IMG-52: rename metrics to monitoring (#1498)

* Removed bufpool

* metrics -> monitoring

* metricsMeta -> monitoringMeta

* monitoring.Meta -> Filter

bufpool/bufpool.go

@@ -1,302 +0,0 @@
-package bufpool
-
-// Based on https://github.com/valyala/bytebufferpool ideas
-
-import (
-	"bytes"
-	"runtime"
-	"sync"
-	"sync/atomic"
-
-	"github.com/imgproxy/imgproxy/v3/config"
-	"github.com/imgproxy/imgproxy/v3/metrics"
-)
-
-const (
-	minBitSize = 6 // 2**6=64 is min bytes.Buffer capacity
-	steps      = 20
-
-	minSize = 1 << minBitSize
-)
-
-var entriesPool = sync.Pool{
-	New: func() any {
-		return new(entry)
-	},
-}
-
-type entry struct {
-	buf        *bytes.Buffer
-	prev, next *entry
-}
-
-type Pool struct {
-	name        string
-	defaultSize int
-	maxSize     uint64
-	root        *entry
-
-	maxLen int
-
-	calls    [steps]uint64
-	tmpCalls [steps]uint64
-	callsNum uint64
-
-	storeMu       sync.Mutex
-	calibratingMu sync.Mutex
-}
-
-func New(name string, n int, defaultSize int) *Pool {
-	pool := Pool{
-		name:        name,
-		defaultSize: defaultSize,
-		root:        &entry{},
-		maxLen:      n,
-	}
-
-	return &pool
-}
-
-func (p *Pool) insert(buf *bytes.Buffer) {
-	e := entriesPool.Get().(*entry)
-	e.buf = buf
-	e.next = p.root.next
-	e.prev = p.root
-
-	p.root.next = e
-}
-
-func (p *Pool) remove(e *entry) {
-	if e.next != nil {
-		e.next.prev = e.prev
-	}
-
-	e.prev.next = e.next
-
-	saveEntry(e)
-}
-
-func (p *Pool) calibrateAndClean() {
-	if !p.calibratingMu.TryLock() {
-		return
-	}
-	defer p.calibratingMu.Unlock()
-
-	var callsSum uint64
-	for i := 0; i < steps; i++ {
-		calls := atomic.SwapUint64(&p.calls[i], 0)
-		callsSum += calls
-		p.tmpCalls[i] = calls
-	}
-
-	if callsSum < uint64(config.BufferPoolCalibrationThreshold) {
-		return
-	}
-
-	atomic.StoreUint64(&p.callsNum, 0)
-
-	defSum := uint64(float64(callsSum) * 0.5)
-	maxSum := uint64(float64(callsSum) * 0.95)
-
-	defStep := -1
-	maxStep := -1
-
-	callsSum = 0
-	for i := 0; i < steps; i++ {
-		callsSum += p.tmpCalls[i]
-
-		if defStep < 0 && callsSum > defSum {
-			defStep = i
-		}
-
-		if callsSum > maxSum {
-			maxStep = i
-			break
-		}
-	}
-
-	p.defaultSize = minSize << defStep
-	p.maxSize = minSize << maxStep
-
-	maxSize := int(p.maxSize)
-
-	metrics.SetBufferDefaultSize(p.name, p.defaultSize)
-	metrics.SetBufferMaxSize(p.name, maxSize)
-
-	p.storeMu.Lock()
-	storeUnlocked := false
-	defer func() {
-		if !storeUnlocked {
-			p.storeMu.Unlock()
-		}
-	}()
-
-	cleaned := false
-	last := p.root
-
-	poolLen := 0
-
-	for entry := p.root.next; entry != nil; entry = last.next {
-		if poolLen >= p.maxLen || entry.buf.Cap() > maxSize {
-			last.next = entry.next
-			saveEntry(entry)
-
-			cleaned = true
-		} else {
-			last.next = entry
-			entry.prev = last
-			last = entry
-
-			poolLen++
-		}
-	}
-
-	// early unlock
-	p.storeMu.Unlock()
-	storeUnlocked = true
-
-	if cleaned {
-		runtime.GC()
-	}
-}
-
-func (p *Pool) Get(size int, grow bool) *bytes.Buffer {
-	p.storeMu.Lock()
-	storeUnlocked := false
-	defer func() {
-		if !storeUnlocked {
-			p.storeMu.Unlock()
-		}
-	}()
-
-	best := (*entry)(nil)
-	bestCap := -1
-
-	min := (*entry)(nil)
-	minCap := -1
-
-	for entry := p.root.next; entry != nil; entry = entry.next {
-		cap := entry.buf.Cap()
-
-		if size > 0 {
-			// If we know the required size, pick a buffer with the smallest size
-			// that is larger than the requested size
-			if cap >= size && (bestCap > cap || best == nil) {
-				best = entry
-				bestCap = cap
-			}
-
-			if cap < minCap || minCap == -1 {
-				min = entry
-				minCap = cap
-			}
-		} else if cap > bestCap {
-			// If we don't know the requested size, pick a largest buffer
-			best = entry
-			bestCap = cap
-		}
-	}
-
-	var buf *bytes.Buffer
-
-	switch {
-	case best != nil:
-		buf = best.buf
-		p.remove(best)
-	case min != nil:
-		buf = min.buf
-		p.remove(min)
-	default:
-		buf = new(bytes.Buffer)
-	}
-
-	// early unlock
-	p.storeMu.Unlock()
-	storeUnlocked = true
-
-	buf.Reset()
-
-	growSize := p.defaultSize
-	if grow {
-		growSize = max(p.normalizeCap(size), growSize)
-	}
-
-	// Grow the buffer only if we know the requested size and it is smaller than
-	// or equal to the grow size. Otherwise we'll grow the buffer twice
-	if size > 0 && size <= growSize && growSize > buf.Cap() {
-		buf.Grow(growSize)
-	}
-
-	return buf
-}
-
-func (p *Pool) Put(buf *bytes.Buffer) {
-	bufLen := buf.Len()
-	bufCap := buf.Cap()
-
-	if bufLen > 0 {
-		ind := index(bufLen)
-
-		atomic.AddUint64(&p.calls[ind], 1)
-
-		if atomic.AddUint64(&p.callsNum, 1) >= uint64(config.BufferPoolCalibrationThreshold) {
-			p.calibrateAndClean()
-		}
-	}
-
-	size := buf.Cap()
-	maxSize := int(atomic.LoadUint64(&p.maxSize))
-	if maxSize > 0 && size > maxSize {
-		return
-	}
-
-	if bufLen > 0 {
-		metrics.ObserveBufferSize(p.name, bufCap)
-	}
-
-	p.storeMu.Lock()
-	defer p.storeMu.Unlock()
-
-	p.insert(buf)
-}
-
-// GrowBuffer growth capacity of the buffer to the normalized provided value
-func (p *Pool) GrowBuffer(buf *bytes.Buffer, cap int) {
-	cap = p.normalizeCap(cap)
-	if buf.Cap() < cap {
-		buf.Grow(cap - buf.Len())
-	}
-}
-
-func (p *Pool) normalizeCap(cap int) int {
-	// Don't normalize cap if it's larger than maxSize
-	// since we'll throw this buf out anyway
-	maxSize := int(atomic.LoadUint64(&p.maxSize))
-	if maxSize > 0 && cap > maxSize {
-		return cap
-	}
-
-	ind := index(cap)
-	return max(cap, minSize<<ind)
-}
-
-func saveEntry(e *entry) {
-	e.buf = nil
-	e.next = nil
-	e.prev = nil
-	entriesPool.Put(e)
-}
-
-func index(n int) int {
-	n--
-	n >>= minBitSize
-	idx := 0
-	for n > 0 {
-		n >>= 1
-		idx++
-	}
-	if idx >= steps {
-		idx = steps - 1
-	}
-	return idx
-}

bufpool/bufpool_test.go

@@ -1,48 +0,0 @@
-package bufpool
-
-import (
-	"math/rand"
-	"sync"
-	"testing"
-
-	"github.com/imgproxy/imgproxy/v3/config"
-)
-
-var (
-	testData     [][]byte
-	testDataOnce sync.Once
-	testMu       sync.Mutex
-)
-
-func initTestData() {
-	testData = make([][]byte, 1000)
-	for i := 6; i < 1000; i++ {
-		testData[i] = make([]byte, i*1271)
-	}
-
-	rand.Shuffle(len(testData), func(i, j int) { testData[i], testData[j] = testData[j], testData[i] })
-}
-
-func BenchmarkBufpool(b *testing.B) {
-	testMu.Lock()
-	defer testMu.Unlock()
-
-	config.Reset()
-
-	testDataOnce.Do(initTestData)
-
-	pool := New("test", 16, 0)
-
-	b.ResetTimer()
-	b.SetParallelism(16)
-
-	b.RunParallel(func(pb *testing.PB) {
-		for pb.Next() {
-			for _, bb := range testData {
-				buf := pool.Get(len(bb), false)
-				buf.Write(bb)
-				pool.Put(buf)
-			}
-		}
-	})
-}

main.go

@@ -20,8 +20,8 @@ import (
 	"github.com/imgproxy/imgproxy/v3/imagedata"
 	"github.com/imgproxy/imgproxy/v3/logger"
 	"github.com/imgproxy/imgproxy/v3/memory"
-	"github.com/imgproxy/imgproxy/v3/metrics"
-	"github.com/imgproxy/imgproxy/v3/metrics/prometheus"
+	"github.com/imgproxy/imgproxy/v3/monitoring"
+	"github.com/imgproxy/imgproxy/v3/monitoring/prometheus"
 	"github.com/imgproxy/imgproxy/v3/options"
 	"github.com/imgproxy/imgproxy/v3/processing"
 	"github.com/imgproxy/imgproxy/v3/server"
@@ -40,7 +40,7 @@ func buildRouter(r *server.Router) *server.Router {
 
 	r.GET(
 		"/", false, handleProcessing,
-		r.WithSecret, r.WithCORS, r.WithPanic, r.WithReportError, r.WithMetrics,
+		r.WithSecret, r.WithCORS, r.WithPanic, r.WithReportError, r.WithMonitoring,
 	)
 
 	r.HEAD("/", false, r.OkHandler, r.WithCORS)
@@ -72,7 +72,7 @@ func initialize() error {
 		return err
 	}
 
-	if err := metrics.Init(); err != nil {
+	if err := monitoring.Init(); err != nil {
 		return err
 	}
 
@@ -108,7 +108,7 @@ func initialize() error {
 
 func shutdown() {
 	vips.Shutdown()
-	metrics.Stop()
+	monitoring.Stop()
 	errorreport.Close()
 }
 

monitoring/cloudwatch/cloudwatch.go

@@ -14,7 +14,7 @@ import (
 	"github.com/sirupsen/logrus"
 
 	"github.com/imgproxy/imgproxy/v3/config"
-	"github.com/imgproxy/imgproxy/v3/metrics/stats"
+	"github.com/imgproxy/imgproxy/v3/monitoring/stats"
 )
 
 type GaugeFunc func() float64

monitoring/datadog/datadog.go

@@ -17,8 +17,8 @@ import (
 	log "github.com/sirupsen/logrus"
 
 	"github.com/imgproxy/imgproxy/v3/config"
-	"github.com/imgproxy/imgproxy/v3/metrics/errformat"
-	"github.com/imgproxy/imgproxy/v3/metrics/stats"
+	"github.com/imgproxy/imgproxy/v3/monitoring/errformat"
+	"github.com/imgproxy/imgproxy/v3/monitoring/stats"
 	"github.com/imgproxy/imgproxy/v3/version"
 )
 

monitoring/monitoring.go

@@ -1,14 +1,14 @@
-package metrics
+package monitoring
 
 import (
 	"context"
 	"net/http"
 
-	"github.com/imgproxy/imgproxy/v3/metrics/cloudwatch"
-	"github.com/imgproxy/imgproxy/v3/metrics/datadog"
-	"github.com/imgproxy/imgproxy/v3/metrics/newrelic"
-	"github.com/imgproxy/imgproxy/v3/metrics/otel"
-	"github.com/imgproxy/imgproxy/v3/metrics/prometheus"
+	"github.com/imgproxy/imgproxy/v3/monitoring/cloudwatch"
+	"github.com/imgproxy/imgproxy/v3/monitoring/datadog"
+	"github.com/imgproxy/imgproxy/v3/monitoring/newrelic"
+	"github.com/imgproxy/imgproxy/v3/monitoring/otel"
+	"github.com/imgproxy/imgproxy/v3/monitoring/prometheus"
 )
 
 const (
@@ -19,6 +19,17 @@ const (
 
 type Meta map[string]any
 
+// Filter creates a copy of Meta with only the specified keys.
+func (m Meta) Filter(only ...string) Meta {
+	filtered := make(Meta)
+	for _, key := range only {
+		if value, ok := m[key]; ok {
+			filtered[key] = value
+		}
+	}
+	return filtered
+}
+
 func Init() error {
 	prometheus.Init()
 

monitoring/monitoring_test.go

@@ -0,0 +1,37 @@
+package monitoring
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestMetaFilter(t *testing.T) {
+	// Create a Meta with some test data
+	meta := Meta{
+		"key1": "value1",
+		"key2": "value2",
+		"key3": "value3",
+		"key4": 42,
+	}
+
+	// Test filtering with existing keys
+	filtered := meta.Filter("key1", "key3")
+
+	// Check that filtered meta has the correct keys
+	require.Len(t, filtered, 2)
+	require.Equal(t, "value1", filtered["key1"])
+	require.Equal(t, "value3", filtered["key3"])
+
+	// Check that non-requested keys are not present
+	require.NotContains(t, filtered, "key2")
+	require.NotContains(t, filtered, "key4")
+
+	// Test filtering with non-existing keys
+	filtered2 := meta.Filter("nonexistent")
+	require.Empty(t, filtered2)
+
+	// Test filtering with empty parameters
+	filtered3 := meta.Filter()
+	require.Empty(t, filtered3)
+}

monitoring/newrelic/newrelic.go

@@ -15,8 +15,8 @@ import (
 	log "github.com/sirupsen/logrus"
 
 	"github.com/imgproxy/imgproxy/v3/config"
-	"github.com/imgproxy/imgproxy/v3/metrics/errformat"
-	"github.com/imgproxy/imgproxy/v3/metrics/stats"
+	"github.com/imgproxy/imgproxy/v3/monitoring/errformat"
+	"github.com/imgproxy/imgproxy/v3/monitoring/stats"
 )
 
 type transactionCtxKey struct{}

monitoring/otel/otel.go

@@ -44,8 +44,8 @@ import (
 	"github.com/imgproxy/imgproxy/v3/config"
 	"github.com/imgproxy/imgproxy/v3/config/configurators"
 	"github.com/imgproxy/imgproxy/v3/ierrors"
-	"github.com/imgproxy/imgproxy/v3/metrics/errformat"
-	"github.com/imgproxy/imgproxy/v3/metrics/stats"
+	"github.com/imgproxy/imgproxy/v3/monitoring/errformat"
+	"github.com/imgproxy/imgproxy/v3/monitoring/stats"
 	"github.com/imgproxy/imgproxy/v3/version"
 )
 

monitoring/prometheus/prometheus.go

@@ -13,7 +13,7 @@ import (
 	log "github.com/sirupsen/logrus"
 
 	"github.com/imgproxy/imgproxy/v3/config"
-	"github.com/imgproxy/imgproxy/v3/metrics/stats"
+	"github.com/imgproxy/imgproxy/v3/monitoring/stats"
 	"github.com/imgproxy/imgproxy/v3/reuseport"
 )
 

processing_handler.go

@@ -22,8 +22,8 @@ import (
 	"github.com/imgproxy/imgproxy/v3/imagedata"
 	"github.com/imgproxy/imgproxy/v3/imagefetcher"
 	"github.com/imgproxy/imgproxy/v3/imagetype"
-	"github.com/imgproxy/imgproxy/v3/metrics"
-	"github.com/imgproxy/imgproxy/v3/metrics/stats"
+	"github.com/imgproxy/imgproxy/v3/monitoring"
+	"github.com/imgproxy/imgproxy/v3/monitoring/stats"
 	"github.com/imgproxy/imgproxy/v3/options"
 	"github.com/imgproxy/imgproxy/v3/processing"
 	"github.com/imgproxy/imgproxy/v3/security"
@@ -261,13 +261,13 @@ func handleProcessing(reqID string, rw http.ResponseWriter, r *http.Request) err
 	errorreport.SetMetadata(r, "Source Image Origin", imageOrigin)
 	errorreport.SetMetadata(r, "Processing Options", po)
 
-	metricsMeta := metrics.Meta{
-		metrics.MetaSourceImageURL:    imageURL,
-		metrics.MetaSourceImageOrigin: imageOrigin,
-		metrics.MetaProcessingOptions: po.Diff().Flatten(),
+	monitoringMeta := monitoring.Meta{
+		monitoring.MetaSourceImageURL:    imageURL,
+		monitoring.MetaSourceImageOrigin: imageOrigin,
+		monitoring.MetaProcessingOptions: po.Diff().Flatten(),
 	}
 
-	metrics.SetMetadata(ctx, metricsMeta)
+	monitoring.SetMetadata(ctx, monitoringMeta)
 
 	err = security.VerifySourceURL(imageURL)
 	if err != nil {
@@ -316,7 +316,7 @@ func handleProcessing(reqID string, rw http.ResponseWriter, r *http.Request) err
 
 	// The heavy part starts here, so we need to restrict worker number
 	err = func() error {
-		defer metrics.StartQueueSegment(ctx)()
+		defer monitoring.StartQueueSegment(ctx)()
 
 		err = processingSem.Acquire(ctx, 1)
 		if err != nil {
@@ -346,10 +346,10 @@ func handleProcessing(reqID string, rw http.ResponseWriter, r *http.Request) err
 	statusCode := http.StatusOK
 
 	originData, originHeaders, err := func() (imagedata.ImageData, http.Header, error) {
-		downloadFinished := metrics.StartDownloadingSegment(ctx, metrics.Meta{
-			metrics.MetaSourceImageURL:    metricsMeta[metrics.MetaSourceImageURL],
-			metrics.MetaSourceImageOrigin: metricsMeta[metrics.MetaSourceImageOrigin],
-		})
+		downloadFinished := monitoring.StartDownloadingSegment(ctx, monitoringMeta.Filter(
+			monitoring.MetaSourceImageURL,
+			monitoring.MetaSourceImageOrigin,
+		))
 
 		downloadOpts := imagedata.DownloadOptions{
 			Header:           imgRequestHeader,
@@ -399,7 +399,7 @@ func handleProcessing(reqID string, rw http.ResponseWriter, r *http.Request) err
 		}
 
 		// Just send error
-		metrics.SendError(ctx, categoryDownload, ierr)
+		monitoring.SendError(ctx, categoryDownload, ierr)
 
 		// We didn't return, so we have to report error
 		if ierr.ShouldReport() {
@@ -452,9 +452,7 @@ func handleProcessing(reqID string, rw http.ResponseWriter, r *http.Request) err
 	}
 
 	result, err := func() (*processing.Result, error) {
-		defer metrics.StartProcessingSegment(ctx, metrics.Meta{
-			metrics.MetaProcessingOptions: metricsMeta[metrics.MetaProcessingOptions],
-		})()
+		defer monitoring.StartProcessingSegment(ctx, monitoringMeta.Filter(monitoring.MetaProcessingOptions))()
 		return processing.ProcessImage(ctx, originData, po)
 	}()
 

server/middlewares.go

@@ -10,22 +10,22 @@ import (
 	"github.com/imgproxy/imgproxy/v3/errorreport"
 	"github.com/imgproxy/imgproxy/v3/httpheaders"
 	"github.com/imgproxy/imgproxy/v3/ierrors"
-	"github.com/imgproxy/imgproxy/v3/metrics"
+	"github.com/imgproxy/imgproxy/v3/monitoring"
 )
 
 const (
 	categoryTimeout = "timeout"
 )
 
-// WithMetrics wraps RouteHandler with metrics handling.
-func (r *Router) WithMetrics(h RouteHandler) RouteHandler {
-	if !metrics.Enabled() {
+// WithMonitoring wraps RouteHandler with monitoring handling.
+func (r *Router) WithMonitoring(h RouteHandler) RouteHandler {
+	if !monitoring.Enabled() {
 		return h
 	}
 
 	return func(reqID string, rw http.ResponseWriter, req *http.Request) error {
-		ctx, metricsCancel, rw := metrics.StartRequest(req.Context(), rw, req)
-		defer metricsCancel()
+		ctx, cancel, rw := monitoring.StartRequest(req.Context(), rw, req)
+		defer cancel()
 
 		return h(reqID, rw, req.WithContext(ctx))
 	}
@@ -92,7 +92,7 @@ func (r *Router) WithPanic(h RouteHandler) RouteHandler {
 }
 
 // WithReportError handles error reporting.
-// It should be placed after `WithMetrics`, but before `WithPanic`.
+// It should be placed after `WithMonitoring`, but before `WithPanic`.
 func (r *Router) WithReportError(h RouteHandler) RouteHandler {
 	return func(reqID string, rw http.ResponseWriter, req *http.Request) error {
 		// Open the error context
@@ -119,7 +119,7 @@ func (r *Router) WithReportError(h RouteHandler) RouteHandler {
 
 		// We do not need to send any canceled context
 		if !errors.Is(ierr, context.Canceled) {
-			metrics.SendError(ctx, errCat, err)
+			monitoring.SendError(ctx, errCat, err)
 		}
 
 		// Report error to error collectors

stream.go

@@ -14,8 +14,8 @@ import (
 	"github.com/imgproxy/imgproxy/v3/httpheaders"
 	"github.com/imgproxy/imgproxy/v3/ierrors"
 	"github.com/imgproxy/imgproxy/v3/imagedata"
-	"github.com/imgproxy/imgproxy/v3/metrics"
-	"github.com/imgproxy/imgproxy/v3/metrics/stats"
+	"github.com/imgproxy/imgproxy/v3/monitoring"
+	"github.com/imgproxy/imgproxy/v3/monitoring/stats"
 	"github.com/imgproxy/imgproxy/v3/options"
 	"github.com/imgproxy/imgproxy/v3/server"
 )
@@ -48,8 +48,7 @@ var (
 func streamOriginImage(ctx context.Context, reqID string, r *http.Request, rw http.ResponseWriter, po *options.ProcessingOptions, imageURL string) error {
 	stats.IncImagesInProgress()
 	defer stats.DecImagesInProgress()
-
-	defer metrics.StartStreamingSegment(ctx)()
+	defer monitoring.StartStreamingSegment(ctx)()
 
 	var (
 		cookieJar http.CookieJar

vips/vips.go

@@ -27,11 +27,11 @@ import (
 	"github.com/imgproxy/imgproxy/v3/ierrors"
 	"github.com/imgproxy/imgproxy/v3/imagedata"
 	"github.com/imgproxy/imgproxy/v3/imagetype"
-	"github.com/imgproxy/imgproxy/v3/metrics/cloudwatch"
-	"github.com/imgproxy/imgproxy/v3/metrics/datadog"
-	"github.com/imgproxy/imgproxy/v3/metrics/newrelic"
-	"github.com/imgproxy/imgproxy/v3/metrics/otel"
-	"github.com/imgproxy/imgproxy/v3/metrics/prometheus"
+	"github.com/imgproxy/imgproxy/v3/monitoring/cloudwatch"
+	"github.com/imgproxy/imgproxy/v3/monitoring/datadog"
+	"github.com/imgproxy/imgproxy/v3/monitoring/newrelic"
+	"github.com/imgproxy/imgproxy/v3/monitoring/otel"
+	"github.com/imgproxy/imgproxy/v3/monitoring/prometheus"
 )
 
 type Image struct {