58 lines
1.1 KiB
Go
58 lines
1.1 KiB
Go
package chunks
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import (
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"encoding/binary"
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"fmt"
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)
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// Encoding is the identifier for a chunk encoding
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type Encoding uint8
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func (e Encoding) String() string {
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switch e {
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case EncNone:
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return "none"
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case EncXOR:
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return "XOR"
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}
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return "<unknown>"
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}
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// The different available chunk encodings.
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const (
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EncNone Encoding = iota
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EncXOR
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)
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// Chunk holds a sequence of sample pairs that can be iterated over and appended to.
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type Chunk interface {
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Bytes() []byte
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Encoding() Encoding
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Appender() (Appender, error)
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Iterator() Iterator
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}
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// FromData returns a chunk from a byte slice of chunk data.
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func FromData(e Encoding, d []byte) (Chunk, error) {
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switch e {
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case EncXOR:
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return &XORChunk{
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b: &bstream{count: 0, stream: d},
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num: binary.BigEndian.Uint16(d),
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}, nil
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}
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return nil, fmt.Errorf("unknown chunk encoding: %d", e)
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}
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// Appender adds sample pairs to a chunk.
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type Appender interface {
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Append(int64, float64)
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}
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// Iterator is a simple iterator that can only get the next value.
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type Iterator interface {
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Values() (int64, float64)
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Err() error
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Next() bool
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}
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