Files
OwnCord/Server/ws/ringbuffer.go
T
jevb f3c9f98b91 fix: resolve 4 server bugs (Phase 1: BUG-085, BUG-087, BUG-090, BUG-091)
- BUG-085: ring buffer EventsSince off-by-one — change < to <= so
  afterSeq == oldestSeq returns nil (triggers full ready payload)
- BUG-087: GracefulStop not idempotent — wrap body in sync.Once to
  prevent double lkProcess.Stop() on concurrent calls
- BUG-090: FTS query truncation at byte boundary — use []rune
  truncation to preserve valid UTF-8 for CJK/emoji input
- BUG-091: updater downloadFile double-closes file on Windows —
  add closed sentinel to guard defer against explicit Close()
2026-04-01 17:52:06 +02:00

80 lines
2.0 KiB
Go

package ws
import "github.com/owncord/server/syncutil"
// eventEntry stores a broadcast event for potential replay.
type eventEntry struct {
seq uint64
data []byte
}
// EventRingBuffer is a bounded, thread-safe ring buffer for recent broadcast events.
type EventRingBuffer struct {
mu syncutil.RWMutex
entries []eventEntry
size int
pos int // next write position
count int // total entries stored (up to size)
}
// NewEventRingBuffer creates a ring buffer with the given capacity.
func NewEventRingBuffer(size int) *EventRingBuffer {
return &EventRingBuffer{
entries: make([]eventEntry, size),
size: size,
}
}
// Push adds an event to the ring buffer.
func (rb *EventRingBuffer) Push(seq uint64, data []byte) {
rb.mu.Lock()
defer rb.mu.Unlock()
rb.entries[rb.pos] = eventEntry{seq: seq, data: data}
rb.pos = (rb.pos + 1) % rb.size
if rb.count < rb.size {
rb.count++
}
}
// EventsSince returns all events with seq > afterSeq, in order.
// Returns nil if afterSeq is too old (no longer in the buffer).
func (rb *EventRingBuffer) EventsSince(afterSeq uint64) [][]byte {
rb.mu.RLock()
defer rb.mu.RUnlock()
if rb.count == 0 {
return nil
}
// Find the oldest entry in the buffer.
oldestIdx := (rb.pos - rb.count + rb.size) % rb.size
oldestSeq := rb.entries[oldestIdx].seq
// If the requested seq is at or older than our oldest, we can't guarantee
// full coverage — return nil to trigger a full ready payload.
if afterSeq <= oldestSeq {
return nil
}
result := make([][]byte, 0)
for i := 0; i < rb.count; i++ {
idx := (oldestIdx + i) % rb.size
e := rb.entries[idx]
if e.seq > afterSeq {
result = append(result, e.data)
}
}
return result
}
// OldestSeq returns the oldest sequence number in the buffer, or 0 if empty.
func (rb *EventRingBuffer) OldestSeq() uint64 {
rb.mu.RLock()
defer rb.mu.RUnlock()
if rb.count == 0 {
return 0
}
oldestIdx := (rb.pos - rb.count + rb.size) % rb.size
return rb.entries[oldestIdx].seq
}