Files
syncthing/internal/db/sqlite/util.go
2025-04-09 17:46:49 +02:00

125 lines
3.1 KiB
Go

// Copyright (C) 2025 The Syncthing Authors.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at https://mozilla.org/MPL/2.0/.
package sqlite
import (
"cmp"
"database/sql/driver"
"errors"
"iter"
"slices"
"github.com/jmoiron/sqlx"
"github.com/syncthing/syncthing/internal/gen/bep"
"github.com/syncthing/syncthing/internal/gen/dbproto"
"github.com/syncthing/syncthing/lib/osutil"
"github.com/syncthing/syncthing/lib/protocol"
"google.golang.org/protobuf/proto"
)
// iterStructs returns an iterator over the given struct type by scanning
// the SQL rows. `rows` is closed when the iterator exits.
func iterStructs[T any](rows *sqlx.Rows, err error) (iter.Seq[T], func() error) {
if err != nil {
return func(_ func(T) bool) {}, func() error { return err }
}
var retErr error
return func(yield func(T) bool) {
defer rows.Close()
for rows.Next() {
v := new(T)
if err := rows.StructScan(v); err != nil {
retErr = err
break
}
if cleanuper, ok := any(v).(interface{ cleanup() }); ok {
cleanuper.cleanup()
}
if !yield(*v) {
return
}
}
if err := rows.Err(); err != nil && retErr == nil {
retErr = err
}
}, func() error { return retErr }
}
// dbVector is a wrapper that allows protocol.Vector values to be serialized
// to and from the database.
type dbVector struct { //nolint:recvcheck
protocol.Vector
}
func (v dbVector) Value() (driver.Value, error) {
return v.String(), nil
}
func (v *dbVector) Scan(value any) error {
str, ok := value.(string)
if !ok {
return errors.New("not a string")
}
if str == "" {
v.Vector = protocol.Vector{}
return nil
}
vec, err := protocol.VectorFromString(str)
if err != nil {
return wrap(err)
}
// This is only necessary because I messed up counter serialisation and
// thereby ordering in 2.0.0 betas, and can be removed in the future.
slices.SortFunc(vec.Counters, func(a, b protocol.Counter) int { return cmp.Compare(a.ID, b.ID) })
v.Vector = vec
return nil
}
// indirectFI constructs a FileInfo from separate marshalled FileInfo and
// BlockList bytes.
type indirectFI struct {
Name string // not used, must be present as dest for Need iterator
FiProtobuf []byte
BlProtobuf []byte
Size int64 // not used
Modified int64 // not used
}
func (i indirectFI) FileInfo() (protocol.FileInfo, error) {
var fi bep.FileInfo
if err := proto.Unmarshal(i.FiProtobuf, &fi); err != nil {
return protocol.FileInfo{}, wrap(err, "unmarshal fileinfo")
}
if len(i.BlProtobuf) > 0 {
var bl dbproto.BlockList
if err := proto.Unmarshal(i.BlProtobuf, &bl); err != nil {
return protocol.FileInfo{}, wrap(err, "unmarshal blocklist")
}
fi.Blocks = bl.Blocks
}
fi.Name = osutil.NativeFilename(fi.Name)
return protocol.FileInfoFromDB(&fi), nil
}
func prefixEnd(s string) string {
if s == "" {
panic("bug: cannot represent end prefix for empty string")
}
bs := []byte(s)
for i := len(bs) - 1; i >= 0; i-- {
if bs[i] < 0xff {
bs[i]++
break
}
}
return string(bs)
}