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			108 lines
		
	
	
	
		
			2.8 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			108 lines
		
	
	
	
		
			2.8 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
/*
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    This file is part of TON Blockchain Library.
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    TON Blockchain Library is free software: you can redistribute it and/or modify
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    it under the terms of the GNU Lesser General Public License as published by
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    the Free Software Foundation, either version 2 of the License, or
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    (at your option) any later version.
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    TON Blockchain Library is distributed in the hope that it will be useful,
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    but WITHOUT ANY WARRANTY; without even the implied warranty of
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    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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    GNU Lesser General Public License for more details.
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    You should have received a copy of the GNU Lesser General Public License
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    along with TON Blockchain Library.  If not, see <http://www.gnu.org/licenses/>.
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    Copyright 2017-2020 Telegram Systems LLP
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*/
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#pragma once
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#include "td/utils/common.h"
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#include <limits>
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namespace td {
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// More strict implementaions of flood control than FloodControlFast.
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// Should be just fine for small counters.
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class FloodControlStrict {
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 public:
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  int32 add_event(int32 now) {
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    events_.push_back(Event{now});
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    if (without_update_ > 0) {
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      without_update_--;
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    } else {
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      update(now);
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    }
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    return wakeup_at_;
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  }
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  // no more than count in each duration.
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  void add_limit(int32 duration, int32 count) {
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    limits_.push_back(Limit{duration, count, 0});
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  }
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  int32 get_wakeup_at() {
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    return wakeup_at_;
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  }
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  void clear_events() {
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    events_.clear();
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    for (auto &limit : limits_) {
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      limit.pos_ = 0;
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    }
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    without_update_ = 0;
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    wakeup_at_ = 0;
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  }
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  int32 update(int32 now) {
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    size_t min_pos = events_.size();
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    without_update_ = std::numeric_limits<size_t>::max();
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    for (auto &limit : limits_) {
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      if (limit.pos_ + limit.count_ < events_.size()) {
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        limit.pos_ = events_.size() - limit.count_;
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      }
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      // binary-search? :D
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      while (limit.pos_ < events_.size() && events_[limit.pos_].timestamp_ + limit.duration_ < now) {
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        limit.pos_++;
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      }
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      if (limit.count_ + limit.pos_ <= events_.size()) {
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        CHECK(limit.count_ + limit.pos_ == events_.size());
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        wakeup_at_ = max(wakeup_at_, events_[limit.pos_].timestamp_ + limit.duration_);
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        without_update_ = 0;
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      } else {
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        without_update_ = min(without_update_, limit.count_ + limit.pos_ - events_.size());
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      }
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      min_pos = min(min_pos, limit.pos_);
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    }
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    if (min_pos * 2 > events_.size()) {
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      for (auto &limit : limits_) {
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        limit.pos_ -= min_pos;
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      }
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      events_.erase(events_.begin(), events_.begin() + min_pos);
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    }
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    return wakeup_at_;
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  }
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 private:
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  int32 wakeup_at_ = 0;
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  struct Event {
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    int32 timestamp_;
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  };
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  struct Limit {
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    int32 duration_;
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    int32 count_;
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    size_t pos_;
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  };
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  size_t without_update_ = 0;
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  std::vector<Event> events_;
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  std::vector<Limit> limits_;
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};
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}  // namespace td
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