[OSM-talk] Why isn't any XAPI server available ?
nroets at gmail.com
Sat Feb 19 11:40:29 GMT 2011
Let me just explain what I see as the major performance bottleneck
with and API implementation: Disk seeks. A typical computer can
perform a million calculations while waiting for the disk to fetch a
few bytes. So a good data structure that can answer most map (bbox)
calls with a single disk seek is what is needed. (Not a debate on the
best programming language). I have ideas how to do that if anyone is
interested. But I willing to wait and see what Ian comes up with.
I'm learning Java right now and I find the array handling quite
peculiar. For storing arrays of dynamic size, I use ArrayList<>. The
only way to index the elements are with the get() method. Compare that
with STL where you can address vectors with the normal  operator.
On Sat, Feb 19, 2011 at 9:46 AM, Anders Arnholm <anders at arnholm.se> wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> 2011-02-18 22:47, David Murn skrev:
>> Is there any language slower or more resource intensive than java?
> Yes, there are many, Java have is strengths and down sides, Java as any
> language have it's strengths and down sides. Speed in Java can be much
> better that C, C++ or even hand optimized Assembler. It can also and
> java's weak sides, for performance, is it's dependence on garbage
> collection. That even is proved mathematically be a more efficient way
> of handling memory allocations tends to do the memory handling at for
> the user bad times.
> And real time performance in almost all applications have very little
> with the language to do, but with the chooses of algorithms and
> data-storage chosen for the application.
>> currently, in the world), then who cares about java, why isnt it written
>> in optimized C or some other similarly lowish level language, rather
>> than java?
> There can be a 1000 reasons, and all valid.
> A good team knowing java but not c.
> C make to much time go into development compared to an object oriented
> C have no good api's to connect to the other services around.
> The bottle neck is not at all in the code for the service but in stuff
> around it.
> When is comes to error's in the code, web, net servers in java are as
> possible to break, using java is not a safe way to make sure the code is
> correct. It still need to be planned and safe for internet usage. The
> typical safety problems thou differ because different things are hard
> ans easy in the two language families.
> Just a few random morning thoughts.
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v1.4.10 (GNU/Linux)
> Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/
> -----END PGP SIGNATURE-----
> This message has been scanned for viruses and
> dangerous content by MailScanner, and is
> believed to be clean.
> talk mailing list
> talk at openstreetmap.org
More information about the talk