checkpointing.hash.stream

View Source

 1import hashlib
 2from checkpointing.config import defaults
 3from typing import Iterable
 4from io import RawIOBase
 5
 6
 7class HashStream(RawIOBase):
 8    """
 9    Binary input stream hasher. It implements a file-like interface, so that it can be used with
10    pickle easily, without needing a copy of the bytes representation of an object and thus saving memory.
11    """
12
13    def __init__(self, algorithm: str = None) -> None:
14        """
15        Args:
16            algorithm: the hash algorithm. Must be supported by the hashlib.
17                        If it's not specified, use the global default `hash.algorithm`.
18        """
19
20        if algorithm is None:
21            algorithm = defaults["hash.algorithm"]
22
23        self.__hash = hashlib.new(algorithm)
24
25    def readable(self) -> bool:
26        return False
27
28    def seekable(self) -> bool:
29        return False
30
31    def writable(self) -> bool:
32        return True
33
34    def writelines(self, lines: Iterable[bytes]) -> None:
35        for line in lines:
36            self.write(line)
37
38    def write(self, b: bytes) -> int:
39        self.__hash.update(b)
40        return len(b)
41
42    def hexdigest(self) -> str:
43        """
44        Returns:
45            The hexdigest of the all the bytes data written to this hash stream
46        """
47
48        return self.__hash.hexdigest()

class HashStream(io.RawIOBase): View Source

 8class HashStream(RawIOBase):
 9    """
10    Binary input stream hasher. It implements a file-like interface, so that it can be used with
11    pickle easily, without needing a copy of the bytes representation of an object and thus saving memory.
12    """
13
14    def __init__(self, algorithm: str = None) -> None:
15        """
16        Args:
17            algorithm: the hash algorithm. Must be supported by the hashlib.
18                        If it's not specified, use the global default `hash.algorithm`.
19        """
20
21        if algorithm is None:
22            algorithm = defaults["hash.algorithm"]
23
24        self.__hash = hashlib.new(algorithm)
25
26    def readable(self) -> bool:
27        return False
28
29    def seekable(self) -> bool:
30        return False
31
32    def writable(self) -> bool:
33        return True
34
35    def writelines(self, lines: Iterable[bytes]) -> None:
36        for line in lines:
37            self.write(line)
38
39    def write(self, b: bytes) -> int:
40        self.__hash.update(b)
41        return len(b)
42
43    def hexdigest(self) -> str:
44        """
45        Returns:
46            The hexdigest of the all the bytes data written to this hash stream
47        """
48
49        return self.__hash.hexdigest()

Binary input stream hasher. It implements a file-like interface, so that it can be used with pickle easily, without needing a copy of the bytes representation of an object and thus saving memory.

HashStream(algorithm: str = None) View Source

14    def __init__(self, algorithm: str = None) -> None:
15        """
16        Args:
17            algorithm: the hash algorithm. Must be supported by the hashlib.
18                        If it's not specified, use the global default `hash.algorithm`.
19        """
20
21        if algorithm is None:
22            algorithm = defaults["hash.algorithm"]
23
24        self.__hash = hashlib.new(algorithm)

Args

algorithm: the hash algorithm. Must be supported by the hashlib. If it's not specified, use the global default hash.algorithm.

def readable(self) -> bool: View Source

26    def readable(self) -> bool:
27        return False

Return whether object was opened for reading.

If False, read() will raise OSError.

def seekable(self) -> bool: View Source

29    def seekable(self) -> bool:
30        return False

Return whether object supports random access.

If False, seek(), tell() and truncate() will raise OSError. This method may need to do a test seek().

def writable(self) -> bool: View Source

32    def writable(self) -> bool:
33        return True

Return whether object was opened for writing.

If False, write() will raise OSError.

def writelines(self, lines: Iterable[bytes]) -> None: View Source

35    def writelines(self, lines: Iterable[bytes]) -> None:
36        for line in lines:
37            self.write(line)

Write a list of lines to stream.

Line separators are not added, so it is usual for each of the lines provided to have a line separator at the end.

def write(self, b: bytes) -> int: View Source

39    def write(self, b: bytes) -> int:
40        self.__hash.update(b)
41        return len(b)

def hexdigest(self) -> str: View Source

43    def hexdigest(self) -> str:
44        """
45        Returns:
46            The hexdigest of the all the bytes data written to this hash stream
47        """
48
49        return self.__hash.hexdigest()

Returns

The hexdigest of the all the bytes data written to this hash stream

Inherited Members

_io._RawIOBase: read; readall; readinto
_io._IOBase: seek; tell; truncate; flush; close; fileno; isatty; readline; readlines; closed