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1 /* statement.c - the statement type
2  *
3  * Copyright (C) 2005-2010 Gerhard Häring <gh@ghaering.de>
4  *
5  * This file is part of pysqlite.
6  *
7  * This software is provided 'as-is', without any express or implied
8  * warranty.  In no event will the authors be held liable for any damages
9  * arising from the use of this software.
10  *
11  * Permission is granted to anyone to use this software for any purpose,
12  * including commercial applications, and to alter it and redistribute it
13  * freely, subject to the following restrictions:
14  *
15  * 1. The origin of this software must not be misrepresented; you must not
16  *    claim that you wrote the original software. If you use this software
17  *    in a product, an acknowledgment in the product documentation would be
18  *    appreciated but is not required.
19  * 2. Altered source versions must be plainly marked as such, and must not be
20  *    misrepresented as being the original software.
21  * 3. This notice may not be removed or altered from any source distribution.
22  */
23 
24 #include "statement.h"
25 #include "cursor.h"
26 #include "connection.h"
27 #include "microprotocols.h"
28 #include "prepare_protocol.h"
29 #include "util.h"
30 
31 /* prototypes */
32 static int pysqlite_check_remaining_sql(const char* tail);
33 
34 typedef enum {
35     LINECOMMENT_1,
36     IN_LINECOMMENT,
37     COMMENTSTART_1,
38     IN_COMMENT,
39     COMMENTEND_1,
40     NORMAL
41 } parse_remaining_sql_state;
42 
43 typedef enum {
44     TYPE_LONG,
45     TYPE_FLOAT,
46     TYPE_UNICODE,
47     TYPE_BUFFER,
48     TYPE_UNKNOWN
49 } parameter_type;
50 
pysqlite_statement_create(pysqlite_Statement * self,pysqlite_Connection * connection,PyObject * sql)51 int pysqlite_statement_create(pysqlite_Statement* self, pysqlite_Connection* connection, PyObject* sql)
52 {
53     const char* tail;
54     int rc;
55     const char* sql_cstr;
56     Py_ssize_t sql_cstr_len;
57     const char* p;
58 
59     self->st = NULL;
60     self->in_use = 0;
61 
62     sql_cstr = PyUnicode_AsUTF8AndSize(sql, &sql_cstr_len);
63     if (sql_cstr == NULL) {
64         rc = PYSQLITE_SQL_WRONG_TYPE;
65         return rc;
66     }
67     if (strlen(sql_cstr) != (size_t)sql_cstr_len) {
68         PyErr_SetString(PyExc_ValueError, "the query contains a null character");
69         return PYSQLITE_SQL_WRONG_TYPE;
70     }
71 
72     self->in_weakreflist = NULL;
73     Py_INCREF(sql);
74     self->sql = sql;
75 
76     /* Determine if the statement is a DML statement.
77        SELECT is the only exception. See #9924. */
78     self->is_dml = 0;
79     for (p = sql_cstr; *p != 0; p++) {
80         switch (*p) {
81             case ' ':
82             case '\r':
83             case '\n':
84             case '\t':
85                 continue;
86         }
87 
88         self->is_dml = (PyOS_strnicmp(p, "insert", 6) == 0)
89                     || (PyOS_strnicmp(p, "update", 6) == 0)
90                     || (PyOS_strnicmp(p, "delete", 6) == 0)
91                     || (PyOS_strnicmp(p, "replace", 7) == 0);
92         break;
93     }
94 
95     Py_BEGIN_ALLOW_THREADS
96     rc = sqlite3_prepare_v2(connection->db,
97                             sql_cstr,
98                             -1,
99                             &self->st,
100                             &tail);
101     Py_END_ALLOW_THREADS
102 
103     self->db = connection->db;
104 
105     if (rc == SQLITE_OK && pysqlite_check_remaining_sql(tail)) {
106         (void)sqlite3_finalize(self->st);
107         self->st = NULL;
108         rc = PYSQLITE_TOO_MUCH_SQL;
109     }
110 
111     return rc;
112 }
113 
pysqlite_statement_bind_parameter(pysqlite_Statement * self,int pos,PyObject * parameter)114 int pysqlite_statement_bind_parameter(pysqlite_Statement* self, int pos, PyObject* parameter)
115 {
116     int rc = SQLITE_OK;
117     const char *string;
118     Py_ssize_t buflen;
119     parameter_type paramtype;
120 
121     if (parameter == Py_None) {
122         rc = sqlite3_bind_null(self->st, pos);
123         goto final;
124     }
125 
126     if (PyLong_CheckExact(parameter)) {
127         paramtype = TYPE_LONG;
128     } else if (PyFloat_CheckExact(parameter)) {
129         paramtype = TYPE_FLOAT;
130     } else if (PyUnicode_CheckExact(parameter)) {
131         paramtype = TYPE_UNICODE;
132     } else if (PyLong_Check(parameter)) {
133         paramtype = TYPE_LONG;
134     } else if (PyFloat_Check(parameter)) {
135         paramtype = TYPE_FLOAT;
136     } else if (PyUnicode_Check(parameter)) {
137         paramtype = TYPE_UNICODE;
138     } else if (PyObject_CheckBuffer(parameter)) {
139         paramtype = TYPE_BUFFER;
140     } else {
141         paramtype = TYPE_UNKNOWN;
142     }
143 
144     switch (paramtype) {
145         case TYPE_LONG: {
146             sqlite_int64 value = _pysqlite_long_as_int64(parameter);
147             if (value == -1 && PyErr_Occurred())
148                 rc = -1;
149             else
150                 rc = sqlite3_bind_int64(self->st, pos, value);
151             break;
152         }
153         case TYPE_FLOAT:
154             rc = sqlite3_bind_double(self->st, pos, PyFloat_AsDouble(parameter));
155             break;
156         case TYPE_UNICODE:
157             string = PyUnicode_AsUTF8AndSize(parameter, &buflen);
158             if (string == NULL)
159                 return -1;
160             if (buflen > INT_MAX) {
161                 PyErr_SetString(PyExc_OverflowError,
162                                 "string longer than INT_MAX bytes");
163                 return -1;
164             }
165             rc = sqlite3_bind_text(self->st, pos, string, (int)buflen, SQLITE_TRANSIENT);
166             break;
167         case TYPE_BUFFER: {
168             Py_buffer view;
169             if (PyObject_GetBuffer(parameter, &view, PyBUF_SIMPLE) != 0) {
170                 PyErr_SetString(PyExc_ValueError, "could not convert BLOB to buffer");
171                 return -1;
172             }
173             if (view.len > INT_MAX) {
174                 PyErr_SetString(PyExc_OverflowError,
175                                 "BLOB longer than INT_MAX bytes");
176                 PyBuffer_Release(&view);
177                 return -1;
178             }
179             rc = sqlite3_bind_blob(self->st, pos, view.buf, (int)view.len, SQLITE_TRANSIENT);
180             PyBuffer_Release(&view);
181             break;
182         }
183         case TYPE_UNKNOWN:
184             rc = -1;
185     }
186 
187 final:
188     return rc;
189 }
190 
191 /* returns 0 if the object is one of Python's internal ones that don't need to be adapted */
_need_adapt(PyObject * obj)192 static int _need_adapt(PyObject* obj)
193 {
194     if (pysqlite_BaseTypeAdapted) {
195         return 1;
196     }
197 
198     if (PyLong_CheckExact(obj) || PyFloat_CheckExact(obj)
199           || PyUnicode_CheckExact(obj) || PyByteArray_CheckExact(obj)) {
200         return 0;
201     } else {
202         return 1;
203     }
204 }
205 
pysqlite_statement_bind_parameters(pysqlite_Statement * self,PyObject * parameters)206 void pysqlite_statement_bind_parameters(pysqlite_Statement* self, PyObject* parameters)
207 {
208     PyObject* current_param;
209     PyObject* adapted;
210     const char* binding_name;
211     int i;
212     int rc;
213     int num_params_needed;
214     Py_ssize_t num_params;
215 
216     Py_BEGIN_ALLOW_THREADS
217     num_params_needed = sqlite3_bind_parameter_count(self->st);
218     Py_END_ALLOW_THREADS
219 
220     if (PyTuple_CheckExact(parameters) || PyList_CheckExact(parameters) || (!PyDict_Check(parameters) && PySequence_Check(parameters))) {
221         /* parameters passed as sequence */
222         if (PyTuple_CheckExact(parameters)) {
223             num_params = PyTuple_GET_SIZE(parameters);
224         } else if (PyList_CheckExact(parameters)) {
225             num_params = PyList_GET_SIZE(parameters);
226         } else {
227             num_params = PySequence_Size(parameters);
228         }
229         if (num_params != num_params_needed) {
230             PyErr_Format(pysqlite_ProgrammingError,
231                          "Incorrect number of bindings supplied. The current "
232                          "statement uses %d, and there are %zd supplied.",
233                          num_params_needed, num_params);
234             return;
235         }
236         for (i = 0; i < num_params; i++) {
237             if (PyTuple_CheckExact(parameters)) {
238                 current_param = PyTuple_GET_ITEM(parameters, i);
239                 Py_XINCREF(current_param);
240             } else if (PyList_CheckExact(parameters)) {
241                 current_param = PyList_GET_ITEM(parameters, i);
242                 Py_XINCREF(current_param);
243             } else {
244                 current_param = PySequence_GetItem(parameters, i);
245             }
246             if (!current_param) {
247                 return;
248             }
249 
250             if (!_need_adapt(current_param)) {
251                 adapted = current_param;
252             } else {
253                 adapted = pysqlite_microprotocols_adapt(current_param, (PyObject*)&pysqlite_PrepareProtocolType, current_param);
254                 Py_DECREF(current_param);
255                 if (!adapted) {
256                     return;
257                 }
258             }
259 
260             rc = pysqlite_statement_bind_parameter(self, i + 1, adapted);
261             Py_DECREF(adapted);
262 
263             if (rc != SQLITE_OK) {
264                 if (!PyErr_Occurred()) {
265                     PyErr_Format(pysqlite_InterfaceError, "Error binding parameter %d - probably unsupported type.", i);
266                 }
267                 return;
268             }
269         }
270     } else if (PyDict_Check(parameters)) {
271         /* parameters passed as dictionary */
272         for (i = 1; i <= num_params_needed; i++) {
273             PyObject *binding_name_obj;
274             Py_BEGIN_ALLOW_THREADS
275             binding_name = sqlite3_bind_parameter_name(self->st, i);
276             Py_END_ALLOW_THREADS
277             if (!binding_name) {
278                 PyErr_Format(pysqlite_ProgrammingError, "Binding %d has no name, but you supplied a dictionary (which has only names).", i);
279                 return;
280             }
281 
282             binding_name++; /* skip first char (the colon) */
283             binding_name_obj = PyUnicode_FromString(binding_name);
284             if (!binding_name_obj) {
285                 return;
286             }
287             if (PyDict_CheckExact(parameters)) {
288                 current_param = PyDict_GetItemWithError(parameters, binding_name_obj);
289                 Py_XINCREF(current_param);
290             } else {
291                 current_param = PyObject_GetItem(parameters, binding_name_obj);
292             }
293             Py_DECREF(binding_name_obj);
294             if (!current_param) {
295                 if (!PyErr_Occurred() || PyErr_ExceptionMatches(PyExc_LookupError)) {
296                     PyErr_Format(pysqlite_ProgrammingError, "You did not supply a value for binding %d.", i);
297                 }
298                 return;
299             }
300 
301             if (!_need_adapt(current_param)) {
302                 adapted = current_param;
303             } else {
304                 adapted = pysqlite_microprotocols_adapt(current_param, (PyObject*)&pysqlite_PrepareProtocolType, current_param);
305                 Py_DECREF(current_param);
306                 if (!adapted) {
307                     return;
308                 }
309             }
310 
311             rc = pysqlite_statement_bind_parameter(self, i, adapted);
312             Py_DECREF(adapted);
313 
314             if (rc != SQLITE_OK) {
315                 if (!PyErr_Occurred()) {
316                     PyErr_Format(pysqlite_InterfaceError, "Error binding parameter :%s - probably unsupported type.", binding_name);
317                 }
318                 return;
319            }
320         }
321     } else {
322         PyErr_SetString(PyExc_ValueError, "parameters are of unsupported type");
323     }
324 }
325 
pysqlite_statement_finalize(pysqlite_Statement * self)326 int pysqlite_statement_finalize(pysqlite_Statement* self)
327 {
328     int rc;
329 
330     rc = SQLITE_OK;
331     if (self->st) {
332         Py_BEGIN_ALLOW_THREADS
333         rc = sqlite3_finalize(self->st);
334         Py_END_ALLOW_THREADS
335         self->st = NULL;
336     }
337 
338     self->in_use = 0;
339 
340     return rc;
341 }
342 
pysqlite_statement_reset(pysqlite_Statement * self)343 int pysqlite_statement_reset(pysqlite_Statement* self)
344 {
345     int rc;
346 
347     rc = SQLITE_OK;
348 
349     if (self->in_use && self->st) {
350         Py_BEGIN_ALLOW_THREADS
351         rc = sqlite3_reset(self->st);
352         Py_END_ALLOW_THREADS
353 
354         if (rc == SQLITE_OK) {
355             self->in_use = 0;
356         }
357     }
358 
359     return rc;
360 }
361 
pysqlite_statement_mark_dirty(pysqlite_Statement * self)362 void pysqlite_statement_mark_dirty(pysqlite_Statement* self)
363 {
364     self->in_use = 1;
365 }
366 
pysqlite_statement_dealloc(pysqlite_Statement * self)367 void pysqlite_statement_dealloc(pysqlite_Statement* self)
368 {
369     if (self->st) {
370         Py_BEGIN_ALLOW_THREADS
371         sqlite3_finalize(self->st);
372         Py_END_ALLOW_THREADS
373     }
374 
375     self->st = NULL;
376 
377     Py_XDECREF(self->sql);
378 
379     if (self->in_weakreflist != NULL) {
380         PyObject_ClearWeakRefs((PyObject*)self);
381     }
382 
383     Py_TYPE(self)->tp_free((PyObject*)self);
384 }
385 
386 /*
387  * Checks if there is anything left in an SQL string after SQLite compiled it.
388  * This is used to check if somebody tried to execute more than one SQL command
389  * with one execute()/executemany() command, which the DB-API and we don't
390  * allow.
391  *
392  * Returns 1 if there is more left than should be. 0 if ok.
393  */
pysqlite_check_remaining_sql(const char * tail)394 static int pysqlite_check_remaining_sql(const char* tail)
395 {
396     const char* pos = tail;
397 
398     parse_remaining_sql_state state = NORMAL;
399 
400     for (;;) {
401         switch (*pos) {
402             case 0:
403                 return 0;
404             case '-':
405                 if (state == NORMAL) {
406                     state  = LINECOMMENT_1;
407                 } else if (state == LINECOMMENT_1) {
408                     state = IN_LINECOMMENT;
409                 }
410                 break;
411             case ' ':
412             case '\t':
413                 break;
414             case '\n':
415             case 13:
416                 if (state == IN_LINECOMMENT) {
417                     state = NORMAL;
418                 }
419                 break;
420             case '/':
421                 if (state == NORMAL) {
422                     state = COMMENTSTART_1;
423                 } else if (state == COMMENTEND_1) {
424                     state = NORMAL;
425                 } else if (state == COMMENTSTART_1) {
426                     return 1;
427                 }
428                 break;
429             case '*':
430                 if (state == NORMAL) {
431                     return 1;
432                 } else if (state == LINECOMMENT_1) {
433                     return 1;
434                 } else if (state == COMMENTSTART_1) {
435                     state = IN_COMMENT;
436                 } else if (state == IN_COMMENT) {
437                     state = COMMENTEND_1;
438                 }
439                 break;
440             default:
441                 if (state == COMMENTEND_1) {
442                     state = IN_COMMENT;
443                 } else if (state == IN_LINECOMMENT) {
444                 } else if (state == IN_COMMENT) {
445                 } else {
446                     return 1;
447                 }
448         }
449 
450         pos++;
451     }
452 
453     return 0;
454 }
455 
456 PyTypeObject pysqlite_StatementType = {
457         PyVarObject_HEAD_INIT(NULL, 0)
458         MODULE_NAME ".Statement",                       /* tp_name */
459         sizeof(pysqlite_Statement),                     /* tp_basicsize */
460         0,                                              /* tp_itemsize */
461         (destructor)pysqlite_statement_dealloc,         /* tp_dealloc */
462         0,                                              /* tp_vectorcall_offset */
463         0,                                              /* tp_getattr */
464         0,                                              /* tp_setattr */
465         0,                                              /* tp_as_async */
466         0,                                              /* tp_repr */
467         0,                                              /* tp_as_number */
468         0,                                              /* tp_as_sequence */
469         0,                                              /* tp_as_mapping */
470         0,                                              /* tp_hash */
471         0,                                              /* tp_call */
472         0,                                              /* tp_str */
473         0,                                              /* tp_getattro */
474         0,                                              /* tp_setattro */
475         0,                                              /* tp_as_buffer */
476         Py_TPFLAGS_DEFAULT,                             /* tp_flags */
477         0,                                              /* tp_doc */
478         0,                                              /* tp_traverse */
479         0,                                              /* tp_clear */
480         0,                                              /* tp_richcompare */
481         offsetof(pysqlite_Statement, in_weakreflist),   /* tp_weaklistoffset */
482         0,                                              /* tp_iter */
483         0,                                              /* tp_iternext */
484         0,                                              /* tp_methods */
485         0,                                              /* tp_members */
486         0,                                              /* tp_getset */
487         0,                                              /* tp_base */
488         0,                                              /* tp_dict */
489         0,                                              /* tp_descr_get */
490         0,                                              /* tp_descr_set */
491         0,                                              /* tp_dictoffset */
492         (initproc)0,                                    /* tp_init */
493         0,                                              /* tp_alloc */
494         0,                                              /* tp_new */
495         0                                               /* tp_free */
496 };
497 
pysqlite_statement_setup_types(void)498 extern int pysqlite_statement_setup_types(void)
499 {
500     pysqlite_StatementType.tp_new = PyType_GenericNew;
501     return PyType_Ready(&pysqlite_StatementType);
502 }
503