uniques.hh

   1 class UniqueBlock{
   2 public:
   3   UniqueBlock* next;
   4   UniqueBlock* gcTo;
   5   hash_t hash;
   6   const VTable* refVT;
   7   virtual bool is(void* extra)=0;
   8   virtual void gc(GC& gc)=0;
   9 };
  10 class UniqueController{
  11   VM& vm;
  12   size_t capacity;
  13   size_t occupancy;
  14   UniqueBlock** tab;
  15 public:
  16   UniqueController(VM& _vm):vm(_vm),capacity(0),occupancy(0),tab(0){}
  17   UniqueBlock* get(hash_t hash,const VTable* refVT, void* extra){
  18     UniqueBlock* c=tab[hash%capacity];
  19     while(c&&!(c->hash==hash&&c->refVT==refVT&&c->is(extra))){
  20       c=c->next;
  21     }
  22     return c;
  23   }
  24   void add(UniqueBlock* n){
  25     if(capacity>>1<occupancy)grow();
  26     n->next=tab[n->hash%capacity];
  27     tab[n->hash%capacity]=n;
  28   }
  29   void grow(){
  30     size_t ocapacity=capacity;
  31     UniqueBlock** otab=tab;
  32     capacity=capacity?((capacity<<1)+1):31;
  33     tab=(UniqueBlock**)operator new (capacity*sizeof(UniqueBlock*),vm);
  34     for(size_t i=0;i<capacity;++i){
  35       tab[i]=0;
  36     }
  37     for(size_t i=0;i<ocapacity;++i){
  38       UniqueBlock* c=otab[i];
  39       while(c){
  40         add(c);
  41         c=c->next;
  42       }
  43     }
  44   }
  45   void gc(){
  46     capacity=(occupancy<<1)+1;
  47     tab=(UniqueBlock**)operator new (capacity*sizeof(UniqueBlock*),vm);
  48     for(size_t i=0;i<capacity;++i){
  49       tab[i]=0;
  50     }
  51   }
  52 };
  53 void gcIntoUnique(Node& it, GC& gc, Node& dest){
  54   UniqueBlock* u=(UniqueBlock*)it.c.ptr;
  55   if(u->gcTo){
  56     dest.vt=u->refVT;
  57     dest.c=u->gcTo;
  58   }else{
  59     u->gc(gc);
  60     dest.vt=u->refVT;
  61     dest.c=u->gcTo;
  62   }
  63 }
  64
  65 m4_define(«PP_VTABLE_UNIQUE»,«PP_VTABLE_SET(«copyable»,«1») PP_VTABLE_SET(«gcInto»,«&gcIntoUnique») PP_VTABLE_SET(«gc»,«&gcDef<&gcIntoUnique>»)»)