Fix notification event stream cleanup, add bounded send concurrency, and reduce overhead (#1224)

crates/notify/src/notification_system_subscriber.rs

@@ -0,0 +1,74 @@
+// Copyright 2024 RustFS Team
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+use crate::BucketNotificationConfig;
+use crate::rules::{BucketRulesSnapshot, DynRulesContainer, SubscriberIndex};
+use rustfs_targets::EventName;
+
+/// NotificationSystemSubscriberView - Provides an interface to manage and query
+/// the subscription status of buckets in the notification system.
+#[derive(Debug)]
+pub struct NotificationSystemSubscriberView {
+    index: SubscriberIndex,
+}
+
+impl NotificationSystemSubscriberView {
+    /// Creates a new NotificationSystemSubscriberView with an empty SubscriberIndex.
+    ///
+    /// Returns a new instance of NotificationSystemSubscriberView.
+    pub fn new() -> Self {
+        Self {
+            index: SubscriberIndex::default(),
+        }
+    }
+
+    /// Checks if a bucket has any subscribers for a specific event.
+    /// This is a quick check using the event mask in the snapshot.
+    ///
+    /// # Arguments
+    /// * `bucket` - The name of the bucket to check.
+    /// * `event` - The event name to check for subscriptions.
+    ///
+    /// Returns `true` if there are subscribers for the event, `false` otherwise.
+    #[inline]
+    pub fn has_subscriber(&self, bucket: &str, event: &EventName) -> bool {
+        self.index.has_subscriber(bucket, event)
+    }
+
+    /// Builds and atomically replaces a bucket's subscription snapshot from the configuration.
+    ///
+    /// Core principle: masks and rules are calculated and stored together in the same update.
+    ///
+    /// # Arguments
+    /// * `bucket` - The name of the bucket to update.
+    /// * `cfg` - The bucket notification configuration to compile into a snapshot.
+    pub fn apply_bucket_config(&self, bucket: &str, cfg: &BucketNotificationConfig) {
+        // *It is recommended to merge compile into one function to ensure the same origin.
+        let snapshot: BucketRulesSnapshot<DynRulesContainer> = cfg.compile_snapshot();
+
+        // *debug to prevent inconsistencies from being introduced when modifying the compile logic in the future.
+        snapshot.debug_assert_mask_consistent();
+
+        self.index.store_snapshot(bucket, snapshot);
+    }
+
+    /// Clears a bucket's subscription snapshot.
+    ///
+    /// #Arguments
+    /// * `bucket` - The name of the bucket to clear.
+    #[inline]
+    pub fn clear_bucket(&self, bucket: &str) {
+        self.index.clear_bucket(bucket);
+    }
+}