Suds is not reusing cached WSDLs and XSDs, although I expect it to

Question

I\'m pretty sure suds is not caching my WSDLs and XSDs like I expect it to. Here\'s how I know that cached objects are not being used:

1. It takes about 30 secon

Answer 1

The problem is in the suds library itself. In cache.py, although ObjectCache.get() is always getting a valid file pointer, it's hitting an exception (EOFError) doing pickle.load(fp). When that happens, the file is just downloaded again.

Here's the sequence of events:

DocumentReader.open():

1. Trying http://172.28.50.249/wsdl/billingServices/v3.0/RequestScrubAddress.wsdl
2. Loading ObjectCache 51012453-document
3. Loading pickled object...
4. Exception raised:
5. Got None from cache
6. Downloading... Done
7. Saving FileCache 51012453-document... Done

So it doesn't really matter that the new cache file was saved, because the same thing happens the next time I run. This happens for ALL of WSDL and XSD files.

I fixed that problem by opening the cache file in binary mode when reading and writing. Specifically, the changes I made were in cache.py:

1) In FileCache.put(), change this line:

f = self.open(fn, 'w')

to

f = self.open(fn, 'wb')

2) In FileCache.getf(), change this line:

return self.open(fn)

to

return self.open(fn, 'rb')

I don't know the codebase well enough to know if these changes are safe, but it is pulling the objects from the file cache, the service is still running successfully, and loading the client went from 16 seconds down to 2.5 seconds. Much better if you ask me.

Hopefully this fix, or something similar can be introduced back into the suds main line. I've already sent this to the suds mailing list (fedora-suds-list at redhat dot com).