feat(bar): 按间隔节流 bar_item 更新

- 新增 base/time: time_monotonic_ms 与 time_create_monotonic_timerfd_by_fps
- bar 初始化改用该工具创建 timerfd，移除内联的 itimerspec 拼装
- bar_item_update 按 update_interval_ms 节流，记录 last_updated_time 跳过过早更新

CMakeLists.txt

@@ -37,6 +37,7 @@ add_executable(${APP_NAME}
     ${SOURCE_DIR}/base/color.c
     ${SOURCE_DIR}/base/log.c
     ${SOURCE_DIR}/base/process.c
+    ${SOURCE_DIR}/base/time.c
     ${SOURCE_DIR}/base/window_list.c
 
     ${SOURCE_DIR}/config/defaults.c

src/bar/bar.c

@@ -1,12 +1,9 @@
 #include "bar/bar.h"
 
 #include <assert.h>
-#include <bits/time.h>
-#include <bits/types/struct_itimerspec.h>
 #include <cairo.h>
 #include <stddef.h>
 #include <stdint.h>
-#include <sys/timerfd.h>
 #include <unistd.h>
 #include <zdwm/bar.h>
 #include <zdwm/types.h>
@@ -18,6 +15,7 @@
 #include "base/array.h"
 #include "base/macros.h"
 #include "base/memory.h"
+#include "base/time.h"
 #include "core/listeners.h"
 
 static zdwm_bar_item_t *bar_add_item(
@@ -91,21 +89,7 @@ void bar_init(bar_t *bar, listeners_t *listeners) {
     bar_output_add_workspace(bar_output, &bar->config, listeners);
   }
 
-  bar->timerfd     = timerfd_create(CLOCK_MONOTONIC, TFD_CLOEXEC);
-  auto interval_ns = 1'000'000'000ULL / bar->config.fps;
-
-  struct itimerspec timer_spec = {
-    .it_interval =
-      {
-        .tv_sec  = interval_ns / 1'000'000'000,
-        .tv_nsec = interval_ns % 1'000'000'000,
-      },
-    .it_value = {
-      .tv_sec  = 0,
-      .tv_nsec = interval_ns % 1'000'000'000,
-    },
-  };
-  timerfd_settime(bar->timerfd, 0, &timer_spec, nullptr);
+  bar->timerfd = time_create_monotonic_timerfd_by_fps(bar->config.fps);
 }
 
 static void bar_side_cleanup(bar_side_t *side) {
@@ -139,7 +123,15 @@ void bar_cleanup(bar_t *bar) {
 
 static inline void bar_item_update(zdwm_bar_item_t *item) {
   auto update = item->api.update;
-  if (update) update(item, &bar_cell_api, item->state);
+  if (!update) return;
+
+  auto update_interval_ms = item->api.update_interval_ms;
+  auto last_updated_time  = item->last_updated_time;
+  auto now                = time_monotonic_ms();
+  if (now < last_updated_time + update_interval_ms) return;
+
+  item->last_updated_time = now;
+  update(item, &bar_cell_api, item->state);
 }
 
 static inline void bar_side_update(bar_side_t *side) {

src/bar/types.h

@@ -32,6 +32,7 @@ struct zdwm_bar_item_t {
   void *state;
   zdwm_bar_item_type_t api;
   bool dirty;
+  uint64_t last_updated_time;
 };
 
 typedef struct bar_side_t {

src/base/time.c

@@ -0,0 +1,56 @@
+#include "base/time.h"
+
+#include <bits/time.h>
+#include <bits/types/struct_itimerspec.h>
+#include <errno.h>
+#include <stdint.h>
+#include <string.h>
+#include <sys/timerfd.h>
+#include <time.h>
+
+#include "base/log.h"
+
+static int time_create_monotonic_timerfd(const struct itimerspec *itimerspec) {
+  auto timerfd = timerfd_create(CLOCK_MONOTONIC, TFD_CLOEXEC);
+  if (timerfd == -1) {
+    auto err = errno;
+    warn("time_create_timerfd failed: %s", strerror(err));
+    return timerfd;
+  }
+
+  timerfd_settime(timerfd, 0, itimerspec, nullptr);
+  return timerfd;
+}
+
+static constexpr auto NANOSECONDS_OF_ONE_SECOND = 1'000'000'000ULL;
+
+int time_create_monotonic_timerfd_by_fps(uint32_t fps) {
+  if (fps == 0) fps = 30;
+
+  auto interval_ns = NANOSECONDS_OF_ONE_SECOND / fps;
+
+  /* clang-format off */
+  struct itimerspec timer_spec = {
+    .it_value = {
+      .tv_sec  = 0,
+      .tv_nsec = interval_ns % NANOSECONDS_OF_ONE_SECOND,
+    },
+    .it_interval = {
+      .tv_sec  = interval_ns / NANOSECONDS_OF_ONE_SECOND,
+      .tv_nsec = interval_ns % NANOSECONDS_OF_ONE_SECOND,
+    },
+  };
+  /* clang-format on */
+
+  return time_create_monotonic_timerfd(&timer_spec);
+}
+
+static uint64_t time_monotonic_ns(void) {
+  struct timespec timestamp = {0};
+  if (clock_gettime(CLOCK_MONOTONIC, &timestamp) == -1) {
+    warn("clock_gettime failed: %s", strerror(errno));
+  }
+  return timestamp.tv_sec * NANOSECONDS_OF_ONE_SECOND + timestamp.tv_nsec;
+}
+
+uint64_t time_monotonic_ms(void) { return time_monotonic_ns() / 1'000'000U; }

src/base/time.h

@@ -0,0 +1,6 @@
+#pragma once
+
+#include <stdint.h>
+
+int time_create_monotonic_timerfd_by_fps(uint32_t fps);
+uint64_t time_monotonic_ms(void);