caches: use new sqlalchemy 1.4 caching query approach

rhodecode/lib/caching_query.py

@@ -1,298 +1,249 b''
 # -*- coding: utf-8 -*-
 
 # Copyright (C) 2010-2020 RhodeCode GmbH
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU Affero General Public License, version 3
 # (only), as published by the Free Software Foundation.
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 # This program is dual-licensed. If you wish to learn more about the
 # RhodeCode Enterprise Edition, including its added features, Support services,
 # and proprietary license terms, please see https://rhodecode.com/licenses/
 
 """caching_query.py
 
 Represent functions and classes
 which allow the usage of Dogpile caching with SQLAlchemy.
 Introduces a query option called FromCache.
 
+.. versionchanged:: 1.4  the caching approach has been altered to work
+   based on a session event.
+
+
 The three new concepts introduced here are:
 
- * CachingQuery - a Query subclass that caches and
+ * ORMCache - an extension for an ORM :class:`.Session`
    retrieves results in/from dogpile.cache.
  * FromCache - a query option that establishes caching
    parameters on a Query
  * RelationshipCache - a variant of FromCache which is specific
    to a query invoked during a lazy load.
- * _params_from_query - extracts value parameters from
-   a Query.
 
 The rest of what's here are standard SQLAlchemy and
 dogpile.cache constructs.
 
 """
-from sqlalchemy.orm.interfaces import MapperOption
-from sqlalchemy.orm.query import Query
-from sqlalchemy.sql import visitors
 from dogpile.cache.api import NO_VALUE
 
-from rhodecode.lib.utils2 import safe_str
+from sqlalchemy import event
+from sqlalchemy.orm import loading
+from sqlalchemy.orm.interfaces import UserDefinedOption
+
+
+DEFAULT_REGION = "sql_cache_short"
 
 
-class CachingQuery(Query):
-    """A Query subclass which optionally loads full results from a dogpile
-    cache region.
+class ORMCache:
 
-    The CachingQuery optionally stores additional state that allows it to consult
-    a dogpile.cache cache before accessing the database, in the form
-    of a FromCache or RelationshipCache object.   Each of these objects
-    refer to the name of a :class:`dogpile.cache.Region` that's been configured
-    and stored in a lookup dictionary.  When such an object has associated
-    itself with the CachingQuery, the corresponding :class:`dogpile.cache.Region`
-    is used to locate a cached result.  If none is present, then the
-    Query is invoked normally, the results being cached.
+    """An add-on for an ORM :class:`.Session` optionally loads full results
+    from a dogpile cache region.
 
-    The FromCache and RelationshipCache mapper options below represent
-    the "public" method of configuring this state upon the CachingQuery.
+    cache = ORMCache(regions={})
+    cache.listen_on_session(Session)
 
     """
-    def _get_region(self):
+
+    def __init__(self, regions):
+        self.cache_regions = regions or self._get_region()
+        self._statement_cache = {}
+
+    @classmethod
+    def _get_region(cls):
         from rhodecode.lib.rc_cache import region_meta
         return region_meta.dogpile_cache_regions
 
-    def __init__(self, regions, *args, **kw):
-        self.cache_regions = regions or self._get_region()
-        Query.__init__(self, *args, **kw)
+    def listen_on_session(self, session_factory):
+        event.listen(session_factory, "do_orm_execute", self._do_orm_execute)
+
+    def _do_orm_execute(self, orm_context):
 
-    def __iter__(self):
-        """override __iter__ to pull results from dogpile
-           if particular attributes have been configured.
+        for opt in orm_context.user_defined_options:
+            if isinstance(opt, RelationshipCache):
+                opt = opt._process_orm_context(orm_context)
+                if opt is None:
+                    continue
+
+            if isinstance(opt, FromCache):
+                dogpile_region = self.cache_regions[opt.region]
 
-           Note that this approach does *not* detach the loaded objects from
-           the current session. If the cache backend is an in-process cache
-           (like "memory") and lives beyond the scope of the current session's
-           transaction, those objects may be expired. The method here can be
-           modified to first expunge() each loaded item from the current
-           session before returning the list of items, so that the items
-           in the cache are not the same ones in the current Session.
+                if opt.cache_key:
+                    our_cache_key = f'SQL_CACHE_{opt.cache_key}'
+                else:
+                    our_cache_key = opt._generate_cache_key(
+                        orm_context.statement, orm_context.parameters, self
+                    )
 
-        """
-        super_ = super(CachingQuery, self)
-
-        if hasattr(self, '_cache_region'):
-            return self.get_value(createfunc=lambda: list(super_.__iter__()))
-        else:
-            return super_.__iter__()
-
-    def _execute_and_instances(self, context):
-        """override _execute_and_instances to pull results from dogpile
-            if the query is invoked directly from an external context.
+                if opt.ignore_expiration:
+                    cached_value = dogpile_region.get(
+                        our_cache_key,
+                        expiration_time=opt.expiration_time,
+                        ignore_expiration=opt.ignore_expiration,
+                    )
+                else:
 
-           This method is necessary in order to maintain compatibility
-           with the "baked query" system now used by default in some
-           relationship loader scenarios.   Note also the
-           RelationshipCache._generate_cache_key method which enables
-           the baked query to be used within lazy loads.
+                    def createfunc():
+                        return orm_context.invoke_statement().freeze()
+
+                    cached_value = dogpile_region.get_or_create(
+                        our_cache_key,
+                        createfunc,
+                        expiration_time=opt.expiration_time,
+                    )
 
-           .. versionadded:: 1.2.7
-        """
-        super_ = super(CachingQuery, self)
+                if cached_value is NO_VALUE:
+                    # keyerror?   this is bigger than a keyerror...
+                    raise KeyError()
 
-        if context.query is not self and hasattr(self, '_cache_region'):
-            # special logic called when the Query._execute_and_instances()
-            # method is called directly from the baked query
-            return self.get_value(
-                createfunc=lambda: list(
-                    super_._execute_and_instances(context)
+                orm_result = loading.merge_frozen_result(
+                    orm_context.session,
+                    orm_context.statement,
+                    cached_value,
+                    load=False,
                 )
-            )
+                return orm_result()
+
         else:
-            return super_._execute_and_instances(context)
+            return None
 
-    def _get_cache_plus_key(self):
-        """Return a cache region plus key."""
-        dogpile_region = self.cache_regions[self._cache_region.region]
-        if self._cache_region.cache_key:
-            key = self._cache_region.cache_key
-        else:
-            key = _key_from_query(self)
-        return dogpile_region, key
+    def invalidate(self, statement, parameters, opt):
+        """Invalidate the cache value represented by a statement."""
+
+        statement = statement.__clause_element__()
 
-    def invalidate(self):
-        """Invalidate the cache value represented by this Query."""
+        dogpile_region = self.cache_regions[opt.region]
 
-        dogpile_region, cache_key = self._get_cache_plus_key()
+        cache_key = opt._generate_cache_key(statement, parameters, self)
+
         dogpile_region.delete(cache_key)
 
-    def get_value(self, merge=True, createfunc=None,
-                  expiration_time=None, ignore_expiration=False):
-        """Return the value from the cache for this query.
 
-        Raise KeyError if no value present and no
-        createfunc specified.
-
-        """
-        dogpile_region, cache_key = self._get_cache_plus_key()
-
-        # ignore_expiration means, if the value is in the cache
-        # but is expired, return it anyway.   This doesn't make sense
-        # with createfunc, which says, if the value is expired, generate
-        # a new value.
-        assert not ignore_expiration or not createfunc, \
-                "Can't ignore expiration and also provide createfunc"
-
-        if ignore_expiration or not createfunc:
-            cached_value = dogpile_region.get(cache_key,
-                                expiration_time=expiration_time,
-                                ignore_expiration=ignore_expiration)
-        else:
-            cached_value = dogpile_region.get_or_create(
-                                    cache_key,
-                                    createfunc,
-                                    expiration_time=expiration_time
-                                )
-        if cached_value is NO_VALUE:
-            raise KeyError(cache_key)
-        if merge:
-            cached_value = self.merge_result(cached_value, load=False)
-        return cached_value
-
-    def set_value(self, value):
-        """Set the value in the cache for this query."""
-
-        dogpile_region, cache_key = self._get_cache_plus_key()
-        dogpile_region.set(cache_key, value)
-
-
-def query_callable(regions=None, query_cls=CachingQuery):
-    def query(*arg, **kw):
-        return query_cls(regions, *arg, **kw)
-    return query
-
-
-def _key_from_query(query, qualifier=None):
-    """Given a Query, create a cache key.
-
-    There are many approaches to this; here we use the simplest,
-    which is to create an md5 hash of the text of the SQL statement,
-    combined with stringified versions of all the bound parameters
-    within it.     There's a bit of a performance hit with
-    compiling out "query.statement" here; other approaches include
-    setting up an explicit cache key with a particular Query,
-    then combining that with the bound parameter values.
-
-    """
-
-    stmt = query.with_labels().statement
-    compiled = stmt.compile()
-    params = compiled.params
-
-    # here we return the key as a long string.  our "key mangler"
-    # set up with the region will boil it down to an md5.
-    return " ".join(
-                    [safe_str(compiled)] +
-                    [safe_str(params[k]) for k in sorted(params)])
-
-
-class FromCache(MapperOption):
+class FromCache(UserDefinedOption):
     """Specifies that a Query should load results from a cache."""
 
     propagate_to_loaders = False
 
-    def __init__(self, region="sql_cache_short", cache_key=None):
+    def __init__(
+        self,
+        region=DEFAULT_REGION,
+        cache_key=None,
+        expiration_time=None,
+        ignore_expiration=False,
+    ):
         """Construct a new FromCache.
 
         :param region: the cache region.  Should be a
-        region configured in the dictionary of dogpile
-        regions.
+         region configured in the dictionary of dogpile
+         regions.
 
         :param cache_key: optional.  A string cache key
-        that will serve as the key to the query.   Use this
-        if your query has a huge amount of parameters (such
-        as when using in_()) which correspond more simply to
-        some other identifier.
+         that will serve as the key to the query.   Use this
+         if your query has a huge amount of parameters (such
+         as when using in_()) which correspond more simply to
+         some other identifier.
 
         """
         self.region = region
         self.cache_key = cache_key
+        self.expiration_time = expiration_time
+        self.ignore_expiration = ignore_expiration
 
-    def process_query(self, query):
-        """Process a Query during normal loading operation."""
-        query._cache_region = self
+    # this is not needed as of SQLAlchemy 1.4.28;
+    # UserDefinedOption classes no longer participate in the SQL
+    # compilation cache key
+    def _gen_cache_key(self, anon_map, bindparams):
+        return None
+
+    def _generate_cache_key(self, statement, parameters, orm_cache):
+        """generate a cache key with which to key the results of a statement.
+
+        This leverages the use of the SQL compilation cache key which is
+        repurposed as a SQL results key.
+
+        """
+        statement_cache_key = statement._generate_cache_key()
+
+        key = statement_cache_key.to_offline_string(
+            orm_cache._statement_cache, statement, parameters
+        ) + repr(self.cache_key)
+        # print("here's our key...%s" % key)
+        return key
 
 
-class RelationshipCache(MapperOption):
+class RelationshipCache(FromCache):
     """Specifies that a Query as called within a "lazy load"
-       should load results from a cache."""
+    should load results from a cache."""
 
     propagate_to_loaders = True
 
-    def __init__(self, attribute, region="sql_cache_short", cache_key=None):
+    def __init__(
+        self,
+        attribute,
+        region=DEFAULT_REGION,
+        cache_key=None,
+        expiration_time=None,
+        ignore_expiration=False,
+    ):
         """Construct a new RelationshipCache.
 
         :param attribute: A Class.attribute which
-        indicates a particular class relationship() whose
-        lazy loader should be pulled from the cache.
+         indicates a particular class relationship() whose
+         lazy loader should be pulled from the cache.
 
         :param region: name of the cache region.
 
         :param cache_key: optional.  A string cache key
-        that will serve as the key to the query, bypassing
-        the usual means of forming a key from the Query itself.
+         that will serve as the key to the query, bypassing
+         the usual means of forming a key from the Query itself.
 
         """
         self.region = region
         self.cache_key = cache_key
+        self.expiration_time = expiration_time
+        self.ignore_expiration = ignore_expiration
         self._relationship_options = {
             (attribute.property.parent.class_, attribute.property.key): self
         }
 
-    def _generate_cache_key(self, path):
-        """Indicate to the lazy-loader strategy that a "baked" query
-        may be used by returning ``None``.
-
-        If this method is omitted, the default implementation of
-        :class:`.MapperOption._generate_cache_key` takes place, which
-        returns ``False`` to disable the "baked" query from being used.
-
-        .. versionadded:: 1.2.7
+    def _process_orm_context(self, orm_context):
+        current_path = orm_context.loader_strategy_path
 
-        """
-        return None
-
-    def process_query_conditionally(self, query):
-        """Process a Query that is used within a lazy loader.
-
-        (the process_query_conditionally() method is a SQLAlchemy
-        hook invoked only within lazyload.)
-
-        """
-        if query._current_path:
-            mapper, prop = query._current_path[-2:]
+        if current_path:
+            mapper, prop = current_path[-2:]
             key = prop.key
 
             for cls in mapper.class_.__mro__:
                 if (cls, key) in self._relationship_options:
-                    relationship_option = self._relationship_options[(cls, key)]
-                    query._cache_region = relationship_option
-                    break
+                    relationship_option = self._relationship_options[
+                        (cls, key)
+                    ]
+                    return relationship_option
 
     def and_(self, option):
         """Chain another RelationshipCache option to this one.
 
         While many RelationshipCache objects can be specified on a single
         Query separately, chaining them together allows for a more efficient
         lookup during load.
 
         """
         self._relationship_options.update(option._relationship_options)
         return self
 

rhodecode/lib/rc_cache/__init__.py

@@ -1,88 +1,89 b''
 # -*- coding: utf-8 -*-
 
 # Copyright (C) 2015-2020 RhodeCode GmbH
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU Affero General Public License, version 3
 # (only), as published by the Free Software Foundation.
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 # This program is dual-licensed. If you wish to learn more about the
 # RhodeCode Enterprise Edition, including its added features, Support services,
 # and proprietary license terms, please see https://rhodecode.com/licenses/
 
 import logging
 from dogpile.cache import register_backend
 module_name = 'rhodecode'
 
 register_backend(
     "dogpile.cache.rc.memory_lru", f"{module_name}.lib.rc_cache.backends",
     "LRUMemoryBackend")
 
 register_backend(
     "dogpile.cache.rc.file_namespace", f"{module_name}.lib.rc_cache.backends",
     "FileNamespaceBackend")
 
 register_backend(
     "dogpile.cache.rc.redis", f"{module_name}.lib.rc_cache.backends",
     "RedisPickleBackend")
 
 register_backend(
     "dogpile.cache.rc.redis_msgpack", f"{module_name}.lib.rc_cache.backends",
     "RedisMsgPackBackend")
 
 
 log = logging.getLogger(__name__)
 
 from . import region_meta
 from .utils import (
     get_default_cache_settings, backend_key_generator, get_or_create_region,
     clear_cache_namespace, make_region, InvalidationContext,
-    FreshRegionCache, ActiveRegionCache)
+    FreshRegionCache, ActiveRegionCache
+)
 
 
 FILE_TREE_CACHE_VER = 'v4'
 LICENSE_CACHE_VER = 'v2'
 
 
 def configure_dogpile_cache(settings):
     cache_dir = settings.get('cache_dir')
     if cache_dir:
         region_meta.dogpile_config_defaults['cache_dir'] = cache_dir
 
     rc_cache_data = get_default_cache_settings(settings, prefixes=['rc_cache.'])
 
     # inspect available namespaces
     avail_regions = set()
     for key in rc_cache_data.keys():
         namespace_name = key.split('.', 1)[0]
         if namespace_name in avail_regions:
             continue
 
         avail_regions.add(namespace_name)
         log.debug('dogpile: found following cache regions: %s', namespace_name)
 
         new_region = make_region(
             name=namespace_name,
             function_key_generator=None
         )
 
         new_region.configure_from_config(settings, 'rc_cache.{}.'.format(namespace_name))
         new_region.function_key_generator = backend_key_generator(new_region.actual_backend)
         if log.isEnabledFor(logging.DEBUG):
             region_args = dict(backend=new_region.actual_backend.__class__,
                                region_invalidator=new_region.region_invalidator.__class__)
             log.debug('dogpile: registering a new region `%s` %s', namespace_name, region_args)
 
         region_meta.dogpile_cache_regions[namespace_name] = new_region
 
 
 def includeme(config):
     configure_dogpile_cache(config.registry.settings)

rhodecode/lib/rc_cache/utils.py

@@ -1,369 +1,372 b''
 # -*- coding: utf-8 -*-
 
 # Copyright (C) 2015-2020 RhodeCode GmbH
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU Affero General Public License, version 3
 # (only), as published by the Free Software Foundation.
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 # This program is dual-licensed. If you wish to learn more about the
 # RhodeCode Enterprise Edition, including its added features, Support services,
 # and proprietary license terms, please see https://rhodecode.com/licenses/
 import os
 import time
 import logging
 import functools
 import decorator
 import threading
 
 from dogpile.cache import CacheRegion
 
 import rhodecode
 from rhodecode.lib.hash_utils import sha1
 from rhodecode.lib.type_utils import str2bool
 from rhodecode.lib.str_utils import safe_bytes
-from rhodecode.model.db import Session, CacheKey, IntegrityError
 
 from rhodecode.lib.rc_cache import cache_key_meta
 from rhodecode.lib.rc_cache import region_meta
 
 log = logging.getLogger(__name__)
 
 
 def isCython(func):
     """
     Private helper that checks if a function is a cython function.
     """
     return func.__class__.__name__ == 'cython_function_or_method'
 
 
 class RhodeCodeCacheRegion(CacheRegion):
 
     def conditional_cache_on_arguments(
             self, namespace=None,
             expiration_time=None,
             should_cache_fn=None,
             to_str=str,
             function_key_generator=None,
             condition=True):
         """
         Custom conditional decorator, that will not touch any dogpile internals if
         condition isn't meet. This works a bit different than should_cache_fn
         And it's faster in cases we don't ever want to compute cached values
         """
         expiration_time_is_callable = callable(expiration_time)
 
         if function_key_generator is None:
             function_key_generator = self.function_key_generator
 
         def get_or_create_for_user_func(key_generator, user_func, *arg, **kw):
 
             if not condition:
                 log.debug('Calling un-cached method:%s', user_func.__name__)
                 start = time.time()
                 result = user_func(*arg, **kw)
                 total = time.time() - start
                 log.debug('un-cached method:%s took %.4fs', user_func.__name__, total)
                 return result
 
             key = key_generator(*arg, **kw)
 
             timeout = expiration_time() if expiration_time_is_callable \
                 else expiration_time
 
             log.debug('Calling cached method:`%s`', user_func.__name__)
             return self.get_or_create(key, user_func, timeout, should_cache_fn, (arg, kw))
 
         def cache_decorator(user_func):
             if to_str is str:
                 # backwards compatible
                 key_generator = function_key_generator(namespace, user_func)
             else:
                 key_generator = function_key_generator(namespace, user_func, to_str=to_str)
 
             def refresh(*arg, **kw):
                 """
                 Like invalidate, but regenerates the value instead
                 """
                 key = key_generator(*arg, **kw)
                 value = user_func(*arg, **kw)
                 self.set(key, value)
                 return value
 
             def invalidate(*arg, **kw):
                 key = key_generator(*arg, **kw)
                 self.delete(key)
 
             def set_(value, *arg, **kw):
                 key = key_generator(*arg, **kw)
                 self.set(key, value)
 
             def get(*arg, **kw):
                 key = key_generator(*arg, **kw)
                 return self.get(key)
 
             user_func.set = set_
             user_func.invalidate = invalidate
             user_func.get = get
             user_func.refresh = refresh
             user_func.key_generator = key_generator
             user_func.original = user_func
 
             # Use `decorate` to preserve the signature of :param:`user_func`.
             return decorator.decorate(user_func, functools.partial(
                 get_or_create_for_user_func, key_generator))
 
         return cache_decorator
 
 
 def make_region(*arg, **kw):
     return RhodeCodeCacheRegion(*arg, **kw)
 
 
 def get_default_cache_settings(settings, prefixes=None):
     prefixes = prefixes or []
     cache_settings = {}
     for key in settings.keys():
         for prefix in prefixes:
             if key.startswith(prefix):
                 name = key.split(prefix)[1].strip()
                 val = settings[key]
                 if isinstance(val, str):
                     val = val.strip()
                 cache_settings[name] = val
     return cache_settings
 
 
 def compute_key_from_params(*args):
     """
     Helper to compute key from given params to be used in cache manager
     """
     return sha1(safe_bytes("_".join(map(str, args))))
 
 
 def backend_key_generator(backend):
     """
     Special wrapper that also sends over the backend to the key generator
     """
     def wrapper(namespace, fn):
         return key_generator(backend, namespace, fn)
     return wrapper
 
 
 def key_generator(backend, namespace, fn):
     fname = fn.__name__
 
     def generate_key(*args):
         backend_prefix = getattr(backend, 'key_prefix', None) or 'backend_prefix'
         namespace_pref = namespace or 'default_namespace'
         arg_key = compute_key_from_params(*args)
         final_key = "{}:{}:{}_{}".format(backend_prefix, namespace_pref, fname, arg_key)
 
         return final_key
 
     return generate_key
 
 
 def get_or_create_region(region_name, region_namespace=None):
     from rhodecode.lib.rc_cache.backends import FileNamespaceBackend
     region_obj = region_meta.dogpile_cache_regions.get(region_name)
     if not region_obj:
         raise EnvironmentError(
             'Region `{}` not in configured: {}.'.format(
                 region_name, list(region_meta.dogpile_cache_regions.keys())))
 
     region_uid_name = '{}:{}'.format(region_name, region_namespace)
     if isinstance(region_obj.actual_backend, FileNamespaceBackend):
         region_exist = region_meta.dogpile_cache_regions.get(region_namespace)
         if region_exist:
             log.debug('Using already configured region: %s', region_namespace)
             return region_exist
         cache_dir = region_meta.dogpile_config_defaults['cache_dir']
         expiration_time = region_obj.expiration_time
 
         if not os.path.isdir(cache_dir):
             os.makedirs(cache_dir)
         new_region = make_region(
             name=region_uid_name,
             function_key_generator=backend_key_generator(region_obj.actual_backend)
         )
         namespace_filename = os.path.join(
             cache_dir, "{}.cache.dbm".format(region_namespace))
         # special type that allows 1db per namespace
         new_region.configure(
             backend='dogpile.cache.rc.file_namespace',
             expiration_time=expiration_time,
             arguments={"filename": namespace_filename}
         )
 
         # create and save in region caches
         log.debug('configuring new region: %s', region_uid_name)
         region_obj = region_meta.dogpile_cache_regions[region_namespace] = new_region
 
     return region_obj
 
 
 def clear_cache_namespace(cache_region, cache_namespace_uid, invalidate=False):
     region = get_or_create_region(cache_region, cache_namespace_uid)
     cache_keys = region.backend.list_keys(prefix=cache_namespace_uid)
     num_delete_keys = len(cache_keys)
     if invalidate:
         region.invalidate(hard=False)
     else:
         if num_delete_keys:
             region.delete_multi(cache_keys)
     return num_delete_keys
 
 
 class ActiveRegionCache(object):
     def __init__(self, context, cache_data):
         self.context = context
         self.cache_data = cache_data
 
     def should_invalidate(self):
         return False
 
 
 class FreshRegionCache(object):
     def __init__(self, context, cache_data):
         self.context = context
         self.cache_data = cache_data
 
     def should_invalidate(self):
         return True
 
 
 class InvalidationContext(object):
     """
     usage::
 
         from rhodecode.lib import rc_cache
 
         cache_namespace_uid = CacheKey.SOME_NAMESPACE.format(1)
         region = rc_cache.get_or_create_region('cache_perms', cache_namespace_uid)
 
         @region.conditional_cache_on_arguments(namespace=cache_namespace_uid, condition=True)
         def heavy_compute(cache_name, param1, param2):
             print('COMPUTE {}, {}, {}'.format(cache_name, param1, param2))
 
         # invalidation namespace is shared namespace key for all process caches
         # we use it to send a global signal
         invalidation_namespace = 'repo_cache:1'
 
         inv_context_manager = rc_cache.InvalidationContext(
             uid=cache_namespace_uid, invalidation_namespace=invalidation_namespace)
         with inv_context_manager as invalidation_context:
             args = ('one', 'two')
             # re-compute and store cache if we get invalidate signal
             if invalidation_context.should_invalidate():
                 result = heavy_compute.refresh(*args)
             else:
                 result = heavy_compute(*args)
 
             compute_time = inv_context_manager.compute_time
             log.debug('result computed in %.4fs', compute_time)
 
         # To send global invalidation signal, simply run
         CacheKey.set_invalidate(invalidation_namespace)
 
     """
 
     def __repr__(self):
         return f'<InvalidationContext:{self.cache_key}[{self.uid}]>'
 
     def __init__(self, uid, invalidation_namespace='',
                  raise_exception=False, thread_scoped=None):
         self.uid = uid
         self.invalidation_namespace = invalidation_namespace
         self.raise_exception = raise_exception
         self.proc_id = rhodecode.CONFIG.get('instance_id') or 'DEFAULT'
         self.thread_id = 'global'
 
         if thread_scoped is None:
             # if we set "default" we can override this via .ini settings
             thread_scoped = str2bool(rhodecode.CONFIG.get('cache_thread_scoped'))
 
         # Append the thread id to the cache key if this invalidation context
         # should be scoped to the current thread.
         if thread_scoped is True:
             self.thread_id = threading.current_thread().ident
 
         self.cache_key = compute_key_from_params(uid)
         self.cache_key = 'proc:{}|thread:{}|params:{}'.format(
             self.proc_id, self.thread_id, self.cache_key)
         self.proc_key = 'proc:{}'.format(self.proc_id)
         self.compute_time = 0
 
     def get_or_create_cache_obj(self, cache_type, invalidation_namespace=''):
+        from rhodecode.model.db import CacheKey
+
         invalidation_namespace = invalidation_namespace or self.invalidation_namespace
         # fetch all cache keys for this namespace and convert them to a map to find if we
         # have specific cache_key object registered. We do this because we want to have
         # all consistent cache_state_uid for newly registered objects
         cache_obj_map = CacheKey.get_namespace_map(invalidation_namespace)
         cache_obj = cache_obj_map.get(self.cache_key)
         log.debug('Fetched cache obj %s using %s cache key.', cache_obj, self.cache_key)
 
         if not cache_obj:
             new_cache_args = invalidation_namespace
             first_cache_obj = next(iter(cache_obj_map.values())) if cache_obj_map else None
             cache_state_uid = None
             if first_cache_obj:
                 cache_state_uid = first_cache_obj.cache_state_uid
             cache_obj = CacheKey(self.cache_key, cache_args=new_cache_args,
                                  cache_state_uid=cache_state_uid)
             cache_key_meta.cache_keys_by_pid.add(self.proc_key)
 
         return cache_obj
 
     def __enter__(self):
         """
         Test if current object is valid, and return CacheRegion function
         that does invalidation and calculation
         """
         log.debug('Entering cache invalidation check context: %s', self.invalidation_namespace)
         # register or get a new key based on uid
         self.cache_obj = self.get_or_create_cache_obj(cache_type=self.uid)
         cache_data = self.cache_obj.get_dict()
         self._start_time = time.time()
         if self.cache_obj.cache_active:
             # means our cache obj is existing and marked as it's
             # cache is not outdated, we return ActiveRegionCache
             self.skip_cache_active_change = True
 
             return ActiveRegionCache(context=self, cache_data=cache_data)
 
         # the key is either not existing or set to False, we return
         # the real invalidator which re-computes value. We additionally set
         # the flag to actually update the Database objects
         self.skip_cache_active_change = False
         return FreshRegionCache(context=self, cache_data=cache_data)
 
     def __exit__(self, exc_type, exc_val, exc_tb):
+        from rhodecode.model.db import Session, IntegrityError
+
         # save compute time
         self.compute_time = time.time() - self._start_time
 
         if self.skip_cache_active_change:
             return
 
         try:
             self.cache_obj.cache_active = True
             Session().add(self.cache_obj)
             Session().commit()
         except IntegrityError:
             # if we catch integrity error, it means we inserted this object
             # assumption is that's really an edge race-condition case and
             # it's safe is to skip it
             Session().rollback()
         except Exception:
             log.exception('Failed to commit on cache key update')
             Session().rollback()
             if self.raise_exception:
                 raise

rhodecode/model/meta.py

@@ -1,51 +1,56 b''
 # -*- coding: utf-8 -*-
 
 # Copyright (C) 2010-2020 RhodeCode GmbH
 #
 # This program is free software: you can redistribute it and/or modify
 # it under the terms of the GNU Affero General Public License, version 3
 # (only), as published by the Free Software Foundation.
 #
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU Affero General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 # This program is dual-licensed. If you wish to learn more about the
 # RhodeCode Enterprise Edition, including its added features, Support services,
 # and proprietary license terms, please see https://rhodecode.com/licenses/
 
 """
 SQLAlchemy Metadata and Session object
 """
 
 from sqlalchemy.orm import declarative_base
 from sqlalchemy.orm import scoped_session, sessionmaker
 from sqlalchemy.orm import Session as SASession
-from rhodecode.lib import caching_query
+from rhodecode.lib.caching_query import ORMCache
+
 
 __all__ = ['Base', 'Session', 'raw_query_executor']
 
 # scoped_session.  Apply our custom CachingQuery class to it,
 # using a callable that will associate the dictionary
 # of regions with the Query.
 # to use cache use this in query
 # .options(FromCache("sqlalchemy_cache_type", "cachekey"))
 Session = scoped_session(
                 sessionmaker(
-                    query_cls=caching_query.query_callable(),
                     expire_on_commit=True,
                 )
           )
 
+# pass empty regions so we can fetch it on-demand inside ORMCache
+cache = ORMCache(regions={})
+cache.listen_on_session(Session)
+
+
 # The declarative Base
 Base = declarative_base()
 
 
 def raw_query_executor():
     engine = Base.metadata.bind
     session = SASession(engine)
     return session