Add Chromium-only Blender WebEngine parity work

blender-5.2.0/intern/cycles/util/time.h

@@ -0,0 +1,112 @@
+/* SPDX-FileCopyrightText: 2011-2022 Blender Foundation
+ *
+ * SPDX-License-Identifier: Apache-2.0 */
+
+#pragma once
+
+#include <functional>
+
+#include "util/string.h"
+
+CCL_NAMESPACE_BEGIN
+
+/* Give current time in seconds in double precision, with good accuracy. */
+
+double time_dt();
+
+/* Sleep for the specified number of seconds. */
+
+void time_sleep(const double t);
+
+/* Fast timer for applications where overhead is critical and some inaccuracy is acceptable.
+ *
+ * On x86, this uses RDTSCP, which also can check which CPU the code runs on, which in turn
+ * allows us to skip measurements where we moved CPU in-between (which might be invalid due
+ * to different clock states between cores and/or misleading due to OS scheduling). Therefore,
+ * we provide last_cpu to time_fast_tick, and it may set it if supported. */
+
+uint64_t time_fast_tick(uint32_t *last_cpu);
+uint64_t time_fast_frequency();
+
+/* Scoped timer. */
+
+class scoped_timer {
+ public:
+  explicit scoped_timer(double *value = nullptr) : value_(value)
+  {
+    time_start_ = time_dt();
+  }
+
+  ~scoped_timer()
+  {
+    if (value_ != nullptr) {
+      *value_ = get_time();
+    }
+  }
+
+  double get_start() const
+  {
+    return time_start_;
+  }
+
+  double get_time() const
+  {
+    return time_dt() - time_start_;
+  }
+
+ protected:
+  double *value_;
+  double time_start_;
+};
+
+class fast_timer {
+ public:
+  fast_timer()
+  {
+    last_cpu = 0;
+    last_value = time_fast_tick(&last_cpu);
+  }
+
+  bool lap(uint64_t &delta)
+  {
+    uint32_t new_cpu = 0;
+    uint64_t new_value = time_fast_tick(&new_cpu);
+
+    const bool cpu_consistent = new_cpu == last_cpu;
+    delta = new_value - last_value;
+
+    last_cpu = new_cpu;
+    last_value = new_value;
+
+    return cpu_consistent;
+  }
+
+ protected:
+  uint32_t last_cpu;
+  uint64_t last_value;
+};
+
+class scoped_callback_timer {
+ public:
+  using callback_type = std::function<void(double)>;
+
+  explicit scoped_callback_timer(callback_type cb) : cb(cb) {}
+
+  ~scoped_callback_timer()
+  {
+    if (cb) {
+      cb(timer.get_time());
+    }
+  }
+
+ protected:
+  scoped_timer timer;
+  callback_type cb;
+};
+
+/* Make human readable string from time, compatible with Blender metadata. */
+
+string time_human_readable_from_seconds(const double seconds);
+double time_human_readable_to_seconds(const string &time_string);
+
+CCL_NAMESPACE_END