Molodetz blogrol volgens DPP-template

molodetz/utils/presence.py

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+# retoor <retoor@molodetz.nl>
+import json
+import threading
+import time
+from datetime import datetime, timedelta, timezone
+
+from molodetz import config
+from molodetz.database import db, get_service_state, now_iso, update_user
+
+_lock = threading.Lock()
+_last_write = {}
+
+
+def touch(uid):
+    if not uid:
+        return
+    now = time.monotonic()
+    throttle = max(1, config.PRESENCE_TIMEOUT_SECONDS // 2)
+    with _lock:
+        if now - _last_write.get(uid, 0) < throttle:
+            return
+        _last_write[uid] = now
+    update_user(uid, last_seen_at=now_iso())
+
+
+def compute_roster():
+    if "users" not in db.tables:
+        return []
+    window = config.PRESENCE_TIMEOUT_SECONDS + config.PRESENCE_ONLINE_MARGIN_SECONDS
+    cutoff = (datetime.now(timezone.utc) - timedelta(seconds=window)).isoformat()
+    rows = db.query(
+        "SELECT uid FROM users WHERE last_seen_at >= :cutoff AND deleted_at IS NULL "
+        "ORDER BY last_seen_at DESC LIMIT :limit",
+        cutoff=cutoff,
+        limit=config.PRESENCE_TRACK_LIMIT,
+    )
+    return [row["uid"] for row in rows]
+
+
+def published_roster():
+    row = get_service_state("presence")
+    if row and row.get("metrics"):
+        try:
+            metrics = json.loads(row["metrics"])
+        except ValueError:
+            metrics = {}
+        if "roster" in metrics:
+            return metrics["roster"]
+    return compute_roster()
+
+
+def online_uids(limit=None):
+    return published_roster()[: limit or config.PRESENCE_ONLINE_LIMIT]