vendor: update buildkit to 539be170

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

vendor/go.opentelemetry.io/otel/internal/metric/registry/registry.go

@@ -0,0 +1,139 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed 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.
+
+package registry // import "go.opentelemetry.io/otel/metric/registry"
+
+import (
+	"context"
+	"fmt"
+	"sync"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/metric"
+)
+
+// UniqueInstrumentMeterImpl implements the metric.MeterImpl interface, adding
+// uniqueness checking for instrument descriptors.
+type UniqueInstrumentMeterImpl struct {
+	lock  sync.Mutex
+	impl  metric.MeterImpl
+	state map[string]metric.InstrumentImpl
+}
+
+var _ metric.MeterImpl = (*UniqueInstrumentMeterImpl)(nil)
+
+// ErrMetricKindMismatch is the standard error for mismatched metric
+// instrument definitions.
+var ErrMetricKindMismatch = fmt.Errorf(
+	"a metric was already registered by this name with another kind or number type")
+
+// NewUniqueInstrumentMeterImpl returns a wrapped metric.MeterImpl
+// with the addition of instrument name uniqueness checking.
+func NewUniqueInstrumentMeterImpl(impl metric.MeterImpl) *UniqueInstrumentMeterImpl {
+	return &UniqueInstrumentMeterImpl{
+		impl:  impl,
+		state: map[string]metric.InstrumentImpl{},
+	}
+}
+
+// MeterImpl gives the caller access to the underlying MeterImpl
+// used by this UniqueInstrumentMeterImpl.
+func (u *UniqueInstrumentMeterImpl) MeterImpl() metric.MeterImpl {
+	return u.impl
+}
+
+// RecordBatch implements metric.MeterImpl.
+func (u *UniqueInstrumentMeterImpl) RecordBatch(ctx context.Context, labels []attribute.KeyValue, ms ...metric.Measurement) {
+	u.impl.RecordBatch(ctx, labels, ms...)
+}
+
+// NewMetricKindMismatchError formats an error that describes a
+// mismatched metric instrument definition.
+func NewMetricKindMismatchError(desc metric.Descriptor) error {
+	return fmt.Errorf("metric %s registered as %s %s: %w",
+		desc.Name(),
+		desc.NumberKind(),
+		desc.InstrumentKind(),
+		ErrMetricKindMismatch)
+}
+
+// Compatible determines whether two metric.Descriptors are considered
+// the same for the purpose of uniqueness checking.
+func Compatible(candidate, existing metric.Descriptor) bool {
+	return candidate.InstrumentKind() == existing.InstrumentKind() &&
+		candidate.NumberKind() == existing.NumberKind()
+}
+
+// checkUniqueness returns an ErrMetricKindMismatch error if there is
+// a conflict between a descriptor that was already registered and the
+// `descriptor` argument.  If there is an existing compatible
+// registration, this returns the already-registered instrument.  If
+// there is no conflict and no prior registration, returns (nil, nil).
+func (u *UniqueInstrumentMeterImpl) checkUniqueness(descriptor metric.Descriptor) (metric.InstrumentImpl, error) {
+	impl, ok := u.state[descriptor.Name()]
+	if !ok {
+		return nil, nil
+	}
+
+	if !Compatible(descriptor, impl.Descriptor()) {
+		return nil, NewMetricKindMismatchError(impl.Descriptor())
+	}
+
+	return impl, nil
+}
+
+// NewSyncInstrument implements metric.MeterImpl.
+func (u *UniqueInstrumentMeterImpl) NewSyncInstrument(descriptor metric.Descriptor) (metric.SyncImpl, error) {
+	u.lock.Lock()
+	defer u.lock.Unlock()
+
+	impl, err := u.checkUniqueness(descriptor)
+
+	if err != nil {
+		return nil, err
+	} else if impl != nil {
+		return impl.(metric.SyncImpl), nil
+	}
+
+	syncInst, err := u.impl.NewSyncInstrument(descriptor)
+	if err != nil {
+		return nil, err
+	}
+	u.state[descriptor.Name()] = syncInst
+	return syncInst, nil
+}
+
+// NewAsyncInstrument implements metric.MeterImpl.
+func (u *UniqueInstrumentMeterImpl) NewAsyncInstrument(
+	descriptor metric.Descriptor,
+	runner metric.AsyncRunner,
+) (metric.AsyncImpl, error) {
+	u.lock.Lock()
+	defer u.lock.Unlock()
+
+	impl, err := u.checkUniqueness(descriptor)
+
+	if err != nil {
+		return nil, err
+	} else if impl != nil {
+		return impl.(metric.AsyncImpl), nil
+	}
+
+	asyncInst, err := u.impl.NewAsyncInstrument(descriptor, runner)
+	if err != nil {
+		return nil, err
+	}
+	u.state[descriptor.Name()] = asyncInst
+	return asyncInst, nil
+}