perf(재생지연): 유튜브 URL 음성접속 전 프리워밍 + 리졸버 진행요청 합치기(coalescing)로 첫 재생 지연 ~2초 단축

resolver/ytresolver.py

@@ -27,6 +27,7 @@ YTDLP = os.environ.get("YTDLP", "/usr/local/bin/yt-dlp")
 COOKIE_FILE = os.environ.get("YTRESOLVER_COOKIE", "/root/bot/db/ytcookie.txt")
 PORT = int(os.environ.get("YTRESOLVER_PORT", "8779"))
 CACHE = {}
+INFLIGHT = {}      # target -> {"event": Event, "url": str|None}  진행 중 리졸브 합치기(coalescing)
 LOCK = threading.Lock()
 TTL = 1800  # 리졸브된 URL 캐시 30분(googlevideo URL 자체는 약 6시간 유효)
 
@@ -53,12 +54,7 @@ def first_url(out):
     return lines[0] if lines else None
 
 
-def resolve(target):
-    now = time.time()
-    with LOCK:
-        hit = CACHE.get(target)
-        if hit and hit[1] > now:
-            return hit[0]
+def _do_resolve(target):
     try:
         out = run_ytdlp(target, use_cookies=False)
         url = first_url(out)
@@ -69,13 +65,45 @@ def resolve(target):
     except subprocess.TimeoutExpired:
         print("[result] TIMEOUT", file=sys.stderr, flush=True)
         return None
-    ok = bool(url and url.startswith("http"))
-    if not ok:
+    if not (url and url.startswith("http")):
         print(f"[result] FAIL {(out.stderr or out.stdout or '')[:240]}", file=sys.stderr, flush=True)
         return None
     print(f"[result] OK {url[:60]}", file=sys.stderr, flush=True)
     with LOCK:
-        CACHE[target] = (url, now + TTL)
+        CACHE[target] = (url, time.time() + TTL)
+    return url
+
+
+def resolve(target):
+    now = time.time()
+    with LOCK:
+        hit = CACHE.get(target)
+        if hit and hit[1] > now:
+            return hit[0]
+        # 같은 target이 이미 리졸브 중이면, 새 yt-dlp를 띄우지 않고 그 결과를 기다린다.
+        # (봇이 음성 접속과 동시에 미리 리졸브를 걸어두면, 실제 재생 요청이 이 진행분에 합쳐져
+        #  음성 접속 시간과 리졸브 시간이 겹쳐 첫 재생 지연이 크게 줄어든다.)
+        entry = INFLIGHT.get(target)
+        owner = entry is None
+        if owner:
+            entry = {"event": threading.Event(), "url": None}
+            INFLIGHT[target] = entry
+    if not owner:
+        entry["event"].wait(50)
+        with LOCK:
+            hit = CACHE.get(target)
+        return hit[0] if hit and hit[1] > time.time() else entry.get("url")
+    # owner: 실제 리졸브 수행
+    url = None
+    try:
+        url = _do_resolve(target)
+    except Exception as e:
+        print(f"[result] ERR {str(e)[:120]}", file=sys.stderr, flush=True)
+    finally:
+        entry["url"] = url
+        with LOCK:
+            INFLIGHT.pop(target, None)
+        entry["event"].set()
     return url