Move conda.core.solve._get_solver_class to `CondaPluginManager.get_…

…solver_backend` (conda#12093)

conda/api.py

@@ -2,10 +2,10 @@
 # SPDX-License-Identifier: BSD-3-Clause
 
 from .base.constants import DepsModifier as _DepsModifier, UpdateModifier as _UpdateModifier
+from .base.context import context
 from .common.constants import NULL
 from .core.package_cache_data import PackageCacheData as _PackageCacheData
 from .core.prefix_data import PrefixData as _PrefixData
-from .core.solve import _get_solver_class
 from .core.subdir_data import SubdirData as _SubdirData
 from .models.channel import Channel
 
@@ -47,8 +47,8 @@ def __init__(self, prefix, channels, subdirs=(), specs_to_add=(), specs_to_remov
                 The set of package specs to remove from the prefix.
 
         """
-        SolverType = _get_solver_class()
-        self._internal = SolverType(prefix, channels, subdirs, specs_to_add, specs_to_remove)
+        solver_backend = context.plugin_manager.get_cached_solver_backend()
+        self._internal = solver_backend(prefix, channels, subdirs, specs_to_add, specs_to_remove)
 
     def solve_final_state(self, update_modifier=NULL, deps_modifier=NULL, prune=NULL,
                           ignore_pinned=NULL, force_remove=NULL):

conda/base/context.py

@@ -842,12 +842,11 @@ def user_agent(self):
         if self.libc_family_version[0]:
             builder.append("%s/%s" % self.libc_family_version)
         if self.solver != "classic":
-            from ..core.solve import _get_solver_class
-
             user_agent_str = "solver/%s" % self.solver
             try:
+                solver_backend = self.plugin_manager.get_cached_solver_backend()
                 # Solver.user_agent has to be a static or class method
-                user_agent_str += f" {_get_solver_class().user_agent()}"
+                user_agent_str += f" {solver_backend().user_agent()}"
             except Exception as exc:
                 log.debug(
                     "User agent could not be fetched from solver class '%s'.",

conda/cli/install.py

@@ -15,7 +15,6 @@
 from ..common.path import paths_equal, is_package_file
 from ..core.index import calculate_channel_urls, get_index
 from ..core.prefix_data import PrefixData
-from ..core.solve import _get_solver_class
 from ..exceptions import (CondaExitZero, CondaImportError, CondaOSError, CondaSystemExit,
                           CondaValueError, DirectoryNotACondaEnvironmentError,
                           DirectoryNotFoundError, DryRunExit, EnvironmentLocationNotFound,
@@ -246,9 +245,15 @@ def install(args, parser, command='install'):
                 unlink_link_transaction = revert_actions(prefix, get_revision(args.revision),
                                                          index)
             else:
-                SolverType = _get_solver_class()
-                solver = SolverType(prefix, context.channels, context.subdirs, specs_to_add=specs,
-                                    repodata_fn=repodata_fn, command=args.cmd)
+                solver_backend = context.plugin_manager.get_cached_solver_backend()
+                solver = solver_backend(
+                    prefix,
+                    context.channels,
+                    context.subdirs,
+                    specs_to_add=specs,
+                    repodata_fn=repodata_fn,
+                    command=args.cmd,
+                )
                 update_modifier = context.update_modifier
                 if (isinstall or isremove) and args.update_modifier == NULL:
                     update_modifier = UpdateModifier.FREEZE_INSTALLED

conda/cli/main_remove.py

@@ -11,7 +11,6 @@
 from ..core.envs_manager import unregister_env
 from ..core.link import PrefixSetup, UnlinkLinkTransaction
 from ..core.prefix_data import PrefixData
-from ..core.solve import _get_solver_class
 from ..exceptions import CondaEnvironmentError, CondaValueError, DirectoryNotACondaEnvironmentError
 from ..gateways.disk.delete import rm_rf, path_is_clean
 from ..models.match_spec import MatchSpec
@@ -84,7 +83,8 @@ def execute(args, parser):
             specs = specs_from_args(args.package_names)
         channel_urls = ()
         subdirs = ()
-        solver = _get_solver_class()(prefix, channel_urls, subdirs, specs_to_remove=specs)
+        solver_backend = context.plugin_manager.get_cached_solver_backend()
+        solver = solver_backend(prefix, channel_urls, subdirs, specs_to_remove=specs)
         txn = solver.solve_for_transaction()
         handle_txn(txn, prefix, args, False, True)
 

conda/core/solve.py

@@ -6,6 +6,7 @@
 from logging import DEBUG, getLogger
 from os.path import join
 import sys
+import warnings
 from textwrap import dedent
 
 try:
@@ -29,7 +30,7 @@
 from ..common.constants import NULL
 from ..common.io import Spinner, dashlist, time_recorder
 from ..common.path import get_major_minor_version, paths_equal
-from ..exceptions import (CondaValueError, PackagesNotFoundError, SpecsConfigurationConflictError,
+from ..exceptions import (PackagesNotFoundError, SpecsConfigurationConflictError,
                           UnsatisfiableError)
 from ..history import History
 from ..models.channel import Channel
@@ -48,21 +49,13 @@ def _get_solver_class(key=None):
 
     See ``context.solver`` for more details.
     """
-    solvers = context.plugin_manager.get_hook_results("solvers")
-    key = (key or context.solver).lower()
-
-    solvers_mapping = {}
-    for solver in solvers:
-        solvers_mapping[solver.name.lower()] = solver.backend
-
-    if key in solvers_mapping:
-        return solvers_mapping[key]
-    else:
-        raise CondaValueError(
-            f"You have chosen a non-default solver backend ({key}) "
-            f"but it was not recognized. Choose one of: "
-            f"{', '.join(solvers_mapping.keys())}"
-        )
+    warnings.warn(
+        "`conda.core.solve._get_solver_class` is pending deprecation and will be removed in a "
+        "future release. Please use `conda.base.context.plugin_manager.get_cached_solver_backend "
+        "instead.",
+        PendingDeprecationWarning,
+    )
+    return context.plugin_manager.get_cached_solver_backend(key or context.solver)
 
 
 class Solver:

conda/plan.py

@@ -441,7 +441,6 @@ def install_actions(prefix, index, specs, force=False, only_names=None, always_c
     }, stack_callback=stack_context_default):
         from os.path import basename
         from ._vendor.boltons.setutils import IndexedSet
-        from .core.solve import _get_solver_class
         from .models.channel import Channel
         from .models.dist import Dist
         if channel_priority_map:
@@ -464,7 +463,8 @@ def install_actions(prefix, index, specs, force=False, only_names=None, always_c
         from .core.prefix_data import PrefixData
         PrefixData._cache_.clear()
 
-        solver = _get_solver_class()(prefix, channels, subdirs, specs_to_add=specs)
+        solver_backend = context.plugin_manager.get_cached_solver_backend()
+        solver = solver_backend(prefix, channels, subdirs, specs_to_add=specs)
         if index:
             solver._index = {prec: prec for prec in index.values()}
         txn = solver.solve_for_transaction(prune=prune, ignore_pinned=not pinned)

conda/plugins/hookspec.py

@@ -15,6 +15,10 @@
 
 
 class CondaSpecs:
+    """
+    The conda plugin hookspecs, to be used by developers.
+    """
+
     @_hookspec
     def conda_solvers(self) -> Iterable[CondaSolver]:
         """

conda/plugins/manager.py

@@ -9,24 +9,34 @@
 from . import solvers, virtual_packages
 from .hookspec import CondaSpecs, spec_name
 from ..auxlib.ish import dals
-from ..exceptions import PluginError
+from ..base.context import context
+from ..core.solve import Solver
+from ..exceptions import CondaValueError, PluginError
 
 
 class CondaPluginManager(pluggy.PluginManager):
     """
     The conda plugin manager to implement behavior additional to
     pluggy's default plugin manager.
     """
+    #: Cached version of the :meth:`~conda.plugins.manager.CondaPluginManager.get_solver_backend`
+    #: method.
+    get_cached_solver_backend = None
 
-    def __init__(self, project_name: str | None = None, *args, **kwargs):
+    def __init__(self, project_name: str | None = None, *args, **kwargs) -> None:
         # Setting the default project name to the spec name for ease of use
         if project_name is None:
             project_name = spec_name
         super().__init__(project_name, *args, **kwargs)
+        # Make the cache containers local to the instances so that the
+        # reference from cache to the instance gets garbage collected with the instance
+        self.get_cached_solver_backend = functools.lru_cache(maxsize=None)(self.get_solver_backend)
 
     def load_plugins(self, *plugins) -> list[str]:
         """
-        Load the provided list of plugins and fail gracefully on failure.
+        Load the provided list of plugins and fail gracefully on error.
+        The provided list plugins can either be classes or modules with
+        :attr:`~conda.plugins.hook_impl`.
         """
         plugin_names = []
         for plugin in plugins:
@@ -41,8 +51,11 @@ def load_plugins(self, *plugins) -> list[str]:
         return plugin_names
 
     def load_setuptools_entrypoints(self, *args, **kwargs) -> int:
-        """"
-        Overloading the parent method to add conda specific exception
+        """
+        Overloading the parent method from pluggy to add conda specific exceptions.
+
+        See :meth:`pluggy.PluginManager.load_setuptools_entrypoints` for
+        more information.
         """
         try:
             return super().load_setuptools_entrypoints(*args, **kwargs)
@@ -83,9 +96,48 @@ def get_hook_results(self, name: str) -> list:
             )
         return plugins
 
+    def get_solver_backend(self, name: str = None) -> type[Solver]:
+        """
+        Get the solver backend with the given name (or fall back to the
+        name provided in the context).
+
+        See ``context.solver`` for more details.
+
+        Please use the cached version of this method called
+        :meth:`get_cached_solver_backend` for high-throughput code paths
+        which is set up as a instance-specific LRU cache.
+        """
+        # Some light data validation in case name isn't given.
+        if name is None:
+            name = context.solver
+        name = name.lower()
+
+        # Build a mapping between a lower cased backend name and
+        # solver backend class provided by the installed plugins.
+        solvers_mapping = {
+            solver.name.lower(): solver.backend
+            for solver in self.get_hook_results("solvers")
+        }
+
+        # Look up the solver mapping an fail loudly if it can't
+        # find the requested solver.
+        backend = solvers_mapping.get(name, None)
+        if backend is None:
+            raise CondaValueError(
+                f"You have chosen a non-default solver backend ({name}) "
+                f"but it was not recognized. Choose one of: "
+                f"{', '.join(solvers_mapping.keys())}"
+            )
+
+        return backend
+
 
 @functools.lru_cache(maxsize=None)  # FUTURE: Python 3.9+, replace w/ functools.cache
 def get_plugin_manager() -> CondaPluginManager:
+    """
+    Get a cached version of the :class:`~conda.plugins.manager.CondaPluginManager`
+    instance, with the built-in and the entrypoints provided plugins loaded.
+    """
     plugin_manager = CondaPluginManager()
     plugin_manager.add_hookspecs(CondaSpecs)
     plugin_manager.load_plugins(solvers, *virtual_packages.plugins)

conda/testing/helpers.py

@@ -23,7 +23,6 @@
 from ..common.compat import encode_arguments
 from ..common.io import argv, captured as common_io_captured, env_var
 from ..core.prefix_data import PrefixData
-from ..core.solve import _get_solver_class
 from ..core.subdir_data import SubdirData, make_feature_record
 from ..gateways.disk.delete import rm_rf
 from ..gateways.disk.read import lexists
@@ -591,7 +590,7 @@ def get_solver(tmpdir, specs_to_add=(), specs_to_remove=(), prefix_records=(), h
             # We need CONDA_ADD_PIP_AS_PYTHON_DEPENDENCY=false here again (it's also in
             # get_index_r_*) to cover solver logics that need to load from disk instead of
             # hitting the SubdirData cache
-            solver = _get_solver_class()(
+            solver = context.plugin_manager.get_cached_solver_backend()(
                 tmpdir,
                 (Channel(f"{EXPORTED_CHANNELS_DIR}/channel-1"),),
                 (context.subdir,),
@@ -620,7 +619,7 @@ def get_solver_2(tmpdir, specs_to_add=(), specs_to_remove=(), prefix_records=(),
             # We need CONDA_ADD_PIP_AS_PYTHON_DEPENDENCY=false here again (it's also in
             # get_index_r_*) to cover solver logics that need to load from disk instead of
             # hitting the SubdirData cache
-            solver = _get_solver_class()(
+            solver = context.plugin_manager.get_cached_solver_backend()(
                 tmpdir,
                 (Channel(f"{EXPORTED_CHANNELS_DIR}/channel-2"),),
                 (context.subdir,),
@@ -649,7 +648,7 @@ def get_solver_4(tmpdir, specs_to_add=(), specs_to_remove=(), prefix_records=(),
             # We need CONDA_ADD_PIP_AS_PYTHON_DEPENDENCY=false here again (it's also in
             # get_index_r_*) to cover solver logics that need to load from disk instead of
             # hitting the SubdirData cache
-            solver = _get_solver_class()(
+            solver = context.plugin_manager.get_cached_solver_backend()(
                 tmpdir,
                 (Channel(f"{EXPORTED_CHANNELS_DIR}/channel-4"),),
                 (context.subdir,),
@@ -678,7 +677,7 @@ def get_solver_5(tmpdir, specs_to_add=(), specs_to_remove=(), prefix_records=(),
             # We need CONDA_ADD_PIP_AS_PYTHON_DEPENDENCY=false here again (it's also in
             # get_index_r_*) to cover solver logics that need to load from disk instead of
             # hitting the SubdirData cache
-            solver = _get_solver_class()(
+            solver = context.plugin_manager.get_cached_solver_backend()(
                 tmpdir,
                 (Channel(f"{EXPORTED_CHANNELS_DIR}/channel-5"),),
                 (context.subdir,),
@@ -711,7 +710,7 @@ def get_solver_aggregate_1(
             # We need CONDA_ADD_PIP_AS_PYTHON_DEPENDENCY=false here again (it's also in
             # get_index_r_*) to cover solver logics that need to load from disk instead of
             # hitting the SubdirData cache
-            solver = _get_solver_class()(
+            solver = context.plugin_manager.get_cached_solver_backend()(
                 tmpdir,
                 (
                     Channel(f"{EXPORTED_CHANNELS_DIR}/channel-2"),
@@ -747,7 +746,7 @@ def get_solver_aggregate_2(
             # We need CONDA_ADD_PIP_AS_PYTHON_DEPENDENCY=false here again (it's also in
             # get_index_r_*) to cover solver logics that need to load from disk instead of
             # hitting the SubdirData cache
-            solver = _get_solver_class()(
+            solver = context.plugin_manager.get_cached_solver_backend()(
                 tmpdir,
                 (
                     Channel(f"{EXPORTED_CHANNELS_DIR}/channel-4"),
@@ -781,7 +780,7 @@ def get_solver_must_unfreeze(
             # We need CONDA_ADD_PIP_AS_PYTHON_DEPENDENCY=false here again (it's also in
             # get_index_r_*) to cover solver logics that need to load from disk instead of
             # hitting the SubdirData cache
-            solver = _get_solver_class()(
+            solver = context.plugin_manager.get_cached_solver_backend()(
                 tmpdir,
                 (Channel(f"{EXPORTED_CHANNELS_DIR}/channel-freeze"),),
                 (context.subdir,),
@@ -812,7 +811,7 @@ def get_solver_cuda(
             # We need CONDA_ADD_PIP_AS_PYTHON_DEPENDENCY=false here again (it's also in
             # get_index_r_*) to cover solver logics that need to load from disk instead of
             # hitting the SubdirData cache
-            solver = _get_solver_class()(
+            solver = context.plugin_manager.get_cached_solver_backend()(
                 tmpdir,
                 (Channel(f"{EXPORTED_CHANNELS_DIR}/channel-1"),),
                 (context.subdir,),
@@ -836,4 +835,4 @@ def convert_to_dist_str(solution):
 
 @pytest.fixture()
 def solver_class():
-    return _get_solver_class()
+    return context.plugin_manager.get_cached_solver_backend()

conda_env/installers/conda.py

@@ -8,12 +8,12 @@
 from conda.base.constants import UpdateModifier
 from conda.base.context import context
 from conda.common.constants import NULL
-from conda.core.solve import _get_solver_class
 from conda.exceptions import UnsatisfiableError
 from conda.models.channel import Channel, prioritize_channels
 
 from ..env import Environment
 
+
 def _solve(prefix, specs, args, env, *_, **kwargs):
     # TODO: support all various ways this happens
     # Including 'nodefaults' in the channels list disables the defaults
@@ -26,7 +26,8 @@ def _solve(prefix, specs, args, env, *_, **kwargs):
     channels = IndexedSet(Channel(url) for url in _channel_priority_map)
     subdirs = IndexedSet(basename(url) for url in _channel_priority_map)
 
-    solver = _get_solver_class()(prefix, channels, subdirs, specs_to_add=specs)
+    solver_backend = context.plugin_manager.get_cached_solver_backend()
+    solver = solver_backend(prefix, channels, subdirs, specs_to_add=specs)
     return solver
 
 

docs/source/conf.py

@@ -50,6 +50,7 @@
     "sphinx.ext.graphviz",
     "sphinx.ext.ifconfig",
     "sphinx.ext.inheritance_diagram",
+    "sphinx.ext.intersphinx",
     "sphinxcontrib.plantuml",
     "conda_umls",
     "sphinx_sitemap",
@@ -234,3 +235,9 @@
 plantuml = f"java -Djava.awt.headless=true -jar {plantuml_jarfile_path}"
 
 add_module_names = False
+
+
+intersphinx_mapping = {
+    'python': ('https://docs.python.org/3', None),
+    'pluggy': ('https://pluggy.readthedocs.io/en/stable/', None),
+}