| 1 | #!/usr/bin/env python |
|---|
| 2 | # -*- coding: utf-8 -*- |
|---|
| 3 | |
|---|
| 4 | """ |
|---|
| 5 | | This file is part of the web2py Web Framework |
|---|
| 6 | | Copyrighted by Massimo Di Pierro <mdipierro@cs.depaul.edu> |
|---|
| 7 | | License: LGPLv3 (http://www.gnu.org/licenses/lgpl.html) |
|---|
| 8 | |
|---|
| 9 | Generates names for cache and session files |
|---|
| 10 | -------------------------------------------- |
|---|
| 11 | """ |
|---|
| 12 | import os |
|---|
| 13 | from gluon._compat import builtin |
|---|
| 14 | |
|---|
| 15 | def generate(filename, depth=2, base=512): |
|---|
| 16 | if os.path.sep in filename: |
|---|
| 17 | path, filename = os.path.split(filename) |
|---|
| 18 | else: |
|---|
| 19 | path = None |
|---|
| 20 | dummyhash = sum(ord(c) * 256 ** (i % 4) for i, c in enumerate(filename)) % base ** depth |
|---|
| 21 | folders = [] |
|---|
| 22 | for level in range(depth - 1, -1, -1): |
|---|
| 23 | code, dummyhash = divmod(dummyhash, base ** level) |
|---|
| 24 | folders.append("%03x" % code) |
|---|
| 25 | folders.append(filename) |
|---|
| 26 | if path: |
|---|
| 27 | folders.insert(0, path) |
|---|
| 28 | return os.path.join(*folders) |
|---|
| 29 | |
|---|
| 30 | |
|---|
| 31 | def exists(filename, path=None): |
|---|
| 32 | if os.path.exists(filename): |
|---|
| 33 | return True |
|---|
| 34 | if path is None: |
|---|
| 35 | path, filename = os.path.split(filename) |
|---|
| 36 | fullfilename = os.path.join(path, generate(filename)) |
|---|
| 37 | if os.path.exists(fullfilename): |
|---|
| 38 | return True |
|---|
| 39 | return False |
|---|
| 40 | |
|---|
| 41 | |
|---|
| 42 | def remove(filename, path=None): |
|---|
| 43 | if os.path.exists(filename): |
|---|
| 44 | return os.unlink(filename) |
|---|
| 45 | if path is None: |
|---|
| 46 | path, filename = os.path.split(filename) |
|---|
| 47 | fullfilename = os.path.join(path, generate(filename)) |
|---|
| 48 | if os.path.exists(fullfilename): |
|---|
| 49 | return os.unlink(fullfilename) |
|---|
| 50 | raise IOError |
|---|
| 51 | |
|---|
| 52 | |
|---|
| 53 | def open(filename, mode="r", path=None): |
|---|
| 54 | if not path: |
|---|
| 55 | path, filename = os.path.split(filename) |
|---|
| 56 | fullfilename = None |
|---|
| 57 | if not mode.startswith('w'): |
|---|
| 58 | fullfilename = os.path.join(path, filename) |
|---|
| 59 | if not os.path.exists(fullfilename): |
|---|
| 60 | fullfilename = None |
|---|
| 61 | if not fullfilename: |
|---|
| 62 | fullfilename = os.path.join(path, generate(filename)) |
|---|
| 63 | if mode.startswith('w') and not os.path.exists(os.path.dirname(fullfilename)): |
|---|
| 64 | os.makedirs(os.path.dirname(fullfilename)) |
|---|
| 65 | return builtin.open(fullfilename, mode) |
|---|
