nostrdb: move everything to src

Signed-off-by: William Casarin <jb55@jb55.com>

nostrdb/src/cpu.h

@@ -0,0 +1,34 @@
+
+#if defined(_WIN32) || defined(_WIN64)
+	#include <windows.h>
+#elif defined(__linux__)
+	#include <unistd.h>
+#elif defined(__APPLE__)
+	#include <sys/types.h>
+	#include <sys/sysctl.h>
+#else
+	#error "Unsupported platform"
+#endif
+
+static inline int get_cpu_cores() {
+	int num_cores = 0;
+
+	// Windows
+	#if defined(_WIN32) || defined(_WIN64)
+		SYSTEM_INFO sysinfo;
+		GetSystemInfo(&sysinfo);
+		num_cores = sysinfo.dwNumberOfProcessors; // This returns logical processors
+		// Further use GetLogicalProcessorInformation for physical cores...
+	// Linux
+	#elif defined(__linux__)
+		num_cores = sysconf(_SC_NPROCESSORS_ONLN); // This returns logical processors
+	// macOS
+	#elif defined(__APPLE__)
+		size_t size = sizeof(num_cores);
+		sysctlbyname("hw.physicalcpu", &num_cores, &size, NULL, 0);
+	#else
+		num_cores = -1; // Unsupported platform
+	#endif
+
+	return num_cores;
+}