hashtable: make more flexible

[model-checker.git] / hashtable.h

diff --git a/hashtable.h b/hashtable.h
index ee7dc19f932fcd08f8ba9b8b7f66a835ecd515f1..e59a995fd92347a361a785a2d5e36c646b1a7656 100644 (file)
--- a/hashtable.h
+++ b/hashtable.h
@@ -1,3 +1,7 @@
+/** @file hashtable.h
+ *  @brief Hashtable.  Standard chained bucket variety.
+ */
+
 #ifndef HASHTABLE_H
 #define HASHTABLE_H
 
@@ -11,31 +15,73 @@ template<typename _Key, typename _Val>
                struct hashlistnode<_Key,_Val> *next;
        };
 
-template<typename _Key, typename _Val, int _Shift>
+/** Hashtable class.  By default it is snapshotting, but you can pass
+               in your own allocation functions. */
+
+template<typename _Key, typename _Val, typename _KeyInt, int _Shift, void * (* _malloc)(size_t)=malloc, void * (* _calloc)(size_t, size_t)=calloc, void (*_free)(void *)=free>
        class HashTable {
  public:
-       HashTable(unsigned int initialcapacity, double factor) {
+       HashTable(unsigned int initialcapacity=1024, double factor=0.5) {
                // Allocate space for the hash table
-               table = calloc(initialcapacity, sizeof(struct hashlistnode<_Key,_Val> *));
+               table = (struct hashlistnode<_Key,_Val> **) _calloc(initialcapacity, sizeof(struct hashlistnode<_Key,_Val> *));
                loadfactor = factor;
                capacity = initialcapacity;
-               threshold = initialcapacity*loadfactor;
+               threshold = (unsigned int) (initialcapacity*loadfactor);
                mask = (capacity << _Shift)-1;
                size = 0; // Initial number of elements in the hash
        }
 
        ~HashTable() {
-               free(table);
+               for(unsigned int i=0;i<capacity;i++) {
+                       struct hashlistnode<_Key,_Val> * bin = table[i];
+                       while(bin!=NULL) {
+                               struct hashlistnode<_Key,_Val> * next=bin->next;
+                               _free(bin);
+                               bin=next;
+                       }
+               }
+               _free(table);
        }
-       
-       void insert(_Key key, _Val val) {
+
+       void * operator new(size_t size) {
+               return _malloc(size);
+       }
+
+       void operator delete(void *p, size_t size) {
+               _free(p);
+       }
+
+       void * operator new[](size_t size) {
+               return _malloc(size);
+       }
+
+       void operator delete[](void *p, size_t size) {\
+               _free(p);
+       }
+
+       /** Reset the table to its initial state. */
+       void reset() {
+               for(int i=0;i<capacity;i++) {
+                       struct hashlistnode<_Key,_Val> * bin = table[i];
+                       while(bin!=NULL) {
+                               struct hashlistnode<_Key,_Val> * next=bin->next;
+                               _free(bin);
+                               bin=next;
+                       }
+               }
+               memset(table, 0, capacity*sizeof(struct hashlistnode<_Key, _Val> *));
+               size=0;
+       }
+
+       /** Put a key value pair into the table. */
+       void put(_Key key, _Val val) {
                if(size > threshold) {
                        //Resize
                        unsigned int newsize = capacity << 1;
                        resize(newsize);
                }
-               
-               struct hashlistnode<_Key,_Val> *ptr = table[(key & mask)>>_Shift];
+
+               struct hashlistnode<_Key,_Val> *ptr = table[(((_KeyInt)key) & mask)>>_Shift];
                size++;
                struct hashlistnode<_Key,_Val> *search = ptr;
 
@@ -47,16 +93,17 @@ template<typename _Key, typename _Val, int _Shift>
                        search=search->next;
                }
 
-               struct hashlistnode<_Key,_Val> *newptr=malloc(sizeof(struct hashlistnode<_Key,_Val>));
+               struct hashlistnode<_Key,_Val> *newptr=(struct hashlistnode<_Key,_Val> *)_malloc(sizeof(struct hashlistnode<_Key,_Val>));
                newptr->key=key;
                newptr->val=val;
                newptr->next=ptr;
-               table[(key&mask)>>_Shift]=newptr;
+               table[(((_KeyInt)key)&mask)>>_Shift]=newptr;
        }
 
+       /** Lookup the corresponding value for the given key. */
        _Val get(_Key key) {
-               struct hashlistnode<_Key,_Val> *search = table[(key & mask)>>_Shift];
-               
+               struct hashlistnode<_Key,_Val> *search = table[(((_KeyInt)key) & mask)>>_Shift];
+
                while(search!=NULL) {
                        if (search->key==key) {
                                return search->val;
@@ -65,44 +112,58 @@ template<typename _Key, typename _Val, int _Shift>
                }
                return (_Val)0;
        }
-       
+
+       /** Check whether the table contains a value for the given key. */
+       bool contains(_Key key) {
+               struct hashlistnode<_Key,_Val> *search = table[(((_KeyInt)key) & mask)>>_Shift];
+
+               while(search!=NULL) {
+                       if (search->key==key) {
+                               return true;
+                       }
+                       search=search->next;
+               }
+               return false;
+       }
+
+       /** Resize the table. */
        void resize(unsigned int newsize) {
                struct hashlistnode<_Key,_Val> ** oldtable = table;
                struct hashlistnode<_Key,_Val> ** newtable;
                unsigned int oldcapacity = capacity;
-               
-               if((newtable = calloc(newsize, sizeof(struct hashlistnode<_Key,_Val> *))) == NULL) {
+
+               if((newtable = (struct hashlistnode<_Key,_Val> **) _calloc(newsize, sizeof(struct hashlistnode<_Key,_Val> *))) == NULL) {
                        printf("Calloc error %s %d\n", __FILE__, __LINE__);
                        exit(-1);
                }
-               
+
                table = newtable;          //Update the global hashtable upon resize()
                capacity = newsize;
-               threshold = newsize * loadfactor;
+               threshold = (unsigned int) (newsize * loadfactor);
                mask = (newsize << _Shift)-1;
-               
+
                for(unsigned int i = 0; i < oldcapacity; i++) {
                        struct hashlistnode<_Key, _Val> * bin = oldtable[i];
-                       
+
                        while(bin!=NULL) {
                                _Key key=bin->key;
                                struct hashlistnode<_Key, _Val> * next=bin->next;
-                               
-                               unsigned int index = (key & mask) >>_Shift;
-                               struct hashlistnode<_Key, _Val> tmp=newtable[index];
+
+                               unsigned int index = (((_KeyInt)key) & mask) >>_Shift;
+                               struct hashlistnode<_Key, _Val> * tmp=newtable[index];
                                bin->next=tmp;
                                newtable[index]=bin;
                                bin = next;
                        }
                }
-               
-               free(oldtable);            //Free the memory of the old hash table
+
+               _free(oldtable);            //Free the memory of the old hash table
        }
-       
+
  private:
        struct hashlistnode<_Key,_Val> **table;
        unsigned int capacity;
-       _Key mask;
+       _KeyInt mask;
        unsigned int size;
        unsigned int threshold;
        double loadfactor;