diff options
Diffstat (limited to 'lib/sqlalchemy/sql/traversals.py')
| -rw-r--r-- | lib/sqlalchemy/sql/traversals.py | 63 |
1 files changed, 57 insertions, 6 deletions
diff --git a/lib/sqlalchemy/sql/traversals.py b/lib/sqlalchemy/sql/traversals.py index a308feb7c..482248ada 100644 --- a/lib/sqlalchemy/sql/traversals.py +++ b/lib/sqlalchemy/sql/traversals.py @@ -179,7 +179,7 @@ class HasCacheKey(object): if NO_CACHE in _anon_map: return None else: - return CacheKey(key, bindparams) + return CacheKey(key, bindparams, self) @classmethod def _generate_cache_key_for_object(cls, obj): @@ -190,7 +190,7 @@ class HasCacheKey(object): if NO_CACHE in _anon_map: return None else: - return CacheKey(key, bindparams) + return CacheKey(key, bindparams, obj) class MemoizedHasCacheKey(HasCacheKey, HasMemoized): @@ -199,9 +199,42 @@ class MemoizedHasCacheKey(HasCacheKey, HasMemoized): return HasCacheKey._generate_cache_key(self) -class CacheKey(namedtuple("CacheKey", ["key", "bindparams"])): +class CacheKey(namedtuple("CacheKey", ["key", "bindparams", "statement"])): def __hash__(self): - return hash(self.key) + """CacheKey itself is not hashable - hash the .key portion""" + + return None + + def to_offline_string(self, statement_cache, parameters): + """generate an "offline string" form of this :class:`.CacheKey` + + The "offline string" is basically the string SQL for the + statement plus a repr of the bound parameter values in series. + Whereas the :class:`.CacheKey` object is dependent on in-memory + identities in order to work as a cache key, the "offline" version + is suitable for a cache that will work for other processes as well. + + The given "statement_cache" is a dictionary-like object where the + string form of the statement itself will be cached. this dictionary + should be in a longer lived scope in order to reduce the time spent + stringifying statements. + + + """ + if self.key not in statement_cache: + statement_cache[self.key] = sql_str = str(self.statement) + else: + sql_str = statement_cache[self.key] + + return repr( + ( + sql_str, + tuple( + parameters.get(bindparam.key, bindparam.value) + for bindparam in self.bindparams + ), + ) + ) def __eq__(self, other): return self.key == other.key @@ -411,7 +444,6 @@ class _CacheKey(ExtendedInternalTraversal): def visit_setup_join_tuple( self, attrname, obj, parent, anon_map, bindparams ): - # TODO: look at attrname for "legacy_join" and use different structure return tuple( ( target._gen_cache_key(anon_map, bindparams), @@ -596,7 +628,6 @@ class _CopyInternals(InternalTraversal): def visit_setup_join_tuple( self, attrname, parent, element, clone=_clone, **kw ): - # TODO: look at attrname for "legacy_join" and use different structure return tuple( ( clone(target, **kw) if target is not None else None, @@ -668,6 +699,15 @@ class _CopyInternals(InternalTraversal): _copy_internals = _CopyInternals() +def _flatten_clauseelement(element): + while hasattr(element, "__clause_element__") and not getattr( + element, "is_clause_element", False + ): + element = element.__clause_element__() + + return element + + class _GetChildren(InternalTraversal): """Generate a _children_traversal internal traversal dispatch for classes with a _traverse_internals collection.""" @@ -696,6 +736,17 @@ class _GetChildren(InternalTraversal): def visit_clauseelement_unordered_set(self, element, **kw): return element + def visit_setup_join_tuple(self, element, **kw): + for (target, onclause, from_, flags) in element: + if from_ is not None: + yield from_ + + if not isinstance(target, str): + yield _flatten_clauseelement(target) + + # if onclause is not None and not isinstance(onclause, str): + # yield _flatten_clauseelement(onclause) + def visit_dml_ordered_values(self, element, **kw): for k, v in element: if hasattr(k, "__clause_element__"): |