summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
Diffstat
-rw-r--r--src/mailman/app/commands.py11
-rw-r--r--src/mailman/bin/mailman.py5
-rw-r--r--src/mailman/chains/base.py3
-rw-r--r--src/mailman/core/chains.py20
-rw-r--r--src/mailman/core/pipelines.py11
-rw-r--r--src/mailman/core/rules.py10
-rw-r--r--src/mailman/styles/manager.py10
-rw-r--r--src/mailman/utilities/modules.py75
-rw-r--r--src/mailman/utilities/tests/test_modules.py139
9 files changed, 214 insertions, 70 deletions
diff --git a/src/mailman/app/commands.py b/src/mailman/app/commands.py
index 9983a25e5..7cf3bc4c5 100644
--- a/src/mailman/app/commands.py
+++ b/src/mailman/app/commands.py
@@ -19,18 +19,11 @@
from mailman.config import config
from mailman.interfaces.command import IEmailCommand
-from mailman.utilities.modules import find_components
+from mailman.utilities.modules import add_components
from public import public
-from zope.interface.verify import verifyObject
@public
def initialize():
"""Initialize the email commands."""
- for command_class in find_components('mailman.commands', IEmailCommand):
- command = command_class()
- verifyObject(IEmailCommand, command)
- assert command_class.name not in config.commands, (
- 'Duplicate email command "{}" found in {}'.format(
- command_class.name, command_class.__module__))
- config.commands[command_class.name] = command_class()
+ add_components('mailman.commands', IEmailCommand, config.commands)
diff --git a/src/mailman/bin/mailman.py b/src/mailman/bin/mailman.py
index eea3603a8..62066175e 100644
--- a/src/mailman/bin/mailman.py
+++ b/src/mailman/bin/mailman.py
@@ -28,7 +28,6 @@ from mailman.interfaces.command import ICLISubCommand
from mailman.utilities.modules import find_components
from mailman.version import MAILMAN_VERSION_FULL
from public import public
-from zope.interface.verify import verifyObject
# --help should display the subcommands by alphabetical order, except that
@@ -76,9 +75,7 @@ def main():
# the plugins. Punt on this for now.
subparser = parser.add_subparsers(title='Commands')
subcommands = []
- for command_class in find_components('mailman.commands', ICLISubCommand):
- command = command_class()
- verifyObject(ICLISubCommand, command)
+ for command in find_components('mailman.commands', ICLISubCommand):
subcommands.append(command)
subcommands.sort(key=cmp_to_key(_help_sorter))
for command in subcommands:
diff --git a/src/mailman/chains/base.py b/src/mailman/chains/base.py
index fdf9477da..59125ba69 100644
--- a/src/mailman/chains/base.py
+++ b/src/mailman/chains/base.py
@@ -21,6 +21,7 @@ from mailman.config import config
from mailman.interfaces.chain import (
IChain, IChainIterator, IChainLink, IMutableChain, LinkAction)
from mailman.interfaces.rules import IRule
+from mailman.utilities.modules import abstract_component
from public import public
from zope.interface import implementer
@@ -55,6 +56,7 @@ class Link:
@public
+@abstract_component
@implementer(IChain, IChainIterator)
class TerminalChainBase:
"""A base chain that always matches and executes a method.
@@ -85,6 +87,7 @@ class TerminalChainBase:
@public
+@abstract_component
@implementer(IMutableChain)
class Chain:
"""Generic chain base class."""
diff --git a/src/mailman/core/chains.py b/src/mailman/core/chains.py
index 0eedd8b8c..c251d38bc 100644
--- a/src/mailman/core/chains.py
+++ b/src/mailman/core/chains.py
@@ -17,12 +17,10 @@
"""Application support for chain processing."""
-from mailman.chains.base import Chain, TerminalChainBase
from mailman.config import config
from mailman.interfaces.chain import IChain, LinkAction
-from mailman.utilities.modules import find_components
+from mailman.utilities.modules import add_components
from public import public
-from zope.interface.verify import verifyObject
@public
@@ -91,19 +89,5 @@ def process(mlist, msg, msgdata, start_chain='default-posting-chain'):
@public
def initialize():
"""Set up chains, both built-in and from the database."""
- for chain_class in find_components('mailman.chains', IChain):
- # FIXME 2010-12-28 barry: We need a generic way to disable automatic
- # instantiation of discovered classes. This is useful not just for
- # chains, but also for rules, handlers, etc. Ideally it should be
- # part of find_components(). For now, hard code the ones we do not
- # want to instantiate.
- if chain_class in (Chain, TerminalChainBase):
- continue
- chain = chain_class()
- verifyObject(IChain, chain)
- assert chain.name not in config.chains, (
- 'Duplicate chain "{}" found in {} (previously: {}'.format(
- chain.name, chain_class, config.chains[chain.name]))
- config.chains[chain.name] = chain
+ add_components('mailman.chains', IChain, config.chains)
# XXX Read chains from the database and initialize them.
- pass
diff --git a/src/mailman/core/pipelines.py b/src/mailman/core/pipelines.py
index 07780dfeb..15e23a022 100644
--- a/src/mailman/core/pipelines.py
+++ b/src/mailman/core/pipelines.py
@@ -25,10 +25,9 @@ from mailman.core.i18n import _
from mailman.interfaces.handler import IHandler
from mailman.interfaces.pipeline import (
DiscardMessage, IPipeline, RejectMessage)
-from mailman.utilities.modules import find_components
+from mailman.utilities.modules import add_components
from public import public
from zope.interface import implementer
-from zope.interface.verify import verifyObject
dlog = logging.getLogger('mailman.debug')
@@ -139,13 +138,7 @@ class VirginPipeline(BasePipeline):
def initialize():
"""Initialize the pipelines."""
# Find all handlers in the registered plugins.
- for handler_class in find_components('mailman.handlers', IHandler):
- handler = handler_class()
- verifyObject(IHandler, handler)
- assert handler.name not in config.handlers, (
- 'Duplicate handler "{}" found in {}'.format(
- handler.name, handler_class))
- config.handlers[handler.name] = handler
+ add_components('mailman.handlers', IHandler, config.handlers)
# Set up some pipelines.
for pipeline_class in (OwnerPipeline, PostingPipeline, VirginPipeline):
pipeline = pipeline_class()
diff --git a/src/mailman/core/rules.py b/src/mailman/core/rules.py
index ce89b06ba..8e0d9197c 100644
--- a/src/mailman/core/rules.py
+++ b/src/mailman/core/rules.py
@@ -19,18 +19,12 @@
from mailman.config import config
from mailman.interfaces.rules import IRule
-from mailman.utilities.modules import find_components
+from mailman.utilities.modules import add_components
from public import public
-from zope.interface.verify import verifyObject
@public
def initialize():
"""Find and register all rules in all plugins."""
# Find rules in plugins.
- for rule_class in find_components('mailman.rules', IRule):
- rule = rule_class()
- verifyObject(IRule, rule)
- assert rule.name not in config.rules, (
- 'Duplicate rule "{}" found in {}'.format(rule.name, rule_class))
- config.rules[rule.name] = rule
+ add_components('mailman.rules', IRule, config.rules)
diff --git a/src/mailman/styles/manager.py b/src/mailman/styles/manager.py
index 2954d8e8b..1ec83b2a9 100644
--- a/src/mailman/styles/manager.py
+++ b/src/mailman/styles/manager.py
@@ -20,7 +20,7 @@
from mailman.interfaces.configuration import ConfigurationUpdatedEvent
from mailman.interfaces.styles import (
DuplicateStyleError, IStyle, IStyleManager)
-from mailman.utilities.modules import find_components
+from mailman.utilities.modules import add_components
from public import public
from zope.component import getUtility
from zope.interface import implementer
@@ -44,13 +44,7 @@ class StyleManager:
paths = filter(None, (path.strip()
for path in config.styles.paths.splitlines()))
for path in paths:
- for style_class in find_components(path, IStyle):
- style = style_class()
- verifyObject(IStyle, style)
- assert style.name not in self._styles, (
- 'Duplicate style "{}" found in {}'.format(
- style.name, style_class))
- self._styles[style.name] = style
+ add_components(path, IStyle, self._styles)
def get(self, name):
"""See `IStyleManager`."""
diff --git a/src/mailman/utilities/modules.py b/src/mailman/utilities/modules.py
index 7aa2ac009..83a4384b7 100644
--- a/src/mailman/utilities/modules.py
+++ b/src/mailman/utilities/modules.py
@@ -25,6 +25,19 @@ from public import public
@public
+def abstract_component(cls):
+ """Decorator preventing `find_components()` from instantiating the class.
+
+ Normally, `find_components()` instantiates any component class that
+ it finds matching the given interface. Some component classes must not be
+ instantiated though, because they act as base classes. Put this decorator
+ on the class definition to prevent instantiation.
+ """
+ cls.__abstract_component__ = True
+ return cls
+
+
+@public
def find_name(dotted_name):
"""Import and return the named object in package space.
@@ -55,24 +68,36 @@ def call_name(dotted_name, *args, **kws):
return named_callable(*args, **kws)
-@public
def scan_module(module, interface):
- """Return all the items in a module that conform to an interface.
+ """Return all the object in a module that conform to an interface.
+
+ Scan every item named in the module's `__all__`. If that item conforms to
+ the given interface, *and* the item is not declared as an
+ `@abstract_component`, then instantiate the item and return the resulting
+ instance.
- :param module: A module object. The module's `__all__` will be scanned.
+ :param module: A module object.
:type module: module
:param interface: The interface that returned objects must conform to.
:type interface: `Interface`
- :return: The sequence of matching components.
- :rtype: objects implementing `interface`
+ :return: The sequence of instantiated matching components.
+ :rtype: instantiated objects implementing `interface`
"""
missing = object()
for name in module.__all__:
component = getattr(module, name, missing)
assert component is not missing, (
'%s has bad __all__: %s' % (module, name)) # pragma: no cover
- if interface.implementedBy(component):
- yield component
+ if (interface.implementedBy(component)
+ # We cannot use getattr() here because that will return True
+ # for all subclasses. __abstract_component__ should *not* be
+ # inherited, meaning subclasses must declare themselves to be
+ # abstract if they also don't want to be instantiated. Only
+ # by looking at the component's __dict__ can we know for sure
+ # where the marker has been placed. The value of
+ # __abstract_component__ doesn't matter, only its presence.
+ and '__abstract_component__' not in component.__dict__):
+ yield component()
@public
@@ -80,14 +105,15 @@ def find_components(package, interface):
"""Find components which conform to a given interface.
Search all the modules in a given package, returning an iterator over all
- objects found that conform to the given interface.
+ objects found that conform to the given interface, unless that object is
+ decorated with `@abstract_component`.
:param package: The package path to search.
:type package: string
:param interface: The interface that returned objects must conform to.
:type interface: `Interface`
- :return: The sequence of matching components.
- :rtype: objects implementing `interface`
+ :return: The sequence of instantiated matching components.
+ :rtype: instantiated objects implementing `interface`
"""
for filename in resource_listdir(package, ''):
basename, extension = os.path.splitext(filename)
@@ -102,6 +128,35 @@ def find_components(package, interface):
@public
+def add_components(package, interface, mapping):
+ """Add components to a given mapping.
+
+ Similarly to `find_components()` this inspects all modules in a given
+ package looking for objects that conform to a given interface. All such
+ found objects (unless decorated with `@abstract_component`) are added to
+ the given mapping, keyed by the object's `.name` attribute, which is
+ required. It is a fatal error if that key already exists in the mapping.
+
+ :param package: The package path to search.
+ :type package: string
+ :param interface: The interface that returned objects must conform to.
+ Objects found must have a `.name` attribute containing a unique
+ string.
+ :type interface: `Interface`
+ :param mapping: The mapping to add the found components to.
+ :type mapping: A dict-like mapping. This only needs to support
+ containment tests (e.g. `in` and `not in`) and `__setitem__()`.
+ :raises RuntimeError: when a duplicate key is found.
+ """
+ for component in find_components(package, interface):
+ if component.name in mapping:
+ raise RuntimeError(
+ 'Duplicate key "{}" found in {}; previously {}'.format(
+ component.name, component, mapping[component.name]))
+ mapping[component.name] = component
+
+
+@public
def expand_path(url):
"""Expand a python: path, returning the absolute file system path."""
# Is the context coming from a file system or Python path?
diff --git a/src/mailman/utilities/tests/test_modules.py b/src/mailman/utilities/tests/test_modules.py
index 068dee2cb..20735486c 100644
--- a/src/mailman/utilities/tests/test_modules.py
+++ b/src/mailman/utilities/tests/test_modules.py
@@ -23,7 +23,7 @@ import unittest
from contextlib import ExitStack, contextmanager
from mailman.interfaces.styles import IStyle
-from mailman.utilities.modules import find_components
+from mailman.utilities.modules import add_components, find_components
from pathlib import Path
from tempfile import TemporaryDirectory
@@ -50,8 +50,8 @@ class TestModuleImports(unittest.TestCase):
def test_find_modules_with_dotfiles(self):
# Emacs creates lock files when a single file is opened by more than
# one user. These files look like .#<filename>.py because of which
- # find_components tries to import them but fails. All such files should
- # be ignored by default.
+ # find_components() tries to import them but fails. All such files
+ # should be ignored by default.
with ExitStack() as resources:
# Creating a temporary directory and adding it to sys.path.
temp_package = resources.enter_context(TemporaryDirectory())
@@ -62,9 +62,9 @@ class TestModuleImports(unittest.TestCase):
module_path = os.path.join(temp_package, 'mypackage')
os.mkdir(module_path)
init_file = os.path.join(module_path, '__init__.py')
+ Path(init_file).touch()
good_file = os.path.join(module_path, 'goodfile.py')
bad_file = os.path.join(module_path, '.#badfile.py')
- Path(init_file).touch()
with open(good_file, 'w', encoding='utf-8') as fp:
print("""\
from public import public
@@ -97,3 +97,134 @@ class BadStyle:
for component
in find_components('mypackage', IStyle)]
self.assertEqual(names, ['good-style'])
+
+ def test_find_components_no_instantiate(self):
+ # find_components() now instantiates the class unless it's been
+ # decorated with the @abstract_component decorator.
+ with ExitStack() as resources:
+ # Creating a temporary directory and adding it to sys.path.
+ temp_package = resources.enter_context(TemporaryDirectory())
+ resources.enter_context(hack_syspath(0, temp_package))
+ resources.callback(clean_mypackage)
+ # Create a module inside the above package along with an
+ # __init__.py file so that we can import from it.
+ module_path = os.path.join(temp_package, 'mypackage')
+ os.mkdir(module_path)
+ init_file = os.path.join(module_path, '__init__.py')
+ Path(init_file).touch()
+ component_file = os.path.join(module_path, 'components.py')
+ with open(component_file, 'w', encoding='utf-8') as fp:
+ print("""\
+from mailman.interfaces.styles import IStyle
+from mailman.utilities.modules import abstract_component
+from public import public
+from zope.interface import implementer
+
+@public
+@implementer(IStyle)
+class ConcreteStyle:
+ name = 'concrete-style'
+ def apply(self):
+ pass
+
+@public
+@implementer(IStyle)
+@abstract_component
+class AbstractStyle:
+ name = 'abstract-style'
+ def apply(self):
+ pass
+""", file=fp)
+ names = [component.name
+ for component
+ in find_components('mypackage', IStyle)]
+ self.assertEqual(names, ['concrete-style'])
+
+ def test_add_components(self):
+ with ExitStack() as resources:
+ # Creating a temporary directory and adding it to sys.path.
+ temp_package = resources.enter_context(TemporaryDirectory())
+ resources.enter_context(hack_syspath(0, temp_package))
+ resources.callback(clean_mypackage)
+ # Create a module inside the above package along with an
+ # __init__.py file so that we can import from it.
+ module_path = os.path.join(temp_package, 'mypackage')
+ os.mkdir(module_path)
+ init_file = os.path.join(module_path, '__init__.py')
+ Path(init_file).touch()
+ component_file = os.path.join(module_path, 'components.py')
+ with open(component_file, 'w', encoding='utf-8') as fp:
+ print("""\
+from mailman.interfaces.styles import IStyle
+from mailman.utilities.modules import abstract_component
+from public import public
+from zope.interface import implementer
+
+@public
+@implementer(IStyle)
+class StyleA:
+ name = 'styleA'
+ def apply(self):
+ pass
+
+@public
+@implementer(IStyle)
+@abstract_component
+class StyleB:
+ name = 'styleB'
+ def apply(self):
+ pass
+
+@public
+@implementer(IStyle)
+class StyleC:
+ name = 'styleC'
+ def apply(self):
+ pass
+""", file=fp)
+ styles = {}
+ add_components('mypackage', IStyle, styles)
+ self.assertEqual(set(styles), {'styleA', 'styleC'})
+
+ def test_add_components_duplicates(self):
+ # A duplicate name exists, so a RuntimeError is raised.
+ with ExitStack() as resources:
+ # Creating a temporary directory and adding it to sys.path.
+ temp_package = resources.enter_context(TemporaryDirectory())
+ resources.enter_context(hack_syspath(0, temp_package))
+ resources.callback(clean_mypackage)
+ # Create a module inside the above package along with an
+ # __init__.py file so that we can import from it.
+ module_path = os.path.join(temp_package, 'mypackage')
+ os.mkdir(module_path)
+ init_file = os.path.join(module_path, '__init__.py')
+ Path(init_file).touch()
+ component_file = os.path.join(module_path, 'components.py')
+ with open(component_file, 'w', encoding='utf-8') as fp:
+ print("""\
+from mailman.interfaces.styles import IStyle
+from mailman.utilities.modules import abstract_component
+from public import public
+from zope.interface import implementer
+
+@public
+@implementer(IStyle)
+class StyleA1:
+ name = 'styleA'
+ def apply(self):
+ pass
+
+@public
+@implementer(IStyle)
+class StyleA2:
+ name = 'styleA'
+ def apply(self):
+ pass
+""", file=fp)
+ with self.assertRaisesRegex(
+ RuntimeError,
+ 'Duplicate key "styleA" found in '
+ '<mypackage.components.StyleA2 object at .*>; '
+ 'previously <mypackage.components.StyleA1 object at '
+ '.*>'):
+ add_components('mypackage', IStyle, {})
generated by cgit v1.2.3-70-g09d2 (git 2.51.2) at 2025-11-08 07:13:27 +0000