src/base/symbol/cl_symbol.cc

   1 // class cl_symbol.
   2
   3 // General includes.
   4 #include "base/cl_sysdep.h"
   5
   6 // Specification.
   7 #include "cln/symbol.h"
   8
   9
  10 // Implementation.
  11
  12 #include "base/hash/cl_hashuniqweak.h"
  13
  14 namespace cln {
  15
  16 inline const cl_string hashkey (const cl_symbol& sym)
  17 {
  18         return (cl_string)sym;
  19 }
  20
  21 // A symbol points to a string, so to convert cl_string -> cl_symbol, we just
  22 // take the pointer and put it into a cl_symbol.
  23 inline cl_symbol::cl_symbol (struct hashuniq * null, const cl_string& s)
  24         : cl_rcpointer (as_cl_private_thing(s)) { unused null; }
  25
  26 typedef cl_htuniqentry<cl_string,cl_symbol> cl_htentry_from_string_to_symbol;
  27
  28 typedef cl_heap_weak_hashtable_uniq<cl_string,cl_symbol> cl_heap_hashtable_from_string_to_symbol;
  29
  30 typedef _cl_hashtable_iterator<cl_htentry_from_string_to_symbol> cl_hashtable_from_string_to_symbol_iterator;
  31
  32 static void cl_hashtable_from_string_to_symbol_destructor (cl_heap* pointer)
  33 {
  34 #if (defined(__mips__) || defined(__mips64__)) && !defined(__GNUC__) // workaround SGI CC bug
  35         (*(cl_heap_hashtable_from_string_to_symbol*)pointer).~cl_heap_weak_hashtable_uniq();
  36 #else
  37         (*(cl_heap_hashtable_from_string_to_symbol*)pointer).~cl_heap_hashtable_from_string_to_symbol();
  38 #endif
  39 }
  40
  41
  42 struct cl_ht_from_string_to_symbol : public cl_gcpointer {
  43         // Constructors.
  44         cl_ht_from_string_to_symbol ();
  45         cl_ht_from_string_to_symbol (const cl_ht_from_string_to_symbol&);
  46         // Assignment operators.
  47         cl_ht_from_string_to_symbol& operator= (const cl_ht_from_string_to_symbol&);
  48         // Iterator.
  49         cl_hashtable_from_string_to_symbol_iterator iterator () const
  50         { return ((cl_heap_hashtable_from_string_to_symbol*)pointer)->iterator(); }
  51         // Lookup.
  52         cl_symbol * get (const cl_string& s) const;
  53         // Store.
  54         void put (const cl_string& s) const;
  55 };
  56
  57 // These are not inline, because they tend to duplicate a lot of template code.
  58
  59 cl_ht_from_string_to_symbol::cl_ht_from_string_to_symbol ()
  60 {
  61         static const cl_class cl_class_hashtable_from_string_to_symbol = {
  62                 cl_hashtable_from_string_to_symbol_destructor,
  63                 0
  64         };
  65         var cl_heap_hashtable_from_string_to_symbol* ht = new cl_heap_hashtable_from_string_to_symbol ();
  66         ht->refcount = 1;
  67         ht->type = &cl_class_hashtable_from_string_to_symbol;
  68         pointer = ht;
  69 }
  70
  71 cl_symbol * cl_ht_from_string_to_symbol::get (const cl_string& s) const
  72 {
  73         return ((cl_heap_hashtable_from_string_to_symbol*)pointer)->get(s);
  74 }
  75
  76 void cl_ht_from_string_to_symbol::put (const cl_string& s) const
  77 {
  78         ((cl_heap_hashtable_from_string_to_symbol*)pointer)->put(s);
  79 }
  80
  81 // The global symbol table.
  82 class global_symbol_table
  83 {
  84         static int count;
  85         static cl_ht_from_string_to_symbol* symbol_table;
  86 public:
  87         inline cl_symbol* get(const cl_string& s)
  88         {
  89                 return symbol_table->get(s);
  90         }
  91
  92         inline void put(const cl_string& s)
  93         {
  94                 symbol_table->put(s);
  95         }
  96
  97         global_symbol_table();
  98         ~global_symbol_table();
  99 };
 100
 101 int global_symbol_table::count = 0;
 102 cl_ht_from_string_to_symbol* global_symbol_table::symbol_table;
 103
 104 global_symbol_table::global_symbol_table()
 105 {
 106         if (count++ == 0)
 107                 symbol_table = new cl_ht_from_string_to_symbol();
 108 }
 109
 110 global_symbol_table::~global_symbol_table()
 111 {
 112         if (--count == 0)
 113                 delete symbol_table;
 114 }
 115
 116 // Create or lookup a symbol from its name.
 117 cl_symbol::cl_symbol (const cl_string& s)
 118 {
 119         static global_symbol_table symbol_table;
 120         var cl_symbol * sym_in_table;
 121         sym_in_table = symbol_table.get(s);
 122         if (!sym_in_table) {
 123                 symbol_table.put(s);
 124                 sym_in_table = symbol_table.get(s);
 125                 if (!sym_in_table)
 126                         throw runtime_exception();
 127         }
 128         var cl_heap* p = sym_in_table->heappointer;
 129         cl_inc_pointer_refcount(p);
 130         pointer = p;
 131 }
 132
 133 }  // namespace cln
 134