folly::detail::DigestBuilder< DigestT > Class Template Reference

#include <DigestBuilder.h>

Classes
struct	CpuLocalBuffer

Public Member Functions
	DigestBuilder (size_t bufferSize, size_t digestSize)
DigestT	build ()
void	append (double value)

Private Attributes
std::vector< CpuLocalBuffer >	cpuLocalBuffers_
size_t	bufferSize_
size_t	digestSize_

Detailed Description

template<typename DigestT>
class folly::detail::DigestBuilder< DigestT >

Definition at line 40 of file DigestBuilder.h.

Constructor & Destructor Documentation

template<typename DigestT >

folly::detail::DigestBuilder< DigestT >::DigestBuilder ( size_t  bufferSize, size_t  digestSize  )

explicit

Definition at line 31 of file DigestBuilder-defs.h.

References folly::detail::DigestBuilder< DigestT >::cpuLocalBuffers_, and folly::CacheLocality::system().

    : bufferSize_(bufferSize), digestSize_(digestSize) {
  auto& cl = CacheLocality::system();
  cpuLocalBuffers_.resize(cl.numCachesByLevel[0]);
}

Member Function Documentation

template<typename DigestT >

void folly::detail::DigestBuilder< DigestT >::append

(

double

value

)

Definition at line 74 of file DigestBuilder-defs.h.

References folly::detail::DigestBuilder< DigestT >::bufferSize_, folly::detail::DigestBuilder< DigestT >::cpuLocalBuffers_, folly::AccessSpreader< Atom >::current(), folly::detail::DigestBuilder< DigestT >::digestSize_, g(), and folly::detail::tls_lastCpuBufferSlot.

Referenced by TEST().

                                                {
  auto& which = tls_lastCpuBufferSlot;
  auto cpuLocalBuf = &cpuLocalBuffers_[which];
  std::unique_lock<SpinLock> g(cpuLocalBuf->mutex, std::try_to_lock_t());
  if (!g.owns_lock()) {
    which = AccessSpreader<>::current(cpuLocalBuffers_.size());
    cpuLocalBuf = &cpuLocalBuffers_[which];
    g = std::unique_lock<SpinLock>(cpuLocalBuf->mutex);
  }
  cpuLocalBuf->buffer.push_back(value);
  if (cpuLocalBuf->buffer.size() == bufferSize_) {
    if (!cpuLocalBuf->digest) {
      cpuLocalBuf->digest = std::make_unique<DigestT>(digestSize_);
    }
    *cpuLocalBuf->digest = cpuLocalBuf->digest->merge(cpuLocalBuf->buffer);
    cpuLocalBuf->buffer.clear();
  }
}

template<typename DigestT >

DigestT folly::detail::DigestBuilder< DigestT >::build

(

)

Definition at line 38 of file DigestBuilder-defs.h.

References count, folly::detail::DigestBuilder< DigestT >::cpuLocalBuffers_, folly::detail::DigestBuilder< DigestT >::digestSize_, g(), merge(), folly::gen::move, and values().

Referenced by TEST().

                                      {
  std::vector<std::vector<double>> valuesVec;
  std::vector<std::unique_ptr<DigestT>> digestPtrs;
  valuesVec.reserve(cpuLocalBuffers_.size());
  digestPtrs.reserve(cpuLocalBuffers_.size());

  for (auto& cpuLocalBuffer : cpuLocalBuffers_) {
    SpinLockGuard g(cpuLocalBuffer.mutex);
    valuesVec.push_back(std::move(cpuLocalBuffer.buffer));
    if (cpuLocalBuffer.digest) {
      digestPtrs.push_back(std::move(cpuLocalBuffer.digest));
    }
  }

  std::vector<DigestT> digests;
  for (auto& digestPtr : digestPtrs) {
    digests.push_back(std::move(*digestPtr));
  }

  size_t count = 0;
  for (const auto& vec : valuesVec) {
    count += vec.size();
  }
  if (count) {
    std::vector<double> values;
    values.reserve(count);
    for (const auto& vec : valuesVec) {
      values.insert(values.end(), vec.begin(), vec.end());
    }
    DigestT digest(digestSize_);
    digests.push_back(digest.merge(values));
  }
  return DigestT::merge(digests);
}

Member Data Documentation

template<typename DigestT>

size_t folly::detail::DigestBuilder< DigestT >::bufferSize_

private

Definition at line 64 of file DigestBuilder.h.

Referenced by folly::detail::DigestBuilder< DigestT >::append().

template<typename DigestT>

std::vector<CpuLocalBuffer> folly::detail::DigestBuilder< DigestT >::cpuLocalBuffers_

private

Definition at line 63 of file DigestBuilder.h.

Referenced by folly::detail::DigestBuilder< DigestT >::append(), folly::detail::DigestBuilder< DigestT >::build(), and folly::detail::DigestBuilder< DigestT >::DigestBuilder().

template<typename DigestT>

size_t folly::detail::DigestBuilder< DigestT >::digestSize_

private

Definition at line 65 of file DigestBuilder.h.

Referenced by folly::detail::DigestBuilder< DigestT >::append(), and folly::detail::DigestBuilder< DigestT >::build().

---

The documentation for this class was generated from the following files:

• proxygen/folly/folly/stats/detail/DigestBuilder.h
• proxygen/folly/folly/stats/detail/DigestBuilder-defs.h