// Created on: 2011-10-05
// Created by: Kirill GAVRILOV
// Copyright (c) 2013-2014 OPEN CASCADE SAS
//
// This file is part of Open CASCADE Technology software library.
//
// This library is free software; you can redistribute it and/or modify it under
// the terms of the GNU Lesser General Public License version 2.1 as published
// by the Free Software Foundation, with special exception defined in the file
// OCCT_LGPL_EXCEPTION.txt. Consult the file LICENSE_LGPL_21.txt included in OCCT
// distribution for complete text of the license and disclaimer of any warranty.
//
// Alternatively, this file may be used under the terms of Open CASCADE
// commercial license or contractual agreement.

#if (defined(_WIN32) || defined(__WIN32__))
  #include <windows.h>
  #include <winbase.h>
  #include <process.h>
  #include <malloc.h>
  #include <psapi.h>
  #ifdef _MSC_VER
    #pragma comment(lib, "Psapi.lib")
  #endif
#elif (defined(__APPLE__))
  #include <mach/task.h>
  #include <mach/mach.h>
  #include <malloc/malloc.h>
#else
  #include <unistd.h>
  #include <malloc.h>
#endif

#include <string>
#include <sstream>
#include <fstream>

#include <OSD_MemInfo.hxx>

#if defined(__EMSCRIPTEN__)
  #include <emscripten.h>

  //! Return WebAssembly heap size in bytes.
  EM_JS(size_t, OSD_MemInfo_getModuleHeapLength, (), {
    return Module.HEAP8.length;
  });
#endif

// =======================================================================
// function : OSD_MemInfo
// purpose  :
// =======================================================================
OSD_MemInfo::OSD_MemInfo (const Standard_Boolean theImmediateUpdate)
{
  SetActive (Standard_True);
  if (theImmediateUpdate)
  {
    Update();
  }
  else
  {
    Clear();
  }
}

// =======================================================================
// function : SetActive
// purpose  :
// =======================================================================
void OSD_MemInfo::SetActive (const Standard_Boolean theActive)
{
  for (Standard_Integer anIter = 0; anIter < MemCounter_NB; ++anIter)
  {
    SetActive ((Counter)anIter, theActive);
  }
}

// =======================================================================
// function : Clear
// purpose  :
// =======================================================================
void OSD_MemInfo::Clear()
{
  for (Standard_Integer anIter = 0; anIter < MemCounter_NB; ++anIter)
  {
    myCounters[anIter] = Standard_Size(-1);
  }
}

// =======================================================================
// function : Update
// purpose  :
// =======================================================================
void OSD_MemInfo::Update()
{
  Clear();
#ifndef OCCT_UWP
#if defined(_WIN32)
#if (_WIN32_WINNT >= 0x0500)
  if (IsActive (MemVirtual))
  {
    MEMORYSTATUSEX aStatEx;
    aStatEx.dwLength = sizeof(aStatEx);
    GlobalMemoryStatusEx (&aStatEx);
    myCounters[MemVirtual] = Standard_Size(aStatEx.ullTotalVirtual - aStatEx.ullAvailVirtual);
  }
#else
  if (IsActive (MemVirtual))
  {
    MEMORYSTATUS aStat;
    aStat.dwLength = sizeof(aStat);
    GlobalMemoryStatus (&aStat);
    myCounters[MemVirtual] = Standard_Size(aStat.dwTotalVirtual - aStat.dwAvailVirtual);
  }
#endif

  if (IsActive (MemPrivate)
   || IsActive (MemWorkingSet)
   || IsActive (MemWorkingSetPeak)
   || IsActive (MemSwapUsage)
   || IsActive (MemSwapUsagePeak))
  {
    // use Psapi library
    HANDLE aProcess = GetCurrentProcess();
  #if (_WIN32_WINNT >= 0x0501)
    PROCESS_MEMORY_COUNTERS_EX aProcMemCnts;
  #else
    PROCESS_MEMORY_COUNTERS    aProcMemCnts;
  #endif
    if (GetProcessMemoryInfo (aProcess, (PROCESS_MEMORY_COUNTERS* )&aProcMemCnts, sizeof(aProcMemCnts)))
    {
    #if (_WIN32_WINNT >= 0x0501)
      myCounters[MemPrivate]        = aProcMemCnts.PrivateUsage;
    #endif
      myCounters[MemWorkingSet]     = aProcMemCnts.WorkingSetSize;
      myCounters[MemWorkingSetPeak] = aProcMemCnts.PeakWorkingSetSize;
      myCounters[MemSwapUsage]      = aProcMemCnts.PagefileUsage;
      myCounters[MemSwapUsagePeak]  = aProcMemCnts.PeakPagefileUsage;
    }
  }

  if (IsActive (MemHeapUsage))
  {
    _HEAPINFO hinfo;
    int heapstatus;
    hinfo._pentry = NULL;

    myCounters[MemHeapUsage] = 0;
    while((heapstatus = _heapwalk(&hinfo)) == _HEAPOK)
    {
      if (hinfo._useflag == _USEDENTRY)
      {
        myCounters[MemHeapUsage] += hinfo._size;
      }
    }
  }

#elif defined(__EMSCRIPTEN__)
  if (IsActive (MemHeapUsage)
   || IsActive (MemWorkingSet)
   || IsActive (MemWorkingSetPeak))
  {
    // /proc/%d/status is not emulated - get more info from mallinfo()
    const struct mallinfo aMI = mallinfo();
    if (IsActive (MemHeapUsage))
    {
      myCounters[MemHeapUsage] = aMI.uordblks;
    }
    if (IsActive (MemWorkingSet))
    {
      myCounters[MemWorkingSet] = aMI.uordblks;
    }
    if (IsActive (MemWorkingSetPeak))
    {
      myCounters[MemWorkingSetPeak] = aMI.usmblks;
    }
  }
  if (IsActive (MemVirtual))
  {
    myCounters[MemVirtual] = OSD_MemInfo_getModuleHeapLength();
  }
#elif (defined(__linux__) || defined(__linux))
  if (IsActive (MemHeapUsage))
  {
    const struct mallinfo aMI = mallinfo();
    myCounters[MemHeapUsage] = aMI.uordblks;
  }

  if (!IsActive (MemVirtual)
   && !IsActive (MemWorkingSet)
   && !IsActive (MemWorkingSetPeak)
   && !IsActive (MemPrivate))
  {
    return;
  }

  // use procfs on Linux
  char aBuff[4096];
  snprintf (aBuff, sizeof(aBuff), "/proc/%d/status", getpid());
  std::ifstream aFile;
  aFile.open (aBuff);
  if (!aFile.is_open())
  {
    return;
  }

  while (!aFile.eof())
  {
    memset (aBuff, 0, sizeof(aBuff));
    aFile.getline (aBuff, 4096);
    if (aBuff[0] == '\0')
    {
      continue;
    }

    if (IsActive (MemVirtual)
     && strncmp (aBuff, "VmSize:", strlen ("VmSize:")) == 0)
    {
      myCounters[MemVirtual] = atol (aBuff + strlen ("VmSize:")) * 1024;
    }
    //else if (strncmp (aBuff, "VmPeak:", strlen ("VmPeak:")) == 0)
    //  myVirtualPeak = atol (aBuff + strlen ("VmPeak:")) * 1024;
    else if (IsActive (MemWorkingSet)
          && strncmp (aBuff, "VmRSS:", strlen ("VmRSS:")) == 0)
    {
      myCounters[MemWorkingSet] = atol (aBuff + strlen ("VmRSS:")) * 1024; // RSS - resident set size
    }
    else if (IsActive (MemWorkingSetPeak)
          && strncmp (aBuff, "VmHWM:", strlen ("VmHWM:")) == 0)
    {
      myCounters[MemWorkingSetPeak] = atol (aBuff + strlen ("VmHWM:")) * 1024; // HWM - high water mark
    }
    else if (IsActive (MemPrivate)
          && strncmp (aBuff, "VmData:", strlen ("VmData:")) == 0)
    {
      if (myCounters[MemPrivate] == Standard_Size(-1)) ++myCounters[MemPrivate];
      myCounters[MemPrivate] += atol (aBuff + strlen ("VmData:")) * 1024;
    }
    else if (IsActive (MemPrivate)
          && strncmp (aBuff, "VmStk:", strlen ("VmStk:")) == 0)
    {
      if (myCounters[MemPrivate] == Standard_Size(-1)) ++myCounters[MemPrivate];
      myCounters[MemPrivate] += atol (aBuff + strlen ("VmStk:")) * 1024;
    }
  }
  aFile.close();
#elif (defined(__APPLE__))
  if (IsActive (MemVirtual)
   || IsActive (MemWorkingSet)
   || IsActive (MemHeapUsage))
  {
    struct task_basic_info aTaskInfo;
    mach_msg_type_number_t aTaskInfoCount = TASK_BASIC_INFO_COUNT;
    if (task_info (mach_task_self(), TASK_BASIC_INFO,
                   (task_info_t )&aTaskInfo, &aTaskInfoCount) == KERN_SUCCESS)
    {
      // On Mac OS X, these values in bytes, not pages!
      myCounters[MemVirtual]    = aTaskInfo.virtual_size;
      myCounters[MemWorkingSet] = aTaskInfo.resident_size;

      //Getting malloc statistics
      malloc_statistics_t aStats;
      malloc_zone_statistics (NULL, &aStats);

      myCounters[MemHeapUsage] = aStats.size_in_use;
    }
  }
#endif
#endif
}

// =======================================================================
// function : ToString
// purpose  :
// =======================================================================
TCollection_AsciiString OSD_MemInfo::ToString() const
{
  TCollection_AsciiString anInfo;
  if (hasValue (MemPrivate))
  {
    anInfo += TCollection_AsciiString("  Private memory:     ") + Standard_Integer (ValueMiB (MemPrivate)) + " MiB\n";
  }
  if (hasValue (MemWorkingSet))
  {
    anInfo += TCollection_AsciiString("  Working Set:        ") +  Standard_Integer (ValueMiB (MemWorkingSet)) + " MiB";
    if (hasValue (MemWorkingSetPeak))
    {
      anInfo += TCollection_AsciiString(" (peak: ") +  Standard_Integer (ValueMiB (MemWorkingSetPeak)) + " MiB)";
    }
    anInfo += "\n";
  }
  if (hasValue (MemSwapUsage))
  {
    anInfo += TCollection_AsciiString("  Pagefile usage:     ") +  Standard_Integer (ValueMiB (MemSwapUsage)) + " MiB";
    if (hasValue (MemSwapUsagePeak))
    {
      anInfo += TCollection_AsciiString(" (peak: ") +  Standard_Integer (ValueMiB (MemSwapUsagePeak)) + " MiB)";
    }
    anInfo += "\n";
  }
  if (hasValue (MemVirtual))
  {
    anInfo += TCollection_AsciiString("  Virtual memory:     ") +  Standard_Integer (ValueMiB (MemVirtual)) + " MiB\n";
  }
  if (hasValue (MemHeapUsage))
  {
    anInfo += TCollection_AsciiString("  Heap memory:     ") +  Standard_Integer (ValueMiB (MemHeapUsage)) + " MiB\n";
  }
  return anInfo;
}

// =======================================================================
// function : Value
// purpose  :
// =======================================================================
Standard_Size OSD_MemInfo::Value (const OSD_MemInfo::Counter theCounter) const
{
  if (theCounter < 0 || theCounter >= MemCounter_NB || !IsActive (theCounter))
  {
    return Standard_Size(-1);
  }
  return myCounters[theCounter];
}

// =======================================================================
// function : ValueMiB
// purpose  :
// =======================================================================
Standard_Size OSD_MemInfo::ValueMiB (const OSD_MemInfo::Counter theCounter) const
{
  if (theCounter < 0 || theCounter >= MemCounter_NB || !IsActive (theCounter))
  {
    return Standard_Size(-1);
  }
  return (myCounters[theCounter] == Standard_Size(-1))
       ? Standard_Size(-1) : (myCounters[theCounter] / (1024 * 1024));
}

// =======================================================================
// function : ValuePreciseMiB
// purpose  :
// =======================================================================
Standard_Real OSD_MemInfo::ValuePreciseMiB (const OSD_MemInfo::Counter theCounter) const
{
  if (theCounter < 0 || theCounter >= MemCounter_NB || !IsActive (theCounter))
  {
    return -1.0;
  }
  return (myCounters[theCounter] == Standard_Size(-1))
       ? -1.0 : ((Standard_Real )myCounters[theCounter] / (1024.0 * 1024.0));
}

// =======================================================================
// function : ShowInfo
// purpose  :
// =======================================================================
TCollection_AsciiString OSD_MemInfo::PrintInfo()
{
  OSD_MemInfo anInfo;
  return anInfo.ToString();
}