1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
|
from typing import Optional
from psycopg import pq
from psycopg.abc import Dumper, Loader, AdaptContext, PyFormat, Buffer
def f() -> None:
d: Dumper = MyStrDumper(str, None)
assert d.dump("abc") == b"abcabc"
assert d.quote("abc") == b"'abcabc'"
lo: Loader = MyTextLoader(0, None)
assert lo.load(b"abc") == "abcabc"
class MyStrDumper:
format = pq.Format.TEXT
oid = 25 # text
def __init__(self, cls: type, context: Optional[AdaptContext] = None):
self._cls = cls
def dump(self, obj: str) -> bytes:
return (obj * 2).encode()
def quote(self, obj: str) -> bytes:
value = self.dump(obj)
esc = pq.Escaping()
return b"'%s'" % esc.escape_string(value.replace(b"h", b"q"))
def get_key(self, obj: str, format: PyFormat) -> type:
return self._cls
def upgrade(self, obj: str, format: PyFormat) -> "MyStrDumper":
return self
class MyTextLoader:
format = pq.Format.TEXT
def __init__(self, oid: int, context: Optional[AdaptContext] = None):
pass
def load(self, data: Buffer) -> str:
return (bytes(data) * 2).decode()
|
