Use retrieve_by, group_by and group_columns in the cache

This removes custom retrieve() functions and Query classes from the
database modules and uses retrieve_sql retrieve_by, group_by and
group_columns to make a custom retrieval query.

In the cache module this completely replaces how the query grouping is
done. The Query class is now only used inside the cache and the
CnAliasedQuery, RowGrouper and related classed have been removed.

1 files changed, 28 insertions, 32 deletions

diff --git a/pynslcd/service.py b/pynslcd/service.py
index 6f55cc1..c27f485 100644
--- a/pynslcd/service.py
+++ b/pynslcd/service.py
@@ -40,33 +40,6 @@ class Search(search.LDAPSearch):
     required = ('cn', 'ipServicePort', 'ipServiceProtocol')
 
 
-class ServiceQuery(cache.CnAliasedQuery):
-
-    sql = '''
-        SELECT `service_cache`.*,
-               `service_alias_cache`.`cn` AS `alias`
-        FROM `service_cache`
-        LEFT JOIN `service_alias_cache`
-          ON `service_alias_cache`.`ipServicePort` = `service_cache`.`ipServicePort`
-          AND `service_alias_cache`.`ipServiceProtocol` = `service_cache`.`ipServiceProtocol`
-        '''
-
-    cn_join = '''
-        LEFT JOIN `service_alias_cache` `cn_alias`
-          ON `cn_alias`.`ipServicePort` = `service_cache`.`ipServicePort`
-          AND `cn_alias`.`ipServiceProtocol` = `service_cache`.`ipServiceProtocol`
-        '''
-
-    def __init__(self, parameters):
-        super(ServiceQuery, self).__init__('service', {})
-        for k, v in parameters.items():
-            if k == 'cn':
-                self.add_query(self.cn_join)
-                self.add_where('(`service_cache`.`cn` = ? OR `cn_alias`.`cn` = ?)', [v, v])
-            else:
-                self.add_where('`service_cache`.`%s` = ?' % k, [v])
-
-
 class Cache(cache.Cache):
 
     tables = ('service_cache', 'service_alias_cache')
@@ -90,6 +63,34 @@ class Cache(cache.Cache):
         CREATE INDEX IF NOT EXISTS `service_alias_idx2` ON `service_alias_cache`(`ipServiceProtocol`);
     '''
 
+    retrieve_sql = '''
+        SELECT `service_cache`.`cn` AS `cn`,
+               `service_alias_cache`.`cn` AS `alias`,
+               `service_cache`.`ipServicePort`,
+               `service_cache`.`ipServiceProtocol`,
+               `mtime`
+        FROM `service_cache`
+        LEFT JOIN `service_alias_cache`
+          ON `service_alias_cache`.`ipServicePort` = `service_cache`.`ipServicePort`
+         AND `service_alias_cache`.`ipServiceProtocol` = `service_cache`.`ipServiceProtocol`
+    '''
+
+    retrieve_by = dict(
+        cn='''
+            ( `service_cache`.`cn` = ? OR
+              0 < (
+                  SELECT COUNT(*)
+                  FROM `service_alias_cache` `by_alias`
+                  WHERE `by_alias`.`cn` = ?
+                    AND `by_alias`.`ipServicePort` = `service_cache`.`ipServicePort`
+                    AND `by_alias`.`ipServiceProtocol` = `service_cache`.`ipServiceProtocol`
+                ))
+        ''',
+    )
+
+    group_by = (0, 2, 3)  # cn, ipServicePort, ipServiceProtocol
+    group_columns = (1, )  # alias
+
     def store(self, name, aliases, port, protocol):
         self.con.execute('''
             INSERT OR REPLACE INTO `service_cache`
@@ -107,11 +108,6 @@ class Cache(cache.Cache):
               (?, ?, ?)
         ''', ((port, protocol, alias) for alias in aliases))
 
-    def retrieve(self, parameters):
-        query = ServiceQuery(parameters)
-        for row in cache.RowGrouper(query.execute(self.con), ('cn', 'ipServicePort', 'ipServiceProtocol'), ('alias', )):
-            yield row['cn'], row['alias'], row['ipServicePort'], row['ipServiceProtocol']
-
 
 class ServiceRequest(common.Request):