X-Git-Url: http://plrg.eecs.uci.edu/git/?p=c11tester.git;a=blobdiff_plain;f=hashtable.h;h=b7cac67410c287004e9861d14db91c4afc0367dd;hp=6bf813520f505bdb6799f9e2e619510df6e1b7ed;hb=251ac4b4bf3a9f2d3cfacc1e6618200ca1c431ac;hpb=a2877303b3cde1e5635921a73216d9a67e24945e

diff --git a/hashtable.h b/hashtable.h
index 6bf81352..b7cac674 100644
--- a/hashtable.h
+++ b/hashtable.h
@@ -1,9 +1,18 @@
+/*      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
+#ifndef __HASHTABLE_H__
+#define __HASHTABLE_H__
 
 #include <stdlib.h>
 #include <stdio.h>
@@ -12,29 +21,34 @@
 #include "common.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.
+ * @brief HashTable node
  *
  * @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;
 };
 
+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;
+}
+
 /**
- * Hashtable class. By default it is snapshotting, but you can pass in your own
- * allocation functions.
+ * @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
@@ -48,11 +62,11 @@ struct hashlistnode {
  * @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:
+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:
 	/**
-	 * Constructor
+	 * @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
@@ -61,17 +75,20 @@ template<typename _Key, typename _Val, typename _KeyInt, int _Shift = 0, void *
 	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>));
+		zero = NULL;
 		loadfactor = factor;
 		capacity = initialcapacity;
 		capacitymask = initialcapacity - 1;
 
 		threshold = (unsigned int)(initialcapacity * loadfactor);
-		size = 0; // Initial number of elements in the hash
+		size = 0;	// Initial number of elements in the hash
 	}
 
-	/** Destructor */
+	/** @brief Hash table destructor */
 	~HashTable() {
 		_free(table);
+		if (zero)
+			_free(zero);
 	}
 
 	/** Override: new operator */
@@ -94,94 +111,284 @@ template<typename _Key, typename _Val, typename _KeyInt, int _Shift = 0, void *
 		_free(p);
 	}
 
-	/** Reset the table to its initial state. */
+	/** @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];
+			if (bin->key != NULL) {
+				bin->key = NULL;
+				if (bin->val != NULL) {
+					delete bin->val;
+					bin->val = NULL;
+				}
+			}
+		}
+		if (zero) {
+			if (zero->val != NULL)
+				delete zero->val;
+			_free(zero);
+			zero = NULL;
+		}
+		size = 0;
+	}
+
+	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;
+				}
+			}
+		}
+		if (zero) {
+			if (zero->val != NULL)
+				_free(zero->val);
+			_free(zero);
+			zero = NULL;
+		}
 		size = 0;
 	}
 
-	/** Put a key value pair into the table. */
+	/**
+	 * @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) {
+		/* 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;
+		}
+
 		if (size > threshold)
 			resize(capacity << 1);
 
 		struct hashlistnode<_Key, _Val> *search;
+		struct hashlistnode<_Key, _Val> *first = NULL;
 
-		unsigned int index = ((_KeyInt)key) >> _Shift;
+		unsigned int index = hash_function(key) & capacitymask;
+		unsigned int oindex = index;
 		do {
-			index = index & capacitymask;
 			search = &table[index];
-			if (search->key == key) {
+			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;
 			}
-			index++;
-		} while (search->key);
+			index = (index + 1) & capacitymask;
+			if (index == oindex) {
+				if (first == NULL)
+					exit(-1);
+				break;
+			}
+		} while (true);
 
-		search->key = key;
-		search->val = val;
+		if (first != NULL) {
+			first->key = key;
+			first->val = val;
+		} else {
+			search->key = key;
+			search->val = val;
+		}
 		size++;
 	}
 
-	/** Lookup the corresponding value for the given key. */
-	_Val get(_Key key) {
+	/**
+	 * @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;
 
-		unsigned int index = ((_KeyInt)key) >> _Shift;
+		/* HashTable cannot handle 0 as a key */
+		if (!key) {
+			if (zero)
+				return zero->val;
+			else
+				return (_Val) 0;
+		}
+
+		unsigned int oindex = hash_function(key) & capacitymask;
+		unsigned int index = oindex;
 		do {
-			index = index&capacitymask;
 			search = &table[index];
-			if (search->key == key) {
+			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;
+		struct hashlistnode<_Key, _Val> *replace;
+
+		/* 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;
+			}
+		}
+
+
+		unsigned int index = hash_function(key);
+		do {
+			index &= capacitymask;
+			search = &table[index];
+			if (!search->key) {
+				if (!search->val)
+					break;
+			} else {
+				// The case where an item is found
+				if (equals(search->key, key)) {
+					unsigned int j = index;
+					_Val v = search->val;
+					size--;
+
+					// Idea: keep bins contiguous
+					while (true) {
+						search->val = 0;
+						search->key = 0;
+
+						while (true) {
+							j = (j + 1) & capacitymask;
+							replace = &table[j];
+
+							if (!replace->key && !replace->val) {
+								return v;
+							}
+
+							unsigned int hash = hash_function(replace->key) & capacitymask;
+							if (index <= j && index < hash && hash <= j)
+								continue;
+							else if (index > j && (index < hash || hash <= j) )
+								continue;
+							else
+								break;
+						}
+
+						table[index] = table[j];
+						index = j;
+						search = &table[index];
+					}
+				}
 			}
 			index++;
-		} while (search->key);
-		return (_Val) 0;
+		} while (true);
+		return (_Val)0;
+	}
+
+	unsigned int getSize() const {
+		return size;
+	}
+
+	bool isEmpty() {
+		return size == 0;
 	}
 
-	/** Check whether the table contains a value for the given key. */
-	bool contains(_Key key) {
+	/**
+	 * @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;
 
-		unsigned int index = ((_KeyInt)key) >> _Shift;
+		/* HashTable cannot handle 0 as a key */
+		if (!key) {
+			return zero!=NULL;
+		}
+
+		unsigned int index = hash_function(key);
 		do {
-			index = index & capacitymask;
+			index &= capacitymask;
 			search = &table[index];
-			if (search->key == key) {
+			if (!search->key) {
+				if (!search->val)
+					break;
+			} else
+			if (equals(search->key, key))
 				return true;
-			}
 			index++;
-		} while (search->key);
+		} while (true);
 		return false;
 	}
 
-	/** Resize the table. */
+	/**
+	 * @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;
 		unsigned int oldcapacity = capacity;
 
-		if ((newtable = (struct hashlistnode<_Key, _Val> *) _calloc(newsize, sizeof(struct hashlistnode<_Key, _Val>))) == NULL) {
-			model_print("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;
 		capacitymask = newsize - 1;
 
-		threshold = (unsigned int) (newsize * loadfactor);
+		threshold = (unsigned int)(newsize * loadfactor);
 
 		struct hashlistnode<_Key, _Val> *bin = &oldtable[0];
 		struct hashlistnode<_Key, _Val> *lastbin = &oldtable[oldcapacity];
-		for (; bin < lastbin; bin++) {
+		for (;bin < lastbin;bin++) {
 			_Key key = bin->key;
 
 			struct hashlistnode<_Key, _Val> *search;
+			if (!key)
+				continue;
 
-			unsigned int index = ((_KeyInt)key) >> _Shift;
+			unsigned int index = hash_function(key);
 			do {
-				index = index & capacitymask;
+				index &= capacitymask;
 				search = &table[index];
 				index++;
 			} while (search->key);
@@ -190,15 +397,18 @@ template<typename _Key, typename _Val, typename _KeyInt, int _Shift = 0, void *
 			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:
+	double getLoadFactor() {return loadfactor;}
+	unsigned int getCapacity() {return capacity;}
 	struct hashlistnode<_Key, _Val> *table;
+	struct hashlistnode<_Key, _Val> *zero;
 	unsigned int capacity;
 	unsigned int size;
+private:
 	unsigned int capacitymask;
 	unsigned int threshold;
 	double loadfactor;
 };
-#endif
+
+#endif	/* __HASHTABLE_H__ */