pdns/statbag.hh

   1 /*
   2  * This file is part of PowerDNS or dnsdist.
   3  * Copyright -- PowerDNS.COM B.V. and its contributors
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of version 2 of the GNU General Public License as
   7  * published by the Free Software Foundation.
   8  *
   9  * In addition, for the avoidance of any doubt, permission is granted to
  10  * link this program with OpenSSL and to (re)distribute the binaries
  11  * produced as the result of such linking.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  21  */
  22 #pragma once
  23 #include <map>
  24 #include <functional>
  25 #include <string>
  26 #include <vector>
  27 #include "lock.hh"
  28 #include "namespaces.hh"
  29 #include "iputils.hh"
  30 #include "circular_buffer.hh"
  31
  32 template<typename T, typename Comp=std::less<T> >
  33 class StatRing
  34 {
  35 public:
  36   StatRing(unsigned int size=10000);
  37   StatRing(const StatRing&) = delete;
  38   StatRing& operator=(const StatRing&) = delete;
  39   StatRing& operator=(StatRing&&) = delete;
  40   StatRing(StatRing&&) = default;
  41
  42   void account(const T &item);
  43
  44   uint64_t getSize() const;
  45   uint64_t getEntriesCount() const;
  46   void resize(unsigned int newsize);
  47   void reset();
  48   void setHelp(const string &str);
  49   string getHelp() const;
  50
  51   vector<pair<T, unsigned int> > get() const;
  52 private:
  53   static bool popisort(const pair<T,int> &a, const pair<T,int> &b)
  54   {
  55     return (a.second > b.second);
  56   }
  57
  58   boost::circular_buffer<T> d_items;
  59   string d_help;
  60 };
  61
  62 enum class StatType : uint8_t {
  63   counter = 1,
  64   gauge = 2,
  65 };
  66
  67 //! use this to gather and query statistics
  68 class StatBag
  69 {
  70   map<string, std::unique_ptr<AtomicCounter>> d_stats;
  71   map<string, string> d_keyDescriptions;
  72   map<string, StatType> d_statTypes;
  73   map<string, LockGuarded<StatRing<string, CIStringCompare> > > d_rings;
  74   map<string, LockGuarded<StatRing<SComboAddress> > > d_comboRings;
  75   map<string, LockGuarded<StatRing<std::tuple<DNSName, QType> > > > d_dnsnameqtyperings;
  76   typedef std::function<uint64_t(const std::string&)> func_t;
  77   typedef map<string, func_t> funcstats_t;
  78   funcstats_t d_funcstats;
  79   bool d_doRings;
  80
  81   std::set<string> d_blacklist;
  82
  83   void registerRingStats(const string& name);
  84
  85 public:
  86   StatBag(); //!< Naked constructor. You need to declare keys before this class becomes useful
  87   ~StatBag();
  88   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
  89   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
  90
  91   void declareRing(const string &name, const string &title, unsigned int size=10000);
  92   void declareComboRing(const string &name, const string &help, unsigned int size=10000);
  93   void declareDNSNameQTypeRing(const string &name, const string &help, unsigned int size=10000);
  94   vector<pair<string, unsigned int> >getRing(const string &name);
  95   string getRingTitle(const string &name);
  96   void ringAccount(const char* name, const string &item)
  97   {
  98     if (d_doRings)  {
  99       auto it = d_rings.find(name);
 100       if (it == d_rings.end()) {
 101         throw runtime_error("Attempting to account to nonexistent ring '"+std::string(name)+"'");
 102       }
 103
 104       it->second.lock()->account(item);
 105     }
 106   }
 107   void ringAccount(const char* name, const ComboAddress &item)
 108   {
 109     if (d_doRings) {
 110       auto it = d_comboRings.find(name);
 111       if (it == d_comboRings.end()) {
 112         throw runtime_error("Attempting to account to nonexistent comboRing '"+std::string(name)+"'");
 113       }
 114       it->second.lock()->account(item);
 115     }
 116   }
 117   void ringAccount(const char* name, const DNSName &dnsname, const QType &qtype)
 118   {
 119     if (d_doRings) {
 120       auto it = d_dnsnameqtyperings.find(name);
 121       if (it == d_dnsnameqtyperings.end()) {
 122         throw runtime_error("Attempting to account to nonexistent dnsname+qtype ring '"+std::string(name)+"'");
 123       }
 124       it->second.lock()->account(std::make_tuple(dnsname, qtype));
 125     }
 126   }
 127
 128   void doRings()
 129   {
 130     d_doRings=true;
 131   }
 132
 133   vector<string>listRings() const;
 134   bool ringExists(const string &name) const;
 135   void resetRing(const string &name);
 136   void resizeRing(const string &name, unsigned int newsize);
 137   uint64_t getRingSize(const string &name);
 138   uint64_t getRingEntriesCount(const string &name);
 139
 140   string directory(const string &prefix = ""); //!< Returns a list of all data stored. If prefix is given, only stats named with this prefix are returned.
 141   vector<string> getEntries(); //!< returns a vector with datums (items)
 142   string getDescrip(const string &item); //!< Returns the description of this datum/item
 143   StatType getStatType(const string &item); //!< Returns the stats type for the metrics endpoint
 144   void exists(const string &key); //!< call this function to throw an exception in case a key does not exist
 145   inline void deposit(const string &key, int value); //!< increment the statistics behind this key by value amount
 146   inline void inc(const string &key); //!< increase this key's value by one
 147   void set(const string &key, unsigned long value); //!< set this key's value
 148   unsigned long read(const string &key); //!< read the value behind this key
 149   AtomicCounter *getPointer(const string &key); //!< get a direct pointer to the value behind a key. Use this for high performance increments
 150   string getValueStr(const string &key); //!< read a value behind a key, and return it as a string
 151   void blacklist(const string &str);
 152
 153   bool d_allowRedeclare; // only set this true during tests, never in production code
 154 };
 155
 156 inline void StatBag::deposit(const string &key, int value)
 157 {
 158   exists(key);
 159
 160   *d_stats[key]+=value;
 161 }
 162
 163 inline void StatBag::inc(const string &key)
 164 {
 165   deposit(key, 1);
 166 }