Additions to support HAAlchemy plugin

- add a connect=True key to connection record to support
  pre-loading of _ConnectionRecord objects
- ensure _ConnectionRecord.close() leaves the record in a good
  state for reopening
- add _ConnectionRecord.record_info for persistent storage
- add "in_use" accessor based on fairy_ref being present or not
- allow for the exclusions system and SuiteRequirements to be
  usable without the full plugin_base setup.
- move some Python-env requirements to the importable
  requirements.py module.
- allow starttime to be queried
- add additional events for engine plugins
- have "dialect" be a first-class parameter to the pool,
  ensure the engine strategy supplies it up front

Change-Id: Ibf549f7a1766e49d335cd6f5e26bacfaef9a8229

3 files changed, 18 insertions, 2 deletions

diff --git a/lib/sqlalchemy/engine/base.py b/lib/sqlalchemy/engine/base.py
index 83f0f0c83..b8acf298f 100644
--- a/lib/sqlalchemy/engine/base.py
+++ b/lib/sqlalchemy/engine/base.py
@@ -1752,7 +1752,6 @@ class Engine(Connectable, log.Identified):
         self.pool = pool
         self.url = url
         self.dialect = dialect
-        self.pool._dialect = dialect
         if logging_name:
             self.logging_name = logging_name
         self.echo = echo
diff --git a/lib/sqlalchemy/engine/interfaces.py b/lib/sqlalchemy/engine/interfaces.py
index 13e8bf1f4..082661216 100644
--- a/lib/sqlalchemy/engine/interfaces.py
+++ b/lib/sqlalchemy/engine/interfaces.py
@@ -900,6 +900,12 @@ class CreateEnginePlugin(object):
         """
         self.url = url
 
+    def handle_dialect_kwargs(self, dialect_cls, dialect_args):
+        """parse and modify dialect kwargs"""
+
+    def handle_pool_kwargs(self, pool_cls, pool_args):
+        """parse and modify pool kwargs"""
+
     def engine_created(self, engine):
         """Receive the :class:`.Engine` object when it is fully constructed.
 
diff --git a/lib/sqlalchemy/engine/strategies.py b/lib/sqlalchemy/engine/strategies.py
index 82800a918..ccda14be4 100644
--- a/lib/sqlalchemy/engine/strategies.py
+++ b/lib/sqlalchemy/engine/strategies.py
@@ -81,6 +81,9 @@ class DefaultEngineStrategy(EngineStrategy):
 
         dialect_args['dbapi'] = dbapi
 
+        for plugin in plugins:
+            plugin.handle_dialect_kwargs(dialect_cls, dialect_args)
+
         # create dialect
         dialect = dialect_cls(**dialect_args)
 
@@ -106,7 +109,9 @@ class DefaultEngineStrategy(EngineStrategy):
             poolclass = pop_kwarg('poolclass', None)
             if poolclass is None:
                 poolclass = dialect_cls.get_pool_class(u)
-            pool_args = {}
+            pool_args = {
+                'dialect': dialect
+            }
 
             # consume pool arguments from kwargs, translating a few of
             # the arguments
@@ -121,6 +126,10 @@ class DefaultEngineStrategy(EngineStrategy):
                 tk = translate.get(k, k)
                 if tk in kwargs:
                     pool_args[k] = pop_kwarg(tk)
+
+            for plugin in plugins:
+                plugin.handle_pool_kwargs(poolclass, pool_args)
+
             pool = poolclass(creator, **pool_args)
         else:
             if isinstance(pool, poollib._DBProxy):
@@ -128,6 +137,8 @@ class DefaultEngineStrategy(EngineStrategy):
             else:
                 pool = pool
 
+            pool._dialect = dialect
+
         # create engine.
         engineclass = self.engine_cls
         engine_args = {}