Custom memory management functions implemented

git-svn-id: http://pugixml.googlecode.com/svn/trunk@105 99668b35-9821-0410-8761-19e4c4f06640

src/pugixml.cpp

@@ -17,8 +17,8 @@
 #include <stdio.h>
 #include <string.h>
 
+// For placement new
 #include <new>
-#include <exception>
 
 #if !defined(PUGIXML_NO_XPATH) && defined(PUGIXML_NO_EXCEPTIONS)
 #error No exception mode can't be used with XPath support
@@ -47,6 +47,22 @@ using std::memcpy;
 
 #define STATIC_ASSERT(cond) { static const char condition_failed[(cond) ? 1 : -1] = {0}; (void)condition_failed[0]; }
 
+namespace
+{
+	void* default_allocate(size_t size)
+	{
+		return malloc(size);
+	}
+
+	void default_deallocate(void* ptr)
+	{
+		free(ptr);
+	}
+
+	pugi::allocation_function global_allocate = default_allocate;
+	pugi::deallocation_function global_deallocate = default_deallocate;
+}
+
 namespace pugi
 {
 	struct xml_document_struct;
@@ -75,7 +91,9 @@ namespace pugi
 			}
 			else
 			{
-				_root->next = new xml_memory_block();
+				void* new_block = global_allocate(sizeof(xml_memory_block));
+
+				_root->next = new (new_block) xml_memory_block();
 				_root = _root->next;
 
 				_root->size = size;
@@ -193,17 +211,17 @@ namespace pugi
 
 	xml_document_struct* xml_allocator::allocate_document()
 	{
-		return new(memalloc(sizeof(xml_document_struct))) xml_document_struct;
+		return new (memalloc(sizeof(xml_document_struct))) xml_document_struct;
 	}
 
 	xml_node_struct* xml_allocator::allocate_node(xml_node_type type)
 	{
-		return new(memalloc(sizeof(xml_node_struct))) xml_node_struct(type);
+		return new (memalloc(sizeof(xml_node_struct))) xml_node_struct(type);
 	}
 
 	xml_attribute_struct* xml_allocator::allocate_attribute()
 	{
-		return new(memalloc(sizeof(xml_attribute_struct))) xml_attribute_struct;
+		return new (memalloc(sizeof(xml_attribute_struct))) xml_attribute_struct;
 	}
 }
 
@@ -266,25 +284,12 @@ namespace
 		}
 		else
 		{
-			char* buf;
+			char* buf = static_cast<char*>(global_allocate(source_size + 1));
-
+			if (!buf) return false;
-		#ifndef PUGIXML_NO_EXCEPTIONS
-			try
-			{
-		#endif
-				buf = new char[source_size + 1];
-				if (!buf) return false;
-		#ifndef PUGIXML_NO_EXCEPTIONS
-			}
-			catch (const std::bad_alloc&)
-			{
-				return false;
-			}
-		#endif
 
 			strcpy(buf, source);
 
-			if (!insitu) delete[] dest;
+			if (!insitu) global_deallocate(dest);
 			
 			dest = buf;
 			insitu = false;
@@ -2625,7 +2630,7 @@ namespace pugi
 
 	void xml_document::destroy()
 	{
-		delete[] _buffer;
+		global_deallocate(_buffer);
 		_buffer = 0;
 
 		if (_root) _root->destroy();
@@ -2635,7 +2640,7 @@ namespace pugi
 		while (current)
 		{
 			xml_memory_block* next = current->next;
-			delete current;
+			global_deallocate(current);
 			current = next;
 		}
 		
@@ -2659,27 +2664,14 @@ namespace pugi
 
 		if (!stream.good()) return false;
 
-		char* s;
+		char* s = static_cast<char*>(global_allocate(length + 1));
-
+		if (!s) return false;
-	#ifndef PUGIXML_NO_EXCEPTIONS
-		try
-		{
-	#endif
-			s = new char[length + 1];
-			if (!s) return false;
-	#ifndef PUGIXML_NO_EXCEPTIONS
-		}
-		catch (const std::bad_alloc&)
-		{
-			return false;
-		}
-	#endif
 
 		stream.read(s, length);
 
 		if (stream.gcount() > length || stream.gcount() == 0)
 		{
-			delete[] s;
+			global_deallocate(s);
 			return false;
 		}
 
@@ -2693,21 +2685,8 @@ namespace pugi
 	{
 		destroy();
 
-		char* s;
+		char* s = static_cast<char*>(global_allocate(strlen(contents) + 1));
-
+		if (!s) return false;
-	#ifndef PUGIXML_NO_EXCEPTIONS
-		try
-		{
-	#endif
-			s = new char[strlen(contents) + 1];
-			if (!s) return false;
-	#ifndef PUGIXML_NO_EXCEPTIONS
-		}
-		catch (const std::bad_alloc&)
-		{
-			return false;
-		}
-	#endif
 
 		strcpy(s, contents);
 
@@ -2731,29 +2710,20 @@ namespace pugi
 			return false;
 		}
 		
-		char* s;
+		char* s = static_cast<char*>(global_allocate(length + 1));
 
-	#ifndef PUGIXML_NO_EXCEPTIONS
+		if (!s)
-		try
-		{
-	#endif
-			s = new char[length + 1];
-			if (!s) return false;
-	#ifndef PUGIXML_NO_EXCEPTIONS
-		}
-		catch (const std::bad_alloc&)
 		{
 			fclose(file);
 			return false;
 		}
-	#endif
 
 		size_t read = fread(s, (size_t)length, 1, file);
 		fclose(file);
 
 		if (read != 1)
 		{
-			delete[] s;
+			global_deallocate(s);
 			return false;
 		}
 
@@ -2778,7 +2748,7 @@ namespace pugi
 		bool res = parse(xmlstr, options);
 
 		if (res) _buffer = xmlstr;
-		else delete[] xmlstr;
+		else global_deallocate(xmlstr);
 
 		return res;
 	}
@@ -2851,4 +2821,10 @@ namespace pugi
 		return result;
 	}
 #endif
+
+    void set_memory_management_functions(allocation_function allocate, deallocation_function deallocate)
+    {
+    	global_allocate = allocate;
+    	global_deallocate = deallocate;
+    }
 }

src/pugixml.hpp

@@ -1745,6 +1745,38 @@ namespace pugi
 	 */
 	std::wstring as_utf16(const char* str);
 #endif
+
+	/**
+	 * Memory allocation function
+	 *
+	 * \param size - allocation size
+	 * \return pointer to allocated memory on success, NULL on failure
+	 */
+	typedef void* (*allocation_function)(size_t size);
+	
+	/**
+	 * Memory deallocation function
+	 *
+	 * \param ptr - pointer to memory previously allocated by allocation function
+	 */
+    typedef void (*deallocation_function)(void* ptr);
+
+    /**
+     * Override default memory management functions
+     *
+     * All subsequent allocations/deallocations will be performed via supplied functions. Take care not to
+     * change memory management functions if any xml_document instances are still alive - this is considered
+     * undefined behaviour (expect crashes/memory damages/etc.).
+     *
+     * \param allocate - allocation function
+     * \param deallocate - deallocation function
+     * 
+     * \note XPath-related allocations, as well as allocations in functions that return std::string (xml_node::path, as_utf8, as_utf16)
+     * are not performed via these functions.
+     * \note If you're using parse() with ownership transfer, you have to allocate the buffer you pass to parse() with allocation
+     * function you set via this function.
+     */
+    void set_memory_management_functions(allocation_function allocate, deallocation_function deallocate);
 }
 
 // Inline implementation