X-Git-Url: http://dolda2000.com/gitweb/?p=didex.git;a=blobdiff_plain;f=didex%2Fstore.py;h=11fe17a031fe665c54997fbc765df6082e582643;hp=15d2eca11beab793506299b83fbe93eabff9adc9;hb=e38ebdef74ec4b11c9ab70677f1c8896ca8ab634;hpb=b080a59cbbe6b293d754bfa97c386eeede6b51ee diff --git a/didex/store.py b/didex/store.py index 15d2eca..11fe17a 100644 --- a/didex/store.py +++ b/didex/store.py @@ -1,22 +1,34 @@ -import threading, pickle +import threading, pickle, inspect, atexit, weakref from . import db, index, cache from .db import txnfun +__all__ = ["environment", "datastore", "autostore"] + class environment(object): - def __init__(self, path): - self.path = path + def __init__(self, *, path=None, getpath=None, recover=False): + if path is not None: + self.path = path + self.getpath = None + else: + self.path = None + self.getpath = getpath + self.recover = recover self.lk = threading.Lock() self.bk = None def __call__(self): with self.lk: if self.bk is None: - self.bk = db.environment(self.path) + if self.path is None: + self.path = self.getpath() + self.bk = db.environment(self.path, recover=self.recover) + atexit.register(self.close) return self.bk def close(self): with self.lk: if self.bk is not None: + atexit.unregister(self.close) self.bk.close() self.bk = None @@ -25,28 +37,54 @@ class storedesc(object): def storedescs(obj): t = type(obj) - ret = getattr(t, "__didex_attr", None) + ret = t.__dict__.get("__didex_attr") if ret is None: ret = [] - for nm, val in t.__dict__.items(): - if isinstance(val, storedesc): - ret.append((nm, val)) + for st in inspect.getmro(t): + for nm, val in st.__dict__.items(): + if isinstance(val, storedesc): + ret.append((nm, val)) t.__didex_attr = ret return ret -class store(object): - def __init__(self, name, *, env=None, path=".", ncache=None): +class icache(object): + def __init__(self): + self.d = weakref.WeakKeyDictionary() + + def __getitem__(self, key): + obj, idx = key + return self.d[obj][idx] + def __setitem__(self, key, val): + obj, idx = key + if obj in self.d: + self.d[obj][idx] = val + else: + self.d[obj] = {idx: val} + def __delitem__(self, key): + obj, idx = key + del self.d[obj][idx] + def get(self, key, default=None): + obj, idx = key + if obj not in self.d: + return default + return self.d[obj].get(idx, default) + +class datastore(object): + def __init__(self, name, *, env=None, path=".", ncache=None, codec=None): self.name = name self.lk = threading.Lock() if env: self.env = env else: - self.env = environment(path) + self.env = environment(path=path) self._db = None if ncache is None: ncache = cache.cache() + if codec is not None: + self._encode, self._decode = codec self.cache = ncache self.cache.load = self._load + self.icache = icache() def db(self): with self.lk: @@ -54,15 +92,24 @@ class store(object): self._db = self.env().db(self.name) return self._db - def _load(self, id): + def _decode(self, data): try: - return pickle.loads(self.db().get(id)) + return pickle.loads(data) except: raise KeyError(id, "could not unpickle data") def _encode(self, obj): return pickle.dumps(obj) + @txnfun(lambda self: self.db().env.env) + def _load(self, id, *, tx): + loaded = self._decode(self.db().get(id, tx=tx)) + if hasattr(loaded, "__didex_loaded__"): + loaded.__didex_loaded__(self, id) + for nm, attr in storedescs(loaded): + attr.loaded(id, loaded, tx) + return loaded + def get(self, id, *, load=True): return self.cache.get(id, load=load) @@ -75,16 +122,42 @@ class store(object): return id @txnfun(lambda self: self.db().env.env) - def unregister(self, id, *, tx): + def unregister(self, id, *, vfy=None, tx): obj = self.get(id) + if vfy is not None and obj is not vfy: + raise RuntimeError("object identity crisis: " + str(vfy) + " is not cached object " + obj) for nm, attr in storedescs(obj): attr.unregister(id, obj, tx) self.db().remove(id, tx=tx) self.cache.remove(id) @txnfun(lambda self: self.db().env.env) - def update(self, id, *, tx): + def update(self, id, *, vfy=None, tx): obj = self.get(id, load=False) + if vfy is not None and obj is not vfy: + raise RuntimeError("object identity crisis: " + str(vfy) + " is not cached object " + obj) for nm, attr, in storedescs(obj): attr.update(id, obj, tx) self.db().replace(id, self._encode(obj), tx=tx) + +class autotype(type): + def __call__(self, *args, **kwargs): + new = super().__call__(*args, **kwargs) + new.id = self.store.register(new) + # XXX? ID is not saved now, but relied upon to be __didex_loaded__ later. + return new + +class autostore(object, metaclass=autotype): + def __init__(self): + self.id = None + + def __didex_loaded__(self, store, id): + assert self.id is None or self.id == id + self.id = id + + def save(self): + self.store.update(self.id, vfy=self) + + def remove(self): + self.store.unregister(self.id, vfy=self) + self.id = None