/*=========================================================================

  Program:   Visualization Toolkit
  Module:    vtkParallelTimer.cxx

  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/
#include "vtkParallelTimer.h"

#if defined(_WIN32)
// The POSIX name for this item is deprecated. Instead, use the ISO C++ conformant name
#pragma warning(disable : 4996)
#endif

#include "vtkMPI.h"
#include "vtkObjectFactory.h"
#include "vtksys/FStream.hxx"

using std::cerr;
using std::endl;
using std::ostringstream;
using std::string;
using std::vector;

#include <ctime>
#if !defined(_WIN32)
#include <sys/time.h>
#include <unistd.h>
#else
#include <Winsock2.h>
#include <ctime>
#include <process.h>
static int gettimeofday(struct timeval* tv, void*)
{
  FILETIME ft;
  GetSystemTimeAsFileTime(&ft);

  __int64 tmpres = 0;
  tmpres = ft.dwHighDateTime;
  tmpres <<= 32;
  tmpres |= ft.dwLowDateTime;

  /*converting file time to unix epoch*/
  const __int64 DELTA_EPOCH_IN_MICROSECS = 11644473600000000;
  tmpres /= 10; /*convert into microseconds*/
  tmpres -= DELTA_EPOCH_IN_MICROSECS;
  tv->tv_sec = (__int32)(tmpres * 0.000001);
  tv->tv_usec = (tmpres % 1000000);

  return 0;
}
#endif

using std::ios_base;

/*
For singleton pattern
**/
vtkParallelTimer* vtkParallelTimer::GlobalInstance = nullptr;
vtkParallelTimer::vtkParallelTimerDestructor vtkParallelTimer::GlobalInstanceDestructor;

//------------------------------------------------------------------------------
vtkParallelTimer::vtkParallelTimerDestructor::~vtkParallelTimerDestructor()
{
  if (this->Log)
  {
    this->Log->Delete();
    this->Log = nullptr;
  }
}

// .NAME vtkParallelTimerBuffer -- A parallel buffer
//
// .SECTION Description
//  A parallel buffer for logging events and other data during an MPI
//  run. This is an implementation class you should not use it directly.
//  Use vtkParallelTimer instead.
class vtkParallelTimerBuffer
{
public:
  vtkParallelTimerBuffer();
  ~vtkParallelTimerBuffer();

  vtkParallelTimerBuffer(const vtkParallelTimerBuffer& other);
  vtkParallelTimerBuffer& operator=(const vtkParallelTimerBuffer& other);

  // Description:
  // Access state and internal data.
  const char* GetData() const { return this->Data; }
  char* GetData() { return this->Data; }
  size_t GetSize() const { return this->At; }
  size_t GetCapacity() const { return this->Size; }

  // Description:
  // Clear the buffer but don't release memory.
  void Clear() { this->At = 0; }

  // Description:
  // Clear the buffer and release all resources.
  void ClearForReal();

  // Description:
  // Stream insertion operators for adding data to the buffer.
  vtkParallelTimerBuffer& operator<<(int v);
  vtkParallelTimerBuffer& operator<<(long long v);
  vtkParallelTimerBuffer& operator<<(double v);
  vtkParallelTimerBuffer& operator<<(const char* v);
  template <size_t N>
  vtkParallelTimerBuffer& operator<<(const char v[N]);

  // Description:
  // Stream extraction operator for getting formatted data out.
  vtkParallelTimerBuffer& operator>>(std::ostringstream& s);

  // Description:
  // Gather buffer to a root process. This is a collective
  // operation.
  void Gather(int rootRank);

protected:
  // Description:
  // Push n bytes onto the buffer, resizing if necessary.
  void PushBack(const void* data, size_t n);

  // Description:
  // resize to at least newSize bytes.
  void Resize(size_t newSize);

private:
  size_t Size;
  size_t At;
  size_t GrowBy;
  char* Data;
};

//------------------------------------------------------------------------------
template <size_t N>
vtkParallelTimerBuffer& vtkParallelTimerBuffer::operator<<(const char v[N])
{
  const char c = 's';
  this->PushBack(&c, 1);
  this->PushBack(&v[0], N);
  return *this;
}

//------------------------------------------------------------------------------
vtkParallelTimerBuffer::vtkParallelTimerBuffer()
  : Size(0)
  , At(0)
  , GrowBy(4096)
  , Data(nullptr)
{
}

//------------------------------------------------------------------------------
vtkParallelTimerBuffer::~vtkParallelTimerBuffer()
{
  free(this->Data);
}

//------------------------------------------------------------------------------
vtkParallelTimerBuffer::vtkParallelTimerBuffer(const vtkParallelTimerBuffer& other)
  : Size(0)
  , At(0)
  , GrowBy(4096)
  , Data(nullptr)
{
  *this = other;
}

//------------------------------------------------------------------------------
vtkParallelTimerBuffer& vtkParallelTimerBuffer::operator=(const vtkParallelTimerBuffer& other)
{
  if (this == &other)
  {
    return *this;
  }
  this->Clear();
  this->Resize(other.GetSize());
  memcpy(this->Data, other.Data, other.GetSize());
  return *this;
}

//------------------------------------------------------------------------------
void vtkParallelTimerBuffer::ClearForReal()
{
  this->At = 0;
  this->Size = 0;
  free(this->Data);
  this->Data = nullptr;
}

//------------------------------------------------------------------------------
vtkParallelTimerBuffer& vtkParallelTimerBuffer::operator<<(int v)
{
  const char c = 'i';
  this->PushBack(&c, 1);
  this->PushBack(&v, sizeof(int));
  return *this;
}

//------------------------------------------------------------------------------
vtkParallelTimerBuffer& vtkParallelTimerBuffer::operator<<(long long v)
{
  const char c = 'l';
  this->PushBack(&c, 1);
  this->PushBack(&v, sizeof(long long));
  return *this;
}

//------------------------------------------------------------------------------
vtkParallelTimerBuffer& vtkParallelTimerBuffer::operator<<(double v)
{
  const char c = 'd';
  this->PushBack(&c, 1);
  this->PushBack(&v, sizeof(double));
  return *this;
}

//------------------------------------------------------------------------------
vtkParallelTimerBuffer& vtkParallelTimerBuffer::operator<<(const char* v)
{
  const char c = 's';
  this->PushBack(&c, 1);
  size_t n = strlen(v) + 1;
  this->PushBack(v, n);
  return *this;
}

//------------------------------------------------------------------------------
vtkParallelTimerBuffer& vtkParallelTimerBuffer::operator>>(ostringstream& s)
{
  size_t i = 0;
  while (i < this->At)
  {
    char c = this->Data[i];
    ++i;
    switch (c)
    {
      case 'i':
      {
        int temp;
        size_t n = sizeof(temp);
        memcpy(&temp, this->Data + i, n);
        s << temp;
        i += n;
      }
      break;

      case 'l':
      {
        long long temp;
        size_t n = sizeof(temp);
        memcpy(&temp, this->Data + i, n);
        s << temp;
        i += n;
      }
      break;

      case 'd':
      {
        double temp;
        size_t n = sizeof(temp);
        memcpy(&temp, this->Data + i, n);
        s << temp;
        i += n;
      }
      break;

      case 's':
      {
        s << this->Data + i;
        size_t n = strlen(this->Data + i) + 1;
        i += n;
      }
      break;

      default:
        cerr << "Bad case at " << i - 1 << " " << c << ", " << (int)c;
        return *this;
    }
  }
  return *this;
}

//------------------------------------------------------------------------------
void vtkParallelTimerBuffer::Gather(int rootRank)
{
  int mpiOk;
  MPI_Initialized(&mpiOk);
  if (!mpiOk)
  {
    return;
  }
  int worldRank;
  MPI_Comm_rank(MPI_COMM_WORLD, &worldRank);
  int worldSize;
  MPI_Comm_size(MPI_COMM_WORLD, &worldSize);

  // in serial this is a no-op
  if (worldSize > 1)
  {
    int* bufferSizes = nullptr;
    int* disp = nullptr;
    if (worldRank == rootRank)
    {
      bufferSizes = static_cast<int*>(malloc(worldSize * sizeof(int)));
      disp = static_cast<int*>(malloc(worldSize * sizeof(int)));
    }
    int bufferSize = static_cast<int>(this->GetSize());
    MPI_Gather(&bufferSize, 1, MPI_INT, bufferSizes, 1, MPI_INT, rootRank, MPI_COMM_WORLD);
    char* log = nullptr;
    int cumSize = 0;
    if (worldRank == rootRank)
    {
      for (int i = 0; i < worldSize; ++i)
      {
        disp[i] = cumSize;
        cumSize += bufferSizes[i];
      }
      log = static_cast<char*>(malloc(cumSize));
    }
    MPI_Gatherv(
      this->Data, bufferSize, MPI_CHAR, log, bufferSizes, disp, MPI_CHAR, rootRank, MPI_COMM_WORLD);
    if (worldRank == rootRank)
    {
      this->Clear();
      this->PushBack(log, cumSize);
      free(bufferSizes);
      free(disp);
      free(log);
    }
    else
    {
      this->Clear();
    }
  }
}

//------------------------------------------------------------------------------
void vtkParallelTimerBuffer::PushBack(const void* data, size_t n)
{
  size_t nextAt = this->At + n;
  this->Resize(nextAt);
  memcpy(this->Data + this->At, data, n);
  this->At = nextAt;
}

//------------------------------------------------------------------------------
void vtkParallelTimerBuffer::Resize(size_t newSize)
{
#if defined(vtkParallelTimerBufferDEBUG)
  size_t oldSize = this->Size;
#endif
  if (newSize <= this->Size)
  {
    return;
  }
  while (this->Size < newSize)
  {
    this->Size += this->GrowBy;
  }
  this->Data = static_cast<char*>(realloc(this->Data, this->Size));
#if defined(vtkParallelTimerBufferDEBUG)
  memset(this->Data + oldSize, -1, this->Size - oldSize);
#endif
}

//------------------------------------------------------------------------------
vtkStandardNewMacro(vtkParallelTimer);

//------------------------------------------------------------------------------
vtkParallelTimer::vtkParallelTimer()
  : GlobalLevel(0)
  , WorldRank(0)
  , WriterRank(0)
  , FileName(nullptr)
  , WriteOnClose(0)
  , Log(nullptr)
{
#if vtkParallelTimerDEBUG > 1
  cerr << "=====vtkParallelTimer::vtkParallelTimer" << endl;
#endif

  MPI_Initialized(&this->Initialized);
  if (this->Initialized)
  {
    MPI_Comm_rank(MPI_COMM_WORLD, &this->WorldRank);
  }
  this->StartTime.reserve(256);
  this->Log = new vtkParallelTimerBuffer;
}

//------------------------------------------------------------------------------
vtkParallelTimer::~vtkParallelTimer()
{
#if vtkParallelTimerDEBUG > 1
  cerr << "=====vtkParallelTimer::~vtkParallelTimer" << endl;
#endif

  // Alert the user that he left events on the stack,
  // this is usually a sign of trouble.
  if (!this->StartTime.empty())
  {
    vtkErrorMacro(<< "Start time stack has " << this->StartTime.size() << " remaining.");
  }

#if vtkParallelTimerDEBUG < 0
  if (!this->EventId.empty())
  {
    size_t nIds = this->EventId.size();
    vtkErrorMacro(<< "Event id stack has " << nIds << " remaining.");
    for (size_t i = 0; i < nIds; ++i)
    {
      cerr << "EventId[" << i << "]=" << this->EventId[i] << endl;
    }
  }
#endif

  this->SetFileName(nullptr);

  delete this->Log;
}

//------------------------------------------------------------------------------
vtkParallelTimer* vtkParallelTimer::GetGlobalInstance()
{
#if vtkParallelTimerDEBUG > 1
  cerr << "=====vtkParallelTimer::GetGlobalInstance" << endl;
#endif

  if (vtkParallelTimer::GlobalInstance == nullptr)
  {
    vtkParallelTimer* log = vtkParallelTimer::New();
    ostringstream oss;
#ifdef _WIN32
    oss << GetCurrentProcessId() << ".log";
#else
    oss << getpid() << ".log";
#endif
    log->SetFileName(oss.str().c_str());

    vtkParallelTimer::GlobalInstance = log;
    vtkParallelTimer::GlobalInstanceDestructor.SetLog(log);
  }
  return vtkParallelTimer::GlobalInstance;
}

//------------------------------------------------------------------------------
void vtkParallelTimer::DeleteGlobalInstance()
{
#if vtkParallelTimerDEBUG > 1
  cerr << "=====vtkParallelTimer::GetGlobalInstance" << endl;
#endif

  if (vtkParallelTimer::GlobalInstance)
  {
    vtkParallelTimer::GlobalInstance->Delete();
    vtkParallelTimer::GlobalInstance = nullptr;

    vtkParallelTimer::GlobalInstanceDestructor.SetLog(nullptr);
  }
}

//------------------------------------------------------------------------------
void vtkParallelTimer::Clear()
{
#if vtkParallelTimerDEBUG > 1
  cerr << "=====vtkParallelTimer::Clear" << endl;
#endif

  this->Log->Clear();
  this->HeaderBuffer.str("");
}

//------------------------------------------------------------------------------
void vtkParallelTimer::StartEvent(int rank, const char* event)
{
#if vtkParallelTimerDEBUG > 2
  cerr << "=====vtkParallelTimer::StartEvent" << endl;
#endif

  if (this->WorldRank != rank)
  {
    return;
  }
  this->StartEvent(event);
}

//------------------------------------------------------------------------------
void vtkParallelTimer::StartEvent(const char* event)
{
#if vtkParallelTimerDEBUG > 1
  cerr << "=====vtkParallelTimer::StartEvent" << endl;
#endif

  timeval wallt;
  gettimeofday(&wallt, nullptr);
  double walls = static_cast<double>(wallt.tv_sec) + static_cast<double>(wallt.tv_usec) / 1.0E6;

#if vtkParallelTimerDEBUG < 0
  this->EventId.emplace_back(event);
#endif

  this->StartTime.push_back(walls);
}

//------------------------------------------------------------------------------
void vtkParallelTimer::EndEvent(int rank, const char* event)
{
#if vtkParallelTimerDEBUG > 2
  cerr << "=====vtkParallelTimer::EndEvent" << endl;
#endif

  if (this->WorldRank != rank)
  {
    return;
  }
  this->EndEvent(event);
}

//------------------------------------------------------------------------------
void vtkParallelTimer::EndEvent(const char* event)
{
#if vtkParallelTimerDEBUG > 1
  cerr << "=====vtkParallelTimer::EndEvent" << endl;
#endif

  timeval wallt;
  gettimeofday(&wallt, nullptr);
  double walle = static_cast<double>(wallt.tv_sec) + static_cast<double>(wallt.tv_usec) / 1.0E6;

#if vtkParallelTimerDEBUG > 0
  if (this->StartTime.empty())
  {
    vtkErrorMacro("No event to end! " << event);
    return;
  }
#endif

  double walls = this->StartTime.back();
  this->StartTime.pop_back();

  *this->Log << this->WorldRank << " " << event << " " << walls << " " << walle << " "
             << walle - walls << "\n";

#if vtkParallelTimerDEBUG < 0
  const string& sEventId = this->EventId.back();
  const string eEventId = event;
  if (sEventId != eEventId)
  {
    vtkErrorMacro(<< "Event mismatch " << sEventId.c_str() << " != " << eEventId.c_str());
  }
  this->EventId.pop_back();
#endif
}

//------------------------------------------------------------------------------
void vtkParallelTimer::EndEventSynch(int rank, const char* event)
{
#if vtkParallelTimerDEBUG > 1
  cerr << "=====vtkParallelTimer::EndEventSynch" << endl;
#endif

  if (this->Initialized)
  {
    MPI_Barrier(MPI_COMM_WORLD);
  }
  if (this->WorldRank != rank)
  {
    return;
  }
  this->EndEvent(event);
}

//------------------------------------------------------------------------------
void vtkParallelTimer::EndEventSynch(const char* event)
{
#if vtkParallelTimerDEBUG > 1
  cerr << "=====vtkParallelTimer::EndEventSynch" << endl;
#endif

  if (this->Initialized)
  {
    MPI_Barrier(MPI_COMM_WORLD);
  }
  this->EndEvent(event);
}

//------------------------------------------------------------------------------
void vtkParallelTimer::Update()
{
#if vtkParallelTimerDEBUG > 1
  cerr << "=====vtkParallelTimer::Update" << endl;
#endif

  if (this->Initialized)
  {
    this->Log->Gather(this->WriterRank);
  }
}

//------------------------------------------------------------------------------
int vtkParallelTimer::Write()
{
#if vtkParallelTimerDEBUG > 1
  cerr << "=====vtkParallelTimer::Write" << endl;
#endif

  if ((this->WorldRank == this->WriterRank) && this->Log->GetSize())
  {
    cerr << "Wrote " << this->FileName << endl;

    ostringstream oss;
    *this->Log >> oss;
    vtksys::ofstream f(this->FileName, ios_base::out | ios_base::app);
    if (!f.good())
    {
      vtkErrorMacro(<< "Failed to open " << this->FileName << " for writing.");
      return -1;
    }
    time_t t;
    time(&t);
    f << "# " << ctime(&t) << this->HeaderBuffer.str() << oss.str();
    f.close();
  }
  return 0;
}

//------------------------------------------------------------------------------
void vtkParallelTimer::PrintSelf(ostream& os, vtkIndent)
{
  time_t t;
  time(&t);
  os << "# " << ctime(&t);
  if (this->WorldRank == this->WriterRank)
  {
    os << this->HeaderBuffer.str();
  }
  ostringstream oss;
  *this->Log >> oss;
  os << oss.str();
}