from win32com.server.util import wrap
import pythoncom, sys, os, time, win32api, win32event, tempfile
from win32com.bits import bits
TIMEOUT = 200 # ms
StopEvent = win32event.CreateEvent(None, 0, 0, None)
job_name = 'bits-pywin32-test'
states = dict([(val, (name[13:]))
for name, val in vars(bits).iteritems()
if name.startswith('BG_JOB_STATE_')])
bcm = pythoncom.CoCreateInstance(bits.CLSID_BackgroundCopyManager,
None,
pythoncom.CLSCTX_LOCAL_SERVER,
bits.IID_IBackgroundCopyManager)
class BackgroundJobCallback:
_com_interfaces_ = [bits.IID_IBackgroundCopyCallback]
_public_methods_ = ["JobTransferred", "JobError", "JobModification"]
def JobTransferred(self, job):
print 'Job Transferred', job
job.Complete()
win32event.SetEvent(StopEvent) # exit msg pump
def JobError(self, job, error):
print 'Job Error', job, error
f = error.GetFile()
print 'While downloading', f.GetRemoteName()
print 'To', f.GetLocalName()
print 'The following error happened:'
self._print_error(error)
if f.GetRemoteName().endswith('missing-favicon.ico'):
print 'Changing to point to correct file'
f2 = f.QueryInterface(bits.IID_IBackgroundCopyFile2)
favicon = 'http://www.python.org/favicon.ico'
print 'Changing RemoteName from', f2.GetRemoteName(), 'to', favicon
f2.SetRemoteName(favicon)
job.Resume()
else:
job.Cancel()
def _print_error(self, err):
ctx, hresult = err.GetError()
try:
hresult_msg = win32api.FormatMessage(hresult)
except win32api.error:
hresult_msg = ""
print "Context=0x%x, hresult=0x%x (%s)" % (ctx, hresult, hresult_msg)
print err.GetErrorDescription()
def JobModification(self, job, reserved):
state = job.GetState()
print 'Job Modification', job.GetDisplayName(), states.get(state)
# Need to catch TRANSIENT_ERROR here, as JobError doesn't get
# called (apparently) when the error is transient.
if state == bits.BG_JOB_STATE_TRANSIENT_ERROR:
print "Error details:"
err = job.GetError()
self._print_error(err)
job = bcm.CreateJob(job_name, bits.BG_JOB_TYPE_DOWNLOAD)
job.SetNotifyInterface(wrap(BackgroundJobCallback()))
job.SetNotifyFlags(bits.BG_NOTIFY_JOB_TRANSFERRED |
bits.BG_NOTIFY_JOB_ERROR |
bits.BG_NOTIFY_JOB_MODIFICATION)
# The idea here is to intentionally make one of the files fail to be
# downloaded. Then the JobError notification will be triggered, where
# we do fix the failing file by calling SetRemoteName to a valid URL
# and call Resume() on the job, making the job finish successfully.
#
# Note to self: A domain that cannot be resolved will cause
# TRANSIENT_ERROR instead of ERROR, and the JobError notification will
# not be triggered! This can bite you during testing depending on how
# your DNS is configured. For example, if you use OpenDNS.org's DNS
# servers, an invalid hostname will *always* be resolved (they
# redirect you to a search page), so be careful when testing.
job.AddFile('http://www.python.org/favicon.ico', os.path.join(tempfile.gettempdir(), 'bits-favicon.ico'))
job.AddFile('http://www.python.org/missing-favicon.ico', os.path.join(tempfile.gettempdir(), 'bits-missing-favicon.ico'))
for f in job.EnumFiles():
print 'Downloading', f.GetRemoteName()
print 'To', f.GetLocalName()
job.Resume()
while True:
rc = win32event.MsgWaitForMultipleObjects(
(StopEvent,),
0,
TIMEOUT,
win32event.QS_ALLEVENTS)
if rc == win32event.WAIT_OBJECT_0:
break
elif rc == win32event.WAIT_OBJECT_0+1:
if pythoncom.PumpWaitingMessages():
break # wm_quit
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