/* Copyright (C) 2014 InfiniDB, Inc.

   This program is free software; you can redistribute it and/or
   modify it under the terms of the GNU General Public License
   as published by the Free Software Foundation; version 2 of
   the License.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
   MA 02110-1301, USA. */

/*****************************************************************************
 * $Id: cvt_em.cpp 1823 2013-01-21 14:13:09Z rdempsey $
 *
 ****************************************************************************/

/*
 * Loads state of the BRM data structures from file.
 *
 * More detailed description
 */

#include <iostream>
#include <map>
using namespace std;

#include "extentmap.h"
using namespace BRM;

namespace
{
void usage(char* name)
{
  cout << "Usage: " << name << " <prefix>" << endl;
  exit(1);
}
}  // namespace

namespace BRM
{
class ExtentMapConverter
{
 public:
  ExtentMapConverter(){};

  int doCvt(unsigned oldExtentSize, unsigned newExtentSize, const string& filename);

 private:
  ExtentMapConverter(const ExtentMapConverter& rhs);
  ExtentMapConverter& operator=(const ExtentMapConverter& rhs);

  ExtentMap em;
};

int ExtentMapConverter::doCvt(unsigned oldExtentSize, unsigned newExtentSize, const string& filename)
{
  int currentSize, loadSize[3];
  ifstream in;

  em.grabEMEntryTable(ExtentMap::WRITE);

  try
  {
    em.grabFreeList(ExtentMap::WRITE);
  }
  catch (...)
  {
    em.releaseEMEntryTable(ExtentMap::WRITE);
    throw;
  }

  div_t d = div((int)oldExtentSize, (int)newExtentSize);
  idbassert(d.quot > 1);
  idbassert(d.rem == 0);

  const unsigned mult = d.quot;

  in.open(filename.c_str());

  if (!in)
  {
    log_errno("ExtentMap::load(): open");
    em.releaseFreeList(ExtentMap::WRITE);
    em.releaseEMEntryTable(ExtentMap::WRITE);
    throw std::ios_base::failure("ExtentMap::load(): open failed. Check the error log.");
  }

  in.exceptions(ios_base::badbit | ios_base::failbit);

  try
  {
    in.read((char*)&loadSize, 3 * sizeof(int));
  }
  catch (...)
  {
    in.close();
    em.releaseFreeList(ExtentMap::WRITE);
    em.releaseEMEntryTable(ExtentMap::WRITE);
    throw;
  }

  const int emVersion = loadSize[0];
  const int emNumElements = loadSize[1];
  const int flNumElements = loadSize[2];
  /* What's a safe upper limit on the # of EM and FL entries? */
#define EM_MAGIC_V3 0x76f78b1e

  if (emVersion != EM_MAGIC_V3 || emNumElements < 0 || flNumElements < 0)
  {
    in.close();
    em.releaseFreeList(ExtentMap::WRITE);
    em.releaseEMEntryTable(ExtentMap::WRITE);
    log("ExtentMap::load64(): That file is not a valid 64-bit ExtentMap image");
    throw std::runtime_error("ExtentMap::load64(): That file is not a valid 64-bit ExtentMap image");
  }

  memset(em.fExtentMap, 0, em.fEMShminfo->allocdSize);
  memset(em.fFreeList, 0, em.fFLShminfo->allocdSize);
  em.fEMShminfo->currentSize = 0;
  em.fFLShminfo->currentSize = 0;

  int j = 0;
  int maxLoops = (emNumElements * (signed)mult - em.fEMShminfo->allocdSize / sizeof(EMEntry)) / 100 + 1;
  int target = (int)(maxLoops * .02);

  if (maxLoops < 50)
    target = 1;

  // allocate shared memory for extent data
  for (currentSize = em.fEMShminfo->allocdSize / sizeof(EMEntry);
       currentSize < (emNumElements * (signed)mult);
       currentSize = em.fEMShminfo->allocdSize / sizeof(EMEntry))
  {
    em.growEMShmseg();

    if ((j % target) == 0)
      cout << '.' << flush;

    j++;
  }

  cout << endl;

  // allocate shared memory for freelist
  for (currentSize = em.fFLShminfo->allocdSize / sizeof(InlineLBIDRange); currentSize < flNumElements;
       currentSize = em.fFLShminfo->allocdSize / sizeof(InlineLBIDRange))
  {
    em.growFLShmseg();
  }

  try
  {
    typedef map<int, vector<int> > OIDMap_t;
    OIDMap_t OIDMap;
    uint8_t buf[emNumElements * sizeof(EMEntry)];
    uint8_t buf2[flNumElements * sizeof(InlineLBIDRange)];

    in.read((char*)buf, emNumElements * sizeof(EMEntry));

    // memcpy(fExtentMap, buf, emNumElements * sizeof(EMEntry));
    EMEntry* emSrc = reinterpret_cast<EMEntry*>(&buf[0]);
    j = 0;

    for (int i = 0; i < emNumElements; i++)
    {
      vector<int>& oidv = OIDMap[emSrc[i].fileID];

      for (unsigned k = 0; k < mult; k++)
      {
        oidv.push_back(j);
        // em.fExtentMap[j].range.start = emSrc[i].range.start;
        em.fExtentMap[j].range.start = emSrc[i].range.start + (k * newExtentSize);
        // em.fExtentMap[j].range.size = emSrc[i].range.size;
        em.fExtentMap[j].range.size = newExtentSize / 1024;
        em.fExtentMap[j].fileID = emSrc[i].fileID;
        em.fExtentMap[j].blockOffset = emSrc[i].blockOffset + (k * newExtentSize);
        em.fExtentMap[j].HWM = emSrc[i].HWM;
        em.fExtentMap[j].txnID = emSrc[i].txnID;
        em.fExtentMap[j].secondHWM = emSrc[i].secondHWM;
        em.fExtentMap[j].nextHeader = emSrc[i].nextHeader;
        em.fExtentMap[j].partition.type = emSrc[i].partition.type;
        // em.fExtentMap[j].partition.cprange.hi_val = emSrc[i].partition.cprange.hi_val;
        em.fExtentMap[j].partition.cprange.hi_val = numeric_limits<int64_t>::min();
        // em.fExtentMap[j].partition.cprange.lo_val = emSrc[i].partition.cprange.lo_val;
        em.fExtentMap[j].partition.cprange.lo_val = numeric_limits<int64_t>::max();
        // em.fExtentMap[j].partition.cprange.sequenceNum = emSrc[i].partition.cprange.sequenceNum;
        em.fExtentMap[j].partition.cprange.sequenceNum = 0;
        // em.fExtentMap[j].partition.cprange.isValid = emSrc[i].partition.cprange.isValid;
        em.fExtentMap[j].partition.cprange.isValid = CP_INVALID;
        j++;
      }
    }

    em.fEMShminfo->currentSize = j * sizeof(EMEntry);

    cout << j << " total new em entries from " << emNumElements << " file entries" << endl;
    cout << OIDMap.size() << " OIDs added to em" << endl;

    OIDMap_t::const_iterator iter = OIDMap.begin();
    OIDMap_t::const_iterator end = OIDMap.end();

    int l = 0;

    while (iter != end)
    {
      const vector<int>& oidv = iter->second;
      vector<int>::const_reverse_iterator riter = oidv.rbegin();
      vector<int>::const_reverse_iterator rend = oidv.rend();
      HWM_t hwm = em.fExtentMap[*riter].HWM;

      while (riter != rend)
      {
        if (em.fExtentMap[*riter].blockOffset > hwm)
        {
          em.fExtentMap[*riter].fileID = numeric_limits<int>::max();
          em.fExtentMap[*riter].blockOffset = 0;
          em.fExtentMap[*riter].HWM = 0;
          l++;
        }
        else
          break;

        ++riter;
      }

      ++iter;
    }

    cout << l << " entries moved to OID " << numeric_limits<int>::max() << endl;

#if 0
        int k = j;

        for (int j = 0; j < k; j++)
            cout << em.fExtentMap[j].range.start << '\t' << em.fExtentMap[j].range.size << '\t' <<
                 em.fExtentMap[j].fileID << '\t' << em.fExtentMap[j].blockOffset << '\t' << em.fExtentMap[j].HWM << '\t' <<
                 em.fExtentMap[j].txnID << '\t' << em.fExtentMap[j].secondHWM << '\t' << em.fExtentMap[j].nextHeader << endl;

#endif
    in.read((char*)buf2, flNumElements * sizeof(InlineLBIDRange));

    // memcpy(fFreeList, buf2, flNumElements * sizeof(InlineLBIDRange));
    InlineLBIDRange* lrSrc = reinterpret_cast<InlineLBIDRange*>(&buf2[0]);
    j = 0;

    for (int i = 0; i < flNumElements; i++)
    {
      em.fFreeList[j].start = lrSrc[i].start;
      em.fFreeList[j].size = lrSrc[i].size;
      j++;
    }

    em.fFLShminfo->currentSize = j * sizeof(InlineLBIDRange);

    cout << j << " total new fl entries from " << flNumElements << " file entries" << endl;
  }
  catch (...)
  {
    in.close();
    em.releaseFreeList(ExtentMap::WRITE);
    em.releaseEMEntryTable(ExtentMap::WRITE);
    throw;
  }

  in.close();
  em.releaseFreeList(ExtentMap::WRITE);
  em.releaseEMEntryTable(ExtentMap::WRITE);

  return 0;
}

}  // namespace BRM

int main(int argc, char** argv)
{
  ExtentMapConverter emc;

  if (emc.doCvt(8192, 1024, "BRM_saves_em") != 0)
  {
    cerr << "Conversion failed." << endl;
    return 1;
  }
  else
  {
    cout << "OK" << endl;
    return 0;
  }
}
