Added calc_padding() convenience function for calculating how much padding to add to a buffer in order for it to fall on a specified byte boundary.

git-svn-id: file:///srv/svn/repos/haiku/trunk/current@8889 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/app/MessageUtils.h

@@ -32,6 +32,8 @@ status_t entry_ref_flatten(char* buffer, size_t* size, const entry_ref* ref);
 status_t entry_ref_unflatten(entry_ref* ref, const char* buffer, size_t size);
 status_t entry_ref_swap(char* buffer, size_t size);
 
+size_t calc_padding(size_t size, size_t boundary);
+
 }	// namespace BPrivate
 
 //------------------------------------------------------------------------------

src/kits/app/MessageUtils.cpp

@@ -138,6 +138,16 @@ status_t entry_ref_swap(char* buffer, size_t size)
 	return B_OK;
 }
 //------------------------------------------------------------------------------
+size_t calc_padding(size_t size, size_t boundary)
+{
+	size_t pad = size % boundary;
+	if (pad)
+	{
+		pad = boundary - pad;
+	}
+	return pad;
+}
+//------------------------------------------------------------------------------
 
 }	// namespace BPrivate