63 lines
1.4 KiB
Go
63 lines
1.4 KiB
Go
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package tsdb
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import (
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"encoding/binary"
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"fmt"
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"github.com/fabxc/tsdb/chunks"
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)
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// SeriesReader provides reading access of serialized time series data.
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type SeriesReader interface {
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// Chunk returns the series data chunk at the given offset.
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Chunk(offset uint32) (chunks.Chunk, error)
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}
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// seriesReader implements a SeriesReader for a serialized byte stream
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// of series data.
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type seriesReader struct {
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// The underlying byte slice holding the encoded series data.
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b []byte
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}
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func newSeriesReader(b []byte) (*seriesReader, error) {
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// Verify magic number.
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if m := binary.BigEndian.Uint32(b[:4]); m != MagicSeries {
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return nil, fmt.Errorf("invalid magic number %x", m)
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}
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return &seriesReader{b: b}, nil
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}
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func (s *seriesReader) Chunk(offset uint32) (chunks.Chunk, error) {
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b := s.b[offset:]
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l, n := binary.Uvarint(b)
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if n < 0 {
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return nil, fmt.Errorf("reading chunk length failed")
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}
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b = b[n:]
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enc := chunks.Encoding(b[0])
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c, err := chunks.FromData(enc, b[1:1+l])
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if err != nil {
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return nil, err
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}
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return c, nil
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}
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// IndexReader provides reading access of serialized index data.
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type IndexReader interface {
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//
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// Close releases resources associated with the reader.
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Close()
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}
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type indexReader struct {
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// The underlying byte slice holding the encoded series data.
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b []byte
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// Cached hashmaps of sections for label values
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labelOffsets map[string]uint32
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}
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