+class LockFile(object):
+ """
+ A file lock monitor class; createas an ${objname}.lock
+ file in directory dir, and locks it exclusively.
+ To be used in 'with' construct.
+ """
+ def __init__(self, dir, objname):
+ self.lockname = path.join(dir, objname + ".lock")
+
+ def __enter__(self):
+ self.lock = open(self.lockname, 'w')
+ flock(self.lock, LOCK_EX)
+
+ def __exit__(self, *err):
+ try:
+ unlink(self.lockname)
+ except OSError as oe:
+ if oe.errno != EEXIST:
+ raise oe
+ self.lock.close()
+
+
+#@task
+def create_zip(paths, zip_slug):
+ """
+ Creates a zip in MEDIA_ROOT/zip directory containing files from path.
+ Resulting archive filename is ${zip_slug}.zip
+ Returns it's path relative to MEDIA_ROOT (no initial slash)
+ """
+ # directory to store zip files
+ zip_path = path.join(settings.MEDIA_ROOT, 'zip')
+
+ try:
+ mkdir(zip_path)
+ except OSError as oe:
+ if oe.errno != EEXIST:
+ raise oe
+ zip_filename = zip_slug + ".zip"
+
+ with LockFile(zip_path, zip_slug):
+ if not path.exists(path.join(zip_path, zip_filename)):
+ zipf = ZipFile(path.join(zip_path, zip_filename), 'w')
+ try:
+ for arcname, p in paths:
+ if arcname is None:
+ arcname = path.basename(p)
+ zipf.write(p, arcname)
+ finally:
+ zipf.close()
+
+ return 'zip/' + zip_filename
+
+
+def remove_zip(zip_slug):
+ """
+ removes the ${zip_slug}.zip file from zip store.
+ """
+ zip_file = path.join(settings.MEDIA_ROOT, 'zip', zip_slug + '.zip')
+ try:
+ unlink(zip_file)
+ except OSError as oe:
+ if oe.errno != ENOENT:
+ raise oe
+
+
+class AttachmentHttpResponse(HttpResponse):
+ """Response serving a file to be downloaded.
+ """
+ def __init__(self, file_path, file_name, mimetype):
+ super(AttachmentHttpResponse, self).__init__(mimetype=mimetype)
+ self['Content-Disposition'] = 'attachment; filename=%s' % file_name
+ self.file_path = file_path
+ self.file_name = file_name
+
+ with open(DefaultStorage().path(self.file_path)) as f:
+ for chunk in read_chunks(f):
+ self.write(chunk)
+
+class MultiQuerySet(object):
+ def __init__(self, *args, **kwargs):
+ self.querysets = args
+ self._count = None
+
+ def count(self):
+ if not self._count:
+ self._count = sum(len(qs) for qs in self.querysets)
+ return self._count
+
+ def __len__(self):
+ return self.count()
+
+ def __getitem__(self, item):
+ try:
+ indices = (offset, stop, step) = item.indices(self.count())
+ except AttributeError:
+ # it's not a slice - make it one
+ return self[item : item + 1][0]
+ items = []
+ total_len = stop - offset
+ for qs in self.querysets:
+ if len(qs) < offset:
+ offset -= len(qs)
+ else:
+ items += list(qs[offset:stop])
+ if len(items) >= total_len:
+ return items
+ else:
+ offset = 0
+ stop = total_len - len(items)
+ continue
+
+class SortedMultiQuerySet(MultiQuerySet):
+ def __init__(self, *args, **kwargs):
+ self.order_by = kwargs.pop('order_by', None)
+ self.sortfn = kwargs.pop('sortfn', None)
+ if self.order_by is not None:
+ self.sortfn = lambda a, b: cmp(getattr(a, self.order_by),
+ getattr(b, self.order_by))
+ super(SortedMultiQuerySet, self).__init__(*args, **kwargs)
+
+ def __getitem__(self, item):
+ sort_heads = [0] * len(self.querysets)
+ try:
+ indices = (offset, stop, step) = item.indices(self.count())
+ except AttributeError:
+ # it's not a slice - make it one
+ return self[item : item + 1][0]
+ items = []
+ total_len = stop - offset
+ skipped = 0
+ i_s = range(len(sort_heads))
+
+ while len(items) < total_len:
+ candidate = None
+ candidate_i = None
+ for i in i_s:
+ def get_next():
+ return self.querysets[i][sort_heads[i]]
+ try:
+ if candidate is None:
+ candidate = get_next()
+ candidate_i = i
+ else:
+ competitor = get_next()
+ if self.sortfn(candidate, competitor) > 0:
+ candidate = competitor
+ candidate_i = i
+ except IndexError:
+ continue # continue next sort_head
+ # we have no more elements:
+ if candidate is None:
+ break
+ sort_heads[candidate_i] += 1
+ if skipped < offset:
+ skipped += 1
+ continue # continue next item
+ items.append(candidate)
fnp / wolnelektury.git / blobdiff