traefik/vendor/github.com/Shopify/sarama/crc32_field.go

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2018-01-10 16:48:04 +00:00
package sarama
import (
"encoding/binary"
"fmt"
"hash/crc32"
)
// crc32Field implements the pushEncoder and pushDecoder interfaces for calculating CRC32s.
type crc32Field struct {
startOffset int
}
func (c *crc32Field) saveOffset(in int) {
c.startOffset = in
}
func (c *crc32Field) reserveLength() int {
return 4
}
func (c *crc32Field) run(curOffset int, buf []byte) error {
crc := crc32.ChecksumIEEE(buf[c.startOffset+4 : curOffset])
binary.BigEndian.PutUint32(buf[c.startOffset:], crc)
return nil
}
func (c *crc32Field) check(curOffset int, buf []byte) error {
crc := crc32.ChecksumIEEE(buf[c.startOffset+4 : curOffset])
expected := binary.BigEndian.Uint32(buf[c.startOffset:])
if crc != expected {
return PacketDecodingError{fmt.Sprintf("CRC didn't match expected %#x got %#x", expected, crc)}
}
return nil
}