Commit | Line | Data |
---|---|---|
36c0a011 | 1 | import threading, pickle, inspect |
b080a59c FT |
2 | from . import db, index, cache |
3 | from .db import txnfun | |
4 | ||
6e81ddd5 | 5 | __all__ = ["environment", "datastore", "autostore"] |
cbf73d3a | 6 | |
b080a59c | 7 | class environment(object): |
eca9b3be FT |
8 | def __init__(self, *, path=None, getpath=None, recover=False): |
9 | if path is not None: | |
10 | self.path = path | |
11 | self.getpath = None | |
12 | else: | |
13 | self.path = None | |
14 | self.getpath = getpath | |
15 | self.recover = recover | |
b080a59c FT |
16 | self.lk = threading.Lock() |
17 | self.bk = None | |
18 | ||
19 | def __call__(self): | |
20 | with self.lk: | |
21 | if self.bk is None: | |
eca9b3be FT |
22 | if self.path is None: |
23 | self.path = self.getpath() | |
24 | self.bk = db.environment(self.path, recover=self.recover) | |
b080a59c FT |
25 | return self.bk |
26 | ||
27 | def close(self): | |
28 | with self.lk: | |
29 | if self.bk is not None: | |
30 | self.bk.close() | |
31 | self.bk = None | |
32 | ||
33 | class storedesc(object): | |
34 | pass | |
35 | ||
36 | def storedescs(obj): | |
37 | t = type(obj) | |
36c0a011 | 38 | ret = t.__dict__.get("__didex_attr") |
b080a59c FT |
39 | if ret is None: |
40 | ret = [] | |
36c0a011 FT |
41 | for st in inspect.getmro(t): |
42 | for nm, val in st.__dict__.items(): | |
43 | if isinstance(val, storedesc): | |
44 | ret.append((nm, val)) | |
45 | t.__dict__["__didex_attr"] = ret | |
b080a59c FT |
46 | return ret |
47 | ||
6e81ddd5 | 48 | class datastore(object): |
b080a59c FT |
49 | def __init__(self, name, *, env=None, path=".", ncache=None): |
50 | self.name = name | |
51 | self.lk = threading.Lock() | |
52 | if env: | |
53 | self.env = env | |
54 | else: | |
eca9b3be | 55 | self.env = environment(path=path) |
b080a59c FT |
56 | self._db = None |
57 | if ncache is None: | |
58 | ncache = cache.cache() | |
59 | self.cache = ncache | |
60 | self.cache.load = self._load | |
61 | ||
62 | def db(self): | |
63 | with self.lk: | |
64 | if self._db is None: | |
65 | self._db = self.env().db(self.name) | |
66 | return self._db | |
67 | ||
68 | def _load(self, id): | |
69 | try: | |
70 | return pickle.loads(self.db().get(id)) | |
71 | except: | |
72 | raise KeyError(id, "could not unpickle data") | |
73 | ||
74 | def _encode(self, obj): | |
75 | return pickle.dumps(obj) | |
76 | ||
77 | def get(self, id, *, load=True): | |
78 | return self.cache.get(id, load=load) | |
79 | ||
80 | @txnfun(lambda self: self.db().env.env) | |
81 | def register(self, obj, *, tx): | |
82 | id = self.db().add(self._encode(obj), tx=tx) | |
83 | for nm, attr in storedescs(obj): | |
84 | attr.register(id, obj, tx) | |
85 | self.cache.put(id, obj) | |
86 | return id | |
87 | ||
88 | @txnfun(lambda self: self.db().env.env) | |
ca180faa | 89 | def unregister(self, id, *, vfy=None, tx): |
b080a59c | 90 | obj = self.get(id) |
ca180faa FT |
91 | if vfy is not None and obj is not vfy: |
92 | raise RuntimeError("object identity crisis: " + str(vfy) + " is not cached object " + obj) | |
b080a59c FT |
93 | for nm, attr in storedescs(obj): |
94 | attr.unregister(id, obj, tx) | |
95 | self.db().remove(id, tx=tx) | |
96 | self.cache.remove(id) | |
97 | ||
98 | @txnfun(lambda self: self.db().env.env) | |
ca180faa | 99 | def update(self, id, *, vfy=None, tx): |
b080a59c | 100 | obj = self.get(id, load=False) |
ca180faa FT |
101 | if vfy is not None and obj is not vfy: |
102 | raise RuntimeError("object identity crisis: " + str(vfy) + " is not cached object " + obj) | |
b080a59c FT |
103 | for nm, attr, in storedescs(obj): |
104 | attr.update(id, obj, tx) | |
105 | self.db().replace(id, self._encode(obj), tx=tx) | |
ca180faa FT |
106 | |
107 | class autotype(type): | |
108 | def __call__(self, *args, **kwargs): | |
109 | new = super().__call__(*args, **kwargs) | |
110 | new.id = self.store.register(new) | |
b914d5dd | 111 | self.store.update(new.id, vfy=new) # This doesn't feel too nice. |
ca180faa FT |
112 | return new |
113 | ||
114 | class autostore(object, metaclass=autotype): | |
115 | def __init__(self): | |
116 | self.id = None | |
117 | ||
118 | def save(self): | |
119 | self.store.update(self.id, vfy=self) | |
120 | ||
121 | def remove(self): | |
122 | self.store.unregister(self.id, vfy=self) | |
123 | self.id = None |