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): | |
61 | def __init__(self, db, name, datatype, duplicates, create=True): | |
62 | super().__init__(db, name, datatype) | |
63 | self.dup = duplicates | |
64 | fl = bd.DB_THREAD | bd.DB_AUTO_COMMIT | |
65 | if create: fl |= bd.DB_CREATE | |
66 | def initdb(db): | |
67 | def compare(a, b): | |
68 | if a == b == "": return 0 | |
69 | return self.typ.compare(self.typ.decode(a), self.typ.decode(b)) | |
70 | db.set_flags(bd.DB_DUPSORT) | |
71 | db.set_bt_compare(compare) | |
72 | self.bk = db._opendb("i-" + name, bd.DB_BTREE, fl, initdb) | |
73 | self.bk.set_get_returns_none(False) | |
74 | ||
75 | def close(self): | |
76 | self.bk.close() | |
77 | ||
78 | class cursor(lib.closable): | |
79 | def __init__(self, idx, cur, item, stop): | |
80 | self.idx = idx | |
81 | self.cur = cur | |
82 | self.item = item | |
83 | self.stop = stop | |
84 | ||
85 | def close(self): | |
86 | if self.cur is not None: | |
87 | self.cur.close() | |
88 | ||
89 | def __iter__(self): | |
90 | return self | |
91 | ||
92 | def peek(self): | |
93 | if self.item is None: | |
94 | raise StopIteration() | |
95 | rk, rv = self.item | |
96 | rk = self.idx.typ.decode(rk) | |
97 | rv = struct.unpack(">Q", rv)[0] | |
98 | if self.stop(rk): | |
99 | self.item = None | |
100 | raise StopIteration() | |
101 | return rk, rv | |
102 | ||
103 | def __next__(self): | |
104 | rk, rv = self.peek() | |
105 | try: | |
106 | while True: | |
107 | try: | |
108 | self.item = self.cur.next() | |
109 | break | |
110 | except deadlock: | |
111 | continue | |
112 | except notfound: | |
113 | self.item = None | |
114 | return rk, rv | |
115 | ||
116 | def skip(self, n=1): | |
117 | try: | |
118 | for i in range(n): | |
119 | next(self) | |
120 | except StopIteration: | |
121 | return | |
122 | ||
123 | def get(self, *, match=missing, ge=missing, gt=missing, lt=missing, le=missing, all=False): | |
124 | while True: | |
125 | try: | |
126 | cur = self.bk.cursor() | |
127 | done = False | |
128 | try: | |
129 | if match is not missing: | |
130 | try: | |
131 | k, v = cur.set(self.typ.encode(match)) | |
132 | except notfound: | |
133 | return self.cursor(None, None, None, None) | |
134 | else: | |
135 | done = True | |
136 | return self.cursor(self, cur, (k, v), lambda o: (self.typ.compare(o, match) != 0)) | |
137 | elif all: | |
138 | try: | |
139 | k, v = cur.first() | |
140 | except notfound: | |
141 | return self.cursor(None, None, None, None) | |
142 | else: | |
143 | done = True | |
144 | return self.cursor(self, cur, (k, v), lambda o: False) | |
145 | elif ge is not missing or gt is not missing or lt is not missing or le is not missing: | |
146 | skip = False | |
147 | try: | |
148 | if ge is not missing: | |
149 | k, v = cur.set_range(self.typ.encode(ge)) | |
150 | elif gt is not missing: | |
151 | k, v = cur.set_range(self.typ.encode(gt)) | |
152 | skip = True | |
153 | else: | |
154 | k, v = cur.first() | |
155 | except notfound: | |
156 | return self.cursor(None, None, None, None) | |
157 | if lt is not missing: | |
158 | stop = lambda o: self.typ.compare(o, lt) >= 0 | |
159 | elif le is not missing: | |
160 | stop = lambda o: self.typ.compare(o, le) > 0 | |
161 | else: | |
162 | stop = lambda o: False | |
163 | ret = self.cursor(self, cur, (k, v), stop) | |
164 | if skip: | |
165 | try: | |
166 | while self.typ.compare(ret.peek()[0], gt) == 0: | |
167 | next(ret) | |
168 | except StopIteration: | |
169 | pass | |
170 | done = True | |
171 | return ret | |
172 | else: | |
173 | raise NameError("invalid get() specification") | |
174 | finally: | |
175 | if not done: | |
176 | cur.close() | |
177 | except deadlock: | |
178 | continue | |
179 | ||
8950191c FT |
180 | @txnfun(lambda self: self.db.env.env) |
181 | def put(self, key, id, *, tx): | |
182 | obid = struct.pack(">Q", id) | |
183 | if not self.db.ob.has_key(obid, txn=tx.tx): | |
184 | raise ValueError("no such object in database: " + str(id)) | |
185 | try: | |
186 | self.bk.put(self.typ.encode(key), obid, txn=tx.tx, flags=bd.DB_NODUPDATA) | |
187 | except bd.DBKeyExistError: | |
188 | return False | |
189 | return True | |
190 | ||
191 | @txnfun(lambda self: self.db.env.env) | |
192 | def remove(self, key, id, *, tx): | |
193 | obid = struct.pack(">Q", id) | |
194 | if not self.db.ob.has_key(obid, txn=tx.tx): | |
195 | raise ValueError("no such object in database: " + str(id)) | |
196 | cur = self.bk.cursor(txn=tx.tx) | |
197 | try: | |
a95055e8 | 198 | try: |
8950191c FT |
199 | cur.get_both(self.typ.encode(key), obid) |
200 | except notfound: | |
201 | return False | |
202 | cur.delete() | |
203 | finally: | |
204 | cur.close() | |
205 | return True |