CpuUsage: support no wait detection on Windows

src/detection/cpuUsage/cpuUsage.c

@@ -0,0 +1,58 @@
+#include "fastfetch.h"
+#include "cpuUsage.h"
+
+#ifndef FF_DETECTION_CPUUSAGE_NOWAIT
+
+#include "common/time.h"
+
+#include <stdint.h>
+
+// We need to use uint64_t because sizeof(long) == 4 on Windows
+const char* ffGetCpuUsageInfo(uint64_t* inUseAll, uint64_t* totalAll);
+
+static uint64_t inUseAll1, totalAll1, startTime;
+
+void ffPrepareCPUUsage()
+{
+    startTime = ffTimeGetTick();
+    ffGetCpuUsageInfo(&inUseAll1, &totalAll1);
+}
+
+const char* ffGetCpuUsageResult(double* result)
+{
+    const char* error = NULL;
+    if(startTime == 0)
+    {
+        error = ffGetCpuUsageInfo(&inUseAll1, &totalAll1);
+        if(error)
+            return error;
+        ffTimeSleep(1000);
+    }
+    else
+    {
+        uint64_t duration = ffTimeGetTick() - startTime;
+        if(duration < 1000)
+            ffTimeSleep(1000 - (uint32_t) duration);
+    }
+
+    uint64_t inUseAll2, totalAll2;
+    error = ffGetCpuUsageInfo(&inUseAll2, &totalAll2);
+    if(error)
+        return error;
+
+    *result = (double)(inUseAll2 - inUseAll1) / (double)(totalAll2 - totalAll1) * 100;
+
+    return NULL;
+}
+
+#else //FF_DETECTION_CPUUSAGE_NOWAIT
+
+const char* ffGetCpuUsageResultNoWait(double* result);
+
+void ffPrepareCPUUsage() {}
+
+const char* ffGetCpuUsageResult(double* result) {
+    return ffGetCpuUsageResultNoWait(result);
+}
+
+#endif //FF_DETECTION_CPUUSAGE_NOWAIT

src/detection/cpuUsage/cpuUsage.h

@@ -3,9 +3,10 @@
 #ifndef FF_INCLUDED_detection_cpu_cpuUsage
 #define FF_INCLUDED_detection_cpu_cpuUsage
 
-#include <stdint.h>
+#if defined(_WIN32) || defined(__CYGWIN__)
+    #define FF_DETECTION_CPUUSAGE_NOWAIT 1
+#endif
 
-// We need to use uint64_t because sizeof(long) == 4 on Windows
-const char* ffGetCpuUsageInfo(uint64_t* inUseAll, uint64_t* totalAll);
+const char* ffGetCpuUsageResult(double* result);
 
 #endif

src/detection/cpuUsage/cpuUsage_nowait_windows.cpp

@@ -0,0 +1,26 @@
+extern "C" {
+#include "cpuUsage.h"
+}
+#include "util/windows/wmi.hpp"
+
+extern "C" const char* ffGetCpuUsageResultNoWait(double* result)
+{
+    IEnumWbemClassObject* pEnumerator = ffQueryWmi(L"SELECT LoadPercentage FROM Win32_Processor", nullptr);
+    if(!pEnumerator)
+        return "Query WMI service failed";
+
+    IWbemClassObject *pclsObj = NULL;
+    ULONG uReturn = 0;
+
+    if(FAILED(pEnumerator->Next(WBEM_INFINITE, 1, &pclsObj, &uReturn)) || uReturn == 0)
+    {
+        pEnumerator->Release();
+        return "No WMI result returned";
+    }
+
+    ffGetWmiObjReal(pclsObj, L"LoadPercentage", result);
+
+    pclsObj->Release();
+    pEnumerator->Release();
+    return NULL;
+}