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From: Lauri L. <pu...@su...> - 2005-02-17 15:19:19
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Hi,
I just noticed this, when I have this kind of code:
---
def copyFile(filename):
bi = open(filename)
bo = open(filename+'.copy', 'w')
b = 1000000
while 1:
l = bi.read(b)
if len(l) == 0:
break
bo.write(l)
bo.close()
bi.close()
return 1
i = raw_input("Give file:")
copyFile(i)
---
and e.g. copy mp3 file with it the .copy mp3 file is somehow mixed and
not working as it should, but when I run this with plain python it works
just as it should. How to fix or workaround this? Is thus known bug?
I have tried to make the same using java's FileInputStream and
FileOutputStream but then the performance is then very bad (about
500kB/s). Is that also known issue?
Sincerely,
Lauri Lehtinen
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From: Kent J. <ke...@td...> - 2005-02-17 15:29:58
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Lauri Lehtinen wrote:
> Hi,
>
> I just noticed this, when I have this kind of code:
> ---
> def copyFile(filename):
> bi = open(filename)
> bo = open(filename+'.copy', 'w')
> b = 1000000
> while 1:
> l = bi.read(b)
> if len(l) == 0:
> break
> bo.write(l)
> bo.close()
> bi.close()
> return 1
> i = raw_input("Give file:")
> copyFile(i)
> ---
> and e.g. copy mp3 file with it the .copy mp3 file is somehow mixed and
> not working as it should, but when I run this with plain python it works
> just as it should. How to fix or workaround this? Is thus known bug?
Maybe you need to use binary mode?
bi = open(filename, 'b')
bo = open(filename+'.copy', 'wb')
How do the two files differ?
Kent
>
> I have tried to make the same using java's FileInputStream and
> FileOutputStream but then the performance is then very bad (about
> 500kB/s). Is that also known issue?
>
> Sincerely,
> Lauri Lehtinen
>
>
>
> -------------------------------------------------------
> SF email is sponsored by - The IT Product Guide
> Read honest & candid reviews on hundreds of IT Products from real users.
> Discover which products truly live up to the hype. Start reading now.
> http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click
> _______________________________________________
> Jython-users mailing list
> Jyt...@li...
> https://lists.sourceforge.net/lists/listinfo/jython-users
>
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|
From: Lauri L. <pu...@su...> - 2005-02-17 16:01:58
|
Setting to use the binary mode worked! Does any one know why java variant of this in jython performs very poorly? Here the basic java variant: --- from java.net import * from java.io import * def copy(filename): bi = FileInputStream(File(filename)) bo = FileOutputStream(File(filename+".copy")) b = [1000000] while 1: l = bi.read(b) if l == -1: break bo.write(b) bo.close() bi.close() return 1 if __name__ == "__main__": i = raw_input("Give file:") copy(i) --- That berforms only about 10kB/s, here one that uses buffers and performs better: --- from java.net import * from java.io import * def copy(filename): bi = BufferedInputStream(FileInputStream(File(filename))) bo = BufferedOutputStream(FileOutputStream(File(filename+".copy"))) while 1: l = bi.read() if l == -1: break bo.write(l) bo.close() bi.close() return 1 if __name__ == "__main__": i = raw_input("Give file:") copy(i) --- This performs about 600kB/s what isn't good at all, that should be much better. I tried also by using static buffer size but that performed even poorly for some reason. Why the performance is so bad? Sincerely, Lauri Lehtinen Kent Johnson wrote: > Lauri Lehtinen wrote: > >> Hi, >> >> I just noticed this, when I have this kind of code: >> --- >> def copyFile(filename): >> bi = open(filename) >> bo = open(filename+'.copy', 'w') >> b = 1000000 >> while 1: >> l = bi.read(b) >> if len(l) == 0: >> break >> bo.write(l) >> bo.close() >> bi.close() >> return 1 >> i = raw_input("Give file:") >> copyFile(i) >> --- >> and e.g. copy mp3 file with it the .copy mp3 file is somehow mixed >> and not working as it should, but when I run this with plain python >> it works just as it should. How to fix or workaround this? Is thus >> known bug? > > > Maybe you need to use binary mode? > bi = open(filename, 'b') > bo = open(filename+'.copy', 'wb') > > How do the two files differ? > > Kent > >> >> I have tried to make the same using java's FileInputStream and >> FileOutputStream but then the performance is then very bad (about >> 500kB/s). Is that also known issue? >> >> Sincerely, >> Lauri Lehtinen >> >> >> >> ------------------------------------------------------- >> SF email is sponsored by - The IT Product Guide >> Read honest & candid reviews on hundreds of IT Products from real users. >> Discover which products truly live up to the hype. Start reading now. >> http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click >> _______________________________________________ >> Jython-users mailing list >> Jyt...@li... >> https://lists.sourceforge.net/lists/listinfo/jython-users >> > > > > > ------------------------------------------------------- > SF email is sponsored by - The IT Product Guide > Read honest & candid reviews on hundreds of IT Products from real users. > Discover which products truly live up to the hype. Start reading now. > http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click > _______________________________________________ > Jython-users mailing list > Jyt...@li... > https://lists.sourceforge.net/lists/listinfo/jython-users > > > |
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From: Jeff E. <jem...@fr...> - 2005-02-17 16:21:01
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Because it does a physical I/O operation for every byte. You need to wrap the file streams with buffered streams, for example: bi = BufferedInputStream(FileInputStream(File(filename))) Lauri Lehtinen wrote: > Setting to use the binary mode worked! > > Does any one know why java variant of this in jython performs very poorly? > > Here the basic java variant: > --- > from java.net import * > from java.io import * > def copy(filename): > bi = FileInputStream(File(filename)) > bo = FileOutputStream(File(filename+".copy")) > b = [1000000] > while 1: > l = bi.read(b) > if l == -1: > break > bo.write(b) bo.close() > bi.close() > return 1 > if __name__ == "__main__": i = raw_input("Give file:") > copy(i) > --- > That berforms only about 10kB/s, here one that uses buffers and performs > better: > --- > from java.net import * > from java.io import * > def copy(filename): > bi = BufferedInputStream(FileInputStream(File(filename))) > bo = BufferedOutputStream(FileOutputStream(File(filename+".copy"))) > while 1: > l = bi.read() > if l == -1: > break > bo.write(l) bo.close() > bi.close() > return 1 > if __name__ == "__main__": i = raw_input("Give file:") > copy(i) > --- > This performs about 600kB/s what isn't good at all, that should be much > better. I tried also by using static buffer size but that performed even > poorly for some reason. Why the performance is so bad? > > Sincerely, > Lauri Lehtinen > > Kent Johnson wrote: > >> Lauri Lehtinen wrote: >> >>> Hi, >>> >>> I just noticed this, when I have this kind of code: >>> --- >>> def copyFile(filename): >>> bi = open(filename) >>> bo = open(filename+'.copy', 'w') >>> b = 1000000 >>> while 1: >>> l = bi.read(b) >>> if len(l) == 0: >>> break >>> bo.write(l) >>> bo.close() >>> bi.close() >>> return 1 >>> i = raw_input("Give file:") >>> copyFile(i) >>> --- >>> and e.g. copy mp3 file with it the .copy mp3 file is somehow mixed >>> and not working as it should, but when I run this with plain python >>> it works just as it should. How to fix or workaround this? Is thus >>> known bug? >> >> >> >> Maybe you need to use binary mode? >> bi = open(filename, 'b') >> bo = open(filename+'.copy', 'wb') >> >> How do the two files differ? >> >> Kent >> >>> >>> I have tried to make the same using java's FileInputStream and >>> FileOutputStream but then the performance is then very bad (about >>> 500kB/s). Is that also known issue? >>> >>> Sincerely, >>> Lauri Lehtinen >>> >>> >>> >>> ------------------------------------------------------- >>> SF email is sponsored by - The IT Product Guide >>> Read honest & candid reviews on hundreds of IT Products from real users. >>> Discover which products truly live up to the hype. Start reading now. >>> http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click >>> _______________________________________________ >>> Jython-users mailing list >>> Jyt...@li... >>> https://lists.sourceforge.net/lists/listinfo/jython-users >>> >> >> >> >> >> ------------------------------------------------------- >> SF email is sponsored by - The IT Product Guide >> Read honest & candid reviews on hundreds of IT Products from real users. >> Discover which products truly live up to the hype. Start reading now. >> http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click >> _______________________________________________ >> Jython-users mailing list >> Jyt...@li... >> https://lists.sourceforge.net/lists/listinfo/jython-users >> >> >> > > > > ------------------------------------------------------- > SF email is sponsored by - The IT Product Guide > Read honest & candid reviews on hundreds of IT Products from real users. > Discover which products truly live up to the hype. Start reading now. > http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click > _______________________________________________ > Jython-users mailing list > Jyt...@li... > https://lists.sourceforge.net/lists/listinfo/jython-users |
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From: Jeff E. <jem...@fr...> - 2005-02-17 16:27:31
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Sorry, I answered before reading your entire post. You already have a buffered stream in the example below. Perhaps you can read a longer array of bytes per iteration of your loop instead of a single byte. ba = jarray.array(64*1024,'b') bi.read(ba) Jeff Emanuel wrote: > Because it does a physical I/O operation for every byte. > You need to wrap the file streams with buffered streams, > for example: > > bi = BufferedInputStream(FileInputStream(File(filename))) > > > Lauri Lehtinen wrote: > >> Setting to use the binary mode worked! >> >> Does any one know why java variant of this in jython performs very >> poorly? >> >> Here the basic java variant: >> --- >> from java.net import * >> from java.io import * >> def copy(filename): >> bi = FileInputStream(File(filename)) >> bo = FileOutputStream(File(filename+".copy")) >> b = [1000000] >> while 1: >> l = bi.read(b) >> if l == -1: >> break >> bo.write(b) bo.close() >> bi.close() >> return 1 >> if __name__ == "__main__": i = raw_input("Give file:") >> copy(i) >> --- >> That berforms only about 10kB/s, here one that uses buffers and >> performs better: >> --- >> from java.net import * >> from java.io import * >> def copy(filename): >> bi = BufferedInputStream(FileInputStream(File(filename))) >> bo = BufferedOutputStream(FileOutputStream(File(filename+".copy"))) >> while 1: >> l = bi.read() >> if l == -1: >> break >> bo.write(l) bo.close() >> bi.close() >> return 1 >> if __name__ == "__main__": i = raw_input("Give file:") >> copy(i) >> --- >> This performs about 600kB/s what isn't good at all, that should be >> much better. I tried also by using static buffer size but that >> performed even poorly for some reason. Why the performance is so bad? >> >> Sincerely, >> Lauri Lehtinen >> >> Kent Johnson wrote: >> >>> Lauri Lehtinen wrote: >>> >>>> Hi, >>>> >>>> I just noticed this, when I have this kind of code: >>>> --- >>>> def copyFile(filename): >>>> bi = open(filename) >>>> bo = open(filename+'.copy', 'w') >>>> b = 1000000 >>>> while 1: >>>> l = bi.read(b) >>>> if len(l) == 0: >>>> break >>>> bo.write(l) >>>> bo.close() >>>> bi.close() >>>> return 1 >>>> i = raw_input("Give file:") >>>> copyFile(i) >>>> --- >>>> and e.g. copy mp3 file with it the .copy mp3 file is somehow mixed >>>> and not working as it should, but when I run this with plain python >>>> it works just as it should. How to fix or workaround this? Is thus >>>> known bug? >>> >>> >>> >>> >>> Maybe you need to use binary mode? >>> bi = open(filename, 'b') >>> bo = open(filename+'.copy', 'wb') >>> >>> How do the two files differ? >>> >>> Kent >>> >>>> >>>> I have tried to make the same using java's FileInputStream and >>>> FileOutputStream but then the performance is then very bad (about >>>> 500kB/s). Is that also known issue? >>>> >>>> Sincerely, >>>> Lauri Lehtinen >>>> >>>> >>>> >>>> ------------------------------------------------------- >>>> SF email is sponsored by - The IT Product Guide >>>> Read honest & candid reviews on hundreds of IT Products from real >>>> users. >>>> Discover which products truly live up to the hype. Start reading now. >>>> http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click >>>> _______________________________________________ >>>> Jython-users mailing list >>>> Jyt...@li... >>>> https://lists.sourceforge.net/lists/listinfo/jython-users >>>> >>> >>> >>> >>> >>> ------------------------------------------------------- >>> SF email is sponsored by - The IT Product Guide >>> Read honest & candid reviews on hundreds of IT Products from real users. >>> Discover which products truly live up to the hype. Start reading now. >>> http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click >>> _______________________________________________ >>> Jython-users mailing list >>> Jyt...@li... >>> https://lists.sourceforge.net/lists/listinfo/jython-users >>> >>> >>> >> >> >> >> ------------------------------------------------------- >> SF email is sponsored by - The IT Product Guide >> Read honest & candid reviews on hundreds of IT Products from real users. >> Discover which products truly live up to the hype. Start reading now. >> http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click >> _______________________________________________ >> Jython-users mailing list >> Jyt...@li... >> https://lists.sourceforge.net/lists/listinfo/jython-users > > > > ------------------------------------------------------- > SF email is sponsored by - The IT Product Guide > Read honest & candid reviews on hundreds of IT Products from real users. > Discover which products truly live up to the hype. Start reading now. > http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click > _______________________________________________ > Jython-users mailing list > Jyt...@li... > https://lists.sourceforge.net/lists/listinfo/jython-users |
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From: Lauri L. <pu...@su...> - 2005-02-17 16:25:52
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Isn't that below my first example, where I do use BufferedInputStream? Or did you mean something else? Jeff Emanuel wrote: > Because it does a physical I/O operation for every byte. > You need to wrap the file streams with buffered streams, > for example: > > bi = BufferedInputStream(FileInputStream(File(filename))) > > > Lauri Lehtinen wrote: > >> Setting to use the binary mode worked! >> >> Does any one know why java variant of this in jython performs very >> poorly? >> >> Here the basic java variant: >> --- >> from java.net import * >> from java.io import * >> def copy(filename): >> bi = FileInputStream(File(filename)) >> bo = FileOutputStream(File(filename+".copy")) >> b = [1000000] >> while 1: >> l = bi.read(b) >> if l == -1: >> break >> bo.write(b) bo.close() >> bi.close() >> return 1 >> if __name__ == "__main__": i = raw_input("Give >> file:") >> copy(i) >> --- >> That berforms only about 10kB/s, here one that uses buffers and >> performs better: >> --- >> from java.net import * >> from java.io import * >> def copy(filename): >> bi = BufferedInputStream(FileInputStream(File(filename))) >> bo = BufferedOutputStream(FileOutputStream(File(filename+".copy"))) >> while 1: >> l = bi.read() >> if l == -1: >> break >> bo.write(l) bo.close() >> bi.close() >> return 1 >> if __name__ == "__main__": i = raw_input("Give >> file:") >> copy(i) >> --- >> This performs about 600kB/s what isn't good at all, that should be >> much better. I tried also by using static buffer size but that >> performed even poorly for some reason. Why the performance is so bad? >> >> Sincerely, >> Lauri Lehtinen >> >> Kent Johnson wrote: >> >>> Lauri Lehtinen wrote: >>> >>>> Hi, >>>> >>>> I just noticed this, when I have this kind of code: >>>> --- >>>> def copyFile(filename): >>>> bi = open(filename) >>>> bo = open(filename+'.copy', 'w') >>>> b = 1000000 >>>> while 1: >>>> l = bi.read(b) >>>> if len(l) == 0: >>>> break >>>> bo.write(l) >>>> bo.close() >>>> bi.close() >>>> return 1 >>>> i = raw_input("Give file:") >>>> copyFile(i) >>>> --- >>>> and e.g. copy mp3 file with it the .copy mp3 file is somehow mixed >>>> and not working as it should, but when I run this with plain python >>>> it works just as it should. How to fix or workaround this? Is thus >>>> known bug? >>> >>> >>> >>> >>> Maybe you need to use binary mode? >>> bi = open(filename, 'b') >>> bo = open(filename+'.copy', 'wb') >>> >>> How do the two files differ? >>> >>> Kent >>> >>>> >>>> I have tried to make the same using java's FileInputStream and >>>> FileOutputStream but then the performance is then very bad (about >>>> 500kB/s). Is that also known issue? >>>> >>>> Sincerely, >>>> Lauri Lehtinen >>>> >>>> >>>> >>>> ------------------------------------------------------- >>>> SF email is sponsored by - The IT Product Guide >>>> Read honest & candid reviews on hundreds of IT Products from real >>>> users. >>>> Discover which products truly live up to the hype. Start reading now. >>>> http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click >>>> _______________________________________________ >>>> Jython-users mailing list >>>> Jyt...@li... >>>> https://lists.sourceforge.net/lists/listinfo/jython-users >>>> >>> >>> >>> >>> >>> ------------------------------------------------------- >>> SF email is sponsored by - The IT Product Guide >>> Read honest & candid reviews on hundreds of IT Products from real >>> users. >>> Discover which products truly live up to the hype. Start reading now. >>> http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click >>> _______________________________________________ >>> Jython-users mailing list >>> Jyt...@li... >>> https://lists.sourceforge.net/lists/listinfo/jython-users >>> >>> >>> >> >> >> >> ------------------------------------------------------- >> SF email is sponsored by - The IT Product Guide >> Read honest & candid reviews on hundreds of IT Products from real users. >> Discover which products truly live up to the hype. Start reading now. >> http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click >> _______________________________________________ >> Jython-users mailing list >> Jyt...@li... >> https://lists.sourceforge.net/lists/listinfo/jython-users > > > > ------------------------------------------------------- > SF email is sponsored by - The IT Product Guide > Read honest & candid reviews on hundreds of IT Products from real users. > Discover which products truly live up to the hype. Start reading now. > http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click > _______________________________________________ > Jython-users mailing list > Jyt...@li... > https://lists.sourceforge.net/lists/listinfo/jython-users > > > > |
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From: Kent J. <ke...@td...> - 2005-02-17 16:33:36
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Lauri Lehtinen wrote: > Setting to use the binary mode worked! > > Does any one know why java variant of this in jython performs very poorly? The first one is using unbuffered file I/O. The second one is copying one byte at a time. You need to combine the two - use Buffered[Input|Output]Stream *and* use a large copy buffer. Kent > > Here the basic java variant: > --- > from java.net import * > from java.io import * > def copy(filename): > bi = FileInputStream(File(filename)) > bo = FileOutputStream(File(filename+".copy")) > b = [1000000] > while 1: > l = bi.read(b) > if l == -1: > break > bo.write(b) bo.close() > bi.close() > return 1 > if __name__ == "__main__": i = raw_input("Give file:") > copy(i) > --- > That berforms only about 10kB/s, here one that uses buffers and performs > better: > --- > from java.net import * > from java.io import * > def copy(filename): > bi = BufferedInputStream(FileInputStream(File(filename))) > bo = BufferedOutputStream(FileOutputStream(File(filename+".copy"))) > while 1: > l = bi.read() > if l == -1: > break > bo.write(l) bo.close() > bi.close() > return 1 > if __name__ == "__main__": i = raw_input("Give file:") > copy(i) > --- > This performs about 600kB/s what isn't good at all, that should be much > better. I tried also by using static buffer size but that performed even > poorly for some reason. Why the performance is so bad? > > Sincerely, > Lauri Lehtinen > |
