[Zodb-checkins] CVS: ZODB3/ZConfig - Storage.py:1.1 StorageTypes.py:1.1

[Guido van Rossum]

Update of /cvs-repository/ZODB3/ZConfig
In directory cvs.zope.org:/tmp/cvs-serv4510

Added Files:
	Storage.py StorageTypes.py 
Log Message:
Adding a new utility module, ZConfig.Storage, which provides utilities
to configure arbitrary storages based on a <Storage> section.  Most of
the code is lifted from Shane's DBTab.  StorageTypes.py is the helper
that defines how the arguments to various known storages must be munged.


=== Added File ZODB3/ZConfig/Storage.py ===
##############################################################################
#
# Copyright (c) 2002 Zope Corporation and Contributors.
# All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.0 (ZPL).  A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE
#
##############################################################################
"""Higher-level support for configuring storages.

Storages are configured a la DBTab.

A storage section has the form

  <Storage Name (dependent)>
    # For example
    type        FileStorage
    file_name   var/Data.fs
    read_only   1
  </Storage>

where Name and (dependent) are optional.  Once you have retrieved the
section object (probably with getSection("Storage", name), the
function creatStorage() in this module will create the storage object
for you.
"""

from StorageTypes import storage_types

def createStorage(section):
    """Create a storage specified by a configuration section."""
    klass, args = getStorageInfo(section)
    return klass(**args)

def getStorageInfo(section):
    """Extract a storage description from a configuration section.

    Return a tuple (klass, args) where klass is the storage class and
    args is a dictionary of keyword arguments.  To create the storage,
    call klass(**args).

    Adapted from DatabaseFactory.setStorageParams() in DBTab.py.
    """
    type = section.get("type")
    if not type:
        raise RuntimeError, "A storage type is required"
    module = None
    pos = type.rfind(".")
    if pos >= 0:
        # Specified the module
        module, type = type[:pos], type[pos+1:]
    converter = None
    if not module:
        # Use a default module and argument converter.
        info = storage_types.get(type)
        if not info:
            raise RuntimeError, "Unknown storage type: %s" % type
        module, converter = info
    m = __import__(module, {}, {}, [type])
    klass = getattr(m, type)

    args = {}
    for key in section.keys():
        if key.lower() != "type":
            args[key] = section.get(key)
    if converter is not None:
        args = converter(**args)
    return (klass, args)


=== Added File ZODB3/ZConfig/StorageTypes.py ===
##############################################################################
#
# Copyright (c) 2002 Zope Corporation and Contributors.
# All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.0 (ZPL).  A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE
#
##############################################################################
"""Default storage types.

Adapted from DBTab/StorageTypes.py.
"""

import re


def asBoolean(s):
    if not s:
        return 0
    ss = str(s).lower()
    if ss in ('1', 'y', 't', 'yes', 'true', 'on'):
        return 1
    elif ss in ('0', 'n', 'f', 'no', 'false', 'off'):
        return 0
    else:
        raise ValueError, 'Not a boolean value: %s' % s


def convertFileStorageArgs(quota=None, stop=None, **kw):
    if kw.has_key('name'):
        # FileStorage doesn't accept a 'name' arg
        del kw['name']
    if quota is not None:
        kw['quota'] = long(quota) or None
    if stop is not None:
        stop = long(stop)
        if not stop:
            stop = None
        else:
            from ZODB.utils import p64
            stop = p64(stop)
        kw['stop'] = stop

    # Boolean args
    for name in (
        'create', 'read_only'
        ):
        if kw.has_key(name):
            kw[name] = asBoolean(kw[name])

    return kw


# Match URLs of the form 'zeo://zope.example.com:1234'
zeo_url_re = re.compile('zeo:/*(?P<host>[A-Za-z0-9\.-]+):(?P<port>[0-9]+)')

def convertAddresses(s):
    # Allow multiple addresses using semicolons as a split character.
    res = []
    for a in s.split(';'):
        a = a.strip()
        if a:
            mo = zeo_url_re.match(a)
            if mo is not None:
                # ZEO URL
                host, port = mo.groups()
                res.append((host, int(port)))
            else:
                # Socket file
                res.append(a)
    return res


def convertClientStorageArgs(addr=None, **kw):
    if addr is None:
        raise RuntimeError, 'An addr parameter is required for ClientStorage.'
    kw['addr'] = convertAddresses(addr)

    # Integer args
    for name in (
        'cache_size', 'min_disconnect_poll', 'max_disconnect_poll',
        ):
        if kw.has_key(name):
            kw[name] = int(kw[name])

    # Boolean args
    for name in (
        'wait', 'read_only', 'read_only_fallback',
        ):
        if kw.has_key(name):
            kw[name] = asBoolean(kw[name])

    # The 'client' parameter must be None to be false.  Yuck.
    if kw.has_key('client') and not kw['client']:
        kw['client'] = None

    return kw


storage_types = {
    'FileStorage': ('ZODB.FileStorage', convertFileStorageArgs),
    'DemoStorage': ('ZODB.DemoStorage', None),
    'MappingStorage': ('ZODB.MappingStorage', None),
    'TemporaryStorage': ('Products.TemporaryFolder.TemporaryStorage', None),
    'ClientStorage': ('ZEO.ClientStorage', convertClientStorageArgs),
    }