src/connectivity/bluetooth/core/bt-host/common/retire_log.cc

// Copyright 2021 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "src/connectivity/bluetooth/core/bt-host/public/pw_bluetooth_sapphire/internal/host/common/retire_log.h"

#include <limits>

namespace bt::internal {

RetireLog::RetireLog(size_t min_depth, size_t max_depth)
    : min_depth_(min_depth), max_depth_(max_depth) {
  BT_ASSERT(min_depth_ > 0);
  BT_ASSERT(min_depth_ <= max_depth_);

  // For simplicity, log indexes are computed with doubles, so limit the depth
  // to 2**53 in which precision is preserved, assuming IEEE-754 DPFPs.
  BT_ASSERT(max_depth_ <=
            (decltype(max_depth_){1} << std::numeric_limits<double>::digits));
  buffer_.reserve(max_depth_);
  std::apply(
      [this](auto&... scratchpad) { (scratchpad.reserve(max_depth_), ...); },
      quantile_scratchpads_);
}

void RetireLog::Retire(size_t byte_count,
                       pw::chrono::SystemClock::duration age) {
  if (depth() < max_depth_) {
    buffer_.push_back({byte_count, age});
    return;
  }
  buffer_[next_insertion_index_] = {byte_count, age};
  next_insertion_index_ = (next_insertion_index_ + 1) % depth();
}

}  // namespace bt::internal