- Make get_total_memory work for windows

- Add test cases for it

src/cpp-utils/system/get_total_memory.cpp

@@ -1,27 +1,58 @@
 #include "get_total_memory.h"
+#include <stdexcept>
+#include <string>
+
+#if defined(__APPLE__)
+
 #include <sys/types.h>
 #include <sys/sysctl.h>
-#include <unistd.h>
-#include <stdexcept>
 
 namespace cpputils {
 	namespace system {
 		uint64_t get_total_memory() {
 			uint64_t mem;
-#if defined(__APPLE__)
 			size_t size = sizeof(mem);
 			int result = sysctlbyname("hw.memsize", &mem, &size, nullptr, 0);
 			if (0 != result) {
 				throw std::runtime_error("sysctlbyname syscall failed");
 			}
-#elif defined(__linux__) || defined(__FreeBSD__)
-            long numRAMPages = sysconf(_SC_PHYS_PAGES);
-            long pageSize = sysconf(_SC_PAGESIZE);
-            mem = numRAMPages * pageSize;
-#else
-#error Not supported on windows yet, TODO http://stackoverflow.com/a/2513561/829568
-#endif
 			return mem;
 		}
 	}
 }
+
+#elif defined(__linux__) || defined(__FreeBSD__)
+
+#include <unistd.h>
+
+namespace cpputils {
+	namespace system {
+		uint64_t get_total_memory() {
+			long numRAMPages = sysconf(_SC_PHYS_PAGES);
+			long pageSize = sysconf(_SC_PAGESIZE);
+			return numRAMPages * pageSize;
+		}
+	}
+}
+
+#elif defined(_MSC_VER)
+
+#include <Windows.h>
+
+namespace cpputils {
+	namespace system {
+		uint64_t get_total_memory() {
+			MEMORYSTATUSEX status;
+			status.dwLength = sizeof(status);
+			if (!::GlobalMemoryStatusEx(&status)) {
+				throw std::runtime_error("Couldn't get system memory information. Error code: " + std::to_string(GetLastError()));
+			}
+			return status.ullTotalPhys;
+		}
+	}
+}
+
+#else
+#error Unsupported platform
+#endif
+

test/cpp-utils/CMakeLists.txt

@@ -45,6 +45,7 @@ set(SOURCES
     assert/backtrace_include_test.cpp
     assert/assert_include_test.cpp
     assert/assert_debug_test.cpp
+    system/GetTotalMemoryTest.cpp
     system/TimeTest.cpp
     system/MemoryTest.cpp
     system/HomedirTest.cpp

test/cpp-utils/system/GetTotalMemoryTest.cpp

@@ -0,0 +1,13 @@
+#include <gtest/gtest.h>
+#include <cpp-utils/system/get_total_memory.h>
+
+using cpputils::system::get_total_memory;
+
+TEST(GetTotalMemoryTest, DoesntCrash) {
+    get_total_memory();
+}
+
+TEST(GetTotalMemoryTest, IsNotZero) {
+    uint64_t mem = get_total_memory();
+    EXPECT_LT(UINT64_C(0), mem);
+}