mirror of https://github.com/grpc/grpc.git
Create a CircularBuffer to store events generated by latent_see. This bounds the total number of generated events.
PiperOrigin-RevId: 658611718pull/37317/head
Vignesh Babu
4 months ago
committed by
Copybara-Service
parent
3e704c7552
commit
449d1b248f
16 changed files with 343 additions and 3 deletions
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#ifndef GRPC_SRC_CORE_UTIL_RING_BUFFER_H_ |
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#define GRPC_SRC_CORE_UTIL_RING_BUFFER_H_ |
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#include <grpc/support/port_platform.h> |
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#include <array> |
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#include <cstddef> |
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#include <iterator> |
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#include "absl/types/optional.h" |
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namespace grpc_core { |
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template <typename T, int kCapacity> |
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class RingBuffer { |
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public: |
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class RingBufferIterator { |
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public: |
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using iterator_category = std::forward_iterator_tag; |
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using value_type = const T; |
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using pointer = void; |
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using reference = void; |
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using difference_type = std::ptrdiff_t; |
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RingBufferIterator& operator++() { |
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if (--size_ <= 0) { |
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head_ = 0; |
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size_ = 0; |
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buffer_ = nullptr; |
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} else { |
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head_ = (head_ + 1) % kCapacity; |
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} |
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return *this; |
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} |
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RingBufferIterator operator++(int) { |
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RingBufferIterator tmp(*this); |
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operator++(); |
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return tmp; |
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} |
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bool operator==(const RingBufferIterator& rhs) const { |
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return (buffer_ == rhs.buffer_ && head_ == rhs.head_ && |
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size_ == rhs.size_); |
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} |
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bool operator!=(const RingBufferIterator& rhs) const { |
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return !operator==(rhs); |
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} |
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T operator*() { return buffer_->data_[head_]; } |
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RingBufferIterator() : buffer_(nullptr), head_(0), size_(0) {}; |
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RingBufferIterator(const RingBufferIterator& other) = default; |
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RingBufferIterator(const RingBuffer<T, kCapacity>* buffer) |
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: buffer_(buffer), head_(buffer->head_), size_(buffer->size_) { |
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if (!size_) { |
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buffer_ = nullptr; |
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} |
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} |
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private: |
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friend class RingBuffer<T, kCapacity>; |
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const RingBuffer<T, kCapacity>* buffer_; |
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int head_ = 0; |
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int size_ = 0; |
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}; |
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RingBuffer() = default; |
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void Append(T data) { |
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if (size_ < kCapacity) { |
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data_[size_] = std::move(data); |
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size_++; |
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} else { |
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data_[head_] = std::move(data); |
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head_ = (head_ + 1) % kCapacity; |
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} |
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} |
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// Returns the data of the first element in the buffer and removes it from
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// the buffer. If the buffer is empty, returns absl::nullopt.
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absl::optional<T> PopIfNotEmpty() { |
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if (!size_) return absl::nullopt; |
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T data = std::move(data_[head_]); |
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--size_; |
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head_ = (head_ + 1) % kCapacity; |
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return data; |
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} |
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void Clear() { |
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head_ = 0; |
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size_ = 0; |
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} |
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RingBufferIterator begin() const { return RingBufferIterator(this); } |
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RingBufferIterator end() const { return RingBufferIterator(); } |
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private: |
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friend class RingBufferIterator; |
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std::array<T, kCapacity> data_; |
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int head_ = 0; |
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int size_ = 0; |
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}; |
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} // namespace grpc_core
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#endif // GRPC_SRC_CORE_UTIL_RING_BUFFER_H_
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@ -0,0 +1,88 @@ |
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//
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//
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// Copyright 2015 gRPC authors.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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//
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//
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#include <grpc/support/port_platform.h> |
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#include "gtest/gtest.h" |
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#include "src/core/util/ring_buffer.h" |
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namespace grpc_core { |
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constexpr int kBufferCapacity = 1000; |
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TEST(RingBufferTest, BufferAppendPopTest) { |
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RingBuffer<int, kBufferCapacity> buffer; |
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EXPECT_FALSE(buffer.PopIfNotEmpty().has_value()); |
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for (int i = 0; i < (3 * kBufferCapacity)/2; ++i) { |
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buffer.Append(i); |
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} |
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// Pop half of the elements. Elements in [kBufferCapacity / 2,
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// kBufferCapacity) are popped.
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int j = kBufferCapacity / 2; |
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for (int i = 0; i < kBufferCapacity / 2; ++i) { |
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EXPECT_EQ(buffer.PopIfNotEmpty(), j++); |
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} |
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EXPECT_EQ(j, kBufferCapacity); |
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// Iterate over the remaining elements.
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for (auto it = buffer.begin(); it != buffer.end(); ++it) { |
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EXPECT_EQ(*it, j++); |
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} |
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// Elements in [kBufferCapacity, (3 * kBufferCapacity) / 2) should be present.
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EXPECT_EQ(j, (3 * kBufferCapacity) / 2); |
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// Append some more elements. The buffer should now have elements in
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// [kBufferCapacity, 2 * kBufferCapacity).
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for (int i = 0; i < kBufferCapacity / 2; ++i) { |
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buffer.Append(j++); |
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} |
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// Pop all the elements.
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j = kBufferCapacity; |
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while (true) { |
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auto ret = buffer.PopIfNotEmpty(); |
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if (!ret.has_value()) break; |
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EXPECT_EQ(*ret, j++); |
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} |
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EXPECT_EQ(j, 2 * kBufferCapacity); |
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} |
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TEST(RingBufferTest, BufferAppendIterateTest) { |
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RingBuffer<int, kBufferCapacity> buffer; |
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for (int i = 0; i < 5 * kBufferCapacity; ++i) { |
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buffer.Append(i); |
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int j = std::max(0, i + 1 - kBufferCapacity); |
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// If i >= kBufferCapacity, check that the buffer contains only the last
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// kBufferCapacity elements [i + 1 - kBufferCapacity, i]. Otherwise check
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// that the buffer contains all elements from 0 to i.
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for (auto it = buffer.begin(); it != buffer.end(); ++it) { |
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EXPECT_EQ(*it, j++); |
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} |
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// Check that j was incremented at each step which implies that all the
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// required elements were present in the buffer.
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EXPECT_EQ(j, i + 1); |
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} |
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buffer.Clear(); |
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EXPECT_EQ(buffer.begin(), buffer.end()); |
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} |
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} // namespace grpc_core
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int main(int argc, char** argv) { |
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::testing::InitGoogleTest(&argc, argv); |
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return RUN_ALL_TESTS(); |
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} |
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