[pkg/winperfcounters] Add support to retrieve raw values (#39835)

Adding public methods that allow to retrieve the raw values of Windows
performance counters. This is needed to allow removal of the vendored
code under `receiver/hostmetricsreceiver/internal/perfcounters/` used
only by that component. This vendored code retrieves raw values of
counters instead of calculated ones, e.g.: it doesn't retrieve rate, but
the actual values used to calculate the rate of a counter. See
#38858 (comment)
for details.

Author: pjanotti

.chloggen/add-raw-value-scrape-to-winperfcounters.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: pkg/winperfcounters
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Add methods to scrape raw values from Windows performance counters.
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [39835]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [api]

pkg/winperfcounters/internal/third_party/telegraf/win_perf_counters/pdh.go

@@ -180,6 +180,8 @@ var (
 	pdh_ValidatePathW             *syscall.Proc
 	pdh_ExpandWildCardPathW       *syscall.Proc
 	pdh_GetCounterInfoW           *syscall.Proc
+	pdh_GetRawCounterValue        *syscall.Proc
+	pdh_GetRawCounterArrayW       *syscall.Proc
 )
 
 func init() {
@@ -198,6 +200,8 @@ func init() {
 	pdh_ValidatePathW = libpdhDll.MustFindProc("PdhValidatePathW")
 	pdh_ExpandWildCardPathW = libpdhDll.MustFindProc("PdhExpandWildCardPathW")
 	pdh_GetCounterInfoW = libpdhDll.MustFindProc("PdhGetCounterInfoW")
+	pdh_GetRawCounterValue = libpdhDll.MustFindProc("PdhGetRawCounterValue")
+	pdh_GetRawCounterArrayW = libpdhDll.MustFindProc("PdhGetRawCounterArrayW")
 }
 
 // PdhAddCounter adds the specified counter to the query. This is the internationalized version. Preferably, use the
@@ -498,3 +502,45 @@ func PdhGetCounterInfo(hCounter PDH_HCOUNTER, bRetrieveExplainText int, pdwBuffe
 
 	return uint32(ret)
 }
+
+// PdhGetRawCounterValue retrieves the current raw value of the specified counter.
+// hCounter [in]
+// Handle of the counter from which you want to retrieve the raw value. The PdhAddCounter function returns this handle.
+//
+// lpdwType [out]
+// Pointer to a variable that receives the counter type. For a list of counter types, see the Counter Types section of the Windows Server documentation.
+//
+// pValue [out]
+// Pointer to a PDH_RAW_COUNTER structure that receives the raw counter value.
+func PdhGetRawCounterValue(hCounter PDH_HCOUNTER, lpdwType *uint32, pValue *PDH_RAW_COUNTER) uint32 {
+	ret, _, _ := pdh_GetRawCounterValue.Call(
+		uintptr(hCounter),
+		uintptr(unsafe.Pointer(lpdwType)),
+		uintptr(unsafe.Pointer(pValue)),
+	)
+
+	return uint32(ret)
+}
+
+// PdhGetRawCounterArrayW retrieves an array of raw counter values for all instances of the specified counter.
+// hCounter [in]
+// Handle of the counter from which you want to retrieve the raw values. The PdhAddCounter function returns this handle.
+//
+// lpdwBufferSize [in, out]
+// Pointer to a variable that specifies the size of the buffer, in bytes. If the buffer is too small, the function sets this variable to the required buffer size.
+//
+// lpdwBufferCount [out]
+// Pointer to a variable that receives the number of elements in the buffer.
+//
+// itemBuffer [out]
+// Pointer to a buffer that receives an array of PDH_RAW_COUNTER_ITEM structures. Each structure contains the raw counter value for an instance.
+func PdhGetRawCounterArrayW(hCounter PDH_HCOUNTER, lpdwBufferSize *uint32, lpdwBufferCount *uint32, itemBuffer *byte) uint32 {
+	ret, _, _ := pdh_GetRawCounterArrayW.Call(
+		uintptr(hCounter),
+		uintptr(unsafe.Pointer(lpdwBufferSize)),
+		uintptr(unsafe.Pointer(lpdwBufferCount)),
+		uintptr(unsafe.Pointer(itemBuffer)),
+	)
+
+	return uint32(ret)
+}

pkg/winperfcounters/internal/third_party/telegraf/win_perf_counters/pdh_386.go

@@ -73,6 +73,24 @@ type PDH_FMT_COUNTERVALUE_ITEM_LONG struct {
 	FmtValue PDH_FMT_COUNTERVALUE_LONG
 }
 
+// PDH_RAW_COUNTER structure contains the raw data value of a counter.
+type PDH_RAW_COUNTER struct {
+	CStatus     uint32 // Counter status that indicates if the counter value is valid.
+	padding     [4]byte
+	TimeStamp   FILETIME // Time at which the sample was taken.
+	FirstValue  int64    // First raw counter value.
+	SecondValue int64    // Second raw counter value (used for some calculations).
+	MultiCount  uint32   // Counter type-specific value.
+	padding2    [4]byte
+}
+
+// PDH_RAW_COUNTER_ITEM structure contains the raw counter value for a specific instance.
+type PDH_RAW_COUNTER_ITEM struct {
+	SzName   *uint16 // Pointer to the instance name.
+	padding  [4]byte
+	RawValue PDH_RAW_COUNTER // Raw counter value for the instance.
+}
+
 // PDH_COUNTER_INFO structure contains information describing the properties of a counter. This information also includes the counter path.
 type PDH_COUNTER_INFO struct {
 	// Size of the structure, including the appended strings, in bytes.

pkg/winperfcounters/internal/third_party/telegraf/win_perf_counters/pdh_amd64.go

@@ -68,6 +68,21 @@ type PDH_FMT_COUNTERVALUE_ITEM_LONG struct {
 	FmtValue PDH_FMT_COUNTERVALUE_LONG
 }
 
+// PDH_RAW_COUNTER structure contains the raw data value of a counter.
+type PDH_RAW_COUNTER struct {
+	CStatus     uint32   // Counter status that indicates if the counter value is valid.
+	TimeStamp   FILETIME // Time at which the sample was taken.
+	FirstValue  int64    // First raw counter value.
+	SecondValue int64    // Second raw counter value (used for some calculations).
+	MultiCount  uint32   // Counter type-specific value.
+}
+
+// PDH_RAW_COUNTER_ITEM structure contains the raw counter value for a specific instance.
+type PDH_RAW_COUNTER_ITEM struct {
+	SzName   *uint16         // Pointer to the instance name.
+	RawValue PDH_RAW_COUNTER // Raw counter value for the instance.
+}
+
 // PDH_COUNTER_INFO structure contains information describing the properties of a counter. This information also includes the counter path.
 type PDH_COUNTER_INFO struct {
 	// Size of the structure, including the appended strings, in bytes.

pkg/winperfcounters/internal/third_party/telegraf/win_perf_counters/performance_query.go

@@ -11,12 +11,18 @@ import (
 	"unsafe"
 )
 
-// PerformanceQuery is abstraction for PDH_FMT_COUNTERVALUE_ITEM_DOUBLE
+// CounterValue is abstraction for PDH_FMT_COUNTERVALUE_ITEM_DOUBLE
 type CounterValue struct {
 	InstanceName string
 	Value        float64
 }
 
+// RawCounterValue is abstraction for PDH_RAW_COUNTER_ITEM
+type RawCounterValue struct {
+	InstanceName string
+	RawValue     int64
+}
+
 // PerformanceQuery provides wrappers around Windows performance counters API for easy usage in GO
 type PerformanceQuery interface {
 	Open() error
@@ -26,6 +32,8 @@ type PerformanceQuery interface {
 	GetCounterPath(counterHandle PDH_HCOUNTER) (string, error)
 	GetFormattedCounterValueDouble(hCounter PDH_HCOUNTER) (float64, error)
 	GetFormattedCounterArrayDouble(hCounter PDH_HCOUNTER) ([]CounterValue, error)
+	GetRawCounterValue(hCounter PDH_HCOUNTER) (int64, error)
+	GetRawCounterArray(hCounter PDH_HCOUNTER) ([]RawCounterValue, error)
 	CollectData() error
 	CollectDataWithTime() (time.Time, error)
 	IsVistaOrNewer() bool
@@ -163,6 +171,45 @@ func (m *PerformanceQueryImpl) GetFormattedCounterArrayDouble(hCounter PDH_HCOUN
 	return nil, NewPdhError(ret)
 }
 
+func (m *PerformanceQueryImpl) GetRawCounterValue(hCounter PDH_HCOUNTER) (int64, error) {
+	var counterType uint32
+	var rawValue PDH_RAW_COUNTER
+	var ret uint32
+
+	if ret = PdhGetRawCounterValue(hCounter, &counterType, &rawValue); ret == ERROR_SUCCESS {
+		if rawValue.CStatus == PDH_CSTATUS_VALID_DATA {
+			return rawValue.FirstValue, nil
+		} else {
+			return 0, NewPdhError(rawValue.CStatus)
+		}
+	} else {
+		return 0, NewPdhError(ret)
+	}
+}
+
+func (m *PerformanceQueryImpl) GetRawCounterArray(hCounter PDH_HCOUNTER) ([]RawCounterValue, error) {
+	var buffSize uint32
+	var itemCount uint32
+	var ret uint32
+
+	if ret = PdhGetRawCounterArrayW(hCounter, &buffSize, &itemCount, nil); ret == PDH_MORE_DATA {
+		buff := make([]byte, buffSize)
+
+		if ret = PdhGetRawCounterArrayW(hCounter, &buffSize, &itemCount, &buff[0]); ret == ERROR_SUCCESS {
+			items := unsafe.Slice((*PDH_RAW_COUNTER_ITEM)(unsafe.Pointer(&buff[0])), itemCount)
+			values := make([]RawCounterValue, 0, itemCount)
+			for _, item := range items {
+				if item.RawValue.CStatus == PDH_CSTATUS_VALID_DATA {
+					val := RawCounterValue{UTF16PtrToString(item.SzName), item.RawValue.FirstValue}
+					values = append(values, val)
+				}
+			}
+			return values, nil
+		}
+	}
+	return nil, NewPdhError(ret)
+}
+
 func (m *PerformanceQueryImpl) CollectData() error {
 	var ret uint32
 	if m.query == 0 {