1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
|
/* statement.c - the statement type
*
* Copyright (C) 2005-2010 Gerhard Häring <gh@ghaering.de>
*
* This file is part of pysqlite.
*
* This software is provided 'as-is', without any express or implied
* warranty. In no event will the authors be held liable for any damages
* arising from the use of this software.
*
* Permission is granted to anyone to use this software for any purpose,
* including commercial applications, and to alter it and redistribute it
* freely, subject to the following restrictions:
*
* 1. The origin of this software must not be misrepresented; you must not
* claim that you wrote the original software. If you use this software
* in a product, an acknowledgment in the product documentation would be
* appreciated but is not required.
* 2. Altered source versions must be plainly marked as such, and must not be
* misrepresented as being the original software.
* 3. This notice may not be removed or altered from any source distribution.
*/
#include "connection.h"
#include "statement.h"
#include "util.h"
/* prototypes */
static const char *lstrip_sql(const char *sql);
pysqlite_Statement *
pysqlite_statement_create(pysqlite_Connection *connection, PyObject *sql)
{
pysqlite_state *state = connection->state;
assert(PyUnicode_Check(sql));
Py_ssize_t size;
const char *sql_cstr = PyUnicode_AsUTF8AndSize(sql, &size);
if (sql_cstr == NULL) {
return NULL;
}
sqlite3 *db = connection->db;
int max_length = sqlite3_limit(db, SQLITE_LIMIT_SQL_LENGTH, -1);
if (size > max_length) {
PyErr_SetString(connection->DataError,
"query string is too large");
return NULL;
}
if (strlen(sql_cstr) != (size_t)size) {
PyErr_SetString(connection->ProgrammingError,
"the query contains a null character");
return NULL;
}
sqlite3_stmt *stmt;
const char *tail;
int rc;
Py_BEGIN_ALLOW_THREADS
rc = sqlite3_prepare_v2(db, sql_cstr, (int)size + 1, &stmt, &tail);
Py_END_ALLOW_THREADS
if (rc != SQLITE_OK) {
_pysqlite_seterror(state, db);
return NULL;
}
if (lstrip_sql(tail) != NULL) {
PyErr_SetString(connection->ProgrammingError,
"You can only execute one statement at a time.");
goto error;
}
/* Determine if the statement is a DML statement.
SELECT is the only exception. See #9924. */
int is_dml = 0;
const char *p = lstrip_sql(sql_cstr);
if (p != NULL) {
is_dml = (PyOS_strnicmp(p, "insert", 6) == 0)
|| (PyOS_strnicmp(p, "update", 6) == 0)
|| (PyOS_strnicmp(p, "delete", 6) == 0)
|| (PyOS_strnicmp(p, "replace", 7) == 0);
}
pysqlite_Statement *self = PyObject_GC_New(pysqlite_Statement,
state->StatementType);
if (self == NULL) {
goto error;
}
self->st = stmt;
self->in_use = 0;
self->is_dml = is_dml;
PyObject_GC_Track(self);
return self;
error:
(void)sqlite3_finalize(stmt);
return NULL;
}
static void
stmt_dealloc(pysqlite_Statement *self)
{
PyTypeObject *tp = Py_TYPE(self);
PyObject_GC_UnTrack(self);
if (self->st) {
Py_BEGIN_ALLOW_THREADS
sqlite3_finalize(self->st);
Py_END_ALLOW_THREADS
self->st = 0;
}
tp->tp_free(self);
Py_DECREF(tp);
}
static int
stmt_traverse(pysqlite_Statement *self, visitproc visit, void *arg)
{
Py_VISIT(Py_TYPE(self));
return 0;
}
/*
* Strip leading whitespace and comments from incoming SQL (null terminated C
* string) and return a pointer to the first non-whitespace, non-comment
* character.
*
* This is used to check if somebody tries to execute more than one SQL query
* with one execute()/executemany() command, which the DB-API don't allow.
*
* It is also used to harden DML query detection.
*/
static inline const char *
lstrip_sql(const char *sql)
{
// This loop is borrowed from the SQLite source code.
for (const char *pos = sql; *pos; pos++) {
switch (*pos) {
case ' ':
case '\t':
case '\f':
case '\n':
case '\r':
// Skip whitespace.
break;
case '-':
// Skip line comments.
if (pos[1] == '-') {
pos += 2;
while (pos[0] && pos[0] != '\n') {
pos++;
}
if (pos[0] == '\0') {
return NULL;
}
continue;
}
return pos;
case '/':
// Skip C style comments.
if (pos[1] == '*') {
pos += 2;
while (pos[0] && (pos[0] != '*' || pos[1] != '/')) {
pos++;
}
if (pos[0] == '\0') {
return NULL;
}
pos++;
continue;
}
return pos;
default:
return pos;
}
}
return NULL;
}
static PyType_Slot stmt_slots[] = {
{Py_tp_dealloc, stmt_dealloc},
{Py_tp_traverse, stmt_traverse},
{0, NULL},
};
static PyType_Spec stmt_spec = {
.name = MODULE_NAME ".Statement",
.basicsize = sizeof(pysqlite_Statement),
.flags = (Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
Py_TPFLAGS_IMMUTABLETYPE | Py_TPFLAGS_DISALLOW_INSTANTIATION),
.slots = stmt_slots,
};
int
pysqlite_statement_setup_types(PyObject *module)
{
PyObject *type = PyType_FromModuleAndSpec(module, &stmt_spec, NULL);
if (type == NULL) {
return -1;
}
pysqlite_state *state = pysqlite_get_state(module);
state->StatementType = (PyTypeObject *)type;
return 0;
}
|
