portal/bao/bao.go

32 lines
595 B
Go
Raw Normal View History

package bao
import (
"bufio"
_ "embed"
"io"
"lukechampine.com/blake3"
)
func ComputeTree(reader io.Reader, size int64) ([]byte, [32]byte, error) {
2023-05-17 14:12:22 +00:00
bufSize := blake3.BaoEncodedSize(int(size), true)
buf := bufferAt{buf: make([]byte, bufSize)}
hash, err := blake3.BaoEncode(&buf, bufio.NewReader(reader), size, true)
if err != nil {
return nil, [32]byte{}, err
}
return buf.buf, hash, nil
}
type bufferAt struct {
buf []byte
}
func (b *bufferAt) WriteAt(p []byte, off int64) (int, error) {
if copy(b.buf[off:], p) != len(p) {
panic("bad buffer size")
}
return len(p), nil
}