Skip to content

bpo-44165: optimise sqlite3 statement preparation by passing string size#26206

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
pablogsal merged 5 commits into from
Jun 2, 2021
Merged

bpo-44165: optimise sqlite3 statement preparation by passing string size #26206

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
f901fd5
bpo-44165: optimise sqlite3 statement preparation by passing string size
May 18, 2021
9febd15
Pass -1 if size >= INT_MAX
May 19, 2021
081de33
Raise OverflowError if SQL string is too long
May 19, 2021
d981be6
Raise DataError iso. OverflowError to keep current behaviour
May 19, 2021
d0d0618
sqlite3_limit is cheap; use it directly iso. caching it in the connec…
May 19, 2021
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
4 changes: 2 additions & 2 deletions Modules/_sqlite/connection.c
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -428,7 +428,7 @@ pysqlite_connection_commit_impl(pysqlite_Connection *self)
if (!sqlite3_get_autocommit(self->db)){

Py_BEGIN_ALLOW_THREADS
rc = sqlite3_prepare_v2(self->db, "COMMIT", -1, &statement, NULL);
rc = sqlite3_prepare_v2(self->db, "COMMIT", 7, &statement, NULL);
Py_END_ALLOW_THREADS
if (rc != SQLITE_OK){
_pysqlite_seterror(self->db);
Expand DownExpand Up@@ -478,7 +478,7 @@ pysqlite_connection_rollback_impl(pysqlite_Connection *self)
pysqlite_do_all_statements(self, ACTION_RESET, 1);

Py_BEGIN_ALLOW_THREADS
rc = sqlite3_prepare_v2(self->db, "ROLLBACK", -1, &statement, NULL);
rc = sqlite3_prepare_v2(self->db, "ROLLBACK", 9, &statement, NULL);
Py_END_ALLOW_THREADS
if (rc != SQLITE_OK){
_pysqlite_seterror(self->db);
Expand Down
20 changes: 16 additions & 4 deletions Modules/_sqlite/cursor.c
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -681,6 +681,7 @@ pysqlite_cursor_executescript(pysqlite_Cursor *self, PyObject *script_obj)
const char* script_cstr;
sqlite3_stmt* statement;
int rc;
Py_ssize_t sql_len;
PyObject* result;

if (!check_cursor(self)){
Expand All@@ -690,10 +691,17 @@ pysqlite_cursor_executescript(pysqlite_Cursor *self, PyObject *script_obj)
self->reset = 0;

if (PyUnicode_Check(script_obj)){
script_cstr = PyUnicode_AsUTF8(script_obj);
script_cstr = PyUnicode_AsUTF8AndSize(script_obj, &sql_len);
if (!script_cstr){
return NULL;
}

int max_length = sqlite3_limit(self->connection->db,
SQLITE_LIMIT_LENGTH, -1);
if (sql_len >= max_length){
PyErr_SetString(pysqlite_DataError, "query string is too large");
return NULL;
}
} else{
PyErr_SetString(PyExc_ValueError, "script argument must be unicode.");
return NULL;
Expand All@@ -707,12 +715,14 @@ pysqlite_cursor_executescript(pysqlite_Cursor *self, PyObject *script_obj)
Py_DECREF(result);

while (1){
const char *tail;

Py_BEGIN_ALLOW_THREADS
rc = sqlite3_prepare_v2(self->connection->db,
script_cstr,
-1,
(int)sql_len + 1,
&statement,
&script_cstr);
&tail);
Py_END_ALLOW_THREADS
if (rc != SQLITE_OK){
_pysqlite_seterror(self->connection->db);
Expand DownExpand Up@@ -740,9 +750,11 @@ pysqlite_cursor_executescript(pysqlite_Cursor *self, PyObject *script_obj)
goto error;
}

if (*script_cstr == (char)0){
if (*tail == (char)0){
break;
}
sql_len -= (tail - script_cstr);
script_cstr = tail;
}

error:
Expand Down
8 changes: 7 additions & 1 deletion Modules/_sqlite/statement.c
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -66,6 +66,12 @@ int pysqlite_statement_create(pysqlite_Statement* self, pysqlite_Connection* con
rc = PYSQLITE_SQL_WRONG_TYPE;
return rc;
}

int max_length = sqlite3_limit(connection->db, SQLITE_LIMIT_LENGTH, -1);
if (sql_cstr_len >= max_length){
PyErr_SetString(pysqlite_DataError, "query string is too large");
return PYSQLITE_TOO_MUCH_SQL;
}
if (strlen(sql_cstr) != (size_t)sql_cstr_len){
PyErr_SetString(PyExc_ValueError, "the query contains a null character");
return PYSQLITE_SQL_WRONG_TYPE;
Expand DownExpand Up@@ -96,7 +102,7 @@ int pysqlite_statement_create(pysqlite_Statement* self, pysqlite_Connection* con
Py_BEGIN_ALLOW_THREADS
rc = sqlite3_prepare_v2(connection->db,
sql_cstr,
-1,
(int)sql_cstr_len + 1,
&self->st,
&tail);
Py_END_ALLOW_THREADS
Expand Down