X-Git-Url: http://plrg.eecs.uci.edu/git/?p=model-checker.git;a=blobdiff_plain;f=hashtable.h;h=71b05cea015d939d7b2b039c4cea8f81afec8170;hp=e59a995fd92347a361a785a2d5e36c646b1a7656;hb=896f385f6690cfbe51ea1c07d7361a01914e9f9f;hpb=8b6e648f00b31633f9d72850df82ecdb4dc2699e

diff --git a/hashtable.h b/hashtable.h
index e59a995..71b05ce 100644
--- a/hashtable.h
+++ b/hashtable.h
@@ -7,164 +7,208 @@
 
 #include <stdlib.h>
 #include <stdio.h>
-
+#include <string.h>
+#include "mymemory.h"
+#include "common.h"
+
+/**
+ * @brief 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;
-	};
 
-/** Hashtable class.  By default it is snapshotting, but you can pass
-		in your own allocation functions. */
+struct hashlistnode {
+	_Key key;
+	_Val val;
+};
 
-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>
+/**
+ * @brief A simple, custom hash table
+ *
+ * By default it is snapshotting, but you can pass in your own allocation
+ * functions. Note that this table does not support 0 (NULL) keys and is
+ * designed primarily with pointer-based keys in mind.
+ *
+ * @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:
-	HashTable(unsigned int initialcapacity=1024, double factor=0.5) {
+	/**
+	 * 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 = (unsigned int) (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);
 	}
 
+	/** 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);
 	}
 
-	void operator delete[](void *p, size_t 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> *));
-		size=0;
+		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);
-		}
+		/* HashTable cannot handle 0 as a key */
+		ASSERT(key);
 
-		struct hashlistnode<_Key,_Val> *ptr = table[(((_KeyInt)key) & mask)>>_Shift];
-		size++;
-		struct hashlistnode<_Key,_Val> *search = ptr;
+		if (size > threshold)
+			resize(capacity << 1);
+
+		struct hashlistnode<_Key, _Val> *search;
 
-		while(search!=NULL) {
-			if (search->key==key) {
-				search->val=val;
+		unsigned int index = ((_KeyInt)key) >> _Shift;
+		do {
+			index &= capacitymask;
+			search = &table[index];
+			if (search->key == key) {
+				search->val = val;
 				return;
 			}
-			search=search->next;
-		}
+			index++;
+		} while (search->key);
 
-		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;
+		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];
+	_Val get(_Key key) const {
+		struct hashlistnode<_Key, _Val> *search;
+
+		/* HashTable cannot handle 0 as a key */
+		ASSERT(key);
 
-		while(search!=NULL) {
-			if (search->key==key) {
+		unsigned int index = ((_KeyInt)key) >> _Shift;
+		do {
+			index &= capacitymask;
+			search = &table[index];
+			if (search->key == key)
 				return search->val;
-			}
-			search=search->next;
-		}
+			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];
+	bool contains(_Key key) const {
+		struct hashlistnode<_Key, _Val> *search;
+
+		/* HashTable cannot handle 0 as a key */
+		ASSERT(key);
 
-		while(search!=NULL) {
-			if (search->key==key) {
+		unsigned int index = ((_KeyInt)key) >> _Shift;
+		do {
+			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) {
-			printf("Calloc error %s %d\n", __FILE__, __LINE__);
-			exit(-1);
+		if ((newtable = (struct hashlistnode<_Key, _Val> *)_calloc(newsize, sizeof(struct hashlistnode<_Key, _Val>))) == NULL) {
+			model_print("calloc error %s %d\n", __FILE__, __LINE__);
+			exit(EXIT_FAILURE);
 		}
 
-		table = newtable;          //Update the global hashtable upon resize()
+		table = newtable;          // Update the global hashtable upon resize()
 		capacity = newsize;
-		threshold = (unsigned int) (newsize * loadfactor);
-		mask = (newsize << _Shift)-1;
+		capacitymask = newsize - 1;
 
-		for(unsigned int i = 0; i < oldcapacity; i++) {
-			struct hashlistnode<_Key, _Val> * bin = oldtable[i];
+		threshold = (unsigned int)(newsize * loadfactor);
 
-			while(bin!=NULL) {
-				_Key key=bin->key;
-				struct hashlistnode<_Key, _Val> * next=bin->next;
+		struct hashlistnode<_Key, _Val> *bin = &oldtable[0];
+		struct hashlistnode<_Key, _Val> *lastbin = &oldtable[oldcapacity];
+		for (; bin < lastbin; bin++) {
+			_Key key = bin->key;
 
-				unsigned int index = (((_KeyInt)key) & mask) >>_Shift;
-				struct hashlistnode<_Key, _Val> * tmp=newtable[index];
-				bin->next=tmp;
-				newtable[index]=bin;
-				bin = next;
-			}
+			struct hashlistnode<_Key, _Val> *search;
+
+			unsigned int index = ((_KeyInt)key) >> _Shift;
+			do {
+				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;
 };