prometheus

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// Copyright 2017 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 storage
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import (
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	"github.com/prometheus/prometheus/util/annotations"
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)
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// lazyGenericSeriesSet is a wrapped series set that is initialised on first call to Next().
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type lazyGenericSeriesSet struct {
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	init func() (genericSeriesSet, bool)
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	set genericSeriesSet
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}
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func (c *lazyGenericSeriesSet) Next() bool {
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	if c.set != nil {
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		return c.set.Next()
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	}
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	var ok bool
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	c.set, ok = c.init()
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	return ok
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}
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func (c *lazyGenericSeriesSet) Err() error {
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	if c.set != nil {
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		return c.set.Err()
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	}
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	return nil
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}
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func (c *lazyGenericSeriesSet) At() Labels {
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	if c.set != nil {
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		return c.set.At()
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	}
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	return nil
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}
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func (c *lazyGenericSeriesSet) Warnings() annotations.Annotations {
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	if c.set != nil {
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		return c.set.Warnings()
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	}
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	return nil
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}
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type warningsOnlySeriesSet annotations.Annotations
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func (warningsOnlySeriesSet) Next() bool                          { return false }
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func (warningsOnlySeriesSet) Err() error                          { return nil }
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func (warningsOnlySeriesSet) At() Labels                          { return nil }
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func (c warningsOnlySeriesSet) Warnings() annotations.Annotations { return annotations.Annotations(c) }
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type errorOnlySeriesSet struct {
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	err error
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}
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func (errorOnlySeriesSet) Next() bool                        { return false }
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func (errorOnlySeriesSet) At() Labels                        { return nil }
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func (s errorOnlySeriesSet) Err() error                      { return s.err }
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func (errorOnlySeriesSet) Warnings() annotations.Annotations { return nil }
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