X-Git-Url: http://plrg.eecs.uci.edu/git/?p=c11tester.git;a=blobdiff_plain;f=hashtable.h;h=b7cac67410c287004e9861d14db91c4afc0367dd;hp=16744bb45f39e89a165bf12a804c96cad466123b;hb=7742256df627848c1c375f979f5369a45c92057b;hpb=110873aa95a98a28561165f803d21a9b050205ed

diff --git a/hashtable.h b/hashtable.h
index 16744bb4..b7cac674 100644
--- a/hashtable.h
+++ b/hashtable.h
@@ -62,7 +62,7 @@ inline bool default_equals(_Key key1, _Key key2) {
  * @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> >
+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:
 	/**
@@ -81,7 +81,7 @@ public:
 		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
 	}
 
 	/** @brief Hash table destructor */
@@ -182,24 +182,38 @@ public:
 			resize(capacity << 1);
 
 		struct hashlistnode<_Key, _Val> *search;
+		struct hashlistnode<_Key, _Val> *first = NULL;
 
-		unsigned int index = hash_function(key);
+		unsigned int index = hash_function(key) & capacitymask;
+		unsigned int oindex = index;
 		do {
-			index &= capacitymask;
 			search = &table[index];
 			if (!search->key) {
 				//key is null, probably done
-				break;
+				if (!search->val)
+					break;
+				if (first == NULL)
+					first = search;
 			}
 			if (equals(search->key, key)) {
 				search->val = val;
 				return;
 			}
-			index++;
+			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++;
 	}
 
@@ -220,7 +234,7 @@ public:
 		}
 
 		unsigned int oindex = hash_function(key) & capacitymask;
-		unsigned int index=oindex;
+		unsigned int index = oindex;
 		do {
 			search = &table[index];
 			if (!search->key) {
@@ -244,6 +258,7 @@ public:
 	 */
 	_Val remove(_Key key) {
 		struct hashlistnode<_Key, _Val> *search;
+		struct hashlistnode<_Key, _Val> *replace;
 
 		/* HashTable cannot handle 0 as a key */
 		if (!key) {
@@ -266,14 +281,40 @@ public:
 			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;
+			} 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 (true);
@@ -284,6 +325,9 @@ public:
 		return size;
 	}
 
+	bool isEmpty() {
+		return size == 0;
+	}
 
 	/**
 	 * @brief Check whether the table contains a value for the given key
@@ -327,7 +371,7 @@ public:
 			exit(EXIT_FAILURE);
 		}
 
-		table = newtable;											// Update the global hashtable upon resize()
+		table = newtable;	// Update the global hashtable upon resize()
 		capacity = newsize;
 		capacitymask = newsize - 1;
 
@@ -353,7 +397,7 @@ public:
 			search->val = bin->val;
 		}
 
-		_free(oldtable);												// Free the memory of the old hash table
+		_free(oldtable);	// Free the memory of the old hash table
 	}
 	double getLoadFactor() {return loadfactor;}
 	unsigned int getCapacity() {return capacity;}
@@ -367,4 +411,4 @@ private:
 	double loadfactor;
 };
 
-#endif/* __HASHTABLE_H__ */
+#endif	/* __HASHTABLE_H__ */