Add new StringHashMap container (bug 5878 part 1, r=ds).

public/amtl/am-hashmap.h

@@ -131,6 +131,10 @@ class HashMap : public AllocPolicy
     return table_.add(i);
   }
 
+  void clear() {
+    table_.clear();
+  }
+
   size_t estimateMemoryUse() const {
     return table_.estimateMemoryUse();
   }

public/amtl/am-hashtable.h

@@ -60,6 +60,10 @@ namespace detail {
       destruct();
       hash_ = kRemovedHash;
     }
+    void setFree() {
+      destruct();
+      hash_ = kFreeHash;
+    }
     void initialize() {
       hash_ = kFreeHash;
     }
@@ -432,6 +436,14 @@ class HashTable : public AllocPolicy
     return true;
   }
 
+  void clear() {
+    for (size_t i = 0; i < capacity_; i++) {
+      table_[i].setFree();
+    }
+    ndeleted_ = 0;
+    nelements_ = 0;
+  }
+
   size_t estimateMemoryUse() const {
     return sizeof(Entry) * capacity_;
   }

public/sm_stringhashmap.h

@@ -0,0 +1,178 @@
+/**
+ * vim: set ts=4 sw=4 tw=99 noet :
+ * =============================================================================
+ * SourceMod
+ * Copyright (C) 2004-2008 AlliedModders LLC.  All rights reserved.
+ * =============================================================================
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, version 3.0, as published by the
+ * Free Software Foundation.
+ * 
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * As a special exception, AlliedModders LLC gives you permission to link the
+ * code of this program (as well as its derivative works) to "Half-Life 2," the
+ * "Source Engine," the "SourcePawn JIT," and any Game MODs that run on software
+ * by the Valve Corporation.  You must obey the GNU General Public License in
+ * all respects for all other code used.  Additionally, AlliedModders LLC grants
+ * this exception to all derivative works.  AlliedModders LLC defines further
+ * exceptions, found in LICENSE.txt (as of this writing, version JULY-31-2007),
+ * or <http://www.sourcemod.net/license.php>.
+ *
+ * Version: $Id$
+ */
+
+#ifndef _include_sourcemod_hashtable_h_
+#define _include_sourcemod_hashtable_h_
+
+#include <am-allocator-policies.h>
+#include <am-hashmap.h>
+#include <am-string.h>
+#include <string.h>
+
+namespace SourceMod
+{
+
+using namespace ke;
+
+namespace detail
+{
+	class CharsAndLength
+	{
+	 public:
+	  CharsAndLength(const char *str)
+		: str_(str),
+		  length_(0)
+	  {
+		  int c;
+		  uint32_t hash = 0;
+		  while ((c = *str++))
+			  hash = c + (hash << 6) + (hash << 16) - hash;
+		  hash_ = hash;
+		  length_ = str - str_ - 1;
+	  }
+
+	  uint32_t hash() const {
+		  return hash_;
+	  }
+	  const char *chars() const {
+		  return str_;
+	  }
+	  size_t length() const {
+		  return length_;
+	  }
+
+	 private:
+	  const char *str_;
+	  size_t length_;
+	  uint32_t hash_;
+	};
+
+	struct StringHashMapPolicy
+	{
+		static inline bool matches(const CharsAndLength &lookup, const AString &key) {
+			return lookup.length() == key.length() &&
+				   memcmp(lookup.chars(), key.chars(), key.length()) == 0;
+		}
+		static inline uint32_t hash(const CharsAndLength &key) {
+			return key.hash();
+		}
+	};
+}
+
+template <typename T>
+class StringHashMap
+{
+	typedef detail::CharsAndLength CharsAndLength;
+	typedef HashMap<AString, T, detail::StringHashMapPolicy> Internal;
+
+public:
+	StringHashMap()
+		: internal_(SystemAllocatorPolicy()),
+		  memory_used_(0)
+	{
+		if (!internal_.init())
+			internal_.reportOutOfMemory();
+	}
+
+	// Some KTrie-like helper functions.
+	bool retrieve(const char *aKey, T *aResult = NULL)
+	{
+		CharsAndLength key(aKey);
+		typename Internal::Result r = internal_.find(key);
+		if (!r.found())
+			return false;
+		if (aResult)
+			*aResult = r->value;
+		return true;
+	}
+
+	bool contains(const char *aKey)
+	{
+		CharsAndLength key(aKey);
+		typename Internal::Result r = internal_.find(key);
+		return r.found();
+	}
+
+	bool replace(const char *aKey, const T &value)
+	{
+		CharsAndLength key(aKey);
+		typename Internal::Insert i = internal_.findForAdd(key);
+		if (!i.found())
+		{
+			memory_used_ += key.length() + 1;
+			return internal_.add(i, value);
+		}
+		i->value = value;
+		return true;
+	}
+
+	bool insert(const char *aKey, const T &value)
+	{
+		CharsAndLength key(aKey);
+		typename Internal::Insert i = internal_.findForAdd(key);
+		if (i.found())
+			return false;
+		if (!internal_.add(i))
+			return false;
+		memory_used_ += key.length() + 1;
+		i->key = aKey;
+		i->value = value;
+		return true;
+	}
+
+	bool remove(const char *aKey)
+	{
+		CharsAndLength key(aKey);
+		typename Internal::Result r = internal_.find(key);
+		if (!r.found())
+			return false;
+		memory_used_ -= key.length() + 1;
+		internal_.remove(r);
+		return true;
+	}
+
+	void clear()
+	{
+		internal_.clear();
+	}
+
+	size_t mem_usage() const {
+		return internal_.estimateMemoryUse() + memory_used_;
+	}
+
+private:
+	Internal internal_;
+	size_t memory_used_;
+};
+
+}
+
+#endif // _include_sourcemod_hashtable_h_

public/sm_trie_tpl.h

@@ -1,5 +1,5 @@
 /**
- * vim: set ts=4 :
+ * vim: set ts=4 sw=4 tw=99 noet :
  * =============================================================================
  * SourceMod
  * Copyright (C) 2004-2008 AlliedModders LLC.  All rights reserved.
@@ -45,11 +45,15 @@ enum NodeType
 };
 
 /**
- * @brief Trie class for storing key/value pairs, based on double array tries.
- * @file sm_trie_tpl.h
+ * @brief DEPRECATED. This class scales extremely poorly; insertion scales
+ * quadratic (O(n^2)) with respect to the number of elements in the table.
+ * Only use this class if you have less than 200 elements or so. Otherwise,
+ * use StringHashMap in sm_hashtable.h which scales linearly and has comparable
+ * retrievable performance.
  *
- * For full works cited and implementation overview, there is a big comment 
- * block at the bottom of this file.
+ * See bug 5878 for more detail.
+ *
+ * @file sm_trie_tpl.h
  */
 
 template <typename K>