fix: l7 throttle is not accurate

Author: lzf575

agent/Cargo.lock

@@ -20,6 +20,7 @@ num_enum = "0.5.6"
 parking_lot = "0.11"
 pnet = "^0.29"
 prost.workspace = true
+rand = "0.8.5"
 regex.workspace = true
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0.72"

agent/crates/public/Cargo.toml

@@ -31,9 +31,11 @@ pub mod pwd;
 pub mod queue;
 pub mod rpc;
 pub mod sender;
+pub mod throttle;
 pub mod utils;
 
 #[cfg(target_os = "linux")]
 pub mod netns;
 
 pub use leaky_bucket::LeakyBucket;
+pub use throttle::Throttle;

agent/crates/public/src/lib.rs

@@ -0,0 +1,82 @@
+/*
+ * Copyright (c) 2025 Yunshan Networks
+ *
+ * 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 std::fmt::Debug;
+
+use log::warn;
+use rand::prelude::{Rng, SeedableRng, SmallRng};
+
+use crate::queue::DebugSender;
+use crate::LeakyBucket;
+
+const BUFFER_SIZE: usize = 1024;
+pub struct Throttle<T: Debug> {
+    leaky_bucket: LeakyBucket,
+    period_count: u32,
+    buffer: Vec<T>,
+    output_queue: DebugSender<T>,
+    small_rng: SmallRng,
+}
+
+impl<T: Debug> Throttle<T> {
+    pub fn new(rate: u64, output_queue: DebugSender<T>) -> Self {
+        Throttle {
+            leaky_bucket: LeakyBucket::new(Some(rate)),
+            buffer: Vec::with_capacity(BUFFER_SIZE),
+            output_queue,
+            small_rng: SmallRng::from_entropy(),
+            period_count: 0,
+        }
+    }
+
+    // return false, indicates that the throttle has been reached
+    // and the item or cached items will be discarded
+    pub fn send(&mut self, item: T) -> bool {
+        if self.buffer.len() > BUFFER_SIZE {
+            self.flush();
+            self.period_count = 0;
+        }
+
+        self.period_count += 1;
+        if self.leaky_bucket.acquire(1) {
+            self.buffer.push(item);
+        } else {
+            let index = self.small_rng.gen_range(0..self.period_count) as usize;
+            if index < self.buffer.len() {
+                self.buffer[index] = item;
+            }
+            return false;
+        }
+        true
+    }
+
+    pub fn flush(&mut self) {
+        if !self.buffer.is_empty() {
+            if let Err(e) = self.output_queue.send_all(&mut self.buffer) {
+                warn!(
+                    "throttle push {} items to queue failed, because {:?}",
+                    self.buffer.len(),
+                    e
+                );
+                self.buffer.clear();
+            }
+        }
+    }
+
+    pub fn set_rate(&mut self, rate: u64) {
+        self.leaky_bucket.set_rate(Some(rate));
+    }
+}

agent/crates/public/src/throttle.rs

@@ -388,6 +388,15 @@ pub struct BoxAppProtoLogsData {
     pub override_resp_status: Option<L7ResponseStatus>,
 }
 
+impl BoxAppProtoLogsData {
+    pub fn new(data: Box<MetaAppProto>, override_resp_status: Option<L7ResponseStatus>) -> Self {
+        Self {
+            data,
+            override_resp_status,
+        }
+    }
+}
+
 impl Sendable for BoxAppProtoLogsData {
     fn encode(self, buf: &mut Vec<u8>) -> Result<usize, prost::EncodeError> {
         let mut pb_proto_logs_data = flow_log::AppProtoLogsData {