fix : reaible vistor count

lib/presence.ts

@@ -36,16 +36,19 @@ async function purge(
 
 export async function updateVisitorPresence({
   tabId,
+  browserId,
   guideId,
   active,
 }: {
   tabId: string;
+  browserId: string;
   guideId: string | null;
   active: boolean;
 }) {
   const redis = await getRedisClient();
   const activeKey = `${prefix()}:visitors`;
   const scopeKey = `${prefix()}:visitor-scopes`;
+  const browserKey = `${prefix()}:visitor-browsers`;
   const now = Date.now();
   const serialized = await redis.eval(`
     local now = tonumber(ARGV[1])
@@ -53,31 +56,52 @@ export async function updateVisitorPresence({
     for _, id in ipairs(expired) do
       redis.call('ZREM', KEYS[1], id)
       redis.call('HDEL', KEYS[2], id)
+      redis.call('HDEL', KEYS[3], id)
     end
     if ARGV[5] == '1' then
       if redis.call('ZCARD', KEYS[1]) >= 10000 and not redis.call('ZSCORE', KEYS[1], ARGV[2]) then
         return redis.error_reply('presence capacity reached')
       end
+      local previousScope = redis.call('HGET', KEYS[2], ARGV[2])
+      local previousBrowser = redis.call('HGET', KEYS[3], ARGV[2])
       redis.call('ZADD', KEYS[1], now + tonumber(ARGV[4]), ARGV[2])
       redis.call('HSET', KEYS[2], ARGV[2], ARGV[3])
+      redis.call('HSET', KEYS[3], ARGV[2], ARGV[6])
+      if previousScope ~= ARGV[3] or previousBrowser ~= ARGV[6] then redis.call('DEL', KEYS[4]) end
     else
       redis.call('ZREM', KEYS[1], ARGV[2])
       redis.call('HDEL', KEYS[2], ARGV[2])
+      redis.call('HDEL', KEYS[3], ARGV[2])
+      redis.call('DEL', KEYS[4])
     end
     redis.call('PEXPIRE', KEYS[1], tonumber(ARGV[4]) * 2)
     redis.call('PEXPIRE', KEYS[2], tonumber(ARGV[4]) * 2)
-    local snapshot = redis.call('GET', KEYS[3])
+    redis.call('PEXPIRE', KEYS[3], tonumber(ARGV[4]) * 2)
+    if #expired > 0 then redis.call('DEL', KEYS[4]) end
+    local snapshot = redis.call('GET', KEYS[4])
     if snapshot then return snapshot end
     local ids = redis.call('ZRANGEBYSCORE', KEYS[1], now + 1, '+inf')
     local counts = {}
+    local browsers = {}
+    local guideBrowsers = {}
     for _, id in ipairs(ids) do
+      local browser = redis.call('HGET', KEYS[3], id) or id
       local scope = redis.call('HGET', KEYS[2], id)
-      if scope and scope ~= '' then counts[scope] = (counts[scope] or 0) + 1 end
+      browsers[browser] = true
+      if scope and scope ~= '' then
+        local key = scope .. ':' .. browser
+        if not guideBrowsers[key] then
+          counts[scope] = (counts[scope] or 0) + 1
+          guideBrowsers[key] = true
+        end
+      end
     end
-    snapshot = cjson.encode({global = #ids, byGuide = counts})
-    redis.call('SET', KEYS[3], snapshot, 'PX', 5000)
+    local global = 0
+    for _ in pairs(browsers) do global = global + 1 end
+    snapshot = cjson.encode({global = global, byGuide = counts})
+    redis.call('SET', KEYS[4], snapshot, 'PX', 5000)
     return snapshot
-  `, 3, activeKey, scopeKey, `${prefix()}:visitor-counts`, now, tabId, guideId ?? "", PRESENCE_TTL_MS, active ? "1" : "0") as string;
+  `, 4, activeKey, scopeKey, browserKey, `${prefix()}:visitor-counts`, now, tabId, guideId ?? "", PRESENCE_TTL_MS, active ? "1" : "0", browserId) as string;
   const snapshot = JSON.parse(serialized) as { global: number; byGuide: Record<string, number> };
   return { ...snapshot, guide: guideId ? snapshot.byGuide[guideId] ?? 0 : null };
 }