From 645f6b9868d75cf98cf0cadf91f0bdd1dc564571 Mon Sep 17 00:00:00 2001
From: Ilya Tyaptin <ityaptin@mirantis.com>
Date: Thu, 19 Feb 2015 13:29:01 +0300
Subject: [PATCH] [PostgreSQL] Fix regexp operator

Add different operators relative to dialect.
It's needed to support same regexp format for all backends.

Closes-bug: 1423171
Change-Id: I0e732358cff754ae9407ba6b1932bcbe1b1ce1b9
---
 ceilometer/alarm/storage/impl_sqlalchemy.py |  4 +++-
 ceilometer/storage/impl_sqlalchemy.py       |  4 +++-
 ceilometer/storage/sqlalchemy/utils.py      | 13 +++++++++++--
 3 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/ceilometer/alarm/storage/impl_sqlalchemy.py b/ceilometer/alarm/storage/impl_sqlalchemy.py
index 9ea599892..a6926f26f 100644
--- a/ceilometer/alarm/storage/impl_sqlalchemy.py
+++ b/ceilometer/alarm/storage/impl_sqlalchemy.py
@@ -105,8 +105,10 @@ class Connection(base.Connection):
             return []
 
         session = self._engine_facade.get_session()
+        engine = self._engine_facade.get_engine()
         query = session.query(table)
-        transformer = sql_utils.QueryTransformer(table, query)
+        transformer = sql_utils.QueryTransformer(table, query,
+                                                 dialect=engine.dialect.name)
         if filter_expr is not None:
             transformer.apply_filter(filter_expr)
 
diff --git a/ceilometer/storage/impl_sqlalchemy.py b/ceilometer/storage/impl_sqlalchemy.py
index 982898e01..65da829b0 100644
--- a/ceilometer/storage/impl_sqlalchemy.py
+++ b/ceilometer/storage/impl_sqlalchemy.py
@@ -577,8 +577,10 @@ class Connection(base.Connection):
             return []
 
         session = self._engine_facade.get_session()
+        engine = self._engine_facade.get_engine()
         query = session.query(models.FullSample)
-        transformer = sql_utils.QueryTransformer(models.FullSample, query)
+        transformer = sql_utils.QueryTransformer(models.FullSample, query,
+                                                 dialect=engine.dialect.name)
         if filter_expr is not None:
             transformer.apply_filter(filter_expr)
 
diff --git a/ceilometer/storage/sqlalchemy/utils.py b/ceilometer/storage/sqlalchemy/utils.py
index 13655c4b2..195396c10 100644
--- a/ceilometer/storage/sqlalchemy/utils.py
+++ b/ceilometer/storage/sqlalchemy/utils.py
@@ -46,6 +46,10 @@ class QueryTransformer(object):
                  "in": lambda field_name, values: field_name.in_(values),
                  "=~": lambda field, value: field.op("regexp")(value)}
 
+    # operators which are differs for different dialects
+    dialect_operators = {'postgresql': {'=~': (lambda field, value:
+                                               field.op("~")(value))}}
+
     complex_operators = {"or": or_,
                          "and": and_,
                          "not": not_}
@@ -53,9 +57,14 @@ class QueryTransformer(object):
     ordering_functions = {"asc": asc,
                           "desc": desc}
 
-    def __init__(self, table, query):
+    def __init__(self, table, query, dialect='mysql'):
         self.table = table
         self.query = query
+        self.dialect_name = dialect
+
+    def _get_operator(self, op):
+        return (self.dialect_operators.get(self.dialect_name, {}).get(op)
+                or self.operators[op])
 
     def _handle_complex_op(self, complex_op, nodes):
         op = self.complex_operators[complex_op]
@@ -68,7 +77,7 @@ class QueryTransformer(object):
         return op(*element_list)
 
     def _handle_simple_op(self, simple_op, nodes):
-        op = self.operators[simple_op]
+        op = self._get_operator(simple_op)
         field_name = nodes.keys()[0]
         value = nodes.values()[0]
         if field_name.startswith('resource_metadata.'):