remo/RegionIO
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Add vanilla parity harness and harden server boundaries

Browse source
This commit is contained in:
Daniar Mannanov 2026-08-10 22:52:44 +03:00
parent 1924cb5591
commit ca019756ec
25 changed files with 1118 additions and 217 deletions
Download patch file Download diff file Expand all files Collapse all files

48
internal/world/regionfile.go
View file

@ -147,26 +147,9 @@ func (r *RegionFile) WriteChunk(localX, localZ int, nbt []byte) error {
defer r.mu.Unlock()
idx := locationIndex(localX, localZ)
old := r.offsets[idx]
oldSectors := 0
if old != 0 {
oldSectors = int(old & 0xFF)
}
// Decide where to write. Reuse the existing allocation if it still fits;
// otherwise append at end-of-file.
var offset int
switch {
case old != 0 && oldSectors == sectorsNeeded:
offset = int(old >> 8)
case old != 0 && oldSectors >= sectorsNeeded:
// Keep the old offset but record the smaller count (the tail of the old
// allocation becomes unreferenced dead space; acceptable for now).
offset = int(old >> 8)
default:
// Append after the last used sector.
offset = r.endSectorLocked()
}
// Always use copy-on-write. Reusing the published allocation would let a
// crash during WriteAt corrupt the only readable copy of the chunk.
offset := r.endSectorLocked()
// Build the on-disk record: length + compression byte + compressed data,
// zero-padded to a sector boundary.
@ -177,13 +160,23 @@ func (r *RegionFile) WriteChunk(localX, localZ int, nbt []byte) error {
if _, err := r.f.WriteAt(rec, off); err != nil {
return err
}
// Update the offset table and timestamp, then persist both tables.
r.offsets[idx] = uint32(offset<<8) | uint32(sectorsNeeded)
if err := r.writeTablesLocked(); err != nil {
// Publish the new location only after the complete record is durable. A
// crash before this sync leaves an unreachable tail and the old slot intact.
if err := r.f.Sync(); err != nil {
return err
}
return r.f.Sync()
location := uint32(offset<<8) | uint32(sectorsNeeded)
var locationBytes [4]byte
binary.BigEndian.PutUint32(locationBytes[:], location)
if _, err := r.f.WriteAt(locationBytes[:], int64(idx*4)); err != nil {
return err
}
if err := r.f.Sync(); err != nil {
return err
}
r.offsets[idx] = location
return nil
}
// writeTablesLocked writes the offset + timestamp tables back to the header.
@ -205,6 +198,11 @@ func (r *RegionFile) writeTablesLocked() error {
// i.e. where new chunk data can be appended. Caller holds r.mu.
func (r *RegionFile) endSectorLocked() int {
maxUsed := headerSectors
if info, err := r.f.Stat(); err == nil {
if sectors := int((info.Size() + sectorSize - 1) / sectorSize); sectors > maxUsed {
maxUsed = sectors
}
}
for _, loc := range r.offsets {
if loc == 0 {
continue