/*
 
  Stockfish, a UCI chess playing engine derived from Glaurung 2.1
 
  Copyright (C) 2004-2008 Tord Romstad (Glaurung author)
 
  Copyright (C) 2008-2015 Marco Costalba, Joona Kiiski, Tord Romstad
 
  Copyright (C) 2015-2016 Marco Costalba, Joona Kiiski, Gary Linscott, Tord Romstad
 
 
 
  Stockfish 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, either version 3 of the License, or
 
  (at your option) any later version.
 
 
 
  Stockfish 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, see <http://www.gnu.org/licenses/>.
 
*/
 
 
 
#include <fstream>
 
#include <iomanip>
 
#include <iostream>
 
#include <sstream>
 
 
 
#include "misc.h"
 
#include "thread.h"
 
 
 
using namespace std;
 
 
 
namespace {
 
 
 
/// Version number. If Version is left empty, then compile date in the format
 
/// DD-MM-YY and show in engine_info.
 
const string Version = "";
 
 
 
/// Our fancy logging facility. The trick here is to replace cin.rdbuf() and
 
/// cout.rdbuf() with two Tie objects that tie cin and cout to a file stream. We
 
/// can toggle the logging of std::cout and std:cin at runtime whilst preserving
 
/// usual I/O functionality, all without changing a single line of code!
 
/// Idea from http://groups.google.com/group/comp.lang.c++/msg/1d941c0f26ea0d81
 
 
 
struct Tie: public streambuf { // MSVC requires split streambuf for cin and cout
 
 
 
  Tie(streambuf* b, streambuf* l) : buf(b), logBuf(l) {}
 
 
 
  int sync() { return logBuf->pubsync(), buf->pubsync(); }
 
  int overflow(int c) { return log(buf->sputc((char)c), "<< "); }
 
  int underflow() { return buf->sgetc(); }
 
  int uflow() { return log(buf->sbumpc(), ">> "); }
 
 
 
  streambuf *buf, *logBuf;
 
 
 
  int log(int c, const char* prefix) {
 
 
 
    static int last = '\n'; // Single log file
 
 
 
    if (last == '\n')
 
        logBuf->sputn(prefix, 3);
 
 
 
    return last = logBuf->sputc((char)c);
 
  }
 
};
 
 
 
class Logger {
 
 
 
  Logger() : in(cin.rdbuf(), file.rdbuf()), out(cout.rdbuf(), file.rdbuf()) {}
 
 ~Logger() { start(false); }
 
 
 
  ofstream file;
 
  Tie in, out;
 
 
 
public:
 
  static void start(bool b) {
 
 
 
    static Logger l;
 
 
 
    if (b && !l.file.is_open())
 
    {
 
        l.file.open("io_log.txt", ifstream::out);
 
        cin.rdbuf(&l.in);
 
        cout.rdbuf(&l.out);
 
    }
 
    else if (!b && l.file.is_open())
 
    {
 
        cout.rdbuf(l.out.buf);
 
        cin.rdbuf(l.in.buf);
 
        l.file.close();
 
    }
 
  }
 
};
 
 
 
} // namespace
 
 
 
/// engine_info() returns the full name of the current Stockfish version. This
 
/// will be either "Stockfish <Tag> DD-MM-YY" (where DD-MM-YY is the date when
 
/// the program was compiled) or "Stockfish <Version>", depending on whether
 
/// Version is empty.
 
 
 
const string engine_info(bool to_uci) {
 
 
 
  const string months("Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec");
 
  string month, day, year;
 
  stringstream ss, date(__DATE__); // From compiler, format is "Sep 21 2008"
 
 
 
  ss << "Stockfish " << Version << setfill('0');
 
 
 
  if (Version.empty())
 
  {
 
      date >> month >> day >> year;
 
      ss << setw(2) << day << setw(2) << (1 + months.find(month) / 4) << year.substr(2);
 
  }
 
 
 
  ss << (Is64Bit ? " 64" : "")
 
     << (HasPext ? " BMI2" : (HasPopCnt ? " POPCNT" : ""))
 
     << (to_uci  ? "\nid author ": " by ")
 
     << "T. Romstad, M. Costalba, J. Kiiski, G. Linscott";
 
 
 
  return ss.str();
 
}
 
 
 
 
 
/// Debug functions used mainly to collect run-time statistics
 
static int64_t hits[2], means[2];
 
 
 
void dbg_hit_on(bool b) { ++hits[0]; if (b) ++hits[1]; }
 
void dbg_hit_on(bool c, bool b) { if (c) dbg_hit_on(b); }
 
void dbg_mean_of(int v) { ++means[0]; means[1] += v; }
 
 
 
void dbg_print() {
 
 
 
  if (hits[0])
 
      cerr << "Total " << hits[0] << " Hits " << hits[1]
 
           << " hit rate (%) " << 100 * hits[1] / hits[0] << endl;
 
 
 
  if (means[0])
 
      cerr << "Total " << means[0] << " Mean "
 
           << (double)means[1] / means[0] << endl;
 
}
 
 
 
 
 
/// Used to serialize access to std::cout to avoid multiple threads writing at
 
/// the same time.
 
 
 
std::ostream& operator<<(std::ostream& os, SyncCout sc) {
 
 
 
  static Mutex m;
 
 
 
  if (sc == IO_LOCK)
 
      m.lock();
 
 
 
  if (sc == IO_UNLOCK)
 
      m.unlock();
 
 
 
  return os;
 
}
 
 
 
 
 
/// Trampoline helper to avoid moving Logger to misc.h
 
void start_logger(bool b) { Logger::start(b); }
 
 
 
 
 
/// prefetch() preloads the given address in L1/L2 cache. This is a non-blocking
 
/// function that doesn't stall the CPU waiting for data to be loaded from memory,
 
/// which can be quite slow.
 
#ifdef NO_PREFETCH
 
 
 
void prefetch(void*) {}
 
 
 
#else
 
 
 
void prefetch(void* addr) {
 
 
 
#  if defined(__INTEL_COMPILER)
 
   // This hack prevents prefetches from being optimized away by
 
   // Intel compiler. Both MSVC and gcc seem not be affected by this.
 
   __asm__ ("");
 
#  endif
 
 
 
#  if defined(__INTEL_COMPILER) || defined(_MSC_VER)
 
  _mm_prefetch((char*)addr, _MM_HINT_T0);
 
#  else
 
  __builtin_prefetch(addr);
 
#  endif
 
}
 
 
 
#endif