Initial commit: testpattern → fakesink pipeline over MXL shared memory

- NodeBase, Signal, FlowDef, V210 shared headers - testpattern node: SMPTE 75% color bars writer at 25fps - fakesink node: non-blocking MXL reader with per-second stats - studio-manager: FlowGraph data model, graph-driven fork/exec launcher - mxl pinned as submodule at 0ae1dc5 Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-06-23 13:35:01 +03:00
commit ca682eaf0a
17 changed files with 1269 additions and 0 deletions
@@ -0,0 +1,97 @@
+#pragma once
+
+#include <cstdarg>
+#include <cstdio>
+#include <cstdlib>
+#include <string>
+#include <nlohmann/json.hpp>
+#include <mxl/mxl.h>
+#include "Signal.hpp"
+
+namespace dmf {
+
+// Base class for all DMF node binaries.
+//
+// Handles the boilerplate every node needs:
+//   - NODE_CONFIG env var → parsed JSON config
+//   - MXL_DOMAIN env var → domain path
+//   - mxlCreateInstance / mxlDestroyInstance lifecycle
+//   - Signal handler installation
+//   - [node_id]-prefixed logging
+//
+// Derived class implements only run(), which receives a valid MXL instance
+// and runs until dmf::g_running is false (set by SIGTERM/SIGINT).
+class NodeBase {
+public:
+    virtual ~NodeBase() = default;
+
+    // Entry point for main(). Returns 0 on success, 1 on error.
+    int execute() {
+        install_signal_handlers();
+
+        const char* config_env = std::getenv("NODE_CONFIG");
+        if (!config_env) {
+            fprintf(stderr, "[node] NODE_CONFIG not set\n");
+            return 1;
+        }
+        cfg_ = nlohmann::json::parse(config_env, nullptr, /*allow_exceptions=*/false);
+        if (cfg_.is_discarded()) {
+            fprintf(stderr, "[node] NODE_CONFIG is not valid JSON\n");
+            return 1;
+        }
+
+        node_id_ = cfg_.value("node_id", std::string("node"));
+
+        const char* domain_env = std::getenv("MXL_DOMAIN");
+#ifdef __APPLE__
+        domain_ = domain_env ? domain_env : "/tmp/dmf-studio";
+#else
+        domain_ = domain_env ? domain_env : "/dev/shm/dmf-studio";
+#endif
+
+        log("domain=%s", domain_.c_str());
+
+        inst_ = mxlCreateInstance(domain_.c_str(), nullptr);
+        if (!inst_) {
+            log("mxlCreateInstance failed at %s", domain_.c_str());
+            return 1;
+        }
+
+        run();
+
+        mxlDestroyInstance(inst_);
+        inst_ = nullptr;
+        return 0;
+    }
+
+protected:
+    // Implement the node's processing loop here.
+    // Create MXL writers/readers, loop while dmf::g_running, release them before returning.
+    virtual void run() = 0;
+
+    const nlohmann::json& config()   const { return cfg_; }
+    mxlInstance           instance() const { return inst_; }
+    const std::string&    node_id()  const { return node_id_; }
+    const std::string&    domain()   const { return domain_; }
+
+    // Printf-style log with automatic "[node_id] " prefix and trailing newline.
+#if defined(__GNUC__) || defined(__clang__)
+    __attribute__((format(printf, 2, 3)))
+#endif
+    void log(const char* fmt, ...) const {
+        fprintf(stderr, "[%s] ", node_id_.c_str());
+        va_list args;
+        va_start(args, fmt);
+        vfprintf(stderr, fmt, args);
+        va_end(args);
+        fputc('\n', stderr);
+    }
+
+private:
+    nlohmann::json cfg_;
+    mxlInstance    inst_{nullptr};
+    std::string    node_id_{"node"};
+    std::string    domain_;
+};
+
+} // namespace dmf