Commit | Line | Data |
---|---|---|
abb94f83 | 1 | import struct, contextlib, math |
a95055e8 | 2 | from . import db, lib |
8950191c | 3 | from .db import bd, txnfun |
a95055e8 | 4 | |
cbf73d3a FT |
5 | __all__ = ["maybe", "t_int", "t_uint", "t_float", "t_str", "ordered"] |
6 | ||
a95055e8 FT |
7 | deadlock = bd.DBLockDeadlockError |
8 | notfound = bd.DBNotFoundError | |
9 | ||
10 | class simpletype(object): | |
11 | def __init__(self, encode, decode): | |
12 | self.enc = encode | |
13 | self.dec = decode | |
14 | ||
15 | def encode(self, ob): | |
16 | return self.enc(ob) | |
17 | def decode(self, dat): | |
18 | return self.dec(dat) | |
19 | def compare(self, a, b): | |
20 | if a < b: | |
21 | return -1 | |
22 | elif a > b: | |
23 | return 1 | |
24 | else: | |
25 | return 0 | |
26 | ||
27 | @classmethod | |
28 | def struct(cls, fmt): | |
29 | return cls(lambda ob: struct.pack(fmt, ob), | |
30 | lambda dat: struct.unpack(fmt, dat)[0]) | |
31 | ||
32 | class maybe(object): | |
33 | def __init__(self, bk): | |
34 | self.bk = bk | |
35 | ||
36 | def encode(self, ob): | |
37 | if ob is None: return b"" | |
38 | return b"\0" + self.bk.encode(ob) | |
39 | def decode(self, dat): | |
40 | if dat == b"": return None | |
41 | return self.bk.dec(dat[1:]) | |
42 | def compare(self, a, b): | |
43 | if a is b is None: | |
44 | return 0 | |
45 | elif a is None: | |
46 | return -1 | |
47 | elif b is None: | |
48 | return 1 | |
49 | else: | |
50 | return self.bk.compare(a[1:], b[1:]) | |
51 | ||
bd14729f FT |
52 | class compound(object): |
53 | def __init__(self, *parts): | |
54 | self.parts = parts | |
55 | ||
56 | def encode(self, obs): | |
57 | if len(obs) != len(self.parts): | |
58 | raise ValueError("invalid length of compound data: " + str(len(obs)) + ", rather than " + len(self.parts)) | |
59 | buf = bytearray() | |
60 | for ob, part in zip(obs, self.parts): | |
61 | dat = part.encode(ob) | |
62 | if len(dat) < 128: | |
63 | buf.append(0x80 | len(dat)) | |
64 | buf.extend(dat) | |
65 | else: | |
66 | buf.extend(struct.pack(">i", len(dat))) | |
67 | buf.extend(dat) | |
68 | return bytes(buf) | |
69 | def decode(self, dat): | |
70 | ret = [] | |
71 | off = 0 | |
72 | for part in self.parts: | |
73 | if dat[off] & 0x80: | |
74 | ln = dat[off] & 0x7f | |
75 | off += 1 | |
76 | else: | |
77 | ln = struct.unpack(">i", dat[off:off + 4])[0] | |
78 | off += 4 | |
79 | ret.append(part.decode(dat[off:off + len])) | |
80 | off += len | |
81 | return tuple(ret) | |
82 | def compare(self, al, bl): | |
83 | if (len(al) != len(self.parts)) or (len(bl) != len(self.parts)): | |
84 | raise ValueError("invalid length of compound data: " + str(len(al)) + ", " + str(len(bl)) + ", rather than " + len(self.parts)) | |
85 | for a, b, part in zip(al, bl, self.parts): | |
86 | c = part.compare(a, b) | |
87 | if c != 0: | |
88 | return c | |
89 | return 0 | |
90 | ||
abb94f83 FT |
91 | def floatcmp(a, b): |
92 | if math.isnan(a) and math.isnan(b): | |
93 | return 0 | |
94 | elif math.isnan(a): | |
95 | return -1 | |
96 | elif math.isnan(b): | |
97 | return 1 | |
98 | elif a < b: | |
99 | return -1 | |
100 | elif a > b: | |
101 | return 1 | |
102 | else: | |
103 | return 0 | |
104 | ||
105 | t_int = simpletype.struct(">q") | |
106 | t_uint = simpletype.struct(">Q") | |
107 | t_float = simpletype.struct(">d") | |
108 | t_float.compare = floatcmp | |
109 | t_str = simpletype((lambda ob: ob.encode("utf-8")), (lambda dat: dat.decode("utf-8"))) | |
a95055e8 FT |
110 | |
111 | class index(object): | |
112 | def __init__(self, db, name, datatype): | |
113 | self.db = db | |
114 | self.nm = name | |
115 | self.typ = datatype | |
116 | ||
117 | missing = object() | |
118 | ||
119 | class ordered(index, lib.closable): | |
eb274691 | 120 | def __init__(self, db, name, datatype, create=True): |
a95055e8 | 121 | super().__init__(db, name, datatype) |
a95055e8 FT |
122 | fl = bd.DB_THREAD | bd.DB_AUTO_COMMIT |
123 | if create: fl |= bd.DB_CREATE | |
124 | def initdb(db): | |
125 | def compare(a, b): | |
126 | if a == b == "": return 0 | |
127 | return self.typ.compare(self.typ.decode(a), self.typ.decode(b)) | |
128 | db.set_flags(bd.DB_DUPSORT) | |
129 | db.set_bt_compare(compare) | |
130 | self.bk = db._opendb("i-" + name, bd.DB_BTREE, fl, initdb) | |
131 | self.bk.set_get_returns_none(False) | |
132 | ||
133 | def close(self): | |
134 | self.bk.close() | |
135 | ||
136 | class cursor(lib.closable): | |
137 | def __init__(self, idx, cur, item, stop): | |
138 | self.idx = idx | |
139 | self.cur = cur | |
140 | self.item = item | |
141 | self.stop = stop | |
142 | ||
143 | def close(self): | |
144 | if self.cur is not None: | |
145 | self.cur.close() | |
146 | ||
147 | def __iter__(self): | |
148 | return self | |
149 | ||
150 | def peek(self): | |
151 | if self.item is None: | |
152 | raise StopIteration() | |
153 | rk, rv = self.item | |
154 | rk = self.idx.typ.decode(rk) | |
155 | rv = struct.unpack(">Q", rv)[0] | |
156 | if self.stop(rk): | |
157 | self.item = None | |
158 | raise StopIteration() | |
159 | return rk, rv | |
160 | ||
161 | def __next__(self): | |
162 | rk, rv = self.peek() | |
163 | try: | |
164 | while True: | |
165 | try: | |
166 | self.item = self.cur.next() | |
167 | break | |
168 | except deadlock: | |
169 | continue | |
170 | except notfound: | |
171 | self.item = None | |
172 | return rk, rv | |
173 | ||
174 | def skip(self, n=1): | |
175 | try: | |
176 | for i in range(n): | |
177 | next(self) | |
178 | except StopIteration: | |
179 | return | |
180 | ||
181 | def get(self, *, match=missing, ge=missing, gt=missing, lt=missing, le=missing, all=False): | |
182 | while True: | |
183 | try: | |
184 | cur = self.bk.cursor() | |
185 | done = False | |
186 | try: | |
187 | if match is not missing: | |
188 | try: | |
189 | k, v = cur.set(self.typ.encode(match)) | |
190 | except notfound: | |
191 | return self.cursor(None, None, None, None) | |
192 | else: | |
193 | done = True | |
194 | return self.cursor(self, cur, (k, v), lambda o: (self.typ.compare(o, match) != 0)) | |
195 | elif all: | |
196 | try: | |
197 | k, v = cur.first() | |
198 | except notfound: | |
199 | return self.cursor(None, None, None, None) | |
200 | else: | |
201 | done = True | |
202 | return self.cursor(self, cur, (k, v), lambda o: False) | |
203 | elif ge is not missing or gt is not missing or lt is not missing or le is not missing: | |
204 | skip = False | |
205 | try: | |
206 | if ge is not missing: | |
207 | k, v = cur.set_range(self.typ.encode(ge)) | |
208 | elif gt is not missing: | |
209 | k, v = cur.set_range(self.typ.encode(gt)) | |
210 | skip = True | |
211 | else: | |
212 | k, v = cur.first() | |
213 | except notfound: | |
214 | return self.cursor(None, None, None, None) | |
215 | if lt is not missing: | |
216 | stop = lambda o: self.typ.compare(o, lt) >= 0 | |
217 | elif le is not missing: | |
218 | stop = lambda o: self.typ.compare(o, le) > 0 | |
219 | else: | |
220 | stop = lambda o: False | |
221 | ret = self.cursor(self, cur, (k, v), stop) | |
222 | if skip: | |
223 | try: | |
224 | while self.typ.compare(ret.peek()[0], gt) == 0: | |
225 | next(ret) | |
226 | except StopIteration: | |
227 | pass | |
228 | done = True | |
229 | return ret | |
230 | else: | |
231 | raise NameError("invalid get() specification") | |
232 | finally: | |
233 | if not done: | |
234 | cur.close() | |
235 | except deadlock: | |
236 | continue | |
237 | ||
8950191c FT |
238 | @txnfun(lambda self: self.db.env.env) |
239 | def put(self, key, id, *, tx): | |
240 | obid = struct.pack(">Q", id) | |
241 | if not self.db.ob.has_key(obid, txn=tx.tx): | |
242 | raise ValueError("no such object in database: " + str(id)) | |
243 | try: | |
244 | self.bk.put(self.typ.encode(key), obid, txn=tx.tx, flags=bd.DB_NODUPDATA) | |
245 | except bd.DBKeyExistError: | |
246 | return False | |
247 | return True | |
248 | ||
249 | @txnfun(lambda self: self.db.env.env) | |
250 | def remove(self, key, id, *, tx): | |
251 | obid = struct.pack(">Q", id) | |
252 | if not self.db.ob.has_key(obid, txn=tx.tx): | |
253 | raise ValueError("no such object in database: " + str(id)) | |
254 | cur = self.bk.cursor(txn=tx.tx) | |
255 | try: | |
a95055e8 | 256 | try: |
8950191c FT |
257 | cur.get_both(self.typ.encode(key), obid) |
258 | except notfound: | |
259 | return False | |
260 | cur.delete() | |
261 | finally: | |
262 | cur.close() | |
263 | return True |