75 lines
2.3 KiB
Go
75 lines
2.3 KiB
Go
// Copyright 2013 Prometheus Team
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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 tiered
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import (
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"encoding/binary"
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"math"
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clientmodel "github.com/prometheus/client_golang/model"
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"github.com/prometheus/prometheus/storage/metric"
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)
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const (
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// sampleSize is the number of bytes per sample in marshalled format.
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sampleSize = 16
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// formatVersion is used as a version marker in the marshalled format.
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formatVersion = 1
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// formatVersionSize is the number of bytes used by the serialized formatVersion.
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formatVersionSize = 1
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)
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// marshal marshals a group of samples for being written to disk into dest or a
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// new slice if dest has insufficient capacity.
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func marshalValues(v metric.Values, dest []byte) []byte {
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sz := formatVersionSize + len(v)*sampleSize
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if cap(dest) < sz {
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dest = make([]byte, sz)
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} else {
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dest = dest[0:sz]
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}
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dest[0] = formatVersion
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for i, val := range v {
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offset := formatVersionSize + i*sampleSize
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binary.LittleEndian.PutUint64(dest[offset:], uint64(val.Timestamp.Unix()))
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binary.LittleEndian.PutUint64(dest[offset+8:], math.Float64bits(float64(val.Value)))
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}
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return dest
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}
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// unmarshalValues decodes marshalled samples into dest and returns either dest
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// or a new slice containing those values if dest has insufficient capacity.
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func unmarshalValues(buf []byte, dest metric.Values) metric.Values {
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if buf[0] != formatVersion {
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panic("unsupported format version")
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}
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n := (len(buf) - formatVersionSize) / sampleSize
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if cap(dest) < n {
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dest = make(metric.Values, n)
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} else {
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dest = dest[0:n]
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}
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for i := 0; i < n; i++ {
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offset := formatVersionSize + i*sampleSize
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dest[i].Timestamp = clientmodel.TimestampFromUnix(int64(binary.LittleEndian.Uint64(buf[offset:])))
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dest[i].Value = clientmodel.SampleValue(math.Float64frombits(binary.LittleEndian.Uint64(buf[offset+8:])))
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}
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return dest
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}
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