Add new process package

Signed-off-by: Kevin Parsons <kevpar@microsoft.com>

pkg/process/process.go

@@ -0,0 +1,86 @@
+package process
+
+import (
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+// EnumProcesses returns a slice containing the process IDs of all processes
+// currently running on the system.
+func EnumProcesses() ([]uint32, error) {
+	count := 256
+	uint32Size := unsafe.Sizeof(uint32(0))
+	for {
+		buf := make([]uint32, count)
+		bufferSize := uint32(len(buf) * int(uint32Size))
+		retBufferSize := uint32(0)
+		if err := enumProcesses(&buf[0], bufferSize, &retBufferSize); err != nil {
+			return nil, err
+		}
+		if retBufferSize == bufferSize {
+			count = count * 2
+			continue
+		}
+		actualCount := retBufferSize / uint32(uint32Size)
+		return buf[:actualCount], nil
+	}
+}
+
+// ProcessMemoryCountersEx is the PROCESS_MEMORY_COUNTERS_EX struct from
+// Windows:
+// https://docs.microsoft.com/en-us/windows/win32/api/psapi/ns-psapi-process_memory_counters_ex
+type ProcessMemoryCountersEx struct {
+	Cb                         uint32
+	PageFaultCount             uint32
+	PeakWorkingSetSize         uint
+	WorkingSetSize             uint
+	QuotaPeakPagedPoolUsage    uint
+	QuotaPagedPoolUsage        uint
+	QuotaPeakNonPagedPoolUsage uint
+	QuotaNonPagedPoolUsage     uint
+	PagefileUsage              uint
+	PeakPagefileUsage          uint
+	PrivateUsage               uint
+}
+
+// GetProcessMemoryInfo returns the memory usage information for the given
+// process. The process handle must have the PROCESS_QUERY_INFORMATION or
+// PROCESS_QUERY_LIMITED_INFORMATION, and the PROCESS_VM_READ access rights.
+func GetProcessMemoryInfo(process windows.Handle) (*ProcessMemoryCountersEx, error) {
+	memCounters := &ProcessMemoryCountersEx{}
+	size := unsafe.Sizeof(*memCounters)
+	if err := getProcessMemoryInfo(process, memCounters, uint32(size)); err != nil {
+		return nil, err
+	}
+	return memCounters, nil
+}
+
+// These constants are used with QueryFullProcessImageName's flags.
+const (
+	// ImageNameFormatWin32Path indicates to format the name as a Win32 path.
+	ImageNameFormatWin32Path = iota
+	// ImageNameFormatNTPath indicates to format the name as a NT path.
+	ImageNameFormatNTPath
+)
+
+// QueryFullProcessImageName returns the full process image name for the given
+// process. The process handle must have the PROCESS_QUERY_INFORMATION or
+// PROCESS_QUERY_LIMITED_INFORMATION access right. The flags can be either
+// `ImageNameFormatWin32Path` or `ImageNameFormatNTPath`.
+func QueryFullProcessImageName(process windows.Handle, flags uint32) (string, error) {
+	bufferSize := uint32(256)
+	for {
+		b := make([]uint16, bufferSize)
+		err := queryFullProcessImageName(process, flags, &b[0], &bufferSize)
+		if err == windows.ERROR_INSUFFICIENT_BUFFER {
+			bufferSize = bufferSize * 2
+			continue
+		}
+		if err != nil {
+			return "", err
+		}
+		return windows.UTF16ToString(b[:bufferSize]), nil
+	}
+
+}