bneradt commented on a change in pull request #7623: URL: https://github.com/apache/trafficserver/pull/7623#discussion_r610872900
########## File path: plugins/experimental/rate_limit/limiter.cc ########## @@ -0,0 +1,159 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you 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. + */ +#include "limiter.h" + +/////////////////////////////////////////////////////////////////////////////// +// This is the continuation that gets scheduled periodically to process the +// deque of waiting TXNs. +// +int +RateLimiter::queue_process_cont(TSCont cont, TSEvent event, void *edata) +{ + RateLimiter *limiter = static_cast<RateLimiter *>(TSContDataGet(cont)); + QueueTime now = std::chrono::system_clock::now(); // Only do this once per "loop" + + // Try to enable some queued txns (if any) if there are slots available + while (limiter->size() > 0 && limiter->reserve()) { + QueueItem item = limiter->pop(); + TSHttpTxn txnp = std::get<0>(item); + std::chrono::microseconds delay = std::chrono::duration_cast<std::chrono::milliseconds>(now - std::get<2>(item)); Review comment: This would be a good place to use auto. The type is clear from the cast on the right hand side. ########## File path: plugins/experimental/rate_limit/limiter.cc ########## @@ -0,0 +1,159 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you 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. + */ +#include "limiter.h" + +/////////////////////////////////////////////////////////////////////////////// +// This is the continuation that gets scheduled periodically to process the +// deque of waiting TXNs. +// +int +RateLimiter::queue_process_cont(TSCont cont, TSEvent event, void *edata) +{ + RateLimiter *limiter = static_cast<RateLimiter *>(TSContDataGet(cont)); + QueueTime now = std::chrono::system_clock::now(); // Only do this once per "loop" + + // Try to enable some queued txns (if any) if there are slots available + while (limiter->size() > 0 && limiter->reserve()) { + QueueItem item = limiter->pop(); Review comment: I suggest structured binding for this: `auto [txnp, continuation, start_time] = limiter->pop();` Those variable names would make things more explicit than the `std::get<n>` calls. ########## File path: plugins/experimental/rate_limit/limiter.h ########## @@ -0,0 +1,182 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you 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. + */ +#include <deque> +#include <tuple> +#include <climits> +#include <atomic> +#include <cstdio> +#include <chrono> +#include <cstring> +#include <string> + +#include <ts/ts.h> + +constexpr char const PLUGIN_NAME[] = "rate_limit"; +constexpr unsigned QUEUE_DELAY_TIME = 100; // Examine the queue every 100ms. Review comment: Might want to consider: ``` constexpr auto QUEUE_DELAY_TIME = std::chrono::milliseconds{100}; ... _action = TSContScheduleEveryOnPool(_queue_cont, QUEUE_DELAY_TIME.count(), TS_THREAD_POOL_TASK); ``` -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected]
