X-Git-Url: http://plrg.eecs.uci.edu/git/?p=model-checker.git;a=blobdiff_plain;f=hashtable.h;h=bf759285fa7899da5a40fc4bb082bdc8cfbcfd35;hp=f372f9e7b96f0efb7f08d6574d768a6cc7cdf2db;hb=dbb1bb205f35f076cf2d82ec443415d858b22e2f;hpb=cf7518cb8c2d9cd3033ca7540ea9dc448b21912a

diff --git a/hashtable.h b/hashtable.h
index f372f9e..bf75928 100644
--- a/hashtable.h
+++ b/hashtable.h
@@ -1,142 +1,201 @@
+/** @file hashtable.h
+ *  @brief Hashtable.  Standard chained bucket variety.
+ */
+
 #ifndef HASHTABLE_H
 #define HASHTABLE_H
 
 #include <stdlib.h>
 #include <stdio.h>
+#include "mymemory.h"
 
+/**
+ * Hashtable linked node class, for chained storage of hash table conflicts. By
+ * default it is snapshotting, but you can pass in your own allocation
+ * functions.
+ *
+ * @tparam _Key    Type name for the key
+ * @tparam _Val    Type name for the values to be stored
+ * @tparam _malloc Provide your own 'malloc' for the table, or default to
+ *                 snapshotting.
+ * @tparam _calloc Provide your own 'calloc' for the table, or default to
+ *                 snapshotting.
+ * @tparam _free   Provide your own 'free' for the table, or default to
+ *                 snapshotting.
+ */
 template<typename _Key, typename _Val>
-	struct hashlistnode {
-		_Key key;
-		_Val val;
-		struct hashlistnode<_Key,_Val> *next;
-	};
 
-template<typename _Key, typename _Val, typename _KeyInt, int _Shift>
+struct hashlistnode {
+	_Key key;
+	_Val val;
+};
+
+/**
+ * Hashtable class. By default it is snapshotting, but you can pass in your own
+ * allocation functions.
+ *
+ * @tparam _Key    Type name for the key
+ * @tparam _Val    Type name for the values to be stored
+ * @tparam _KeyInt Integer type that is at least as large as _Key. Used for key
+ *                 manipulation and storage.
+ * @tparam _Shift  Logical shift to apply to all keys. Default 0.
+ * @tparam _malloc Provide your own 'malloc' for the table, or default to
+ *                 snapshotting.
+ * @tparam _calloc Provide your own 'calloc' for the table, or default to
+ *                 snapshotting.
+ * @tparam _free   Provide your own 'free' for the table, or default to
+ *                 snapshotting.
+ */
+template<typename _Key, typename _Val, typename _KeyInt, int _Shift=0, void * (* _malloc)(size_t)=snapshot_malloc, void * (* _calloc)(size_t, size_t)=snapshot_calloc, void (*_free)(void *)=snapshot_free>
 	class HashTable {
  public:
+	/**
+	 * Constructor
+	 * @param initialcapacity Sets the initial capacity of the hash table.
+	 * Default size 1024.
+	 * @param factor Sets the percentage full before the hashtable is
+	 * resized. Default ratio 0.5.
+	 */
 	HashTable(unsigned int initialcapacity=1024, double factor=0.5) {
 		// Allocate space for the hash table
-		table = (struct hashlistnode<_Key,_Val> **) 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;
-		mask = (capacity << _Shift)-1;
+		capacitymask = initialcapacity - 1;
+
+		threshold = (unsigned int) (initialcapacity*loadfactor);
 		size = 0; // Initial number of elements in the hash
 	}
 
+	/** Destructor */
 	~HashTable() {
-		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);
+		_free(table);
+	}
+
+	/** Override: new operator */
+	void * operator new(size_t size) {
+		return _malloc(size);
+	}
+
+	/** Override: delete operator */
+	void operator delete(void *p, size_t size) {
+		_free(p);
+	}
+
+	/** Override: new[] operator */
+	void * operator new[](size_t size) {
+		return _malloc(size);
+	}
+
+	/** Override: delete[] operator */
+	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> *));
+		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[(((_KeyInt)key) & mask)>>_Shift];
-		size++;
-		struct hashlistnode<_Key,_Val> *search = ptr;
+		if (size > threshold)
+			resize(capacity << 1);
 
-		while(search!=NULL) {
+		struct hashlistnode<_Key,_Val> *search;
+
+		unsigned int index=((_KeyInt)key)>>_Shift;
+		do {
+			index=index&capacitymask;
+			search = &table[index];
 			if (search->key==key) {
 				search->val=val;
 				return;
 			}
-			search=search->next;
-		}
-
-		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[(((_KeyInt)key)&mask)>>_Shift]=newptr;
+			index++;
+		} while(search->key);
+		
+		search->key=key;
+		search->val=val;
+		size++;
 	}
 
+	/** Lookup the corresponding value for the given key. */
 	_Val get(_Key key) {
-		struct hashlistnode<_Key,_Val> *search = table[(((_KeyInt)key) & mask)>>_Shift];
-		
-		while(search!=NULL) {
+		struct hashlistnode<_Key,_Val> *search;
+
+		unsigned int index=((_KeyInt)key)>>_Shift;
+		do {
+			index=index&capacitymask;
+			search = &table[index];
 			if (search->key==key) {
 				return search->val;
 			}
-			search=search->next;
-		}
-		return (_Val)0;
+			index++;
+		} while(search->key);
+		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) {
+		struct hashlistnode<_Key,_Val> *search;
+
+		unsigned int index=((_KeyInt)key)>>_Shift;
+		do {
+			index=index&capacitymask;
+			search = &table[index];
 			if (search->key==key) {
 				return true;
 			}
-			search=search->next;
-		}
+			index++;
+		} while(search->key);
 		return false;
 	}
-	
+
+	/** Resize the table. */
 	void resize(unsigned int newsize) {
-		struct hashlistnode<_Key,_Val> ** oldtable = table;
-		struct hashlistnode<_Key,_Val> ** newtable;
+		struct hashlistnode<_Key,_Val> * oldtable = table;
+		struct hashlistnode<_Key,_Val> * newtable;
 		unsigned int oldcapacity = capacity;
-		
-		if((newtable = (struct hashlistnode<_Key,_Val> **) 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;
-		mask = (newsize << _Shift)-1;
-		
-		for(unsigned int i = 0; i < oldcapacity; i++) {
-			struct hashlistnode<_Key, _Val> * bin = oldtable[i];
+		capacitymask = newsize - 1;
+
+		threshold = (unsigned int) (newsize * loadfactor);
+
+		struct hashlistnode<_Key, _Val> * bin = &oldtable[0];
+		struct hashlistnode<_Key, _Val> * lastbin = &oldtable[oldcapacity];
+		for(; bin < lastbin; bin++) {
+			_Key key=bin->key;
+
+			struct hashlistnode<_Key,_Val> *search;
 			
-			while(bin!=NULL) {
-				_Key key=bin->key;
-				struct hashlistnode<_Key, _Val> * next=bin->next;
-				
-				unsigned int index = (((_KeyInt)key) & mask) >>_Shift;
-				struct hashlistnode<_Key, _Val> * tmp=newtable[index];
-				bin->next=tmp;
-				newtable[index]=bin;
-				bin = next;
-			}
+			unsigned int index=((_KeyInt)key)>>_Shift;
+			do {
+				index=index&capacitymask;
+				search = &table[index];
+				index++;
+			} while(search->key);
+
+			search->key=key;
+			search->val=bin->val;
 		}
-		
-		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;
+	struct hashlistnode<_Key,_Val> *table;
 	unsigned int capacity;
-	_KeyInt mask;
 	unsigned int size;
+	unsigned int capacitymask;
 	unsigned int threshold;
 	double loadfactor;
 };