persistence 0.0.6

A resizable, mutable array type implemented on top of mmap, providing persistence for arrays of data in memory.
Documentation 
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

#!/usr/bin/env python3
# coding=utf-8

#
# Copyright (c) 2019 Erik Nordstrøm <erik@nordstroem.no>
#
# Permission to use, copy, modify, and/or distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
#

import sys, fcntl

try:

  fd = open(sys.argv[1], 'ab')

  fcntl.flock(fd, fcntl.LOCK_EX|fcntl.LOCK_NB)

except BlockingIOError:

  sys.exit(35)

except Exception as e:

  print(e, file=sys.stderr)
  sys.exit(2)