/* Copyright (C) 2014 InfiniDB, Inc.
   Copyright (C) 2016 MariaDB Corporation

   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: stats.cpp 699 2008-09-09 19:44:18Z rdempsey $
 */

#include <ctime>
#include <sys/time.h>
#include <pthread.h>
#include <iomanip>
#include <map>
#define NDEBUG
#include <cassert>
#include <csignal>
using namespace std;

#include <boost/thread.hpp>
#include <boost/shared_ptr.hpp>
using namespace boost;

#include "stats.h"
#include "messagelog.h"

using namespace BRM;

namespace
{
void pause_(unsigned delay)
{
  struct timespec req;
  struct timespec rem;

  req.tv_sec = delay;
  req.tv_nsec = 0;

  rem.tv_sec = 0;
  rem.tv_nsec = 0;

again:

  if (nanosleep(&req, &rem) != 0)
    if (rem.tv_sec > 0 || rem.tv_nsec > 0)
    {
      req = rem;
      goto again;
    }
}

const string timestr()
{
  // Get a timestamp for output.
  struct tm tm;
  struct timeval tv;

  gettimeofday(&tv, 0);
  localtime_r(&tv.tv_sec, &tm);

  ostringstream oss;
  oss << setfill('0') << setw(2) << tm.tm_hour << ':' << setw(2) << tm.tm_min << ':' << setw(2) << tm.tm_sec
      << '.' << setw(4) << tv.tv_usec / 100;

  return oss.str();
}

class TraceFile
{
 public:
  TraceFile(uint32_t sessionID, const char* name)
  {
    if (sessionID > 0)
    {
      const char* outName;

      if (name == 0)
        outName = "lbids";
      else
        outName = name;

      ostringstream oss;
      oss << MCSLOGDIR << "/trace/" << outName << '.' << sessionID;
      oFile.reset(new ofstream());
      oFile->open(oss.str().c_str(), ios_base::out | ios_base::ate | ios_base::app);
    }
  }

  ~TraceFile()
  {
  }

  void close()
  {
    if (oFile)
    {
      oFile->close();
    }
  }

  void log(OID_t oid, uint64_t lbid, pthread_t thdid, char event = '\0')
  {
    *oFile << oid << ' ' << timestr() << ' ' << lbid << ' ' << thdid;

    if (event != '\0')
      *oFile << ' ' << event;

    *oFile << endl;
    oFile->flush();
  }

 private:
  // Compiler defaults okay
  // TraceFile(const TraceFile& rhs);
  // TraceFile operator=(const TraceFile& rhs);
  shared_ptr<ofstream> oFile;
};

struct TraceFileInfo
{
  TraceFileInfo(uint32_t session = 0, const char* name = 0) : traceFile(session, name), lastTouched(0)
  {
  }
  ~TraceFileInfo()
  {
  }

  void log(OID_t oid, uint64_t lbid, pthread_t thdid, char event = '\0')
  {
    traceFile.log(oid, lbid, thdid, event);
    lastTouched = time(0);
  }

  void close()
  {
    traceFile.close();
  }

  TraceFile traceFile;
  time_t lastTouched;

 private:
  // Compiler defaults okay
  // TraceFileInfo(const TraceFileInfo& rhs);
  // TraceFileInfo operator=(const TraceFileInfo& rhs);
};

// map a session id to a trace file
typedef map<uint32_t, TraceFileInfo> TraceFileMap_t;

TraceFileMap_t traceFileMap;
// map mutex
mutex traceFileMapMutex;

class StatMon
{
 public:
  StatMon()
  {
    sigset_t sigset;
    sigemptyset(&sigset);
    sigaddset(&sigset, SIGPIPE);
    sigaddset(&sigset, SIGUSR1);
    sigaddset(&sigset, SIGUSR2);
    pthread_sigmask(SIG_BLOCK, &sigset, 0);
  }
  void operator()() const
  {
    // struct timespec ts = { 60 * 1, 0 };
    mutex::scoped_lock lk(traceFileMapMutex);
    TraceFileMap_t::iterator iter;
    TraceFileMap_t::iterator end;

    for (;;)
    {
      lk.unlock();
      time_t beforeSleep = time(0);
      // nanosleep(&ts, 0);
      pause_(60);
      lk.lock();
      iter = traceFileMap.begin();
      end = traceFileMap.end();

      while (iter != end)
      {
        if (iter->second.lastTouched < beforeSleep)
        {
          // remove this session trace file
          iter->second.close();
          traceFileMap.erase(iter++);
        }
        else
          ++iter;
      }
    }
  }

 private:
  // Compiler defaults okay
  // StatMon(const StatMon& rhs);
  // StatMon operator=(const StatMon& rhs);
};

}  // namespace

namespace dbbc
{
Stats::Stats() : fMonitorp(0)
{
  fMonitorp = new thread(StatMon());
}

Stats::Stats(const char* name) : fMonitorp(0), fName(name)
{
  fMonitorp = new thread(StatMon());
  // fName << name;
}

Stats::~Stats()
{
  delete fMonitorp;
}

void Stats::touchedLBID(uint64_t lbid, pthread_t thdid, uint32_t session)
{
  if (lbid < 0 || session == 0)
    return;

  mutex::scoped_lock lk(traceFileMapMutex);
  TraceFileMap_t::iterator iter = traceFileMap.find(session);

  if (iter == traceFileMap.end())
  {
    traceFileMap[session] = TraceFileInfo(session);
    iter = traceFileMap.find(session);
    idbassert(iter != traceFileMap.end());
  }

  iter->second.log(lbid2oid(lbid), lbid, thdid);
}

void Stats::markEvent(const uint64_t lbid, const pthread_t thdid, const uint32_t session, const char event)
{
  if (lbid < 0 || session == 0)
    return;

  mutex::scoped_lock lk(traceFileMapMutex);
  TraceFileMap_t::iterator iter = traceFileMap.find(session);

  if (iter == traceFileMap.end())
  {
    traceFileMap[session] = TraceFileInfo(session, fName);
    iter = traceFileMap.find(session);
    idbassert(iter != traceFileMap.end());
  }

  iter->second.log(lbid2oid(lbid), lbid, thdid, event);
}

}  // namespace dbbc