deepCopy

[Jacob Carlborg]

On 2010-10-19 00:01, Denis Koroskin wrote:
> Okay, we've finished what we started with Aleksey today, so I decided to
> share it with you. This is a rough cut, it lacks comments, but it is
> already usable.
>
> deepCopy is a function that makes a deep copy of your object, and
> everything it points to. As simple as that.
>
> Essentially it is a binary serializer except that it doesn't store
> pointers as offsets (although it is capable of doing that, too - change
> a single line - so serialize and deepCopy share 99% of the code).
>
> deepCopy and serialize are similar in design yet different in usage:
> serialized data are usually transmitted to other application, and one
> must worry about different endianness, pointer size etc. On the contrary
> deepCopy is to be used within the same address space and is free from
> such issues.
>
> deepCopy is useful for making sure there are no aliases to your data
> left. This can be used to create a safe immutable copy of your objects,
> or to avoid with memory leaks.
>
> We've written deepCopy to solve memory leaks in ddmd the following way:
> a) hook all the memory allocations
> b) run code, produce result
> c) make a deep copy of the result
> d) release all the allocated memory
>
> Since you are deallocating all the memory at once, you can use faster
> allocation methods e.g preallocate a memory and simply advance a
> pointer, or use dsimcha's tempAlloc
> (http://dsource.org/projects/scrapple/browser/trunk/tempAlloc). BTW, I
> remember a discussion about integrating it into druntime, did it go
> anywhere since then?.
>
> deepCopy stores all the data sequentially, so it should reduce memory
> fragmentation and should be more cache-friendly. As a downside, the
> whole block will only be release once last reference to it expires.
>
> If your struct has pointers you can manually specify if that pointer is
> a pointer to one element (default), many or none (excluding it from
> being copied). Exclusion works with references, too:
>
> class Foo : ISerializeable
> {
> mixin Serializeable;
>
> // optional, only needed for precise serialization control
> void describe(SerializeInfo* info)
> {
> info.setLength(buffer, length);
> info.exclude(cachedValue);
> }
>
> ubyte* buffer;
> size_t length;
> Object cachedValue;
> }
>
> I hope someone will find it useful, the code with tests is located here:
> http://bitbucket.org/korDen/serialize/src/tip/
>
> Suggestions are welcome!

What types does this support, all types? Does it support array slices?

-- 
/Jacob Carlborg