Add foundation tracing and platform build wrapper

src/foundation/trace.cpp

@@ -0,0 +1,98 @@
+#include "foundation/trace.h"
+
+#include <limits>
+
+namespace pp::foundation {
+
+Result<TraceSpanId> TraceRecorder::begin_span(TraceSpanDesc desc, std::uint64_t start_us)
+{
+    if (desc.component.empty()) {
+        return Result<TraceSpanId>::failure(
+            Status::invalid_argument("trace component must not be empty"));
+    }
+
+    if (desc.name.empty()) {
+        return Result<TraceSpanId>::failure(
+            Status::invalid_argument("trace span name must not be empty"));
+    }
+
+    if (next_id_ == std::numeric_limits<TraceSpanId>::max()) {
+        return Result<TraceSpanId>::failure(
+            Status::out_of_range("trace span id space is exhausted"));
+    }
+
+    const auto id = next_id_++;
+    ActiveSpan span;
+    span.id = id;
+    span.component.assign(desc.component);
+    span.name.assign(desc.name);
+    span.desc = desc;
+    span.desc.component = span.component;
+    span.desc.name = span.name;
+    span.start_us = start_us;
+    span.active = true;
+    active_spans_.push_back(span);
+
+    return Result<TraceSpanId>::success(id);
+}
+
+Status TraceRecorder::end_span(TraceSpanId id, std::uint64_t end_us)
+{
+    ActiveSpan* span = find_active_span(id);
+    if (span == nullptr) {
+        return Status::out_of_range("trace span id is not active");
+    }
+
+    if (end_us < span->start_us) {
+        return Status::invalid_argument("trace span cannot end before it starts");
+    }
+
+    TraceEvent event;
+    event.component = span->component;
+    event.name = span->name;
+    event.thread_id = span->desc.thread_id;
+    event.frame_id = span->desc.frame_id;
+    event.stroke_id = span->desc.stroke_id;
+    event.start_us = span->start_us;
+    event.duration_us = end_us - span->start_us;
+    events_.push_back(event);
+
+    span->active = false;
+    return Status::success();
+}
+
+std::span<const TraceEvent> TraceRecorder::events() const noexcept
+{
+    return events_;
+}
+
+std::size_t TraceRecorder::active_span_count() const noexcept
+{
+    std::size_t count = 0;
+    for (const auto& span : active_spans_) {
+        if (span.active) {
+            ++count;
+        }
+    }
+    return count;
+}
+
+void TraceRecorder::clear() noexcept
+{
+    active_spans_.clear();
+    events_.clear();
+    next_id_ = 1;
+}
+
+TraceRecorder::ActiveSpan* TraceRecorder::find_active_span(TraceSpanId id) noexcept
+{
+    for (auto& span : active_spans_) {
+        if (span.active && span.id == id) {
+            return &span;
+        }
+    }
+
+    return nullptr;
+}
+
+}

src/foundation/trace.h

@@ -0,0 +1,60 @@
+#pragma once
+
+#include "foundation/result.h"
+
+#include <cstdint>
+#include <span>
+#include <string>
+#include <string_view>
+#include <vector>
+
+namespace pp::foundation {
+
+using TraceSpanId = std::uint64_t;
+
+struct TraceSpanDesc {
+    std::string_view component;
+    std::string_view name;
+    std::uint64_t thread_id = 0;
+    std::uint64_t frame_id = 0;
+    std::uint64_t stroke_id = 0;
+};
+
+struct TraceEvent {
+    std::string component;
+    std::string name;
+    std::uint64_t thread_id = 0;
+    std::uint64_t frame_id = 0;
+    std::uint64_t stroke_id = 0;
+    std::uint64_t start_us = 0;
+    std::uint64_t duration_us = 0;
+};
+
+class TraceRecorder {
+public:
+    [[nodiscard]] Result<TraceSpanId> begin_span(TraceSpanDesc desc, std::uint64_t start_us);
+    [[nodiscard]] Status end_span(TraceSpanId id, std::uint64_t end_us);
+
+    [[nodiscard]] std::span<const TraceEvent> events() const noexcept;
+    [[nodiscard]] std::size_t active_span_count() const noexcept;
+
+    void clear() noexcept;
+
+private:
+    struct ActiveSpan {
+        TraceSpanId id = 0;
+        TraceSpanDesc desc;
+        std::string component;
+        std::string name;
+        std::uint64_t start_us = 0;
+        bool active = false;
+    };
+
+    [[nodiscard]] ActiveSpan* find_active_span(TraceSpanId id) noexcept;
+
+    std::vector<ActiveSpan> active_spans_;
+    std::vector<TraceEvent> events_;
+    TraceSpanId next_id_ = 1;
+};
+
+}