Add GetProcessMemoryInfo (#2)

* Fix typo in uft16.go filename

* Add GetProcessMemoryInfo

* Add changelog

CHANGELOG.md

@@ -0,0 +1,3 @@
+# Changelog
+
+* Add GetProcessMemoryInfo: [#2](https://github.com/elastic/go-windows/pull/2)

doc.go

@@ -20,4 +20,4 @@ package windows
 
 // Use "GOOS=windows go generate -v -x" to generate the sources.
 // Add -trace to enable debug prints around syscalls.
-//go:generate go run $GOROOT/src/syscall/mksyscall_windows.go -systemdll=false -output zsyscall_windows.go kernel32.go version.go
+//go:generate go run $GOROOT/src/syscall/mksyscall_windows.go -systemdll=false -output zsyscall_windows.go kernel32.go version.go psapi.go

psapi.go

@@ -0,0 +1,62 @@
+// Licensed to Elasticsearch B.V. under one or more contributor
+// license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright
+// ownership. Elasticsearch B.V. licenses this file to you under
+// the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+// +build windows
+
+package windows
+
+import (
+	"syscall"
+	"unsafe"
+
+	"github.com/pkg/errors"
+)
+
+// Syscalls
+//sys   _GetProcessMemoryInfo(handle syscall.Handle, psmemCounters *ProcessMemoryCountersEx, cb uint32) (err error) = psapi.GetProcessMemoryInfo
+
+var (
+	sizeofProcessMemoryCountersEx = uint32(unsafe.Sizeof(ProcessMemoryCountersEx{}))
+)
+
+// ProcessMemoryCountersEx is an equivalent representation of
+// PROCESS_MEMORY_COUNTERS_EX in the Windows API. It contains information about
+// the memory usage of a process.
+// https://docs.microsoft.com/en-au/windows/desktop/api/psapi/ns-psapi-_process_memory_counters_ex
+type ProcessMemoryCountersEx struct {
+	cb                         uint32
+	PageFaultCount             uint32
+	PeakWorkingSetSize         uintptr
+	WorkingSetSize             uintptr
+	QuotaPeakPagedPoolUsage    uintptr
+	QuotaPagedPoolUsage        uintptr
+	QuotaPeakNonPagedPoolUsage uintptr
+	QuotaNonPagedPoolUsage     uintptr
+	PagefileUsage              uintptr
+	PeakPagefileUsage          uintptr
+	PrivateUsage               uintptr
+}
+
+// GetProcessMemoryInfo retrieves memory info for the given process handle.
+// https://docs.microsoft.com/en-us/windows/desktop/api/psapi/nf-psapi-getprocessmemoryinfo
+func GetProcessMemoryInfo(process syscall.Handle) (ProcessMemoryCountersEx, error) {
+	var info ProcessMemoryCountersEx
+	if err := _GetProcessMemoryInfo(process, &info, sizeofProcessMemoryCountersEx); err != nil {
+		return ProcessMemoryCountersEx{}, errors.Wrap(err, "GetProcessMemoryInfo failed")
+	}
+	return info, nil
+}

zsyscall_windows.go

@@ -37,6 +37,7 @@ func errnoErr(e syscall.Errno) error {
 var (
 	modkernel32 = syscall.NewLazyDLL("kernel32.dll")
 	modversion  = syscall.NewLazyDLL("version.dll")
+	modpsapi    = syscall.NewLazyDLL("psapi.dll")
 
 	procGetNativeSystemInfo     = modkernel32.NewProc("GetNativeSystemInfo")
 	procGetTickCount64          = modkernel32.NewProc("GetTickCount64")
@@ -45,6 +46,7 @@ var (
 	procGetFileVersionInfoW     = modversion.NewProc("GetFileVersionInfoW")
 	procGetFileVersionInfoSizeW = modversion.NewProc("GetFileVersionInfoSizeW")
 	procVerQueryValueW          = modversion.NewProc("VerQueryValueW")
+	procGetProcessMemoryInfo    = modpsapi.NewProc("GetProcessMemoryInfo")
 )
 
 func _GetNativeSystemInfo(systemInfo *SystemInfo) (err error) {
@@ -161,3 +163,15 @@ func __VerQueryValueW(data *byte, subBlock *uint16, pBuffer *uintptr, len *uint3
 	}
 	return
 }
+
+func _GetProcessMemoryInfo(handle syscall.Handle, psmemCounters *ProcessMemoryCountersEx, cb uint32) (err error) {
+	r1, _, e1 := syscall.Syscall(procGetProcessMemoryInfo.Addr(), 3, uintptr(handle), uintptr(unsafe.Pointer(psmemCounters)), uintptr(cb))
+	if r1 == 0 {
+		if e1 != 0 {
+			err = errnoErr(e1)
+		} else {
+			err = syscall.EINVAL
+		}
+	}
+	return
+}