Re: [Boost-users] How to improve property_tree performance

On Wed, Oct 13, 2010 at 2:47 AM, Bo Jensen wrote:

On Wed, Oct 13, 2010 at 8:33 AM, Sebastian Redl wrote:

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On 13.10.2010 10:15, Bo Jensen wrote:

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I tried that, it was only slightly faster. I also tried to do a bunch of independent trees and then merge them later, but still same speed. Is it correct, that you can not choose the underlying storage method or preallocate some space ? In my case I know exactly the sizes of each tree and number of items.

No, because of the way PTree is structured at the high level (nesting trees where each branch can be treated as an independent tree), providing generic allocator support is impractical. Internally, a tree node consists of its local value and a node-based container of children, so preallocation through an interface would only be able to provide storage for that particular node, and would also require a special allocator. However, if you want to try the performance effect of using a stateless Boost Pool allocator, I believe all you have to do is add it to the base_container typedef in boost/property_tree/detail/ptree_implementation.hpp, near the top. See that big multi_index_container? That's the storage for child nodes. If you give it an alternative (stateless!) allocator, it will be used.

Sebastian _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

Thanks for the input, I will try it out. Otherwise I might use the serialization with xml, since my usage is so simple.

You could just try using Spirit/Karma for that, there is about nothing faster then those for input/output streaming. You will have to define your own format (xml is *easy* to emulate it in, see its examples, already done), but it would certainly be faster then any other method if you have a real need for speed.