Add static network

include/kpn/fanout.hpp

@@ -0,0 +1,175 @@
+#pragma once
+#include "channel.hpp"
+#include "diagnostics.hpp"
+#include "node.hpp"
+#include "port.hpp"
+#include "traits.hpp"
+
+#include <array>
+#include <atomic>
+#include <iostream>
+#include <memory>
+#include <thread>
+#include <tuple>
+#include <utility>
+
+namespace kpn {
+
+namespace detail {
+
+// Produces std::tuple<T, T, ..., T> with N repetitions — used so that
+// Network::connect can do its normal return_tuple type-check against FanoutNode.
+template<typename T, std::size_t N, typename Seq = std::make_index_sequence<N>>
+struct repeat_tuple;
+
+template<typename T, std::size_t N, std::size_t... Is>
+struct repeat_tuple<T, N, std::index_sequence<Is...>> {
+    template<std::size_t> using always_T = T;
+    using type = std::tuple<always_T<Is>...>;
+};
+
+template<typename T, std::size_t N>
+using repeat_tuple_t = typename repeat_tuple<T, N>::type;
+
+} // namespace detail
+
+// ── FanoutNode ────────────────────────────────────────────────────────────────
+//
+// Reads one item from its single input channel and pushes a copy to each of
+// N output channels. All N downstream nodes receive every item.
+//
+// Usage:
+//   auto fan = make_fanout<Image, 2>(/*capacity=*/8);
+//   net.connect("src",  src.output<0>(),   "fan",   fan.input<0>())
+//      .connect("fan",  fan.output<0>(),   "nodeA", nodeA.input<0>())
+//      .connect("fan",  fan.output<1>(),   "nodeB", nodeB.input<0>())
+
+template<typename T, std::size_t N>
+class FanoutNode : public INode {
+public:
+    using args_tuple   = std::tuple<T>;
+    using return_tuple = detail::repeat_tuple_t<T, N>;
+    using return_raw   = return_tuple;
+
+    static constexpr std::size_t input_count  = 1;
+    static constexpr std::size_t output_count = N;
+
+    explicit FanoutNode(std::size_t fifo_capacity = 5)
+        : fifo_capacity_(fifo_capacity)
+    {
+        input_ch_ = std::make_shared<Channel<T>>(fifo_capacity);
+    }
+
+    ~FanoutNode() override { stop(); }
+
+    // ── INode ─────────────────────────────────────────────────────────────────
+
+    void start() override {
+        input_ch_->enable();
+        stop_flag_.store(false, std::memory_order_relaxed);
+        thread_ = std::jthread([this](std::stop_token) { run_loop(); });
+    }
+
+    void stop() override {
+        stop_flag_.store(true, std::memory_order_relaxed);
+        input_ch_->disable();
+        if (thread_.joinable()) thread_.request_stop(), thread_.join();
+    }
+
+    bool running() const override {
+        return thread_.joinable() && !stop_flag_.load(std::memory_order_relaxed);
+    }
+
+    void set_name(std::string name) override { name_ = std::move(name); }
+
+    const NodeStats& stats() const override { return stats_; }
+
+    NodeSnapshot node_snapshot(const std::string& name, double elapsed_s) const override {
+        uint64_t frames   = stats_.frames_processed.load(std::memory_order_relaxed);
+        double exec_ms    = stats_.ema_exec_us.load(std::memory_order_relaxed) / 1000.0;
+        double blocked_ms = stats_.total_blocked_us.load(std::memory_order_relaxed) / 1000.0;
+        double total_ms   = exec_ms + blocked_ms;
+        return {name, frames, exec_ms,
+                stats_.max_exec_us.load(std::memory_order_relaxed) / 1000.0,
+                blocked_ms,
+                elapsed_s > 0 ? frames / elapsed_s : 0.0,
+                stats_.total_cpu_us.load(std::memory_order_relaxed) / 1000.0,
+                total_ms > 0 ? 100.0 * exec_ms / total_ms : 0.0};
+    }
+
+    // ── Port access ───────────────────────────────────────────────────────────
+
+    template<std::size_t I = 0>
+    InputPort<FanoutNode, I> input() {
+        static_assert(I == 0, "FanoutNode has exactly one input");
+        return {*this};
+    }
+
+    template<std::size_t I>
+    OutputPort<FanoutNode, I> output() {
+        static_assert(I < N, "FanoutNode output index out of range");
+        return {*this};
+    }
+
+    // ── Internal channel accessors (called by Network::connect) ───────────────
+
+    template<std::size_t I>
+    Channel<T>& input_channel() {
+        static_assert(I == 0);
+        return *input_ch_;
+    }
+
+    template<std::size_t I>
+    void set_input_channel(std::shared_ptr<Channel<T>> ch) {
+        static_assert(I == 0);
+        input_ch_ = std::move(ch);
+    }
+
+    template<std::size_t I>
+    void set_output_channel(Channel<T>* ch) {
+        static_assert(I < N);
+        out_channels_[I] = ch;
+    }
+
+private:
+    void run_loop() {
+        while (!stop_flag_.load(std::memory_order_relaxed)) {
+            try {
+                auto t0  = clock_t::now();
+                T    val = input_ch_->pop();
+                auto t1  = clock_t::now();
+                auto cpu0 = NodeStats::cpu_now();
+
+                for (std::size_t i = 0; i < N; ++i) {
+                    if (out_channels_[i])
+                        out_channels_[i]->push(val);
+                }
+
+                auto cpu1 = NodeStats::cpu_now();
+                auto t2   = clock_t::now();
+                stats_.record_exec(duration_t(t2 - t1), duration_t(t1 - t0), cpu0, cpu1);
+            } catch (const ChannelClosedError&) {
+                break;
+            } catch (const ChannelOverflowError& e) {
+                std::cerr << "[kpn] fanout overflow: " << e.what() << "\n";
+            }
+        }
+    }
+
+    std::string                 name_;
+    std::size_t                 fifo_capacity_;
+    std::shared_ptr<Channel<T>> input_ch_;
+    std::array<Channel<T>*, N>  out_channels_{};
+    std::atomic<bool>           stop_flag_{false};
+    std::jthread                thread_;
+    NodeStats                   stats_;
+};
+
+// ── Factory ───────────────────────────────────────────────────────────────────
+
+template<typename T, std::size_t N>
+FanoutNode<T, N> make_fanout(std::size_t fifo_capacity = 5) {
+    return FanoutNode<T, N>(fifo_capacity);
+}
+
+} // namespace kpn