1 files changed, 132 insertions, 0 deletions
diff --git a/vendor/github.com/elastic/gosigar/sys/windows/ntquery.go b/vendor/github.com/elastic/gosigar/sys/windows/ntquery.go
new file mode 100644
index 000000000..85de365e1
--- /dev/null
+++ b/vendor/github.com/elastic/gosigar/sys/windows/ntquery.go
@@ -0,0 +1,132 @@
+// +build windows
+
+package windows
+
+import (
+	"bytes"
+	"encoding/binary"
+	"io"
+	"runtime"
+	"syscall"
+	"time"
+	"unsafe"
+
+	"github.com/pkg/errors"
+)
+
+// On both 32-bit and 64-bit systems NtQuerySystemInformation expects the
+// size of SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION to be 48.
+const sizeofSystemProcessorPerformanceInformation = 48
+
+// ProcessBasicInformation is an equivalent representation of
+// PROCESS_BASIC_INFORMATION in the Windows API.
+// https://msdn.microsoft.com/en-us/library/windows/desktop/ms684280(v=vs.85).aspx
+type ProcessBasicInformation struct {
+	ExitStatus                   uint
+	PebBaseAddress               uintptr
+	AffinityMask                 uint
+	BasePriority                 uint
+	UniqueProcessID              uint
+	InheritedFromUniqueProcessID uint
+}
+
+// NtQueryProcessBasicInformation queries basic information about the process
+// associated with the given handle (provided by OpenProcess). It uses the
+// NtQueryInformationProcess function to collect the data.
+// https://msdn.microsoft.com/en-us/library/windows/desktop/ms684280(v=vs.85).aspx
+func NtQueryProcessBasicInformation(handle syscall.Handle) (ProcessBasicInformation, error) {
+	var processBasicInfo ProcessBasicInformation
+	processBasicInfoPtr := (*byte)(unsafe.Pointer(&processBasicInfo))
+	size := uint32(unsafe.Sizeof(processBasicInfo))
+	ntStatus, _ := _NtQueryInformationProcess(handle, 0, processBasicInfoPtr, size, nil)
+	if ntStatus != 0 {
+		return ProcessBasicInformation{}, errors.Errorf("NtQueryInformationProcess failed, NTSTATUS=0x%X", ntStatus)
+	}
+
+	return processBasicInfo, nil
+}
+
+// SystemProcessorPerformanceInformation contains CPU performance information
+// for a single CPU.
+type SystemProcessorPerformanceInformation struct {
+	IdleTime   time.Duration // Amount of time spent idle.
+	KernelTime time.Duration // Kernel time does NOT include time spent in idle.
+	UserTime   time.Duration // Amount of time spent executing in user mode.
+}
+
+// _SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION is an equivalent representation of
+// SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION in the Windows API. This struct is
+// used internally with NtQuerySystemInformation call and is not exported. The
+// exported equivalent is SystemProcessorPerformanceInformation.
+// https://msdn.microsoft.com/en-us/library/windows/desktop/ms724509(v=vs.85).aspx
+type _SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION struct {
+	IdleTime   int64
+	KernelTime int64
+	UserTime   int64
+	Reserved1  [2]int64
+	Reserved2  uint32
+}
+
+// NtQuerySystemProcessorPerformanceInformation queries CPU performance
+// information for each CPU. It uses the NtQuerySystemInformation function to
+// collect the SystemProcessorPerformanceInformation.
+// https://msdn.microsoft.com/en-us/library/windows/desktop/ms724509(v=vs.85).aspx
+func NtQuerySystemProcessorPerformanceInformation() ([]SystemProcessorPerformanceInformation, error) {
+	// NTSTATUS code for success.
+	// https://msdn.microsoft.com/en-us/library/cc704588.aspx
+	const STATUS_SUCCESS = 0
+
+	// From the _SYSTEM_INFORMATION_CLASS enum.
+	// http://processhacker.sourceforge.net/doc/ntexapi_8h.html#ad5d815b48e8f4da1ef2eb7a2f18a54e0
+	const systemProcessorPerformanceInformation = 8
+
+	// Create a buffer large enough to hold an entry for each processor.
+	b := make([]byte, runtime.NumCPU()*sizeofSystemProcessorPerformanceInformation)
+
+	// Query the performance information. Note that this function uses 0 to
+	// indicate success. Most other Windows functions use non-zero for success.
+	var returnLength uint32
+	ntStatus, _ := _NtQuerySystemInformation(systemProcessorPerformanceInformation, &b[0], uint32(len(b)), &returnLength)
+	if ntStatus != STATUS_SUCCESS {
+		return nil, errors.Errorf("NtQuerySystemInformation failed, NTSTATUS=0x%X, bufLength=%v, returnLength=%v", ntStatus, len(b), returnLength)
+	}
+
+	return readSystemProcessorPerformanceInformationBuffer(b)
+}
+
+// readSystemProcessorPerformanceInformationBuffer reads from a buffer
+// containing SYSTEM_PROCESSOR_PERFORMANCE_INFORMATION data. The buffer should
+// contain one entry for each CPU.
+// https://msdn.microsoft.com/en-us/library/windows/desktop/ms724509(v=vs.85).aspx
+func readSystemProcessorPerformanceInformationBuffer(b []byte) ([]SystemProcessorPerformanceInformation, error) {
+	n := len(b) / sizeofSystemProcessorPerformanceInformation
+	r := bytes.NewReader(b)
+
+	rtn := make([]SystemProcessorPerformanceInformation, 0, n)
+	for i := 0; i < n; i++ {
+		_, err := r.Seek(int64(i*sizeofSystemProcessorPerformanceInformation), io.SeekStart)
+		if err != nil {
+			return nil, errors.Wrapf(err, "failed to seek to cpuN=%v in buffer", i)
+		}
+
+		times := make([]uint64, 3)
+		for j := range times {
+			err := binary.Read(r, binary.LittleEndian, &times[j])
+			if err != nil {
+				return nil, errors.Wrapf(err, "failed reading cpu times for cpuN=%v", i)
+			}
+		}
+
+		idleTime := time.Duration(times[0] * 100)
+		kernelTime := time.Duration(times[1] * 100)
+		userTime := time.Duration(times[2] * 100)
+
+		rtn = append(rtn, SystemProcessorPerformanceInformation{
+			IdleTime:   idleTime,
+			KernelTime: kernelTime - idleTime, // Subtract out idle time from kernel time.
+			UserTime:   userTime,
+		})
+	}
+
+	return rtn, nil
+}