disambiguate frontend types: rename frontend Request to MetricsQueryRequest

pkg/frontend/querymiddleware/blocker.go

@@ -15,7 +15,7 @@ import (
 )
 
 type queryBlockerMiddleware struct {
-	next                  Handler
+	next                  MetricsQueryHandler
 	limits                Limits
 	logger                log.Logger
 	blockedQueriesCounter *prometheus.CounterVec
@@ -25,12 +25,12 @@ func newQueryBlockerMiddleware(
 	limits Limits,
 	logger log.Logger,
 	registerer prometheus.Registerer,
-) Middleware {
+) MetricsQueryMiddleware {
 	blockedQueriesCounter := promauto.With(registerer).NewCounterVec(prometheus.CounterOpts{
 		Name: "cortex_query_frontend_rejected_queries_total",
 		Help: "Number of queries that were rejected by the cluster administrator.",
 	}, []string{"user", "reason"})
-	return MiddlewareFunc(func(next Handler) Handler {
+	return MetricsQueryMiddlewareFunc(func(next MetricsQueryHandler) MetricsQueryHandler {
 		return &queryBlockerMiddleware{
 			next:                  next,
 			limits:                limits,
@@ -40,7 +40,7 @@ func newQueryBlockerMiddleware(
 	})
 }
 
-func (qb *queryBlockerMiddleware) Do(ctx context.Context, req Request) (Response, error) {
+func (qb *queryBlockerMiddleware) Do(ctx context.Context, req MetricsQueryRequest) (Response, error) {
 	tenants, err := tenant.TenantIDs(ctx)
 	if err != nil {
 		return qb.next.Do(ctx, req)
@@ -56,7 +56,7 @@ func (qb *queryBlockerMiddleware) Do(ctx context.Context, req Request) (Response
 	return qb.next.Do(ctx, req)
 }
 
-func (qb *queryBlockerMiddleware) isBlocked(tenant string, req Request) bool {
+func (qb *queryBlockerMiddleware) isBlocked(tenant string, req MetricsQueryRequest) bool {
 	blocks := qb.limits.BlockedQueries(tenant)
 	if len(blocks) <= 0 {
 		return false

pkg/frontend/querymiddleware/blocker_test.go

@@ -20,15 +20,15 @@ import (
 func Test_queryBlocker_Do(t *testing.T) {
 	tests := []struct {
 		name           string
-		request        Request
+		request        MetricsQueryRequest
 		shouldContinue bool
 		limits         mockLimits
 	}{
 		{
 			name:           "doesn't block queries due to empty limits",
 			limits:         mockLimits{},
 			shouldContinue: true,
-			request: Request(&PrometheusRangeQueryRequest{
+			request: MetricsQueryRequest(&PrometheusRangeQueryRequest{
 				Query: "rate(metric_counter[5m])",
 			}),
 		},
@@ -39,7 +39,7 @@ func Test_queryBlocker_Do(t *testing.T) {
 					{Pattern: "rate(metric_counter[5m])", Regex: false},
 				},
 			},
-			request: Request(&PrometheusRangeQueryRequest{
+			request: MetricsQueryRequest(&PrometheusRangeQueryRequest{
 				Query: "rate(metric_counter[5m])",
 			}),
 		},
@@ -52,7 +52,7 @@ func Test_queryBlocker_Do(t *testing.T) {
 			},
 			shouldContinue: true,
 
-			request: Request(&PrometheusRangeQueryRequest{
+			request: MetricsQueryRequest(&PrometheusRangeQueryRequest{
 				Query: "rate(metric_counter[15m])",
 			}),
 		},
@@ -64,7 +64,7 @@ func Test_queryBlocker_Do(t *testing.T) {
 rate(other_counter[5m])`, Regex: false},
 				},
 			},
-			request: Request(&PrometheusRangeQueryRequest{
+			request: MetricsQueryRequest(&PrometheusRangeQueryRequest{
 				Query: `rate(metric_counter[5m])/
 rate(other_counter[5m])`,
 			}),
@@ -78,7 +78,7 @@ rate(other_counter[5m])`,
 			},
 			shouldContinue: true,
 
-			request: Request(&PrometheusRangeQueryRequest{
+			request: MetricsQueryRequest(&PrometheusRangeQueryRequest{
 				Query: `rate(metric_counter[15m])/
 rate(other_counter[15m])`,
 			}),
@@ -90,7 +90,7 @@ rate(other_counter[15m])`,
 					{Pattern: ".*metric_counter.*", Regex: true},
 				},
 			},
-			request: Request(&PrometheusRangeQueryRequest{
+			request: MetricsQueryRequest(&PrometheusRangeQueryRequest{
 				Query: "rate(metric_counter[5m])",
 			}),
 		},
@@ -102,7 +102,7 @@ rate(other_counter[15m])`,
 					{Pattern: "(?s).*metric_counter.*", Regex: true},
 				},
 			},
-			request: Request(&PrometheusRangeQueryRequest{
+			request: MetricsQueryRequest(&PrometheusRangeQueryRequest{
 				Query: `rate(other_counter[15m])/
 		rate(metric_counter[15m])`,
 			}),
@@ -116,7 +116,7 @@ rate(other_counter[15m])`,
 			},
 			shouldContinue: true,
 
-			request: Request(&PrometheusRangeQueryRequest{
+			request: MetricsQueryRequest(&PrometheusRangeQueryRequest{
 				Query: "rate(metric_counter[5m])",
 			}),
 		},
@@ -150,7 +150,7 @@ type mockNextHandler struct {
 	shouldContinue bool
 }
 
-func (h *mockNextHandler) Do(_ context.Context, _ Request) (Response, error) {
+func (h *mockNextHandler) Do(_ context.Context, _ MetricsQueryRequest) (Response, error) {
 	if !h.shouldContinue {
 		h.t.Error("The next middleware should not be called.")
 	}

pkg/frontend/querymiddleware/cardinality.go

@@ -34,23 +34,23 @@ const (
 	cacheErrorToleranceFraction = 0.1
 )
 
-// cardinalityEstimation is a Handler that caches estimates for a query's
+// cardinalityEstimation is a MetricsQueryHandler that caches estimates for a query's
 // cardinality based on similar queries seen previously.
 type cardinalityEstimation struct {
 	cache  cache.Cache
-	next   Handler
+	next   MetricsQueryHandler
 	logger log.Logger
 
 	estimationError prometheus.Histogram
 }
 
-func newCardinalityEstimationMiddleware(cache cache.Cache, logger log.Logger, registerer prometheus.Registerer) Middleware {
+func newCardinalityEstimationMiddleware(cache cache.Cache, logger log.Logger, registerer prometheus.Registerer) MetricsQueryMiddleware {
 	estimationError := promauto.With(registerer).NewHistogram(prometheus.HistogramOpts{
 		Name:    "cortex_query_frontend_cardinality_estimation_difference",
 		Help:    "Difference between estimated and actual query cardinality",
 		Buckets: prometheus.ExponentialBuckets(100, 2, 10),
 	})
-	return MiddlewareFunc(func(next Handler) Handler {
+	return MetricsQueryMiddlewareFunc(func(next MetricsQueryHandler) MetricsQueryHandler {
 		return &cardinalityEstimation{
 			cache:  cache,
 			next:   next,
@@ -63,7 +63,7 @@ func newCardinalityEstimationMiddleware(cache cache.Cache, logger log.Logger, re
 
 // Do injects a cardinality estimate into the query hints (if available) and
 // caches the actual cardinality observed for this query.
-func (c *cardinalityEstimation) Do(ctx context.Context, request Request) (Response, error) {
+func (c *cardinalityEstimation) Do(ctx context.Context, request MetricsQueryRequest) (Response, error) {
 	spanLog := spanlogger.FromContext(ctx, c.logger)
 
 	tenants, err := tenant.TenantIDs(ctx)
@@ -162,7 +162,7 @@ func isCardinalitySimilar(actualCardinality, estimatedCardinality uint64) bool {
 // with respect to both start time and range size. To avoid expiry of all
 // estimates at the bucket boundary, an offset is added based on the hash of the
 // query string.
-func generateCardinalityEstimationCacheKey(userID string, r Request, bucketSize time.Duration) string {
+func generateCardinalityEstimationCacheKey(userID string, r MetricsQueryRequest, bucketSize time.Duration) string {
 	hasher := fnv.New64a()
 	_, _ = hasher.Write([]byte(r.GetQuery()))
 

pkg/frontend/querymiddleware/cardinality_test.go

@@ -29,7 +29,7 @@ func Test_cardinalityEstimateBucket_QueryRequest_keyFormat(t *testing.T) {
 	tests := []struct {
 		name     string
 		userID   string
-		r        Request
+		r        MetricsQueryRequest
 		expected string
 	}{
 		{
@@ -133,7 +133,7 @@ func Test_cardinalityEstimation_Do(t *testing.T) {
 		Query: "up",
 	}
 	addSeriesHandler := func(estimate, actual uint64) HandlerFunc {
-		return func(ctx context.Context, request Request) (Response, error) {
+		return func(ctx context.Context, request MetricsQueryRequest) (Response, error) {
 			require.NotNil(t, request.GetHints())
 			request.GetHints().GetCardinalityEstimate()
 			require.Equal(t, request.GetHints().GetEstimatedSeriesCount(), estimate)
@@ -158,7 +158,7 @@ func Test_cardinalityEstimation_Do(t *testing.T) {
 		{
 			name:     "no tenantID",
 			tenantID: "",
-			downstreamHandler: func(_ context.Context, _ Request) (Response, error) {
+			downstreamHandler: func(_ context.Context, _ MetricsQueryRequest) (Response, error) {
 				return &PrometheusResponse{}, nil
 			},
 			expectedLoads:  0,
@@ -168,7 +168,7 @@ func Test_cardinalityEstimation_Do(t *testing.T) {
 		{
 			name:     "downstream error",
 			tenantID: "1",
-			downstreamHandler: func(_ context.Context, _ Request) (Response, error) {
+			downstreamHandler: func(_ context.Context, _ MetricsQueryRequest) (Response, error) {
 				return nil, errors.New("test error")
 			},
 			expectedLoads:  1,
@@ -205,7 +205,7 @@ func Test_cardinalityEstimation_Do(t *testing.T) {
 		{
 			name:     "with empty cache",
 			tenantID: "1",
-			downstreamHandler: func(ctx context.Context, request Request) (Response, error) {
+			downstreamHandler: func(ctx context.Context, request MetricsQueryRequest) (Response, error) {
 				queryStats := stats.FromContext(ctx)
 				queryStats.AddFetchedSeries(numSeries)
 				return &PrometheusResponse{}, nil
@@ -251,8 +251,8 @@ func Test_cardinalityEstimateBucket_QueryRequest_requestEquality(t *testing.T) {
 		name          string
 		tenantA       string
 		tenantB       string
-		requestA      Request
-		requestB      Request
+		requestA      MetricsQueryRequest
+		requestB      MetricsQueryRequest
 		expectedEqual bool
 	}{
 		{

pkg/frontend/querymiddleware/codec.go

@@ -65,16 +65,16 @@ const (
 // Codec is used to encode/decode query requests and responses so they can be passed down to middlewares.
 type Codec interface {
 	Merger
-	// DecodeRequest decodes a Request from an http request.
-	DecodeRequest(context.Context, *http.Request) (Request, error)
+	// DecodeMetricsQueryRequest decodes a MetricsQueryRequest from an http request.
+	DecodeMetricsQueryRequest(context.Context, *http.Request) (MetricsQueryRequest, error)
 	// DecodeLabelsQueryRequest decodes a LabelsQueryRequest from an http request.
 	DecodeLabelsQueryRequest(context.Context, *http.Request) (LabelsQueryRequest, error)
 	// DecodeResponse decodes a Response from an http response.
 	// The original request is also passed as a parameter this is useful for implementation that needs the request
 	// to merge result or build the result correctly.
-	DecodeResponse(context.Context, *http.Response, Request, log.Logger) (Response, error)
-	// EncodeRequest encodes a Request into an http request.
-	EncodeRequest(context.Context, Request) (*http.Request, error)
+	DecodeResponse(context.Context, *http.Response, MetricsQueryRequest, log.Logger) (Response, error)
+	// EncodeMetricsQueryRequest encodes a MetricsQueryRequest into an http request.
+	EncodeMetricsQueryRequest(context.Context, MetricsQueryRequest) (*http.Request, error)
 	// EncodeLabelsQueryRequest encodes a LabelsQueryRequest into an http request.
 	EncodeLabelsQueryRequest(context.Context, LabelsQueryRequest) (*http.Request, error)
 	// EncodeResponse encodes a Response into an http response.
@@ -87,8 +87,8 @@ type Merger interface {
 	MergeResponse(...Response) (Response, error)
 }
 
-// Request represents an instant or query range request that can be process by middlewares.
-type Request interface {
+// MetricsQueryRequest represents an instant or query range request that can be process by middlewares.
+type MetricsQueryRequest interface {
 	// GetId returns the ID of the request used to correlate downstream requests and responses.
 	GetId() int64
 	// GetStart returns the start timestamp of the request in milliseconds.
@@ -105,15 +105,15 @@ type Request interface {
 	// These hints can be used to optimize the query execution.
 	GetHints() *Hints
 	// WithID clones the current request with the provided ID.
-	WithID(id int64) Request
+	WithID(id int64) MetricsQueryRequest
 	// WithStartEnd clone the current request with different start and end timestamp.
-	WithStartEnd(startTime int64, endTime int64) Request
+	WithStartEnd(startTime int64, endTime int64) MetricsQueryRequest
 	// WithQuery clone the current request with a different query.
-	WithQuery(string) Request
+	WithQuery(string) MetricsQueryRequest
 	// WithTotalQueriesHint adds the number of total queries to this request's Hints.
-	WithTotalQueriesHint(int32) Request
+	WithTotalQueriesHint(int32) MetricsQueryRequest
 	// WithEstimatedSeriesCountHint WithEstimatedCardinalityHint adds a cardinality estimate to this request's Hints.
-	WithEstimatedSeriesCountHint(uint64) Request
+	WithEstimatedSeriesCountHint(uint64) MetricsQueryRequest
 	proto.Message
 	// AddSpanTags writes information about this request to an OpenTracing span
 	AddSpanTags(opentracing.Span)
@@ -246,7 +246,7 @@ func (prometheusCodec) MergeResponse(responses ...Response) (Response, error) {
 	}, nil
 }
 
-func (c prometheusCodec) DecodeRequest(_ context.Context, r *http.Request) (Request, error) {
+func (c prometheusCodec) DecodeMetricsQueryRequest(_ context.Context, r *http.Request) (MetricsQueryRequest, error) {
 	switch {
 	case IsRangeQuery(r.URL.Path):
 		return c.decodeRangeQueryRequest(r)
@@ -257,7 +257,7 @@ func (c prometheusCodec) DecodeRequest(_ context.Context, r *http.Request) (Requ
 	}
 }
 
-func (prometheusCodec) decodeRangeQueryRequest(r *http.Request) (Request, error) {
+func (prometheusCodec) decodeRangeQueryRequest(r *http.Request) (MetricsQueryRequest, error) {
 	var result PrometheusRangeQueryRequest
 	var err error
 	reqValues, err := util.ParseRequestFormWithoutConsumingBody(r)
@@ -276,7 +276,7 @@ func (prometheusCodec) decodeRangeQueryRequest(r *http.Request) (Request, error)
 	return &result, nil
 }
 
-func (c prometheusCodec) decodeInstantQueryRequest(r *http.Request) (Request, error) {
+func (c prometheusCodec) decodeInstantQueryRequest(r *http.Request) (MetricsQueryRequest, error) {
 	var result PrometheusInstantQueryRequest
 	var err error
 	reqValues, err := util.ParseRequestFormWithoutConsumingBody(r)
@@ -460,7 +460,7 @@ func decodeCacheDisabledOption(r *http.Request) bool {
 	return false
 }
 
-func (c prometheusCodec) EncodeRequest(ctx context.Context, r Request) (*http.Request, error) {
+func (c prometheusCodec) EncodeMetricsQueryRequest(ctx context.Context, r MetricsQueryRequest) (*http.Request, error) {
 	var u *url.URL
 	switch r := r.(type) {
 	case *PrometheusRangeQueryRequest:
@@ -594,7 +594,7 @@ func encodeOptions(req *http.Request, o Options) {
 	}
 }
 
-func (c prometheusCodec) DecodeResponse(ctx context.Context, r *http.Response, _ Request, logger log.Logger) (Response, error) {
+func (c prometheusCodec) DecodeResponse(ctx context.Context, r *http.Response, _ MetricsQueryRequest, logger log.Logger) (Response, error) {
 	switch r.StatusCode {
 	case http.StatusServiceUnavailable:
 		return nil, apierror.New(apierror.TypeUnavailable, string(mustReadResponseBody(r)))

pkg/frontend/querymiddleware/codec_test.go

@@ -44,7 +44,7 @@ func TestMetricsQueryRequest(t *testing.T) {
 
 	for i, tc := range []struct {
 		url         string
-		expected    Request
+		expected    MetricsQueryRequest
 		expectedErr error
 	}{
 		{
@@ -97,14 +97,14 @@ func TestMetricsQueryRequest(t *testing.T) {
 			ctx := user.InjectOrgID(context.Background(), "1")
 			r = r.WithContext(ctx)
 
-			req, err := codec.DecodeRequest(ctx, r)
+			req, err := codec.DecodeMetricsQueryRequest(ctx, r)
 			if err != nil || tc.expectedErr != nil {
 				require.EqualValues(t, tc.expectedErr, err)
 				return
 			}
 			require.EqualValues(t, tc.expected, req)
 
-			rdash, err := codec.EncodeRequest(context.Background(), req)
+			rdash, err := codec.EncodeMetricsQueryRequest(context.Background(), req)
 			require.NoError(t, err)
 			require.EqualValues(t, tc.url, rdash.RequestURI)
 		})
@@ -282,7 +282,7 @@ func TestPrometheusCodec_EncodeRequest_AcceptHeader(t *testing.T) {
 		t.Run(queryResultPayloadFormat, func(t *testing.T) {
 			codec := NewPrometheusCodec(prometheus.NewPedanticRegistry(), queryResultPayloadFormat)
 			req := PrometheusInstantQueryRequest{}
-			encodedRequest, err := codec.EncodeRequest(context.Background(), &req)
+			encodedRequest, err := codec.EncodeMetricsQueryRequest(context.Background(), &req)
 			require.NoError(t, err)
 
 			switch queryResultPayloadFormat {
@@ -302,7 +302,7 @@ func TestPrometheusCodec_EncodeRequest_ReadConsistency(t *testing.T) {
 		t.Run(consistencyLevel, func(t *testing.T) {
 			codec := NewPrometheusCodec(prometheus.NewPedanticRegistry(), formatProtobuf)
 			ctx := api.ContextWithReadConsistency(context.Background(), consistencyLevel)
-			encodedRequest, err := codec.EncodeRequest(ctx, &PrometheusInstantQueryRequest{})
+			encodedRequest, err := codec.EncodeMetricsQueryRequest(ctx, &PrometheusInstantQueryRequest{})
 			require.NoError(t, err)
 			require.Equal(t, consistencyLevel, encodedRequest.Header.Get(api.ReadConsistencyHeader))
 		})
@@ -1133,14 +1133,14 @@ func TestPrometheusCodec_DecodeEncode(t *testing.T) {
 				expected.Header = make(http.Header)
 			}
 
-			// This header is set by EncodeRequest according to the codec's config, so we
+			// This header is set by EncodeMetricsQueryRequest according to the codec's config, so we
 			// should always expect it to be present on the re-encoded request.
 			expected.Header.Set("Accept", "application/json")
 
 			ctx := context.Background()
-			decoded, err := codec.DecodeRequest(ctx, expected)
+			decoded, err := codec.DecodeMetricsQueryRequest(ctx, expected)
 			require.NoError(t, err)
-			encoded, err := codec.EncodeRequest(ctx, decoded)
+			encoded, err := codec.EncodeMetricsQueryRequest(ctx, decoded)
 			require.NoError(t, err)
 
 			assert.Equal(t, expected.URL, encoded.URL)