Imported growable TinyHash class to replace std::map

--HG--
extra : convert_revision : svn%3Ac2935e3e-5518-0410-8daf-afa5dab7d4e3/trunk%40103

sourcehook/sh_tinyhash.h

@@ -0,0 +1,287 @@
+/* ======== SourceMM ========
+* Copyright (C) 2004-2005 Metamod:Source Development Team
+* No warranties of any kind
+*
+* License: zlib/libpng
+*
+* Author(s): David "BAILOPAN" Anderson
+* ============================
+*/
+
+#ifndef _INCLUDE_SH_TINYHASH_H_
+#define _INCLUDE_SH_TINYHASH_H_
+
+#include "sh_list.h"
+
+#define _T_INIT_HASH_SIZE	32
+
+namespace SourceHook
+{
+	template <class K>
+	int HashFunction(const K & k);
+
+	template <class K>
+	int Compare(const K & k1, const K & k2);
+
+	/**
+	 * This is a tiny, growable hash class.
+	 * Meant for quick and dirty dictionaries only!
+	 */
+	template <class K, class V> 
+	class THash
+	{
+	public:
+		struct THashNode
+		{
+			THashNode(const K & k, const V & v) : 
+				key(k), val(v)
+				{
+				};
+			K key;
+			V val;
+		};
+		typedef List<THashNode *> *	NodePtr;
+	public:
+		THash() : m_numBuckets(0), m_Buckets(NULL)
+		{
+			_Refactor();
+		}
+		size_t GetBuckets()
+		{
+			return m_numBuckets;
+		}
+		float PercentUsed()
+		{
+			return m_percentUsed;
+		}
+		V & operator [](const K & key)
+		{
+			THashNode *pNode = _FindOrInsert(key);
+			return pNode->val;
+		}
+	private:
+		THashNode *_FindOrInsert(const K & key)
+		{
+			size_t place = HashFunction(key) % m_numBuckets;
+			THashNode *pNode = NULL;
+			if (!m_Buckets[place])
+			{
+				m_Buckets[place] = new List<THashNode *>;
+				pNode = new THashNode(key, V());
+				m_Buckets[place]->push_back(pNode);
+				m_percentUsed += (1.0f / (float)m_numBuckets);
+			} else {
+				List<THashNode *>::iterator iter;
+				for (iter=m_Buckets[place]->begin(); iter!=m_Buckets[place]->end(); iter++)
+				{
+					if (Compare((*iter)->key, key) == 0)
+						return (*iter);
+				}
+				//node does not exist
+				pNode = new THashNode(key, V());
+				m_Buckets[place]->push_back(pNode);
+			}
+			if (PercentUsed() > 0.75f)
+				_Refactor();
+			return pNode;
+		}
+		void _Refactor()
+		{
+			m_percentUsed = 0.0f;
+			if (!m_numBuckets)
+			{
+				m_numBuckets = _T_INIT_HASH_SIZE;
+				m_Buckets = new NodePtr[m_numBuckets];
+				for (size_t i=0; i<m_numBuckets; i++)
+					m_Buckets[i] = NULL;
+			} else {
+				size_t oldSize = m_numBuckets;
+				m_numBuckets *= 2;
+				List<THashNode *>::iterator iter;
+				size_t place;
+				THashNode *pHashNode;
+                NodePtr *temp = new NodePtr[m_numBuckets];
+				for (size_t i=0; i<m_numBuckets; i++)
+					temp[i] = NULL;
+				//look in old hash table
+				for (size_t i=0; i<oldSize; i++)
+				{
+					//does a bucket have anything?
+					if (m_Buckets[i])
+					{
+						//go through the list of items
+						for (iter = m_Buckets[i]->begin(); iter != m_Buckets[i]->end(); iter++)
+						{
+							pHashNode = (*iter);
+							//rehash it with the new bucket filter
+							place = HashFunction(pHashNode->key) % m_numBuckets;
+							//add it to the new hash table
+							if (!temp[place])
+							{
+								temp[place] = new List<THashNode *>;
+								m_percentUsed += (1.0f / (float)m_numBuckets);
+							}
+							temp[place]->push_back(pHashNode);
+						}
+						//delete that bucket!
+						delete m_Buckets[i];
+						m_Buckets[i] = NULL;
+					}
+				}
+				//reassign bucket table
+				delete [] m_Buckets;
+				m_Buckets = temp;
+			}
+		}
+	public:
+		friend class iterator;
+		class iterator
+		{
+			friend class THash;
+		public:
+			iterator() : hash(NULL), end(true)
+			{
+			};
+			iterator(THash *h) : hash(h), end(false)
+			{
+				if (!h->m_Buckets)
+					end = true;
+				else
+					_Inc();
+			};
+			//pre increment
+			iterator & operator++()
+			{
+				_Inc();
+				return *this;
+			}
+			//post increment
+			iterator operator++(int)
+			{
+				iterator old(*this);
+				_Inc();
+				return old;
+			}
+			THashNode & operator * () const
+			{
+				return *(*iter);
+			}
+			THashNode & operator * ()
+			{
+				return *(*iter);
+			}
+			THashNode * operator ->() const
+			{
+				return (*iter);
+			}
+			THashNode * operator ->()
+			{
+				return (*iter);
+			}
+			bool operator ==(const iterator &where) const
+			{
+				if (where.hash == this->hash
+					&& where.end == this->end
+					&& 
+					 (this->end || 
+					   ((where.curbucket == this->curbucket) 
+					     && (where.iter == iter))
+						 ))
+					return true;
+				return false;
+			}
+			bool operator !=(const iterator &where) const
+			{
+				return !( (*this) == where );
+			}
+		private:
+			void _Inc()
+			{
+				if (end || !hash)
+					return;
+				if (curbucket < 0)
+				{
+					for (int i=0; i<(int)hash->m_numBuckets; i++)
+					{
+						if (hash->m_Buckets[i])
+						{
+							iter = hash->m_Buckets[i]->begin();
+							if (iter == hash->m_Buckets[i]->end())
+								continue;
+							curbucket = i;
+							break;
+						}
+					}
+					if (curbucket < 0)
+						end = true;
+				} else {
+					if (iter != hash->m_Buckets[curbucket]->end())
+						iter++;
+					if (iter == hash->m_Buckets[curbucket]->end())
+					{
+						int oldbucket = curbucket;
+						for (int i=curbucket+1; i<(int)hash->m_numBuckets; i++)
+						{
+							if (hash->m_Buckets[i])
+							{
+								iter = hash->m_Buckets[i]->begin();
+								if (iter == hash->m_Buckets[i]->end())
+									continue;
+								curbucket = i;
+								break;
+							}
+						}
+						if (curbucket == oldbucket)
+							end = true;
+					}
+				}
+			}
+		private:
+			int curbucket;
+			typename SourceHook::List<THashNode *>::iterator iter;
+			THash *hash;
+			bool end;
+		};
+	public:
+		iterator begin()
+		{
+			return iterator(this);
+		}
+		iterator end()
+		{
+			iterator iter;
+			iter.hash = this;
+			return iter;
+		}
+		template <typename U>
+		iterator find(const U & u) const
+		{
+			iterator b = begin();
+			iterator e = end();
+			for (iterator iter = b; iter != e; iter++)
+			{
+				if ( (*iter).key == u )
+					return iter;
+			}
+			return end();
+		}
+		template <typename U>
+		iterator find(const U & u)
+		{
+			iterator b = begin();
+			iterator e = end();
+			for (iterator iter = b; iter != e; iter++)
+			{
+				if ( (*iter).key == u )
+					return iter;
+			}
+			return end();
+		}
+	private:
+		NodePtr	*m_Buckets;
+		size_t m_numBuckets;
+		float m_percentUsed;
+	};
+};
+
+#endif //_INCLUDE_SH_TINYHASH_H_