just a minor refactoring

This commit is contained in:
Miroslav Stampar 2012-06-14 09:10:28 +00:00
parent a51d8c4c79
commit 19c0efec59

View File

@ -13,9 +13,19 @@ import tempfile
from lib.core.settings import BIGARRAY_CHUNK_LENGTH
class Cache:
"""
Auxiliary class used for storing cached chunks
"""
def __init__(self, index, data, dirty):
self.index = index
self.data = data
self.dirty = dirty
class BigArray(list):
"""
List-like object used for storing large amounts of data (disk cached)
List-like class used for storing large amounts of data (disk cached)
"""
def __init__(self):
@ -35,7 +45,7 @@ class BigArray(list):
def pop(self):
if len(self.chunks[-1]) < 1:
self.chunks.pop()
with open(self.chunks[-1], 'rb') as fp:
with open(self.chunks[-1], "rb") as fp:
self.chunks[-1] = pickle.load(fp)
return self.chunks[-1].pop()
@ -49,16 +59,16 @@ class BigArray(list):
handle, filename = tempfile.mkstemp()
self.filenames.add(filename)
os.close(handle)
with open(filename, 'w+b') as fp:
with open(filename, "w+b") as fp:
pickle.dump(value, fp)
return filename
def _checkcache(self, index):
if (self.cache and self.cache[0] != index and self.cache[2]):
filename = self._dump(self.cache[1])
self.chunks[self.cache[0]] = filename
if not (self.cache and self.cache[0] == index):
with open(self.chunks[index], 'rb') as fp:
if (self.cache and self.cache.index != index and self.cache.dirty):
filename = self._dump(self.cache.data)
self.chunks[self.cache.index] = filename
if not (self.cache and self.cache.index == index):
with open(self.chunks[index], "rb") as fp:
self.cache = (index, pickle.load(fp), False)
def __getitem__(self, y):
@ -69,7 +79,7 @@ class BigArray(list):
return chunk[offset]
else:
self._checkcache(index)
return self.cache[1][offset]
return self.cache.data[offset]
def __setitem__(self, y, value):
index = y / BIGARRAY_CHUNK_LENGTH
@ -79,8 +89,8 @@ class BigArray(list):
chunk[offset] = value
else:
self._checkcache(index)
self.cache[1][offset] = value
self.cache[2] = True # dirty flag
self.cache.data[offset] = value
self.cache.dirty = True
def __repr__(self):
return "%s%s" % ("..." if len(self.chunks) > 1 else "", self.chunks[-1].__repr__())