85 lines
1.9 KiB
Go
85 lines
1.9 KiB
Go
// Copyright 2015 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 chunk
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import (
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"math"
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"github.com/prometheus/common/model"
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)
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type deltaBytes byte
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const (
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d0 deltaBytes = 0
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d1 deltaBytes = 1
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d2 deltaBytes = 2
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d4 deltaBytes = 4
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d8 deltaBytes = 8
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)
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func bytesNeededForUnsignedTimestampDelta(deltaT model.Time) deltaBytes {
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switch {
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case deltaT > math.MaxUint32:
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return d8
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case deltaT > math.MaxUint16:
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return d4
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case deltaT > math.MaxUint8:
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return d2
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default:
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return d1
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}
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}
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func bytesNeededForSignedTimestampDelta(deltaT model.Time) deltaBytes {
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switch {
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case deltaT > math.MaxInt32 || deltaT < math.MinInt32:
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return d8
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case deltaT > math.MaxInt16 || deltaT < math.MinInt16:
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return d4
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case deltaT > math.MaxInt8 || deltaT < math.MinInt8:
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return d2
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default:
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return d1
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}
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}
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func bytesNeededForIntegerSampleValueDelta(deltaV model.SampleValue) deltaBytes {
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switch {
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case deltaV < math.MinInt32 || deltaV > math.MaxInt32:
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return d8
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case deltaV < math.MinInt16 || deltaV > math.MaxInt16:
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return d4
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case deltaV < math.MinInt8 || deltaV > math.MaxInt8:
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return d2
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case deltaV != 0:
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return d1
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default:
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return d0
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}
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}
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func max(a, b deltaBytes) deltaBytes {
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if a > b {
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return a
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}
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return b
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}
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// isInt64 returns true if v can be represented as an int64.
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func isInt64(v model.SampleValue) bool {
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// Note: Using math.Modf is slower than the conversion approach below.
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return model.SampleValue(int64(v)) == v
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}
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