X-Git-Url: http://plrg.eecs.uci.edu/git/?p=c11tester.git;a=blobdiff_plain;f=hashtable.h;h=81772a8f039addae09c726c0f7bf3e37ab626ef1;hp=b1cd3273290a47e94d0c3000c06e88a43e2cb97d;hb=8690d27f56658be9800f5dd2232f73fbe0381c1d;hpb=8548c711d71b6474802af83f5a4800eb4ac30718

diff --git a/hashtable.h b/hashtable.h
index b1cd3273..81772a8f 100644
--- a/hashtable.h
+++ b/hashtable.h
@@ -1,143 +1,387 @@
-#ifndef HASHTABLE_H
-#define HASHTABLE_H
+/*      Copyright (c) 2015 Regents of the University of California
+ *
+ *      Author: Brian Demsky <bdemsky@uci.edu>
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      version 2 as published by the Free Software Foundation.
+ */
+
+/** @file hashtable.h
+ *  @brief Hashtable.  Standard chained bucket variety.
+ */
+
+#ifndef __HASHTABLE_H__
+#define __HASHTABLE_H__
 
 #include <stdlib.h>
 #include <stdio.h>
+#include <string.h>
+#include "mymemory.h"
+#include "common.h"
 
+/**
+ * @brief HashTable node
+ *
+ * @tparam _Key    Type name for the key
+ * @tparam _Val    Type name for the values to be stored
+ */
 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>
-	class HashTable {
- public:
-	HashTable(unsigned int initialcapacity=1024, double factor=0.5) {
+struct hashlistnode {
+	_Key key;
+	_Val val;
+};
+
+template<typename _Key, int _Shift, typename _KeyInt>
+inline unsigned int default_hash_function(_Key hash) {
+	return (unsigned int)(((_KeyInt)hash) >> _Shift);
+}
+
+template<typename _Key>
+inline bool default_equals(_Key key1, _Key key2) {
+	return key1 == key2;
+}
+
+/**
+ * @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 the value 0 (NULL) used as
+ * a key and is designed primarily with pointer-based keys in mind. Other
+ * primitive key types are supported only for non-zero values.
+ *
+ * @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, unsigned int (*hash_function)(_Key) = default_hash_function<_Key, _Shift, _KeyInt>, bool (*equals)(_Key, _Key) = default_equals<_Key> >
+class HashTable {
+public:
+	/**
+	 * @brief Hash table 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>));
+		zero = NULL;
 		loadfactor = factor;
 		capacity = initialcapacity;
-		threshold = (unsigned int) (initialcapacity*loadfactor);
-		mask = (capacity << _Shift)-1;
-		size = 0; // Initial number of elements in the hash
+		capacitymask = initialcapacity - 1;
+
+		threshold = (unsigned int)(initialcapacity * loadfactor);
+		size = 0;	// Initial number of elements in the hash
 	}
 
+	/** @brief Hash table destructor */
 	~HashTable() {
+		_free(table);
+		if (zero)
+			_free(zero);
+	}
+
+	/** 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);
+	}
+
+	/** @brief Reset the table to its initial state. */
+	void reset() {
+		memset(table, 0, capacity * sizeof(struct hashlistnode<_Key, _Val>));
+		if (zero) {
+			_free(zero);
+			zero = NULL;
+		}
+		size = 0;
+	}
+
+	void resetanddelete() {
 		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;
+			struct hashlistnode<_Key, _Val> *bin = &table[i];
+			if (bin->key != NULL) {
+				bin->key = NULL;
+				if (bin->val != NULL) {
+					delete bin->val;
+					bin->val = NULL;
+				}
 			}
 		}
-		free(table);
+		if (zero) {
+			if (zero->val != NULL)
+				delete zero->val;
+			_free(zero);
+			zero = NULL;
+		}
+		size = 0;
 	}
 
-	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;
+	void resetandfree() {
+		for(unsigned int i=0;i<capacity;i++) {
+			struct hashlistnode<_Key, _Val> *bin = &table[i];
+			if (bin->key != NULL) {
+				bin->key = NULL;
+				if (bin->val != NULL) {
+					_free(bin->val);
+					bin->val = NULL;
+				}
 			}
 		}
-		memset(table, 0, capacity*sizeof(struct hashlistnode<_Key, _Val> *));
-		size=0;
+		if (zero) {
+			if (zero->val != NULL)
+				_free(zero->val);
+			_free(zero);
+			zero = NULL;
+		}
+		size = 0;
 	}
 
+	/**
+	 * @brief Put a key/value pair into the table
+	 * @param key The key for the new value; must not be 0 or NULL
+	 * @param val The value to store in 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 */
+		if (!key) {
+			if (!zero) {
+				zero=(struct hashlistnode<_Key, _Val> *)_malloc(sizeof(struct hashlistnode<_Key, _Val>));
+				size++;
+			}
+			zero->key=key;
+			zero->val=val;
+			return;
 		}
 
-		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;
+		struct hashlistnode<_Key, _Val> *first = NULL;
 
-		while(search!=NULL) {
-			if (search->key==key) {
-				search->val=val;
+		unsigned int index = hash_function(key) & capacitymask;
+		unsigned int oindex = index;
+		do {
+			search = &table[index];
+			if (!search->key) {
+				//key is null, probably done
+				if (!search->val)
+					break;
+				if (first == NULL)
+					first = search;
+			}
+			if (equals(search->key, key)) {
+				search->val = val;
 				return;
 			}
-			search=search->next;
-		}
+			index = (index + 1) & capacitymask;
+			if (index == oindex) {
+				if (first == NULL)
+					exit(-1);
+				break;
+			}
+		} while (true);
 
-		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;
+		if (first != NULL) {
+			first->key = key;
+			first->val = val;
+		} else {
+			search->key = key;
+			search->val = val;
+		}
+		size++;
 	}
 
-	_Val get(_Key key) {
-		struct hashlistnode<_Key,_Val> *search = table[(((_KeyInt)key) & mask)>>_Shift];
+	/**
+	 * @brief Lookup the corresponding value for the given key
+	 * @param key The key for finding the value; must not be 0 or NULL
+	 * @return The value in the table, if the key is found; otherwise 0
+	 */
+	_Val get(_Key key) const {
+		struct hashlistnode<_Key, _Val> *search;
+
+		/* HashTable cannot handle 0 as a key */
+		if (!key) {
+			if (zero)
+				return zero->val;
+			else
+				return (_Val) 0;
+		}
 
-		while(search!=NULL) {
-			if (search->key==key) {
+		unsigned int oindex = hash_function(key) & capacitymask;
+		unsigned int index = oindex;
+		do {
+			search = &table[index];
+			if (!search->key) {
+				if (!search->val)
+					break;
+			} else
+			if (equals(search->key, key))
 				return search->val;
+			index++;
+			index &= capacitymask;
+			if (index==oindex)
+				break;
+		} while (true);
+		return (_Val)0;
+	}
+
+	/**
+	 * @brief Remove the given key and return the corresponding value
+	 * @param key The key for finding the value; must not be 0 or NULL
+	 * @return The value in the table, if the key is found; otherwise 0
+	 */
+	_Val remove(_Key key) {
+		struct hashlistnode<_Key, _Val> *search;
+
+		/* HashTable cannot handle 0 as a key */
+		if (!key) {
+			if (!zero) {
+				return (_Val)0;
+			} else {
+				_Val v=zero->val;
+				_free(zero);
+				zero=NULL;
+				size--;
+				return v;
 			}
-			search=search->next;
 		}
+
+
+		unsigned int index = hash_function(key);
+		do {
+			index &= capacitymask;
+			search = &table[index];
+			if (!search->key) {
+				if (!search->val)
+					break;
+			} else
+			if (equals(search->key, key)) {
+				_Val v=search->val;
+				//empty out this bin
+				search->val=(_Val) 1;
+				search->key=0;
+				size--;
+				return v;
+			}
+			index++;
+		} while (true);
 		return (_Val)0;
 	}
 
-	bool contains(_Key key) {
-		struct hashlistnode<_Key,_Val> *search = table[(((_KeyInt)key) & mask)>>_Shift];
+	unsigned int getSize() const {
+		return size;
+	}
 
-		while(search!=NULL) {
-			if (search->key==key) {
-				return true;
-			}
-			search=search->next;
+	bool isEmpty() {
+		return size == 0;
+	}
+
+	/**
+	 * @brief Check whether the table contains a value for the given key
+	 * @param key The key for finding the value; must not be 0 or NULL
+	 * @return True, if the key is found; false otherwise
+	 */
+	bool contains(_Key key) const {
+		struct hashlistnode<_Key, _Val> *search;
+
+		/* HashTable cannot handle 0 as a key */
+		if (!key) {
+			return zero!=NULL;
 		}
+
+		unsigned int index = hash_function(key);
+		do {
+			index &= capacitymask;
+			search = &table[index];
+			if (!search->key) {
+				if (!search->val)
+					break;
+			} else
+			if (equals(search->key, key))
+				return true;
+			index++;
+		} while (true);
 		return false;
 	}
 
+	/**
+	 * @brief Resize the table
+	 * @param newsize The new size of 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;
+			if (!key)
+				continue;
+
+			unsigned int index = hash_function(key);
+			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;
+	double getLoadFactor() {return loadfactor;}
+	unsigned int getCapacity() {return capacity;}
+	struct hashlistnode<_Key, _Val> *table;
+	struct hashlistnode<_Key, _Val> *zero;
 	unsigned int capacity;
-	_KeyInt mask;
 	unsigned int size;
+private:
+	unsigned int capacitymask;
 	unsigned int threshold;
 	double loadfactor;
 };
-#endif
+
+#endif	/* __HASHTABLE_H__ */