Support regexes in search

Implement support for regular expressions in search terms.

Change-Id: I090d23f50b0ce8e61b6257bea9f84a49aaf57553

gertty/app.py

@@ -27,6 +27,7 @@ import urlparse
 import warnings
 import webbrowser
 
+import sqlalchemy.exc
 import urwid
 
 from gertty import db
@@ -417,6 +418,10 @@ class App(object):
                 changes = session.getChanges(query)
             except gertty.search.SearchSyntaxError as e:
                 return self.error(e.message)
+            except sqlalchemy.exc.OperationalError as e:
+                return self.error(e.message)
+            except Exception as e:
+                return self.error(str(e))
             change_key = None
             if len(changes) == 1:
                 change_key = changes[0].key

gertty/db.py

@@ -13,6 +13,7 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+import re
 import time
 import logging
 import threading
@@ -497,6 +498,15 @@ mapper(Approval, approval_table, properties=dict(
 mapper(PendingCherryPick, pending_cherry_pick_table)
 mapper(SyncQuery, sync_query_table)
 
+def match(expr, item):
+    if item is None:
+        return False
+    return re.match(expr, item) is not None
+
+@sqlalchemy.event.listens_for(sqlalchemy.engine.Engine, "connect")
+def add_sqlite_match(dbapi_connection, connection_record):
+    dbapi_connection.create_function("matches", 2, match)
+
 class Database(object):
     def __init__(self, app):
         self.log = logging.getLogger('gertty.db')

gertty/search/__init__.py

@@ -62,7 +62,7 @@ class SearchCompiler(object):
 if __name__ == '__main__':
     class Dummy(object):
         pass
-    query = 'status:open AND topic:enable_swift'
+    query = 'ref:^refs/heads/foo.*'
     lexer = tokenizer.SearchTokenizer()
     lexer.input(query)
     while True:

gertty/search/parser.py

@@ -16,7 +16,7 @@ import datetime
 import re
 
 import ply.yacc as yacc
-from sqlalchemy.sql.expression import and_, or_, not_, select
+from sqlalchemy.sql.expression import and_, or_, not_, select, func
 
 import gertty.db
 import gertty.search
@@ -157,8 +157,10 @@ def SearchParser():
 
     def p_project_term(p):
         '''project_term : OP_PROJECT string'''
-        #TODO: support regex
-        p[0] = gertty.db.project_table.c.name == p[2]
+        if p[2].startswith('^'):
+            p[0] = func.matches(p[2], gertty.db.project_table.c.name)
+        else:
+            p[0] = gertty.db.project_table.c.name == p[2]
 
     def p_project_key_term(p):
         '''project_key_term : OP_PROJECT_KEY NUMBER'''
@@ -166,18 +168,24 @@ def SearchParser():
 
     def p_branch_term(p):
         '''branch_term : OP_BRANCH string'''
-        #TODO: support regex
-        p[0] = gertty.db.change_table.c.branch == p[2]
+        if p[2].startswith('^'):
+            p[0] = func.matches(p[2], gertty.db.change_table.c.branch)
+        else:
+            p[0] = gertty.db.change_table.c.branch == p[2]
 
     def p_topic_term(p):
         '''topic_term : OP_TOPIC string'''
-        #TODO: support regex
-        p[0] = gertty.db.change_table.c.topic == p[2]
+        if p[2].startswith('^'):
+            p[0] = func.matches(p[2], gertty.db.change_table.c.topic)
+        else:
+            p[0] = gertty.db.change_table.c.topic == p[2]
 
     def p_ref_term(p):
         '''ref_term : OP_REF string'''
-        #TODO: support regex
-        p[0] = gertty.db.change_table.c.branch == p[2][len('refs/heads/'):]
+        if p[2].startswith('^'):
+            p[0] = func.matches(p[2], 'refs/heads/'+gertty.db.change_table.c.branch)
+        else:
+            p[0] = gertty.db.change_table.c.branch == p[2][len('refs/heads/'):]
 
     label_re = re.compile(r'(?P<label>[a-zA-Z0-9_-]+([a-zA-Z]|((?<![-+])[0-9])))'
                           r'(?P<operator>[<>]?=?)(?P<value>[-+]?[0-9]+)'