Create one database connection per thread

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 - #710, #561 Implement `except*` syntax (@lieryan)
 - #711 allow building documentation without having rope module installed (@kloczek)
+- #720 create one sqlite3.Connection per thread using a thread local (@tkrabel)
 
 # Release 1.10.0
 

rope/contrib/autoimport/sqlite.py

@@ -11,6 +11,7 @@
 from datetime import datetime
 from itertools import chain
 from pathlib import Path
+from threading import local
 from typing import Generator, Iterable, Iterator, List, Optional, Set, Tuple
 
 from rope.base import exceptions, libutils, resourceobserver, taskhandle, versioning
@@ -78,9 +79,10 @@ class AutoImport:
     """
 
     connection: sqlite3.Connection
-    underlined: bool
+    memory: bool
     project: Project
     project_package: Package
+    underlined: bool
 
     def __init__(
         self,
@@ -114,15 +116,17 @@ def __init__(
         assert project_package.path is not None
         self.project_package = project_package
         self.underlined = underlined
+        self.memory = memory
         if memory is _deprecated_default:
-            memory = True
+            self.memory = True
             warnings.warn(
                 "The default value for `AutoImport(memory)` argument will "
                 "change to use an on-disk database by default in the future. "
                 "If you want to use an in-memory database, you need to pass "
                 "`AutoImport(memory=True)` explicitly.",
                 DeprecationWarning,
             )
+        self.thread_local = local()
         self.connection = self.create_database_connection(
             project=project,
             memory=memory,
@@ -158,6 +162,24 @@ def create_database_connection(
             db_path = str(Path(project.ropefolder.real_path) / "autoimport.db")
         return sqlite3.connect(db_path)
 
+    @property
+    def connection(self):
+        """
+        Creates a new connection if called from a new thread.
+
+        This makes sure AutoImport can be shared across threads.
+        """
+        if not hasattr(self.thread_local, "connection"):
+            self.thread_local.connection = self.create_database_connection(
+                project=self.project,
+                memory=self.memory,
+            )
+        return self.thread_local.connection
+
+    @connection.setter
+    def connection(self, value: sqlite3.Connection):
+        self.thread_local.connection = value
+
     def _setup_db(self):
         models.Metadata.create_table(self.connection)
         version_hash = list(

ropetest/conftest.py

@@ -18,6 +18,13 @@ def project_path(project):
     yield pathlib.Path(project.address)
 
 
+@pytest.fixture
+def project2():
+    project = testutils.sample_project("sample_project2")
+    yield project
+    testutils.remove_project(project)
+
+
 """
 Standard project structure for pytest fixtures
 /mod1.py            -- mod1

ropetest/contrib/autoimport/autoimporttest.py

@@ -1,3 +1,4 @@
+from concurrent.futures import ThreadPoolExecutor
 from contextlib import closing, contextmanager
 from textwrap import dedent
 from unittest.mock import ANY, patch
@@ -85,6 +86,37 @@ def foo():
     assert [("from pkg1 import foo", "foo")] == results
 
 
+def test_multithreading(
+    autoimport: AutoImport,
+    project: Project,
+    pkg1: Folder,
+    mod1: File,
+):
+    mod1_init = pkg1.get_child("__init__.py")
+    mod1_init.write(dedent("""\
+        def foo():
+            pass
+    """))
+    mod1.write(dedent("""\
+        foo
+    """))
+    autoimport = AutoImport(project, memory=False)
+    autoimport.generate_cache([mod1_init])
+
+    tp = ThreadPoolExecutor(1)
+    results = tp.submit(autoimport.search, "foo", True).result()
+    assert [("from pkg1 import foo", "foo")] == results
+
+
+def test_connection(project: Project, project2: Project):
+    ai1 = AutoImport(project)
+    ai2 = AutoImport(project)
+    ai3 = AutoImport(project2)
+
+    assert ai1.connection is not ai2.connection
+    assert ai1.connection is not ai3.connection
+
+
 @contextmanager
 def assert_database_is_reset(conn):
     conn.execute("ALTER TABLE names ADD COLUMN deprecated_column")