struct timer *timer = &entry->value;
+    callback(timer, userdata);
+  }
+}
-- 
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