module.add(user,problem,record)

hydro/model/opcount.js

@@ -0,0 +1,35 @@
+const
+    { OpcountExceededError } = require('../error'),
+    db = require('../service/db.js'),
+    coll = db.collection('opcount');
+
+module.exports = {
+    /**
+     * @param {string} op 
+     * @param {string} ident 
+     * @param {number} period_secs 
+     * @param {number} max_operations 
+     */
+    async inc(op, ident, period_secs, max_operations) {
+        let cur_time = new Date().getTime();
+        let begin_at = new Date(cur_time - cur_time % (period_secs * 1000));
+        let expire_at = new Date(begin_at.getTime() + period_secs * 1000);
+        try {
+            await coll.find_one_and_update({
+                ident, begin_at, expire_at,
+                op: { $not: { $gte: max_operations } }
+            }, { $inc: { op: 1 } }, { upsert: true });
+        } catch (e) {
+            throw new OpcountExceededError(op, period_secs, max_operations);
+        }
+    }
+};
+/*
+@argmethod.wrap
+async def ensure_indexes():
+  coll = db.coll('opcount')
+  await coll.create_index([('ident', 1),
+                           ('begin_at', 1),
+                           ('expire_at', 1)], unique=True)
+  await coll.create_index('expire_at', expireAfterSeconds=0)
+*/