mirror of https://github.com/certusone/dc4bc.git
61 lines
1.3 KiB
Go
61 lines
1.3 KiB
Go
package qr
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import (
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"bytes"
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"encoding/gob"
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"fmt"
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"math"
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)
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type chunk struct {
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Data []byte
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Index uint
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Total uint
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}
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// DataToChunks divides a data on chunks with a size chunkSize
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func DataToChunks(data []byte, chunkSize int) ([][]byte, error) {
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chunksCount := int(math.Ceil(float64(len(data)) / float64(chunkSize)))
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chunks := make([][]byte, 0, chunksCount)
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index := uint(0)
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for offset := 0; offset < len(data); offset += chunkSize {
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offsetEnd := offset + chunkSize
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if offsetEnd > len(data) {
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offsetEnd = len(data)
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}
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chunkBz, err := encodeChunk(chunk{
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Data: data[offset:offsetEnd],
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Total: uint(chunksCount),
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Index: index,
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})
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if err != nil {
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return nil, fmt.Errorf("failed to encode chunk: %w", err)
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}
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chunks = append(chunks, chunkBz)
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index++
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}
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return chunks, nil
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}
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func decodeChunk(data []byte) (*chunk, error) {
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var (
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c chunk
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err error
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)
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dec := gob.NewDecoder(bytes.NewBuffer(data))
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if err = dec.Decode(&c); err != nil {
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return nil, fmt.Errorf("failed to decode chunk: %w", err)
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}
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return &c, nil
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}
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func encodeChunk(c chunk) ([]byte, error) {
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buf := bytes.NewBuffer(nil)
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enc := gob.NewEncoder(buf)
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if err := enc.Encode(c); err != nil {
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return nil, fmt.Errorf("failed to encode chunk: %w", err)
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}
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return buf.Bytes(), nil
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}
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