diff options
Diffstat (limited to 'lru.py')
| -rw-r--r-- | lru.py | 44 |
1 files changed, 24 insertions, 20 deletions
@@ -67,12 +67,8 @@ class lrucache(object): def __len__(self): return len(self.table) + # Does not call callback to write any changes! def clear(self): - if self.callback: - for key in self.table: - node = self.table[key] - self.callback(node.key, node.obj) - self.table.clear() node = self.head @@ -80,11 +76,16 @@ class lrucache(object): node.key = None node.obj = None node = node.next + def __contains__(self, key): return key in self.table # XXX Should this move the object to front of list? XXX + def peek(self, key): + # Look up the node + node = self.table[key] + return node.obj def __getitem__(self, key): @@ -258,30 +259,32 @@ class lrucache(object): -# Wrapper using write-through semantics class lruwrap(object): def __init__(self, store, size, writethrough=True): + self.store = store self.writethrough = writethrough if self.writethrough: self.cache = lrucache(size) else: - self.cache = lrucache(size, self.ejectCallBack) self.dirty = set() - - self.store = store - - + def callback(key, value): + if key in self.dirty: + self.store[key] = value + self.dirty.remove(key) + self.cache = lrucache(size, callback) def __len__(self): - # XXX We could cache the size return len(self.store) + def size(self, size=None): + self.cache.size(size) + def clear(self): self.cache.clear() - if self.writethrough: # XXX Remove this test XXX - assert len(self.dirty) == 0 self.store.clear() + if not self.writethrough: + self.dirty.clear() def __contains__(self, key): # XXX Should this bring the key/value into the cache? @@ -317,15 +320,16 @@ class lruwrap(object): pass del self.store[key] - def ejectCallback(self, key, value): - if key in self.dirty: - self.store[key] = value - self.dirty.remove(key) + + def sync(self): + if not self.writethrough: + for key in self.dirty: + value = self.cache.peek(key) # Doesn't change the cache's order + self.store[key] = value + self.dirty.clear() def __del__(self): - # Flush the dirty objects self.sync() - class lrudecorator(object): |