http_pool/http2/
pool.rs

1use crate::http2::{SendRequest, Sender};
2use hyper::client::conn::http2;
3use net_pool::backend::{Address, BackendState};
4use net_pool::{Error, Strategy, debug, instrument_current_span, tokio_spawn};
5use std::collections::HashMap;
6use std::sync::atomic::Ordering::Relaxed;
7use std::sync::atomic::{AtomicBool, AtomicU32, AtomicUsize};
8use std::sync::{Arc, LazyLock, Mutex};
9
10/// sender id 分配
11static SENDER_ID: LazyLock<AtomicU32> = LazyLock::new(|| AtomicU32::new(1));
12
13struct Inner(SendRequest, Arc<()>, u32);
14
15impl Inner {
16    fn new(sender: SendRequest) -> Self {
17        Inner(sender, Arc::new(()), SENDER_ID.fetch_add(1, Relaxed))
18    }
19
20    fn id(&self) -> u32 {
21        self.2
22    }
23
24    fn new_sender(&self, base_url: String) -> Sender {
25        Sender::new(self.0.clone(), base_url, self.1.clone())
26    }
27
28    /// 引用数量
29    fn ref_count(&self) -> usize {
30        Arc::strong_count(&self.1)
31    }
32
33    /// 是否达到最大数
34    fn limited(&self, max_streams: Option<usize>) -> bool {
35        if let Some(max) = max_streams {
36            if self.ref_count() >= max + 1 {
37                return true;
38            }
39        }
40        return false;
41    }
42
43    fn is_closed(&self) -> bool {
44        self.0.is_closed()
45    }
46
47    fn reference(&self) -> Arc<()> {
48        self.1.clone()
49    }
50}
51
52/// http2连接池
53/// 连接池中的连接受max_conn数据限制
54/// 默认的keepalive是一分钟
55/// 连接池中的每个连接可并发流数受max_streams影响, 默认是20个
56/// 有三种行为会导致连接池中的连接被释放
57///     1.对方主动关闭连接
58///     2.remove_backend被调用清除后端地址, 这会导致该地址的所有连接失效
59///     3.在外界没有引用sender达到keepalive时间后, 注意如果没有设置keepalive则此条无效
60pub struct Pool {
61    state: net_pool::pool::BaseState,
62    max_streams: AtomicUsize,
63    free_conn_map: Mutex<HashMap<u64, Vec<Inner>>>,
64    use_tls: AtomicBool,
65}
66
67impl Pool {
68    pub fn new(strategy: Arc<dyn Strategy>, mut max_streams: Option<usize>) -> Self {
69        if let Some(0) = max_streams {
70            max_streams = None;
71        }
72
73        let p = Pool {
74            state: net_pool::pool::BaseState::new(strategy),
75            max_streams: AtomicUsize::new(usize::MAX),
76            free_conn_map: Mutex::new(HashMap::new()),
77            use_tls: AtomicBool::new(false),
78        };
79
80        p.set_max_streams(max_streams);
81        <Pool as net_pool::pool::Pool>::set_keepalive(
82            &p,
83            Some(std::time::Duration::from_secs(60 * 1)),
84        );
85        p
86    }
87
88    pub fn set_max_streams(&self, mut max_streams: Option<usize>) {
89        if let Some(0) = max_streams {
90            max_streams = None;
91        }
92
93        match max_streams {
94            None => self.max_streams.store(usize::MAX, Relaxed),
95            Some(v) => self.max_streams.store(v, Relaxed),
96        }
97    }
98    pub fn get_max_streams(&self) -> Option<usize> {
99        match self.max_streams.load(Relaxed) {
100            usize::MAX => None,
101            v => Some(v),
102        }
103    }
104}
105
106impl Default for Pool {
107    fn default() -> Self {
108        Pool::new(
109            Arc::new(net_pool::strategy::CHStrategy::default()),
110            Some(200),
111        )
112    }
113}
114
115impl<L: Strategy + 'static> From<L> for Pool {
116    fn from(value: L) -> Self {
117        Self::new(Arc::new(value), Some(200))
118    }
119}
120
121impl net_pool::pool::Pool for Pool {
122    net_pool::macros::base_pool_impl! {state}
123
124    fn remove_backend(&self, addr: &Address) -> bool {
125        if self.state.lb_strategy.remove_backend(addr) {
126            // 清除缓存
127            self.clear_bs_inner(addr);
128            true
129        } else {
130            false
131        }
132    }
133
134    fn use_tls(&self, tls: bool) {
135        self.use_tls.store(tls, Relaxed);
136    }
137
138    fn tls(&self) -> bool {
139        self.use_tls.load(Relaxed)
140    }
141}
142
143impl Pool {
144    fn get_sender(&self, bs: &BackendState) -> Option<Sender> {
145        let mut guard = self.free_conn_map.lock().unwrap();
146
147        // 这里虽然删除了一些closed状态的, 但算法却有延迟性,它无法及时删除所有的closed
148        let inners = guard.get_mut(&bs.hash_code())?;
149        for idx in (0..inners.len()).rev() {
150            let inner = &mut inners[idx];
151            if inner.is_closed() {
152                // 无效了
153                assert!(self.state.cur_conn.fetch_sub(1, Relaxed) > 0);
154                debug!(
155                    "[http/2.0 pool] [desc] current connection count: {}",
156                    self.state.cur_conn.load(Relaxed)
157                );
158                inners.remove(idx);
159                continue;
160            }
161
162            if inner.limited(self.get_max_streams()) {
163                continue;
164            }
165
166            let tls = <Pool as net_pool::pool::Pool>::tls(self);
167            return Some(inner.new_sender(crate::utils::base_url(tls, bs.get_address())));
168        }
169
170        None
171    }
172
173    fn add_inner(&self, hash_code: u64, inner: Inner) {
174        let mut guard = self.free_conn_map.lock().unwrap();
175        if let Some(inners) = guard.get_mut(&hash_code) {
176            inners.push(inner);
177        } else {
178            guard.insert(hash_code, vec![inner]);
179        }
180    }
181
182    fn clear_bs_inner(&self, addr: &Address) {
183        let mut guard = self.free_conn_map.lock().unwrap();
184        if let Some(inners) = guard.remove(&addr.hash_code()) {
185            assert!(self.state.cur_conn.fetch_sub(inners.len(), Relaxed) > 0);
186            debug!(
187                "[http/2.0 pool] [desc] current connection count: {}",
188                self.state.cur_conn.load(Relaxed)
189            );
190        }
191    }
192
193    fn remove_inner(&self, hash_code: u64, id: u32) {
194        let mut guard = self.free_conn_map.lock().unwrap();
195        if let Some(inners) = guard.get_mut(&hash_code) {
196            let mut del = false;
197            inners.retain(|inner| {
198                if inner.id() == id {
199                    del = true;
200                    assert!(self.state.cur_conn.fetch_sub(1, Relaxed) > 0);
201                    false
202                } else {
203                    true
204                }
205            });
206            if del {
207                debug!(
208                    "[http/2.0 pool] [desc] current connection count: {}",
209                    self.state.cur_conn.load(Relaxed)
210                );
211            }
212        }
213    }
214
215    fn run_conn<C: Future<Output = Result<(), hyper::Error>> + Send + 'static>(
216        pool: Arc<Self>,
217        c: C,
218        sr: SendRequest,
219        bs: &BackendState,
220    ) -> Sender {
221        let tls = <Pool as net_pool::pool::Pool>::tls(&pool);
222        let inner = Inner::new(sr);
223        let sender = inner.new_sender(crate::utils::base_url(tls, bs.get_address()));
224
225        let tuple = (
226            bs.hash_code(),
227            <Pool as net_pool::pool::Pool>::get_keepalive(&pool),
228            inner.reference(),
229            inner.id(),
230        );
231
232        // 加入
233        // 添加inner进去缓存时, 可能此时bs已经被删除了
234        // 由于缓存中持有inner, 所以有可能会导致在connection没有设置超时的情况下一直在运行,从而一直占用最大连接数
235        // 由于缓存和bs是通过不同的锁持有的, 所以暂时无法对它们进行一致性限制
236        pool.add_inner(tuple.0, inner);
237
238        // 驱动
239        tokio_spawn! {
240            instrument_current_span! {
241                async move {
242                    let _r = crate::utils::run_conn(tuple.2, c, tuple.1).await;
243                    debug!("[http/2.0 pool] connection closed: {:?}", _r);
244                    pool.remove_inner(tuple.0, tuple.3);
245                }
246            }
247        };
248
249        sender
250    }
251
252    async fn create_tls_sender(
253        self: Arc<Self>,
254        bs: &BackendState,
255        exec: hyper_util::rt::TokioExecutor,
256    ) -> Result<Sender, Error> {
257        let addr = bs.get_address();
258
259        // 获取连接
260        let tcp = crate::utils::create_https_stream(addr).await?;
261        let tls_tcp =
262            crate::utils::create_tls_tcp(tcp, addr, crate::utils::HTTP2_TLS_CLIENT_CFG.clone())
263                .await?;
264
265        // 握手建立 sender 和 connection
266        let max_streams = self.get_max_streams();
267        let io = hyper_util::rt::TokioIo::new(tls_tcp);
268        let pair = http2::Builder::new(exec)
269            .max_concurrent_streams(max_streams.map(|m| m as u32))
270            .handshake(io)
271            .await
272            .map_err(|e| Error::from_other(e))?;
273
274        // 启动连接驱动
275        let sender = Pool::run_conn(self, pair.1, pair.0, &bs);
276        Ok(sender)
277    }
278
279    async fn create_non_tls_sender(
280        self: Arc<Self>,
281        bs: &BackendState,
282        exec: hyper_util::rt::TokioExecutor,
283    ) -> Result<Sender, Error> {
284        let tcp = crate::utils::create_http_stream(bs.get_address()).await?;
285
286        // 握手建立 sender 和 connection
287        let io = hyper_util::rt::TokioIo::new(tcp);
288        let pair = http2::handshake(exec, io)
289            .await
290            .map_err(|e| Error::from_other(e))?;
291
292        // 启动连接驱动
293        let sender = Pool::run_conn(self, pair.1, pair.0, bs);
294        Ok(sender)
295    }
296
297    async fn create_sender(self: Arc<Self>, bs: &BackendState) -> Result<Sender, Error> {
298        let exec = hyper_util::rt::tokio::TokioExecutor::new();
299        if <Pool as net_pool::pool::Pool>::tls(&self) {
300            self.create_tls_sender(bs, exec).await
301        } else {
302            self.create_non_tls_sender(bs, exec).await
303        }
304    }
305
306    async fn real(self: Arc<Self>, bs: BackendState) -> Result<Sender, Error> {
307        let sender = match self.get_sender(&bs) {
308            Some(s) => Ok(s),
309            None => {
310                // 预分配数量
311                net_pool::pool::increase_current(&self.state.max_conn, &self.state.cur_conn)?;
312                self.clone().create_sender(&bs).await.map(|s| {
313                    debug!(
314                        "[http/2.0 pool] [incr] current connection count: {}",
315                        self.state.cur_conn.load(Relaxed)
316                    );
317                    s
318                })
319            }
320        };
321
322        if sender.is_err() {
323            assert!(self.state.cur_conn.fetch_sub(1, Relaxed) > 0);
324        }
325
326        sender
327    }
328}
329
330pub trait HttpPool {
331    fn get(self: Arc<Self>, key: &str) -> impl Future<Output = Result<Sender, Error>> + Send;
332
333    fn target(
334        self: Arc<Self>,
335        addr: &Address,
336    ) -> impl Future<Output = Result<Sender, Error>> + Send;
337}
338
339impl HttpPool for Pool {
340    async fn get(self: Arc<Self>, key: &str) -> Result<Sender, Error> {
341        let bs = self
342            .state
343            .lb_strategy
344            .get_backend(key)
345            .ok_or(Error::NoBackend);
346
347        self.real(bs?).await
348    }
349
350    async fn target(self: Arc<Self>, addr: &Address) -> Result<Sender, Error> {
351        if !self.state.lb_strategy.contain(addr) {
352            Err(Error::NoBackend)
353        } else {
354            self.real(BackendState::new(None, addr.clone())).await
355        }
356    }
357}
358
359pub async fn get<P: HttpPool>(pool: Arc<P>, key: &str) -> Result<Sender, Error> {
360    HttpPool::get(pool, key).await
361}