72 lines
2.3 KiB
Go
72 lines
2.3 KiB
Go
// Copyright 2013 The Prometheus Authors
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package retrieval
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import (
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"errors"
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"time"
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"github.com/prometheus/client_golang/extraction"
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clientmodel "github.com/prometheus/client_golang/model"
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)
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const ingestTimeout = 100 * time.Millisecond // TODO(beorn7): Adjust this to a fraction of the actual HTTP timeout.
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var errIngestChannelFull = errors.New("ingestion channel full")
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// MergeLabelsIngester merges a labelset ontop of a given extraction result and
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// passes the result on to another ingester. Label collisions are avoided by
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// appending a label prefix to any newly merged colliding labels.
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type MergeLabelsIngester struct {
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Labels clientmodel.LabelSet
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CollisionPrefix clientmodel.LabelName
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Ingester extraction.Ingester
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}
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// Ingest ingests the provided extraction result by merging in i.Labels and then
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// handing it over to i.Ingester.
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func (i *MergeLabelsIngester) Ingest(samples clientmodel.Samples) error {
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for _, s := range samples {
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s.Metric.MergeFromLabelSet(i.Labels, i.CollisionPrefix)
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}
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return i.Ingester.Ingest(samples)
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}
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// ChannelIngester feeds results into a channel without modifying them.
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type ChannelIngester chan<- clientmodel.Samples
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// Ingest ingests the provided extraction result by sending it to its channel.
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// If the channel was not able to receive the samples within the ingestTimeout,
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// an error is returned. This is important to fail fast and to not pile up
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// ingestion requests in case of overload.
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func (i ChannelIngester) Ingest(s clientmodel.Samples) error {
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// Since the regular case is that i is ready to receive, first try
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// without setting a timeout so that we don't need to allocate a timer
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// most of the time.
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select {
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case i <- s:
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return nil
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default:
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select {
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case i <- s:
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return nil
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case <-time.After(ingestTimeout):
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return errIngestChannelFull
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}
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}
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}
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