| // Copyright 2023 gRPC authors. |
| // |
| // 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. |
| |
| #ifndef GRPC_SRC_CORE_LIB_BACKOFF_RANDOM_EARLY_DETECTION_H |
| #define GRPC_SRC_CORE_LIB_BACKOFF_RANDOM_EARLY_DETECTION_H |
| |
| #include <grpc/support/port_platform.h> |
| |
| #include <limits.h> |
| |
| #include <cstdint> |
| |
| #include "absl/random/random.h" |
| |
| namespace grpc_core { |
| |
| // Implements the random early detection algorithm - allows items to be rejected |
| // or accepted based upon their size. |
| class RandomEarlyDetection { |
| public: |
| RandomEarlyDetection() : soft_limit_(INT_MAX), hard_limit_(INT_MAX) {} |
| RandomEarlyDetection(uint64_t soft_limit, uint64_t hard_limit) |
| : soft_limit_(soft_limit), hard_limit_(hard_limit) {} |
| |
| // Returns true if the size is greater than or equal to the hard limit - ie if |
| // this item must be rejected. |
| bool MustReject(uint64_t size) { return size >= hard_limit_; } |
| |
| // Returns true if the item should be rejected. |
| bool Reject(uint64_t size); |
| |
| uint64_t soft_limit() const { return soft_limit_; } |
| uint64_t hard_limit() const { return hard_limit_; } |
| |
| private: |
| // The soft limit is the size at which we start rejecting items with a |
| // probability that increases linearly to 1 as the size approaches the hard |
| // limit. |
| uint64_t soft_limit_; |
| // The hard limit is the size at which we reject all items. |
| uint64_t hard_limit_; |
| // The bit generator used to generate random numbers. |
| absl::InsecureBitGen bitgen_; |
| }; |
| |
| } // namespace grpc_core |
| |
| #endif // GRPC_SRC_CORE_LIB_BACKOFF_RANDOM_EARLY_DETECTION_H |