merge: P27 Rumor 长局成本修复（去装箱扫描 + O(1) 裁剪 + rumor-bench）— Hermes 复验通过

1 files changed, 59 insertions, 14 deletions

diff --git a/src/LivingVillage.Kernel/Sim.fs b/src/LivingVillage.Kernel/Sim.fs
index cedadfa..5c4e107 100644
--- a/src/LivingVillage.Kernel/Sim.fs
+++ b/src/LivingVillage.Kernel/Sim.fs
@@ -192,6 +192,12 @@ module Sim =
           Npcs: Npc[]
           Events: InteractionEvent list
           Rumors: RumorEvent list
+          /// 派生镜像：工作集条数（= Rumors.Length）。不参与存档序列化，读档由列表重建；
+          /// 用于把每追加一条都要全表扫描的裁剪判定降为 O(1)。
+          RumorCount: int
+          /// 派生镜像：工作集内最小 DayIndex（空表为 Int64.MaxValue）。语义等价于
+          /// `rumorsNeedTrim` 的「存在早于保留窗口的条目」判定。
+          RumorOldestDay: int64
           Annals: AnnalEntry list }
 
     type DialogueFailure =
@@ -481,6 +487,8 @@ module Sim =
           Npcs = [| npc |]
           Events = []
           Rumors = []
+          RumorCount = 0
+          RumorOldestDay = System.Int64.MaxValue
           Annals = [] }
 
     let initialWorldN (seed: uint64) (count: int) : World =
@@ -680,19 +688,49 @@ module Sim =
         else
             rumors
 
-    /// 追加一条谣言并顺手裁剪工作集；容量内且新鲜时等价于 `rumor :: rumors`。
-    let private consRumor (nowTick: int64) (rumor: RumorEvent) (rumors: RumorEvent list) : RumorEvent list =
-        trimRumors nowTick (rumor :: rumors)
+    /// 工作集派生统计：(条数, 最小 DayIndex；空表为 Int64.MaxValue)。仅裁剪/读档等非热路径调用。
+    let rumorWorkingSetStats (rumors: RumorEvent list) : int * int64 =
+        rumors.Length,
+        (rumors |> List.fold (fun acc rumor -> min acc rumor.DayIndex) System.Int64.MaxValue)
+
+    let private oldestRumorDay (rumors: RumorEvent list) : int64 = snd (rumorWorkingSetStats rumors)
+
+    /// 追加一条谣言并维护派生元数据。容量内且新鲜时等价于 `rumor :: rumors`，且**不再全表扫描**
+    /// 判断是否需要裁剪（旧 `consRumor` 每次追加都会 `rumorsNeedTrim` 走一遍工作集）；
+    /// 仅当条数超容量或存在早于保留窗口的条目时才走 `trimRumors`，保留集合与旧实现逐条相同。
+    let private appendRumor (nowTick: int64) (rumor: RumorEvent) (world: World) : World =
+        let cutoffDay = max 0L (rumorDayIndex nowTick - rumorRetentionDays)
+        let nextCount = world.RumorCount + 1
+        let nextOldest = min world.RumorOldestDay rumor.DayIndex
+        if nextCount > rumorCapacity || nextOldest < cutoffDay then
+            let trimmed = trimRumors nowTick (rumor :: world.Rumors)
+            { world with
+                Rumors = trimmed
+                RumorCount = trimmed.Length
+                RumorOldestDay = oldestRumorDay trimmed }
+        else
+            { world with
+                Rumors = rumor :: world.Rumors
+                RumorCount = nextCount
+                RumorOldestDay = nextOldest }
+
+    /// `NpcId`/`RumorId` 是 `[<Struct>]` 单例判别联合：直接用 `=` 比较会走泛型结构相等并
+    /// 在每次比较时为两侧装箱（实测 ~24 B/次）。在按 tick 全表扫描的热路径里逐条比较，
+    /// 这是 Rumor 分配的主要来源。这里改为先解构出底层 int/int64 再比较（语义完全等价，
+    /// 仅去掉装箱），扫描不再产生逐条分配。
+    let inline private npcIdValue (NpcId id) : int = id
+    let inline private rumorIdValue (RumorId id) : int64 = id
 
     let private latestRumorFor (receiver: NpcId) (world: World) : RumorEvent option =
         // 工作集最新在前且 Tick 非递增：第一条命中的即“Tick 最大、Id 最大”，与原实现
         // （filter 后 sortByDescending 取头）等价；窗口外无分配提前返回。
+        let receiverId = npcIdValue receiver
         let rec loop (rest: RumorEvent list) : RumorEvent option =
             match rest with
             | [] -> None
             | rumor :: tail ->
                 if world.Tick - rumor.Tick > rumorFreshnessTicks then None
-                elif rumor.Receiver = receiver
+                elif npcIdValue rumor.Receiver = receiverId
                      && rumor.Tick <= world.Tick
                      && rumorStrengthAt world.Tick rumor >= rumorMinimumStrength then Some rumor
                 else loop tail
@@ -783,11 +821,13 @@ module Sim =
                 let avatarMemory = recordMemory world.Tick (Dialogue(target, intent, response)) world.Avatar.Mind.Memory
                 let event = { Tick = world.Tick; Kind = DialogueEvent outcome }
                 let updated =
-                    { world with
-                        Avatar = { world.Avatar with Mind = { world.Avatar.Mind with Memory = avatarMemory } }
-                        Npcs = newNpcs
-                        Events = world.Events @ [ event ]
-                        Rumors = consRumor world.Tick rumor world.Rumors }
+                    appendRumor
+                        world.Tick
+                        rumor
+                        { world with
+                            Avatar = { world.Avatar with Mind = { world.Avatar.Mind with Memory = avatarMemory } }
+                            Npcs = newNpcs
+                            Events = world.Events @ [ event ] }
                 let withRumorAnnal =
                     appendAnnal
                         { Tick = world.Tick
@@ -826,16 +866,21 @@ module Sim =
               RecentMemory = List.truncate 8 npc.Mind.Memory })
 
     let private rumorIsDuplicate (request: ChatRequest) (parent: RumorEvent option) (world: World) : bool =
-        let parentId = parent |> Option.map (fun rumor -> rumor.Id)
+        let parentId = parent |> Option.map (fun rumor -> rumorIdValue rumor.Id)
+        let narratorId = npcIdValue request.Narrator
+        let receiverId = npcIdValue request.Receiver
         // 窗口外条目强度必 < rumorMinimumStrength，与原全表 exists 等价；命中或越窗即无分配返回。
+        // `Parent` 用底层 int64 比较而非 `RumorId option` 结构相等，避免逐条装箱。
         let rec loop (rest: RumorEvent list) : bool =
             match rest with
             | [] -> false
             | rumor :: tail ->
                 if world.Tick - rumor.Tick > rumorFreshnessTicks then false
-                elif rumor.Narrator = request.Narrator
-                     && rumor.Receiver = request.Receiver
-                     && rumor.Parent = parentId
+                elif npcIdValue rumor.Narrator = narratorId
+                     && npcIdValue rumor.Receiver = receiverId
+                     && (match rumor.Parent with
+                         | Some parentRumor -> parentId = Some(rumorIdValue parentRumor)
+                         | None -> parentId.IsNone)
                      && rumor.Tick <= world.Tick
                      && rumorStrengthAt world.Tick rumor >= rumorMinimumStrength then true
                 else loop tail
@@ -936,7 +981,7 @@ module Sim =
                                 { npc with
                                     Mind = { npc.Mind with Memory = recordMemory world.Tick (Rumor rumor.Id) npc.Mind.Memory } }
                             { chatted with Npcs = newNpcs }
-                    let updated = { withReceiverRumor with Rumors = consRumor world.Tick rumor world.Rumors }
+                    let updated = appendRumor world.Tick rumor withReceiverRumor
                     ChatSucceeded(
                         Some rumor,
                         appendAnnal