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- small image queue fix

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- refactoring

bzr-revno: 1677
This commit is contained in:
Andreas Preikschat 2011-07-08 14:41:44 +02:00
commit 5ff8d9d326
1 changed files with 30 additions and 21 deletions
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51
openlp/core/lib/imagemanager.py
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@ -112,17 +112,29 @@ class PriorityQueue(Queue.PriorityQueue):
"""
Customised ``Queue.PriorityQueue``.
"""
def remove(self, item):
def modify_priority(self, image, new_priority):
"""
Removes the given ``item`` from the queue.
Modifies the priority of the given ``image``.
``item``
The item to remove. This should be a tuple::
``image``
The image to remove. This should be an ``Image`` instance.
``(Priority, Image)``
``new_priority``
The image's new priority.
"""
if item in self.queue:
self.queue.remove(item)
self.remove(image)
image.priority = new_priority
self.put((image.priority, image))
def remove(self, image):
"""
Removes the given ``image`` from the queue.
``image``
The image to remove. This should be an ``Image`` instance.
"""
if (image.priority, image) in self.queue:
self.queue.remove((image.priority, image))
class ImageManager(QtCore.QObject):
@ -168,12 +180,16 @@ class ImageManager(QtCore.QObject):
log.debug(u'get_image %s' % name)
image = self._cache[name]
if image.image is None:
self._conversion_queue.remove((image.priority, image))
image.priority = Priority.High
self._conversion_queue.put((image.priority, image))
self._conversion_queue.modify_priority(image, Priority.High)
while image.image is None:
log.debug(u'get_image - waiting')
time.sleep(0.1)
elif image.image_bytes is None:
# Set the priority to Low, because the image was requested but the
# byte stream was not generated yet. However, we only need to do
# this, when the image was generated before it was requested
# (otherwise this is already taken care of).
self._conversion_queue.modify_priority(image, Priority.Low)
return image.image
def get_image_bytes(self, name):
@ -184,9 +200,7 @@ class ImageManager(QtCore.QObject):
log.debug(u'get_image_bytes %s' % name)
image = self._cache[name]
if image.image_bytes is None:
self._conversion_queue.remove((image.priority, image))
image.priority = Priority.Urgent
self._conversion_queue.put((image.priority, image))
self._conversion_queue.modify_priority(image, Priority.Urgent)
while image.image_bytes is None:
log.debug(u'get_image_bytes - waiting')
time.sleep(0.1)
@ -198,8 +212,7 @@ class ImageManager(QtCore.QObject):
"""
log.debug(u'del_image %s' % name)
if name in self._cache:
self._conversion_queue.remove(
(self._cache[name].priority, self._cache[name]))
self._conversion_queue.remove(self._cache[name])
del self._cache[name]
def add_image(self, name, path):
@ -238,18 +251,14 @@ class ImageManager(QtCore.QObject):
# Set the priority to Lowest and stop here as we need to process
# more important images first.
if image.priority == Priority.Normal:
self._conversion_queue.remove((image.priority, image))
image.priority = Priority.Lowest
self._conversion_queue.put((image.priority, image))
self._conversion_queue.modify_priority(image, Priority.Lowest)
return
# For image with high priority we set the priority to Low, as the
# byte stream might be needed earlier the byte stream of image with
# Normal priority. We stop here as we need to process more important
# images first.
elif image.priority == Priority.High:
self._conversion_queue.remove((image.priority, image))
image.priority = Priority.Low
self._conversion_queue.put((image.priority, image))
self._conversion_queue.modify_priority(image, Priority.Low)
return
# Generate the byte stream for the image.
if image.image_bytes is None: