syncthing/lib/db/leveldb.go
Jakob Borg 6a87aac84f
lib/db: Refactor key handling (ref #5198) (#5199)
This breaks out the key generation stuff into a separate type. It's
cleaner on its own, and it prepares for future stuff.
2018-09-18 10:41:06 +02:00

119 lines
3.2 KiB
Go

// Copyright (C) 2014 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 db
import (
"bytes"
"fmt"
"github.com/syncthing/syncthing/lib/protocol"
)
func (vl VersionList) String() string {
var b bytes.Buffer
var id protocol.DeviceID
b.WriteString("{")
for i, v := range vl.Versions {
if i > 0 {
b.WriteString(", ")
}
copy(id[:], v.Device)
fmt.Fprintf(&b, "{%v, %v}", v.Version, id)
}
b.WriteString("}")
return b.String()
}
// update brings the VersionList up to date with file. It returns the updated
// VersionList, a potentially removed old FileVersion and its index, as well as
// the index where the new FileVersion was inserted.
func (vl VersionList) update(folder, device []byte, file protocol.FileInfo, db *Instance) (_ VersionList, removedFV FileVersion, removedAt int, insertedAt int) {
removedAt, insertedAt = -1, -1
for i, v := range vl.Versions {
if bytes.Equal(v.Device, device) {
removedAt = i
removedFV = v
vl.Versions = append(vl.Versions[:i], vl.Versions[i+1:]...)
break
}
}
nv := FileVersion{
Device: device,
Version: file.Version,
Invalid: file.IsInvalid(),
}
for i, v := range vl.Versions {
switch v.Version.Compare(file.Version) {
case protocol.Equal:
if nv.Invalid {
continue
}
fallthrough
case protocol.Lesser:
// The version at this point in the list is equal to or lesser
// ("older") than us. We insert ourselves in front of it.
vl = vl.insertAt(i, nv)
return vl, removedFV, removedAt, i
case protocol.ConcurrentLesser, protocol.ConcurrentGreater:
// The version at this point is in conflict with us. We must pull
// the actual file metadata to determine who wins. If we win, we
// insert ourselves in front of the loser here. (The "Lesser" and
// "Greater" in the condition above is just based on the device
// IDs in the version vector, which is not the only thing we use
// to determine the winner.)
//
// A surprise missing file entry here is counted as a win for us.
if of, ok := db.getFile(db.keyer.GenerateDeviceFileKey(nil, folder, v.Device, []byte(file.Name))); !ok || file.WinsConflict(of) {
vl = vl.insertAt(i, nv)
return vl, removedFV, removedAt, i
}
}
}
// We didn't find a position for an insert above, so append to the end.
vl.Versions = append(vl.Versions, nv)
return vl, removedFV, removedAt, len(vl.Versions) - 1
}
func (vl VersionList) insertAt(i int, v FileVersion) VersionList {
vl.Versions = append(vl.Versions, FileVersion{})
copy(vl.Versions[i+1:], vl.Versions[i:])
vl.Versions[i] = v
return vl
}
func (vl VersionList) Get(device []byte) (FileVersion, bool) {
for _, v := range vl.Versions {
if bytes.Equal(v.Device, device) {
return v, true
}
}
return FileVersion{}, false
}
type fileList []protocol.FileInfo
func (fl fileList) Len() int {
return len(fl)
}
func (fl fileList) Swap(a, b int) {
fl[a], fl[b] = fl[b], fl[a]
}
func (fl fileList) Less(a, b int) bool {
return fl[a].Name < fl[b].Name
}
// Flush batches to disk when they contain this many records.
const batchFlushSize = 64