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class ContentCache(object):
def __init__(self):
self._entries = {}
self._accessor_ticks = {}
def advance_accessor(self, accessor):
if accessor not in self._accessor_ticks:
self._accessor_ticks[accessor] = 0
ta = self._accessor_ticks[accessor]
delete = []
for path_segment, entry in self._entries.items():
t = entry[2].get(accessor, ta)
if t < ta:
del entry[2][accessor]
if not entry[2]:
delete.append(path_segment)
for path_segment in delete:
del self._entries[path_segment]
self._accessor_ticks[accessor] += 1
def clear_accessor(self, accessor):
delete = []
for path_segment, entry in self._entries.items():
del entry[2][accessor]
if not entry[2]:
delete.append(path_segment)
for path_segment in delete:
del self._entries[path_segment]
del self._accessor_ticks[accessor]
def clear(self):
self._entries = {}
self._accessor_ticks = {}
def has(self, nut):
path, segment, element, nut_mtime = nut.key
try:
cache_mtime = self._entries[path, segment][0]
except KeyError:
return False
return cache_mtime == nut_mtime
def get(self, nut, accessor='default'):
path, segment, element, mtime = nut.key
entry = self._entries[path, segment]
if accessor not in self._accessor_ticks:
self._accessor_ticks[accessor] = 0
entry[2][accessor] = self._accessor_ticks[accessor]
return entry[1][element]
def _prune_outdated(self, path, segment, nut_mtime):
try:
cache_mtime = self._entries[path, segment][0]
except KeyError:
return
if cache_mtime != nut_mtime:
del self._entries[path, segment]
def put(self, nut):
path, segment, element, mtime = nut.key
self._prune_outdated(path, segment, nut.file_mtime)
if (path, segment) not in self._entries:
self._entries[path, segment] = nut.file_mtime, {}, {}
self._entries[path, segment][1][element] = nut.content
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