Initial open source release

internal/store/redisstore/user_counter_allocator.go

@@ -0,0 +1,112 @@
+package redisstore
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/redis/go-redis/v9"
+
+	"telesrv/internal/store"
+)
+
+// UserCounterAllocator 在一次 Lua 往返内同时分配某 user 的下一个 pts 与 box_id。
+//
+// counter:pts:{userID} 与 counter:box_id:{userID} 共享 hash-tag {userID}，处于同一
+// Redis Cluster slot，可被单个 Lua 脚本原子操作——把发送热路径上「pts + box 两次往返」
+// 合并成一次。语义与 PtsAllocator/BoxIDAllocator 各自调用等价：pts 账号级无洞、
+// Redis 冷 miss 时从 PG durable log 恢复基线。
+type UserCounterAllocator struct {
+	c         *redis.Client
+	ptsSource store.CounterSource
+	boxSource store.CounterSource
+}
+
+// NewUserCounterAllocator 创建合并 allocator。ptsSource 恢复 pts（MAX(user_update_events.pts)），
+// boxSource 恢复 box_id（MAX(message_boxes.box_id)）。
+func NewUserCounterAllocator(c *redis.Client, ptsSource, boxSource store.CounterSource) *UserCounterAllocator {
+	return &UserCounterAllocator{c: c, ptsSource: ptsSource, boxSource: boxSource}
+}
+
+// userCountersNextScript 热路径：两 key 都存在时各自 INCR 并返回；任一缺失返回 {-1,-1} 触发恢复。
+var userCountersNextScript = redis.NewScript(`
+local pts = redis.call("GET", KEYS[1])
+local box = redis.call("GET", KEYS[2])
+if pts and box then
+  return {redis.call("INCR", KEYS[1]), redis.call("INCR", KEYS[2])}
+end
+return {-1, -1}
+`)
+
+// userCountersRecoverScript 冷路径：每个 key「缺失才用 PG 基线 SET，再 INCR」。
+// 对已存在的 key 跳过 SET 只 INCR，故对「一存一缺」也安全；Redis 单线程串行化保证无重复无洞。
+var userCountersRecoverScript = redis.NewScript(`
+local function recnext(key, base)
+  if not redis.call("GET", key) then
+    redis.call("SET", key, base)
+  end
+  return redis.call("INCR", key)
+end
+return {recnext(KEYS[1], ARGV[1]), recnext(KEYS[2], ARGV[2])}
+`)
+
+// NextUserCounters 返回该 user 的下一个 (pts, boxID)。
+func (a *UserCounterAllocator) NextUserCounters(ctx context.Context, userID int64) (int, int, error) {
+	if userID == 0 {
+		return 0, 0, fmt.Errorf("redis user counters: missing user id")
+	}
+	if a.c == nil {
+		return 0, 0, fmt.Errorf("redis user counters: nil client")
+	}
+	keys := []string{ptsKey(userID), boxIDKey(userID)}
+
+	pts, box, err := runTwoCounters(ctx, a.c, userCountersNextScript, keys)
+	if err != nil {
+		return 0, 0, fmt.Errorf("redis next user counters: %w", err)
+	}
+	if pts != missingCounterSentinel && box != missingCounterSentinel {
+		return int(pts), int(box), nil
+	}
+
+	// 冷路径：至少一个 key 缺失，从 PG durable log 恢复两个基线，再 recover-next。
+	ptsBase, err := recoverBase(ctx, a.ptsSource, userID, "pts")
+	if err != nil {
+		return 0, 0, err
+	}
+	boxBase, err := recoverBase(ctx, a.boxSource, userID, "box_id")
+	if err != nil {
+		return 0, 0, err
+	}
+	pts, box, err = runTwoCounters(ctx, a.c, userCountersRecoverScript, keys, ptsBase, boxBase)
+	if err != nil {
+		return 0, 0, fmt.Errorf("redis recover user counters: %w", err)
+	}
+	return int(pts), int(box), nil
+}
+
+// runTwoCounters 执行返回二元整数表的 Lua 脚本，用 .Slice() 手动解析（不依赖 Int64Slice）。
+func runTwoCounters(ctx context.Context, c *redis.Client, script *redis.Script, keys []string, args ...any) (int64, int64, error) {
+	raw, err := script.Run(ctx, c, keys, args...).Slice()
+	if err != nil {
+		return 0, 0, err
+	}
+	if len(raw) != 2 {
+		return 0, 0, fmt.Errorf("unexpected reply len %d, want 2", len(raw))
+	}
+	a, okA := raw[0].(int64)
+	b, okB := raw[1].(int64)
+	if !okA || !okB {
+		return 0, 0, fmt.Errorf("unexpected reply element types %T,%T, want int64", raw[0], raw[1])
+	}
+	return a, b, nil
+}
+
+func recoverBase(ctx context.Context, source store.CounterSource, userID int64, name string) (int, error) {
+	if source == nil {
+		return 0, nil
+	}
+	v, err := source.Current(ctx, userID)
+	if err != nil {
+		return 0, fmt.Errorf("recover %s counter: %w", name, err)
+	}
+	return v, nil
+}