projets / auf_roundup.git / blame
| Commit | Line | Data |
|---|---|---|
| c638d827 CR |
1 | # |
| 2 | # Copyright (c) 2001 Bizar Software Pty Ltd (http://www.bizarsoftware.com.au/) | |
| 3 | # This module is free software, and you may redistribute it and/or modify | |
| 4 | # under the same terms as Python, so long as this copyright message and | |
| 5 | # disclaimer are retained in their original form. | |
| 6 | # | |
| 7 | # IN NO EVENT SHALL BIZAR SOFTWARE PTY LTD BE LIABLE TO ANY PARTY FOR | |
| 8 | # DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES ARISING | |
| 9 | # OUT OF THE USE OF THIS CODE, EVEN IF THE AUTHOR HAS BEEN ADVISED OF THE | |
| 10 | # POSSIBILITY OF SUCH DAMAGE. | |
| 11 | # | |
| 12 | # BIZAR SOFTWARE PTY LTD SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, | |
| 13 | # BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS | |
| 14 | # FOR A PARTICULAR PURPOSE. THE CODE PROVIDED HEREUNDER IS ON AN "AS IS" | |
| 15 | # BASIS, AND THERE IS NO OBLIGATION WHATSOEVER TO PROVIDE MAINTENANCE, | |
| 16 | # SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. | |
| 17 | # | |
| 18 | # $Id: __init__.py,v 1.40 2007-11-07 20:47:12 richard Exp $ | |
| 19 | ||
| 20 | '''Container for the hyperdb storage backend implementations. | |
| 21 | ''' | |
| 22 | __docformat__ = 'restructuredtext' | |
| 23 | ||
| 24 | import sys | |
| 25 | ||
| 26 | # These names are used to suppress import errors. | |
| 27 | # If get_backend raises an ImportError with appropriate | |
| 28 | # module name, have_backend quietly returns False. | |
| 29 | # Otherwise the error is reraised. | |
| 30 | _modules = { | |
| 31 | 'mysql': ('MySQLdb',), | |
| 32 | 'postgresql': ('psycopg',), | |
| 33 | 'tsearch2': ('psycopg',), | |
| 34 | 'sqlite': ('pysqlite', 'pysqlite2', 'sqlite3', '_sqlite3', 'sqlite'), | |
| 35 | } | |
| 36 | ||
| 37 | def get_backend(name): | |
| 38 | '''Get a specific backend by name.''' | |
| 39 | vars = globals() | |
| 40 | # if requested backend has been imported yet, return current instance | |
| 41 | if name in vars: | |
| 42 | return vars[name] | |
| 43 | # import the backend module | |
| 44 | module_name = 'back_%s' % name | |
| 45 | try: | |
| 46 | module = __import__(module_name, vars) | |
| 47 | except: | |
| 48 | # import failed, but in versions prior to 2.4, a (broken) | |
| 49 | # module is left in sys.modules and package globals; | |
| 50 | # subsequent imports would succeed and get the broken module. | |
| 51 | # This no longer happens in Python 2.4 and later. | |
| 52 | if sys.version_info < (2, 4): | |
| 53 | del sys.modules['.'.join((__name__, module_name))] | |
| 54 | del vars[module_name] | |
| 55 | raise | |
| 56 | else: | |
| 57 | vars[name] = module | |
| 58 | return module | |
| 59 | ||
| 60 | def have_backend(name): | |
| 61 | '''Is backend "name" available?''' | |
| 62 | if name == 'tsearch2': | |
| 63 | # currently not working | |
| 64 | return 0 | |
| 65 | try: | |
| 66 | get_backend(name) | |
| 67 | return 1 | |
| 68 | except ImportError, e: | |
| 69 | for name in _modules.get(name, (name,)): | |
| 70 | if str(e).startswith('No module named %s'%name): | |
| 71 | return 0 | |
| 72 | raise | |
| 73 | return 0 | |
| 74 | ||
| 75 | def list_backends(): | |
| 76 | '''List all available backend names. | |
| 77 | ||
| 78 | This function has side-effect of registering backward-compatible | |
| 79 | globals for all available backends. | |
| 80 | ||
| 81 | ''' | |
| 82 | l = [] | |
| 83 | for name in 'anydbm', 'mysql', 'sqlite', 'postgresql': | |
| 84 | if have_backend(name): | |
| 85 | l.append(name) | |
| 86 | return l | |
| 87 | ||
| 88 | # vim: set filetype=python sts=4 sw=4 et si : |