/*

 * This file is part of PowerDNS or dnsdist.

 * Copyright -- PowerDNS.COM B.V. and its contributors

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of version 2 of the GNU General Public License as

 * published by the Free Software Foundation.

 *

 * In addition, for the avoidance of any doubt, permission is granted to

 * link this program with OpenSSL and to (re)distribute the binaries

 * produced as the result of such linking.

 *

 * 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.

 */

#pragma once

#include <map>

#include <functional>

#include <string>

#include <vector>

#include "lock.hh"

#include "namespaces.hh"

#include "iputils.hh"

#include "circular_buffer.hh"

template<typename T, typename Comp=std::less<T> >

class StatRing

{

public:

  StatRing(unsigned int size=10000);

  StatRing(const StatRing&) = delete;

  StatRing& operator=(const StatRing&) = delete;

  StatRing& operator=(StatRing&&) = delete;

  StatRing(StatRing&&) = default;

Unexecuted instantiation: StatRing<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, CIStringCompare>::StatRing(StatRing<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, CIStringCompare>&&)

Unexecuted instantiation: StatRing<SComboAddress, std::__1::less<SComboAddress> >::StatRing(StatRing<SComboAddress, std::__1::less<SComboAddress> >&&)

Unexecuted instantiation: StatRing<std::__1::tuple<DNSName, QType>, std::__1::less<std::__1::tuple<DNSName, QType> > >::StatRing(StatRing<std::__1::tuple<DNSName, QType>, std::__1::less<std::__1::tuple<DNSName, QType> > >&&)

  void account(const T &item);

  uint64_t getSize() const;

  uint64_t getEntriesCount() const;

  void resize(unsigned int newsize);

  void reset();

  void setHelp(const string &str);

  string getHelp() const;

  vector<pair<T, unsigned int> > get() const;

private:

  static bool popisort(const pair<T,int> &a, const pair<T,int> &b)

  {

    return (a.second > b.second);

  }

Unexecuted instantiation: StatRing<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, CIStringCompare>::popisort(std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, int> const&, std::__1::pair<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, int> const&)

Unexecuted instantiation: StatRing<SComboAddress, std::__1::less<SComboAddress> >::popisort(std::__1::pair<SComboAddress, int> const&, std::__1::pair<SComboAddress, int> const&)

Unexecuted instantiation: StatRing<std::__1::tuple<DNSName, QType>, std::__1::less<std::__1::tuple<DNSName, QType> > >::popisort(std::__1::pair<std::__1::tuple<DNSName, QType>, int> const&, std::__1::pair<std::__1::tuple<DNSName, QType>, int> const&)

  boost::circular_buffer<T> d_items;

  string d_help;

};

enum class StatType : uint8_t {

  counter = 1,

  gauge = 2,

};

//! use this to gather and query statistics

class StatBag

{

  map<string, std::unique_ptr<AtomicCounter>> d_stats;

  map<string, string> d_keyDescriptions;

  map<string, StatType> d_statTypes;

  map<string, LockGuarded<StatRing<string, CIStringCompare> > > d_rings;

  map<string, LockGuarded<StatRing<SComboAddress> > > d_comboRings;

  map<string, LockGuarded<StatRing<std::tuple<DNSName, QType> > > > d_dnsnameqtyperings;

  typedef std::function<uint64_t(const std::string&)> func_t;

  typedef map<string, func_t> funcstats_t;

  funcstats_t d_funcstats;

  bool d_doRings;

  std::set<string> d_blacklist;

  void registerRingStats(const string& name);

public:

  StatBag(); //!< Naked constructor. You need to declare keys before this class becomes useful

  ~StatBag();

  void declare(const string &key, const string &descrip="", StatType statType=StatType::counter); //!< Before you can store or access a key, you need to declare it

  void declare(const string &key, const string &descrip, func_t func, StatType statType); //!< Before you can store or access a key, you need to declare it

  void declareRing(const string &name, const string &title, unsigned int size=10000);

  void declareComboRing(const string &name, const string &help, unsigned int size=10000);

  void declareDNSNameQTypeRing(const string &name, const string &help, unsigned int size=10000);

  vector<pair<string, unsigned int> >getRing(const string &name);

  string getRingTitle(const string &name);

  void ringAccount(const char* name, const string &item)

  {

    if (d_doRings)  {

      auto it = d_rings.find(name);

      if (it == d_rings.end()) {

  throw runtime_error("Attempting to account to nonexistent ring '"+std::string(name)+"'");

      }

      it->second.lock()->account(item);

    }

  }

  void ringAccount(const char* name, const ComboAddress &item)

  {

    if (d_doRings) {

      auto it = d_comboRings.find(name);

      if (it == d_comboRings.end()) {

  throw runtime_error("Attempting to account to nonexistent comboRing '"+std::string(name)+"'");

      }

      it->second.lock()->account(item);

    }

  }

  void ringAccount(const char* name, const DNSName &dnsname, const QType &qtype)

  {

    if (d_doRings) {

      auto it = d_dnsnameqtyperings.find(name);

      if (it == d_dnsnameqtyperings.end()) {

  throw runtime_error("Attempting to account to nonexistent dnsname+qtype ring '"+std::string(name)+"'");

      }

      it->second.lock()->account(std::tuple(dnsname, qtype));

    }

  }

  void doRings()

  {

    d_doRings=true;

  }

  vector<string>listRings() const;

  bool ringExists(const string &name) const;

  void resetRing(const string &name);

  void resizeRing(const string &name, unsigned int newsize);

  uint64_t getRingSize(const string &name);

  uint64_t getRingEntriesCount(const string &name);

  string directory(const string &prefix = ""); //!< Returns a list of all data stored. If prefix is given, only stats named with this prefix are returned.

  vector<string> getEntries(); //!< returns a vector with datums (items)

  string getDescrip(const string &item); //!< Returns the description of this datum/item

  StatType getStatType(const string &item); //!< Returns the stats type for the metrics endpoint

  void exists(const string &key); //!< call this function to throw an exception in case a key does not exist

  inline void deposit(const string &key, int value); //!< increment the statistics behind this key by value amount

  inline void inc(const string &key); //!< increase this key's value by one

  void set(const string &key, unsigned long value); //!< set this key's value

  unsigned long read(const string &key); //!< read the value behind this key

  AtomicCounter *getPointer(const string &key); //!< get a direct pointer to the value behind a key. Use this for high performance increments

  string getValueStr(const string &key); //!< read a value behind a key, and return it as a string

  void blacklist(const string &str);

  bool d_allowRedeclare; // only set this true during tests, never in production code

};

inline void StatBag::deposit(const string &key, int value)

{

  exists(key);

  *d_stats[key]+=value;

}

inline void StatBag::inc(const string &key)

{

  deposit(key, 1);

}