Enable log information

core/ANSLicensingSystem/ANSLicense.cpp

@@ -14,6 +14,11 @@
 #include "base64.h"
 #include <spdlog/sinks/base_sink.h>
 #include <winnt.h>
+#include <atomic>
+#include <chrono>
+#include <filesystem>
+#include <system_error>
+#include <cstdlib>
 
 #define MAX_CUSTOMER_NAME_LEN 100
 #define FEATURE_1 0x1
@@ -2963,4 +2968,45 @@ namespace ANSCENTER
 		return logger.Release();
 	}
 
+}
+
+// ============================================================================
+// Runtime DebugView toggle — gates ANS_DBG without requiring a rebuild.
+//
+// Precedence per poll: env var ANSCENTER_DBGVIEW wins over the sentinel file.
+// Poll interval is 2 s, so toggling takes effect within that window. Hot-path
+// cost on a cache hit is a single relaxed atomic load + branch.
+// ============================================================================
+extern "C" ANSLICENSE_API int ANSCENTER_IsDebugViewEnabled(void) {
+	using clock = std::chrono::steady_clock;
+	static std::atomic<int> s_enabled{0};
+	static std::atomic<long long> s_nextCheckTick{0};
+
+	const long long now = clock::now().time_since_epoch().count();
+	const long long next = s_nextCheckTick.load(std::memory_order_relaxed);
+	if (now < next) {
+		return s_enabled.load(std::memory_order_relaxed);
+	}
+
+	int enabled = 0;
+	const char* env = std::getenv("ANSCENTER_DBGVIEW");
+	if (env && env[0] == '1' && env[1] == '\0') {
+		enabled = 1;
+	} else if (env && env[0] == '0' && env[1] == '\0') {
+		enabled = 0;
+	} else {
+#ifdef _WIN32
+		const wchar_t* kSentinel = L"C:\\ProgramData\\ANSCENTER\\ansvisdebugview.txt";
+#else
+		const char* kSentinel = "/tmp/ansvisdebugview.txt";
+#endif
+		std::error_code ec;
+		enabled = std::filesystem::exists(kSentinel, ec) ? 1 : 0;
+	}
+
+	s_enabled.store(enabled, std::memory_order_relaxed);
+	const long long deadline = now +
+		std::chrono::duration_cast<clock::duration>(std::chrono::seconds(2)).count();
+	s_nextCheckTick.store(deadline, std::memory_order_relaxed);
+	return enabled;
 }