/
block.go
83 lines (76 loc) · 1.47 KB
/
block.go
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// SPDX-License-Identifier: Apache-2.0
// Copyright © 2021 Wrangle Ltd
package objects
import (
"encoding/binary"
"io"
)
const BlockSize = 255
func CombineRowBytesIntoBlock(blk [][]byte) []byte {
m := 4
for _, b := range blk {
m += len(b)
}
b := make([]byte, m)
n := len(blk)
binary.BigEndian.PutUint32(b, uint32(n))
off := 4
for _, row := range blk {
copy(b[off:], row)
off += len(row)
}
return b
}
func WriteBlockTo(enc *StrListEncoder, w io.Writer, blk [][]string) (int64, error) {
n := len(blk)
b := make([]byte, 4)
binary.BigEndian.PutUint32(b, uint32(n))
_, err := w.Write(b)
if err != nil {
return 0, err
}
var total int64 = 4
for _, line := range blk {
b := enc.Encode(line)
m, err := w.Write(b)
if err != nil {
return 0, err
}
total += int64(m)
}
return total, nil
}
func ReadBlockFrom(r io.Reader) (int64, [][]string, error) {
b := make([]byte, 4)
m, err := r.Read(b)
if err != nil {
return 0, nil, err
}
total := int64(m)
n := binary.BigEndian.Uint32(b)
blk := make([][]string, n)
var i uint32
dec := NewStrListDecoder(false)
for i = 0; i < n; i++ {
m, line, err := dec.Read(r)
if err != nil {
return 0, nil, err
}
blk[i] = line
total += int64(m)
}
return total, blk, nil
}
func ValidateBlockBytes(b []byte) (err error) {
var off int
n := int(binary.BigEndian.Uint32(b))
off += 4
for i := 0; i < n; i++ {
m, err := ValidateStrListBytes(b[off:])
if err != nil {
return err
}
off += m
}
return nil
}