hphp/util/hash-map-typedefs.h

   1 /*
   2    +----------------------------------------------------------------------+
   3    | HipHop for PHP                                                       |
   4    +----------------------------------------------------------------------+
   5    | Copyright (c) 2010-present Facebook, Inc. (http://www.facebook.com)  |
   6    +----------------------------------------------------------------------+
   7    | This source file is subject to version 3.01 of the PHP license,      |
   8    | that is bundled with this package in the file LICENSE, and is        |
   9    | available through the world-wide-web at the following url:           |
  10    | http://www.php.net/license/3_01.txt                                  |
  11    | If you did not receive a copy of the PHP license and are unable to   |
  12    | obtain it through the world-wide-web, please send a note to          |
  13    | license@php.net so we can mail you a copy immediately.               |
  14    +----------------------------------------------------------------------+
  15 */
  16 #ifndef incl_HPHP_HASH_MAP_TYPEDEFS_H_
  17 #define incl_HPHP_HASH_MAP_TYPEDEFS_H_
  18
  19 #include <unordered_map>
  20 #include <unordered_set>
  21 #include <functional>
  22 #include <string>
  23
  24 #include "hphp/util/functional.h"
  25
  26 namespace HPHP {
  27
  28 //////////////////////////////////////////////////////////////////////
  29
  30 /*
  31  * Note: these deliberately change the default-constructor behavior of
  32  * unordered_{map,set} to allocate slightly less memory.
  33  *
  34  * Generally be careful about using these hashtables.  They're not
  35  * cheap, although they may be convenient.
  36  */
  37
  38 #if (defined(__GNUC__) && __GNUC__ >= 5) ||\
  39     (defined(__clang) && (__clang_major__ > 3 ||\
  40                            __clang_major__ == 3 && __clang_minor__ >= 4))
  41 // default constructors of unordered containers do not allocate
  42 #define GOOD_UNORDERED_CTOR ()
  43 #else
  44 // minimize allocation when default constructed
  45 #define GOOD_UNORDERED_CTOR (0)
  46 #endif
  47
  48 template <class T, class U,
  49           class V = std::hash<T>,
  50           class W = std::equal_to<T> >
  51 struct hphp_hash_map : std::unordered_map<T,U,V,W> {
  52   hphp_hash_map() : std::unordered_map<T,U,V,W> GOOD_UNORDERED_CTOR {}
  53 };
  54
  55 template <class T,
  56           class V = std::hash<T>,
  57           class W = std::equal_to<T> >
  58 struct hphp_hash_set : std::unordered_set<T,V,W> {
  59   hphp_hash_set() : std::unordered_set<T,V,W> GOOD_UNORDERED_CTOR {}
  60 };
  61
  62 //////////////////////////////////////////////////////////////////////
  63
  64 template<class type, class T> struct hphp_string_hash_map :
  65   public hphp_hash_map<std::string,type,string_hash> {
  66 };
  67
  68 template<class T> using hphp_const_char_map =
  69   hphp_hash_map<const char*,T,cstr_hash,eqstr>;
  70
  71 template<typename T>
  72 using hphp_string_map = hphp_hash_map<std::string, T, string_hash>;
  73
  74 typedef hphp_hash_set<std::string, string_hash> hphp_string_set;
  75
  76 typedef hphp_hash_map<void*, void*, pointer_hash<void> > PointerMap;
  77 typedef hphp_hash_map<void*, int, pointer_hash<void> > PointerCounterMap;
  78 typedef hphp_hash_set<void*, pointer_hash<void> > PointerSet;
  79
  80 template<typename T>
  81 using hphp_const_char_imap = hphp_hash_map<const char *, T, hashi, eqstri>;
  82
  83 using hphp_const_char_iset = hphp_hash_set<const char *, hashi, eqstri>;
  84
  85 template<typename T>
  86 using hphp_string_imap =
  87   hphp_hash_map<std::string, T, string_hashi, string_eqstri>;
  88
  89 using hphp_string_iset =
  90   hphp_hash_set<std::string, string_hashi, string_eqstri>;
  91
  92 //////////////////////////////////////////////////////////////////////
  93
  94 }
  95
  96 #endif