Inefficiency of http_request::extract_vector() method

[davemcincork]

I'm looking at using the C++ REST SDK to implement a relatively simple but performance-critical REST server in our project. I've put together a PoC and it all looks good. But I've just hit upon what I think is a major performance issue.

When using the http_request::extract_vector() method, the Task completion routine is passed the retrieved vector by value. Our server will sometimes be posted a large content body (1MB or more). The pass-by-value means that this vector will be copied. This completely removes one of the major advantage of using C/C++ for this kind of work, i.e. the fact that if you know what you're doing, you can avoid the huge amount of copying that can be a bottleneck on platforms like NodeJS.

Am I missing something obvious here or will I have to implement a custom extract_vector_ptr() method myself?

[grahamreeds]

Without looking at the code it sounds like it is ripe for a compiler
optimisation to use the move constructor and not the copy constructor.

If you measure and do find it is causing problems then feel free to submit
a pull request.

GR

Sent from my Nexus 5.
On 24 Mar 2016 10:00 p.m., "Dave McCormack" notifications@github.com
wrote:

I'm looking at using the C++ REST SDK to implement a relatively simple but
performance-critical REST server in our project. I've put together a PoC
and it all looks good. But I've just hit upon what I think is a major
performance issue.

When using the http_request::retrieve_vector() method, the Task
completion routine is passed the retrieved vector by value. Our server
will sometimes be posted a large content body (1MB or more). The
pass-by-value means that this vector will be copied. This completely
removes one of the major advantage of using C/C++ for this kind of work,
i.e. the fact that if you know what you're doing, you can avoid the huge
amount of copying that can be a bottleneck on platforms like NodeJS.

Am I missing something obvious here or will I have to implement a custom
retrieve_vector_ptr() method myself?

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#103

[davemcincork]

OK. If we decide to proceed beyond my PoC, I'll benchmark the impact of this issue and come up with a '&' or '&&' alternative. Thanks.