| 1 | package extension |
| 2 | |
| 3 | import ( |
| 4 | "strings" |
| 5 | "sync" |
| 6 | ) |
| 7 | |
| 8 | // MessageSendGuard prevents duplicate irreversible message-send receipts for |
| 9 | // the same (generation, messageID) pair within a process. |
| 10 | type MessageSendGuard struct { |
| 11 | mu sync.Mutex |
| 12 | seen map[string]struct{} |
| 13 | } |
| 14 | |
| 15 | // DefaultMessageSendGuard belongs to the compatibility runtime owner. |
| 16 | var DefaultMessageSendGuard = DefaultRuntimeOwner.Messages |
| 17 | |
| 18 | // NewMessageSendGuard returns an empty guard. |
| 19 | func NewMessageSendGuard() *MessageSendGuard { |
| 20 | return &MessageSendGuard{seen: make(map[string]struct{})} |
| 21 | } |
| 22 | |
| 23 | // TryRecord returns true when this is the first observation of messageID for |
| 24 | // gen and records it. Second calls return false (duplicate send protection). |
| 25 | func (g *MessageSendGuard) TryRecord(gen uint64, messageID string) bool { |
| 26 | if g == nil || messageID == "" { |
| 27 | return true |
| 28 | } |
| 29 | key := itoaU64(gen) + ":" + messageID |
| 30 | g.mu.Lock() |
| 31 | defer g.mu.Unlock() |
| 32 | if _, ok := g.seen[key]; ok { |
| 33 | return false |
| 34 | } |
| 35 | g.seen[key] = struct{}{} |
| 36 | return true |
| 37 | } |
| 38 | |
| 39 | // Forget removes a message key when its matching receipt leaves retention. |
| 40 | func (g *MessageSendGuard) Forget(gen uint64, messageID string) { |
| 41 | if g == nil || messageID == "" { |
| 42 | return |
| 43 | } |
| 44 | g.mu.Lock() |
| 45 | delete(g.seen, itoaU64(gen)+":"+messageID) |
| 46 | g.mu.Unlock() |
| 47 | } |
| 48 | |
| 49 | // ForgetReceipt keeps dedup retention aligned with ReceiptStore eviction. |
| 50 | func (g *MessageSendGuard) ForgetReceipt(r EffectReceipt) { |
| 51 | const prefix = "message-sent:" |
| 52 | if g == nil || !strings.HasPrefix(r.ID, prefix) { |
| 53 | return |
| 54 | } |
| 55 | messageID := r.Component |
| 56 | if messageID == "" { |
| 57 | messageID = strings.TrimPrefix(r.ID, prefix) |
| 58 | messageID = strings.TrimSuffix(messageID, "#gen-"+itoaU64(r.Generation)) |
| 59 | } |
| 60 | g.Forget(r.Generation, messageID) |
| 61 | } |
| 62 | |
| 63 | // RecordMessageSentOnce records an irreversible message-send receipt only on |
| 64 | // the first observation of (generation, messageID). |
| 65 | func RecordMessageSentOnce(generation uint64, messageID, owner string) bool { |
| 66 | return RuntimeOwnerOrDefault(nil).RecordMessageSentOnce(generation, messageID, owner) |
| 67 | } |
| 68 |