> On 04 Nov 2015, at 17:38, Martin Patzak (GMX) <martin.pat...@gmx.de> wrote: > > Stefano, > > thanks for bringing pyownet to my attention. I definitely will try it out. > > > > On 11/04/2015 03:56 PM, Stefano Miccoli wrote: >> Minimal instruction for use are >> >>> from pyownet import protocol >> >>> owproxy = protocol.proxy(host="server.example.com >> >>> <http://server.example.com/>", port=4304) >> >>> owproxy.dir() >> [u'/10.A7F1D92A82C8/', u'/05.D8FE434D9855/', u'/26.8CE2B3471711/'] >> >>> owproxy.read('/10.A7F1D92A82C8/temperature') >> ' 6.68422' > thanks for the quick-kick-start > >> The only thing you should be aware of is that creating an owproxy object is >> quite time consuming, so usually you have a single owproxy instance, shared >> globally. > I have several tasks writing independently to owfs. The tasks stay alive and > so I would have to create an owproxy only once during startup... > Would there be a drawback to that procedure?
There is no drawback, this is the correct way to go, for non-persistent connections (which are the default), see http://pyownet.readthedocs.org/en/latest/protocol.html#persistent-vs-non-persistent-proxy-objects <http://pyownet.readthedocs.org/en/latest/protocol.html#persistent-vs-non-persistent-proxy-objects>. Non persistent owproxy should be thread safe (but I’ve done no extensive testing) so no problem here. Non-persistent means that you bind and tear down a new socket for each owserver operation (read, write, etc.). New socket binding is less than 1ms overhead on my test machine, so usually I do not care. Just a few numbers, collected with https://github.com/miccoli/pyownet/blob/master/test/timing.py <https://github.com/miccoli/pyownet/blob/master/test/timing.py> querying a non localhost production owserver pyownet: ver. 0.8.2 proxy_obj: ownet server at ('10.48.74.112', 4304) server info: pid 2662, ver. unknown timeit: statement: proxy_obj.dir("/") number: 20 repetitions: 5 ** non persistent : 1.29 ms, 1.30 ms, 1.30 ms, 1.33 ms, 1.36 ms, ** persistent : 0.77 ms, 0.77 ms, 0.79 ms, 0.80 ms, 0.97 ms, timeit: statement: proxy_obj.read("/26.xxxxxxxxxxxx/temperature") number: 20 repetitions: 5 ** non persistent : 1.14 ms, 1.16 ms, 1.16 ms, 1.19 ms, 1.40 ms, ** persistent : 0.63 ms, 0.64 ms, 0.66 ms, 0.95 ms, 0.98 ms, The figure reported here are time for a single call to the given method, computed as the average of 20 consecutive calls. (Please note that I read the cached temperature value… uncached is of course much slower, but this is due to 1-wire) Just to put numbers in the correct perspective: $ ping -c 5 10.48.74.112 PING 10.48.74.112 (10.48.74.112): 56 data bytes 64 bytes from 10.48.74.112: icmp_seq=0 ttl=64 time=0.478 ms 64 bytes from 10.48.74.112: icmp_seq=1 ttl=64 time=0.701 ms 64 bytes from 10.48.74.112: icmp_seq=2 ttl=64 time=0.563 ms 64 bytes from 10.48.74.112: icmp_seq=3 ttl=64 time=0.563 ms 64 bytes from 10.48.74.112: icmp_seq=4 ttl=64 time=0.587 ms --- 10.48.74.112 ping statistics --- 5 packets transmitted, 5 packets received, 0.0% packet loss round-trip min/avg/max/stddev = 0.478/0.578/0.701/0.072 ms Stefano > > Thanks for your input, > > Martin > > ------------------------------------------------------------------------------ > _______________________________________________ > Owfs-developers mailing list > Owfs-developers@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/owfs-developers
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