bpo-45138: Revert GH-28240: Expand traced SQL statements (GH-31788)

Erlend Egeberg Aasland · web-flow · commit e801e88744f3 · 2022-03-09T09:39:49.000-08:00
This reverts commit d177751. Automerge-Triggered-By: GH:JelleZijlstra
diff --git a/Doc/library/sqlite3.rst b/Doc/library/sqlite3.rst
@@ -560,9 +560,6 @@ Connection Objects
 
       Passing :const:`None` as *trace_callback* will disable the trace callback.
 
-      For SQLite 3.14.0 and newer, bound parameters are expanded in the passed
-      statement string.
-
       .. note::
          Exceptions raised in the trace callback are not propagated. As a
          development and debugging aid, use
@@ -571,9 +568,6 @@ Connection Objects
 
       .. versionadded:: 3.3
 
-      .. versionchanged:: 3.11
-         Added support for expanded SQL statements.
-
 
    .. method:: enable_load_extension(enabled)
 
diff --git a/Doc/whatsnew/3.11.rst b/Doc/whatsnew/3.11.rst
@@ -334,10 +334,6 @@ sqlite3
   Instead we leave it to the SQLite library to handle these cases.
   (Contributed by Erlend E. Aasland in :issue:`44092`.)
 
-* For SQLite 3.14.0 and newer, bound parameters are expanded in the statement
-  string passed to the trace callback. See :meth:`~sqlite3.Connection.set_trace_callback`.
-  (Contributed by Erlend E. Aasland in :issue:`45138`.)
-
 
 sys
 ---
diff --git a/Lib/test/test_sqlite3/test_hooks.py b/Lib/test/test_sqlite3/test_hooks.py
@@ -20,16 +20,12 @@
 #    misrepresented as being the original software.
 # 3. This notice may not be removed or altered from any source distribution.
 
-import contextlib
-import sqlite3 as sqlite
 import unittest
+import sqlite3 as sqlite
 
 from test.support.os_helper import TESTFN, unlink
-
-from test.test_sqlite3.test_dbapi import memory_database, cx_limit
 from test.test_sqlite3.test_userfunctions import with_tracebacks
 
-
 class CollationTests(unittest.TestCase):
     def test_create_collation_not_string(self):
         con = sqlite.connect(":memory:")
@@ -228,16 +224,6 @@ def bad_progress():
 
 
 class TraceCallbackTests(unittest.TestCase):
-    @contextlib.contextmanager
-    def check_stmt_trace(self, cx, expected):
-        try:
-            traced = []
-            cx.set_trace_callback(lambda stmt: traced.append(stmt))
-            yield
-        finally:
-            self.assertEqual(traced, expected)
-            cx.set_trace_callback(None)
-
     def test_trace_callback_used(self):
         """
         Test that the trace callback is invoked once it is set.
@@ -303,51 +289,6 @@ def trace(statement):
             con2.close()
         self.assertEqual(traced_statements, queries)
 
-    @unittest.skipIf(sqlite.sqlite_version_info < (3, 14, 0),
-                     "Requires SQLite 3.14.0 or newer")
-    def test_trace_expanded_sql(self):
-        expected = [
-            "create table t(t)",
-            "BEGIN ",
-            "insert into t values(0)",
-            "insert into t values(1)",
-            "insert into t values(2)",
-            "COMMIT",
-        ]
-        with memory_database() as cx, self.check_stmt_trace(cx, expected):
-            with cx:
-                cx.execute("create table t(t)")
-                cx.executemany("insert into t values(?)", ((v,) for v in range(3)))
-
-    @with_tracebacks(
-        sqlite.DataError,
-        regex="Expanded SQL string exceeds the maximum string length"
-    )
-    def test_trace_too_much_expanded_sql(self):
-        # If the expanded string is too large, we'll fall back to the
-        # unexpanded SQL statement. The resulting string length is limited by
-        # SQLITE_LIMIT_LENGTH.
-        template = "select 'b' as \"a\" from sqlite_master where \"a\"="
-        category = sqlite.SQLITE_LIMIT_LENGTH
-        with memory_database() as cx, cx_limit(cx, category=category) as lim:
-            nextra = lim - (len(template) + 2) - 1
-            ok_param = "a" * nextra
-            bad_param = "a" * (nextra + 1)
-
-            unexpanded_query = template + "?"
-            with self.check_stmt_trace(cx, [unexpanded_query]):
-                cx.execute(unexpanded_query, (bad_param,))
-
-            expanded_query = f"{template}'{ok_param}'"
-            with self.check_stmt_trace(cx, [expanded_query]):
-                cx.execute(unexpanded_query, (ok_param,))
-
-    @with_tracebacks(ZeroDivisionError, regex="division by zero")
-    def test_trace_bad_handler(self):
-        with memory_database() as cx:
-            cx.set_trace_callback(lambda stmt: 5/0)
-            cx.execute("select 1")
-
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/Misc/NEWS.d/next/Library/2021-09-08-16-21-03.bpo-45138.yghUrK.rst b/Misc/NEWS.d/next/Library/2021-09-08-16-21-03.bpo-45138.yghUrK.rst
diff --git a/Modules/_sqlite/connection.c b/Modules/_sqlite/connection.c
@@ -1079,10 +1079,11 @@ progress_callback(void *ctx)
  * to ensure future compatibility.
  */
 static int
-trace_callback(unsigned int type, void *ctx, void *stmt, void *sql)
+trace_callback(unsigned int type, void *ctx, void *prepared_statement,
+               void *statement_string)
 #else
 static void
-trace_callback(void *ctx, const char *sql)
+trace_callback(void *ctx, const char *statement_string)
 #endif
 {
 #ifdef HAVE_TRACE_V2
@@ -1093,46 +1094,24 @@ trace_callback(void *ctx, const char *sql)
 
     PyGILState_STATE gilstate = PyGILState_Ensure();
 
-    assert(ctx != NULL);
     PyObject *py_statement = NULL;
-#ifdef HAVE_TRACE_V2
-    assert(stmt != NULL);
-    const char *expanded_sql = sqlite3_expanded_sql((sqlite3_stmt *)stmt);
-    if (expanded_sql == NULL) {
-        sqlite3 *db = sqlite3_db_handle((sqlite3_stmt *)stmt);
-        if (sqlite3_errcode(db) == SQLITE_NOMEM) {
-            (void)PyErr_NoMemory();
-            goto exit;
-        }
-
-        pysqlite_state *state = ((callback_context *)ctx)->state;
-        assert(state != NULL);
-        PyErr_SetString(state->DataError,
-                        "Expanded SQL string exceeds the maximum string "
-                        "length");
-        print_or_clear_traceback((callback_context *)ctx);
-
-        // Fall back to unexpanded sql
-        py_statement = PyUnicode_FromString((const char *)sql);
-    }
-    else {
-        py_statement = PyUnicode_FromString(expanded_sql);
-        sqlite3_free((void *)expanded_sql);
-    }
-#else
-    py_statement = PyUnicode_FromString(sql);
-#endif
+    PyObject *ret = NULL;
+    py_statement = PyUnicode_DecodeUTF8(statement_string,
+            strlen(statement_string), "replace");
+    assert(ctx != NULL);
     if (py_statement) {
         PyObject *callable = ((callback_context *)ctx)->callable;
-        PyObject *ret = PyObject_CallOneArg(callable, py_statement);
+        ret = PyObject_CallOneArg(callable, py_statement);
         Py_DECREF(py_statement);
-        Py_XDECREF(ret);
     }
 
-exit:
-    if (PyErr_Occurred()) {
-        print_or_clear_traceback((callback_context *)ctx);
+    if (ret) {
+        Py_DECREF(ret);
     }
+    else {
+        print_or_clear_traceback(ctx);
+    }
+
     PyGILState_Release(gilstate);
 #ifdef HAVE_TRACE_V2
     return 0;
