Custom memory management functions implemented

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

2 files changed, 75 insertions, 67 deletions

diff --git a/src/pugixml.cpp b/src/pugixml.cpp
index 99a13c2..ad57086 100644
--- a/src/pugixml.cpp
+++ b/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;

-

-		#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

+			char* buf = static_cast<char*>(global_allocate(source_size + 1));

+			if (!buf) return false;

 

 			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;

-

-	#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

+		char* s = static_cast<char*>(global_allocate(length + 1));

+		if (!s) return false;

 

 		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;

-

-	#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

+		char* s = static_cast<char*>(global_allocate(strlen(contents) + 1));

+		if (!s) return false;

 

 		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

-		try

-		{

-	#endif

-			s = new char[length + 1];

-			if (!s) return false;

-	#ifndef PUGIXML_NO_EXCEPTIONS

-		}

-		catch (const std::bad_alloc&)

+		if (!s)

 		{

 			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;

+    }

 }

diff --git a/src/pugixml.hpp b/src/pugixml.hpp
index b1096fe..fd25077 100644
--- a/src/pugixml.hpp
+++ b/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