[OSM-dev] Perl/GD problems

[Brent Easton]

Yep,

That seems to have got it going - it's not stopping now.

It doesn't quite to a restart of processing since the level 12 tiles are deleted after being combined into a level 11 tile, so most of them don't exist anymore. I can see a few things we can do:

 1. Try (say) 10 times to mirror the tile, then give up, rather than infinite loop (as per your suggestion).
 2. Check if the supertile exists and not recreate it if it does. This will give proper restart capability
 3. Add an optional 'clean' parameter to force a cleanup of temp. If 'clean' not specified, but files exist in temp, then ask user if they want to do a cleanup.

I might have a play with these options.

Thanks again,
Brent.

*********** REPLY SEPARATOR  ***********

On 3/08/2007 at 10:00 AM D Tucny  wrote:

>This is an email I sent to the tiles at home list at some point about
>failed
>downloads, hope it helps...
>
>Hi Folks,
>
>I was playing with lowzoom yesterday... Each time I ran it, somewhere along
>the way a tile would fail to download, at this point it died with an
>ImageMagick error about object not being of correct type or similar when
>trying to join the tiles up... So, I reran it, only to find it get to a
>different point and fail again... So... I modded lowzoom.pl to improve this
>in two ways... firstly, if a tile already exists in the tmp folder, don't
>try to download it again (the tmp folder is cleared down at the end of a
>good run), secondly if a tile fails to get downloaded for some reason, like
>bad connectivity here, try again... The result is a very simple change, too
>simple probably, it could loop horribly etc... but, I'll share it here for
>anyone else who experiences the same problem...
>
>-
>-  mirror($f1,$f2);
>+
>+  while (!-f $f2)
>+  {
>+    mirror($f1,$f2);
>+  }
>
>Hope this helps, maybe someone can think of a safer/nicer way of doing
>this,
>maybe adding a limit to the loop etc, then maybe it could go into svn...
>
>d
>
>On 03/08/07, Brent Easton <b.easton at exemail.com.au> wrote:
>>
>> Thanks,
>>
>> ppm install http://theoryx5.uwinnipeg.ca/ppmpackages/GD.ppd
>>
>> got GD installed on 5.6.1. I stumbled on this just a moment ago.
>>
>> Getting another problem now. The process starts running and downloading
>> tiles until it get's to a certain tile when I get:
>>
>> Can't use an undefined value as a symbol reference at
>> C:/Perl/site/lib/GD/Image.
>> pm line 175.
>>
>> This is a call to newFromPNG to create a particular image from a
>> downloaded tile. Am debugging now. Looks like one of the level 12 tiles
>is
>> failing to download?
>
>
>I've had that one lots, I blamed poor connectivity here and a dodgy
>script...
>
>No virus found in this incoming message.
>Checked by AVG Free Edition. 
>Version: 7.5.476 / Virus Database: 269.11.2/933 - Release Date: 2/08/2007 2:22 PM


____________________________________________________________
Brent Easton                       
Analyst/Programmer                               
University of Western Sydney                                   
Email: b.easton at uws.edu.au