Subject: Re: [geometry] [index] support for serialization and external memory?
From: Adam Wulkiewicz (adam.wulkiewicz_at_[hidden])
Date: 2013-07-13 22:16:57
Hi,
Adam Wulkiewicz wrote:
> Mateusz Loskot wrote:
>> On 11 July 2013 15:58, feverzsj <feverzsj_at_[hidden]> wrote:
>>> hi, list
>>> Is it possible for the index to serialize its internal tree
>>> structure(and
>>> user data), so that the index can be rebuilt without reinsert?
>>
>> There is no such mechanism provided. AFAIK, it's planned in future.
>>
>
> Currently you can't do it without using hidden internals. There are
> plans to expose some mechanisms or provide new ones to allow users
> handling arbitrary serialization routine, along with incremental and
> automatic saving of modified nodes. But I don't know when they'll be
> available.
>
After some thinking I realized that serialization should probably be
separated from external/persistent memory storage functionality. I've
added a preliminary, experimental support for Boost.Serialization. To
use it you must define BOOST_GEOMETRY_INDEX_DETAIL_EXPERIMENTAL, see
libs/geometry/index/example/serialize.cpp. There are some things that
should probably be improved but it is something you can play with. So
the rtree may be saved in/loaded from various archives already
implemented in Boost. The tree is saved and loaded depth-first. Do you
think that it's enough or would you like to have more control over
serialization process? Theoretically you may implement your version of
archive but I didn't played with it enough to say what can be done with it.
Btw, what do you think about supporting serialization of Geometries?
Regards,
Adam