Commit | Line | Data |
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a95055e8 FT |
1 | import struct, contextlib |
2 | from . import db, lib | |
8950191c | 3 | from .db import bd, txnfun |
a95055e8 FT |
4 | |
5 | deadlock = bd.DBLockDeadlockError | |
6 | notfound = bd.DBNotFoundError | |
7 | ||
8 | class simpletype(object): | |
9 | def __init__(self, encode, decode): | |
10 | self.enc = encode | |
11 | self.dec = decode | |
12 | ||
13 | def encode(self, ob): | |
14 | return self.enc(ob) | |
15 | def decode(self, dat): | |
16 | return self.dec(dat) | |
17 | def compare(self, a, b): | |
18 | if a < b: | |
19 | return -1 | |
20 | elif a > b: | |
21 | return 1 | |
22 | else: | |
23 | return 0 | |
24 | ||
25 | @classmethod | |
26 | def struct(cls, fmt): | |
27 | return cls(lambda ob: struct.pack(fmt, ob), | |
28 | lambda dat: struct.unpack(fmt, dat)[0]) | |
29 | ||
30 | class maybe(object): | |
31 | def __init__(self, bk): | |
32 | self.bk = bk | |
33 | ||
34 | def encode(self, ob): | |
35 | if ob is None: return b"" | |
36 | return b"\0" + self.bk.encode(ob) | |
37 | def decode(self, dat): | |
38 | if dat == b"": return None | |
39 | return self.bk.dec(dat[1:]) | |
40 | def compare(self, a, b): | |
41 | if a is b is None: | |
42 | return 0 | |
43 | elif a is None: | |
44 | return -1 | |
45 | elif b is None: | |
46 | return 1 | |
47 | else: | |
48 | return self.bk.compare(a[1:], b[1:]) | |
49 | ||
50 | t_int = simpletype.struct(">Q") | |
51 | ||
52 | class index(object): | |
53 | def __init__(self, db, name, datatype): | |
54 | self.db = db | |
55 | self.nm = name | |
56 | self.typ = datatype | |
57 | ||
58 | missing = object() | |
59 | ||
60 | class ordered(index, lib.closable): | |
eb274691 | 61 | def __init__(self, db, name, datatype, create=True): |
a95055e8 | 62 | super().__init__(db, name, datatype) |
a95055e8 FT |
63 | fl = bd.DB_THREAD | bd.DB_AUTO_COMMIT |
64 | if create: fl |= bd.DB_CREATE | |
65 | def initdb(db): | |
66 | def compare(a, b): | |
67 | if a == b == "": return 0 | |
68 | return self.typ.compare(self.typ.decode(a), self.typ.decode(b)) | |
69 | db.set_flags(bd.DB_DUPSORT) | |
70 | db.set_bt_compare(compare) | |
71 | self.bk = db._opendb("i-" + name, bd.DB_BTREE, fl, initdb) | |
72 | self.bk.set_get_returns_none(False) | |
73 | ||
74 | def close(self): | |
75 | self.bk.close() | |
76 | ||
77 | class cursor(lib.closable): | |
78 | def __init__(self, idx, cur, item, stop): | |
79 | self.idx = idx | |
80 | self.cur = cur | |
81 | self.item = item | |
82 | self.stop = stop | |
83 | ||
84 | def close(self): | |
85 | if self.cur is not None: | |
86 | self.cur.close() | |
87 | ||
88 | def __iter__(self): | |
89 | return self | |
90 | ||
91 | def peek(self): | |
92 | if self.item is None: | |
93 | raise StopIteration() | |
94 | rk, rv = self.item | |
95 | rk = self.idx.typ.decode(rk) | |
96 | rv = struct.unpack(">Q", rv)[0] | |
97 | if self.stop(rk): | |
98 | self.item = None | |
99 | raise StopIteration() | |
100 | return rk, rv | |
101 | ||
102 | def __next__(self): | |
103 | rk, rv = self.peek() | |
104 | try: | |
105 | while True: | |
106 | try: | |
107 | self.item = self.cur.next() | |
108 | break | |
109 | except deadlock: | |
110 | continue | |
111 | except notfound: | |
112 | self.item = None | |
113 | return rk, rv | |
114 | ||
115 | def skip(self, n=1): | |
116 | try: | |
117 | for i in range(n): | |
118 | next(self) | |
119 | except StopIteration: | |
120 | return | |
121 | ||
122 | def get(self, *, match=missing, ge=missing, gt=missing, lt=missing, le=missing, all=False): | |
123 | while True: | |
124 | try: | |
125 | cur = self.bk.cursor() | |
126 | done = False | |
127 | try: | |
128 | if match is not missing: | |
129 | try: | |
130 | k, v = cur.set(self.typ.encode(match)) | |
131 | except notfound: | |
132 | return self.cursor(None, None, None, None) | |
133 | else: | |
134 | done = True | |
135 | return self.cursor(self, cur, (k, v), lambda o: (self.typ.compare(o, match) != 0)) | |
136 | elif all: | |
137 | try: | |
138 | k, v = cur.first() | |
139 | except notfound: | |
140 | return self.cursor(None, None, None, None) | |
141 | else: | |
142 | done = True | |
143 | return self.cursor(self, cur, (k, v), lambda o: False) | |
144 | elif ge is not missing or gt is not missing or lt is not missing or le is not missing: | |
145 | skip = False | |
146 | try: | |
147 | if ge is not missing: | |
148 | k, v = cur.set_range(self.typ.encode(ge)) | |
149 | elif gt is not missing: | |
150 | k, v = cur.set_range(self.typ.encode(gt)) | |
151 | skip = True | |
152 | else: | |
153 | k, v = cur.first() | |
154 | except notfound: | |
155 | return self.cursor(None, None, None, None) | |
156 | if lt is not missing: | |
157 | stop = lambda o: self.typ.compare(o, lt) >= 0 | |
158 | elif le is not missing: | |
159 | stop = lambda o: self.typ.compare(o, le) > 0 | |
160 | else: | |
161 | stop = lambda o: False | |
162 | ret = self.cursor(self, cur, (k, v), stop) | |
163 | if skip: | |
164 | try: | |
165 | while self.typ.compare(ret.peek()[0], gt) == 0: | |
166 | next(ret) | |
167 | except StopIteration: | |
168 | pass | |
169 | done = True | |
170 | return ret | |
171 | else: | |
172 | raise NameError("invalid get() specification") | |
173 | finally: | |
174 | if not done: | |
175 | cur.close() | |
176 | except deadlock: | |
177 | continue | |
178 | ||
8950191c FT |
179 | @txnfun(lambda self: self.db.env.env) |
180 | def put(self, key, id, *, tx): | |
181 | obid = struct.pack(">Q", id) | |
182 | if not self.db.ob.has_key(obid, txn=tx.tx): | |
183 | raise ValueError("no such object in database: " + str(id)) | |
184 | try: | |
185 | self.bk.put(self.typ.encode(key), obid, txn=tx.tx, flags=bd.DB_NODUPDATA) | |
186 | except bd.DBKeyExistError: | |
187 | return False | |
188 | return True | |
189 | ||
190 | @txnfun(lambda self: self.db.env.env) | |
191 | def remove(self, key, id, *, tx): | |
192 | obid = struct.pack(">Q", id) | |
193 | if not self.db.ob.has_key(obid, txn=tx.tx): | |
194 | raise ValueError("no such object in database: " + str(id)) | |
195 | cur = self.bk.cursor(txn=tx.tx) | |
196 | try: | |
a95055e8 | 197 | try: |
8950191c FT |
198 | cur.get_both(self.typ.encode(key), obid) |
199 | except notfound: | |
200 | return False | |
201 | cur.delete() | |
202 | finally: | |
203 | cur.close() | |
204 | return True |