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1 /*
2     An implementation of Text I/O as defined by PEP 3116 - "New I/O"
3 
4     Classes defined here: TextIOBase, IncrementalNewlineDecoder, TextIOWrapper.
5 
6     Written by Amaury Forgeot d'Arc and Antoine Pitrou
7 */
8 
9 #define PY_SSIZE_T_CLEAN
10 #include "Python.h"
11 #include "structmember.h"
12 #include "_iomodule.h"
13 
14 /* TextIOBase */
15 
16 PyDoc_STRVAR(textiobase_doc,
17     "Base class for text I/O.\n"
18     "\n"
19     "This class provides a character and line based interface to stream\n"
20     "I/O. There is no readinto method because Python's character strings\n"
21     "are immutable. There is no public constructor.\n"
22     );
23 
24 static PyObject *
_unsupported(const char * message)25 _unsupported(const char *message)
26 {
27     PyErr_SetString(_PyIO_unsupported_operation, message);
28     return NULL;
29 }
30 
31 PyDoc_STRVAR(textiobase_detach_doc,
32     "Separate the underlying buffer from the TextIOBase and return it.\n"
33     "\n"
34     "After the underlying buffer has been detached, the TextIO is in an\n"
35     "unusable state.\n"
36     );
37 
38 static PyObject *
textiobase_detach(PyObject * self)39 textiobase_detach(PyObject *self)
40 {
41     return _unsupported("detach");
42 }
43 
44 PyDoc_STRVAR(textiobase_read_doc,
45     "Read at most n characters from stream.\n"
46     "\n"
47     "Read from underlying buffer until we have n characters or we hit EOF.\n"
48     "If n is negative or omitted, read until EOF.\n"
49     );
50 
51 static PyObject *
textiobase_read(PyObject * self,PyObject * args)52 textiobase_read(PyObject *self, PyObject *args)
53 {
54     return _unsupported("read");
55 }
56 
57 PyDoc_STRVAR(textiobase_readline_doc,
58     "Read until newline or EOF.\n"
59     "\n"
60     "Returns an empty string if EOF is hit immediately.\n"
61     );
62 
63 static PyObject *
textiobase_readline(PyObject * self,PyObject * args)64 textiobase_readline(PyObject *self, PyObject *args)
65 {
66     return _unsupported("readline");
67 }
68 
69 PyDoc_STRVAR(textiobase_write_doc,
70     "Write string to stream.\n"
71     "Returns the number of characters written (which is always equal to\n"
72     "the length of the string).\n"
73     );
74 
75 static PyObject *
textiobase_write(PyObject * self,PyObject * args)76 textiobase_write(PyObject *self, PyObject *args)
77 {
78     return _unsupported("write");
79 }
80 
81 PyDoc_STRVAR(textiobase_encoding_doc,
82     "Encoding of the text stream.\n"
83     "\n"
84     "Subclasses should override.\n"
85     );
86 
87 static PyObject *
textiobase_encoding_get(PyObject * self,void * context)88 textiobase_encoding_get(PyObject *self, void *context)
89 {
90     Py_RETURN_NONE;
91 }
92 
93 PyDoc_STRVAR(textiobase_newlines_doc,
94     "Line endings translated so far.\n"
95     "\n"
96     "Only line endings translated during reading are considered.\n"
97     "\n"
98     "Subclasses should override.\n"
99     );
100 
101 static PyObject *
textiobase_newlines_get(PyObject * self,void * context)102 textiobase_newlines_get(PyObject *self, void *context)
103 {
104     Py_RETURN_NONE;
105 }
106 
107 PyDoc_STRVAR(textiobase_errors_doc,
108     "The error setting of the decoder or encoder.\n"
109     "\n"
110     "Subclasses should override.\n"
111     );
112 
113 static PyObject *
textiobase_errors_get(PyObject * self,void * context)114 textiobase_errors_get(PyObject *self, void *context)
115 {
116     Py_RETURN_NONE;
117 }
118 
119 
120 static PyMethodDef textiobase_methods[] = {
121     {"detach", (PyCFunction)textiobase_detach, METH_NOARGS, textiobase_detach_doc},
122     {"read", textiobase_read, METH_VARARGS, textiobase_read_doc},
123     {"readline", textiobase_readline, METH_VARARGS, textiobase_readline_doc},
124     {"write", textiobase_write, METH_VARARGS, textiobase_write_doc},
125     {NULL, NULL}
126 };
127 
128 static PyGetSetDef textiobase_getset[] = {
129     {"encoding", (getter)textiobase_encoding_get, NULL, textiobase_encoding_doc},
130     {"newlines", (getter)textiobase_newlines_get, NULL, textiobase_newlines_doc},
131     {"errors", (getter)textiobase_errors_get, NULL, textiobase_errors_doc},
132     {NULL}
133 };
134 
135 PyTypeObject PyTextIOBase_Type = {
136     PyVarObject_HEAD_INIT(NULL, 0)
137     "_io._TextIOBase",          /*tp_name*/
138     0,                          /*tp_basicsize*/
139     0,                          /*tp_itemsize*/
140     0,                          /*tp_dealloc*/
141     0,                          /*tp_print*/
142     0,                          /*tp_getattr*/
143     0,                          /*tp_setattr*/
144     0,                          /*tp_compare */
145     0,                          /*tp_repr*/
146     0,                          /*tp_as_number*/
147     0,                          /*tp_as_sequence*/
148     0,                          /*tp_as_mapping*/
149     0,                          /*tp_hash */
150     0,                          /*tp_call*/
151     0,                          /*tp_str*/
152     0,                          /*tp_getattro*/
153     0,                          /*tp_setattro*/
154     0,                          /*tp_as_buffer*/
155     Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,  /*tp_flags*/
156     textiobase_doc,             /* tp_doc */
157     0,                          /* tp_traverse */
158     0,                          /* tp_clear */
159     0,                          /* tp_richcompare */
160     0,                          /* tp_weaklistoffset */
161     0,                          /* tp_iter */
162     0,                          /* tp_iternext */
163     textiobase_methods,         /* tp_methods */
164     0,                          /* tp_members */
165     textiobase_getset,          /* tp_getset */
166     &PyIOBase_Type,             /* tp_base */
167     0,                          /* tp_dict */
168     0,                          /* tp_descr_get */
169     0,                          /* tp_descr_set */
170     0,                          /* tp_dictoffset */
171     0,                          /* tp_init */
172     0,                          /* tp_alloc */
173     0,                          /* tp_new */
174 };
175 
176 
177 /* IncrementalNewlineDecoder */
178 
179 PyDoc_STRVAR(incrementalnewlinedecoder_doc,
180     "Codec used when reading a file in universal newlines mode.  It wraps\n"
181     "another incremental decoder, translating \\r\\n and \\r into \\n.  It also\n"
182     "records the types of newlines encountered.  When used with\n"
183     "translate=False, it ensures that the newline sequence is returned in\n"
184     "one piece. When used with decoder=None, it expects unicode strings as\n"
185     "decode input and translates newlines without first invoking an external\n"
186     "decoder.\n"
187     );
188 
189 typedef struct {
190     PyObject_HEAD
191     PyObject *decoder;
192     PyObject *errors;
193     signed int pendingcr: 1;
194     signed int translate: 1;
195     unsigned int seennl: 3;
196 } nldecoder_object;
197 
198 static int
incrementalnewlinedecoder_init(nldecoder_object * self,PyObject * args,PyObject * kwds)199 incrementalnewlinedecoder_init(nldecoder_object *self,
200                                PyObject *args, PyObject *kwds)
201 {
202     PyObject *decoder;
203     int translate;
204     PyObject *errors = NULL;
205     char *kwlist[] = {"decoder", "translate", "errors", NULL};
206 
207     if (!PyArg_ParseTupleAndKeywords(args, kwds, "Oi|O:IncrementalNewlineDecoder",
208                                      kwlist, &decoder, &translate, &errors))
209         return -1;
210 
211     self->decoder = decoder;
212     Py_INCREF(decoder);
213 
214     if (errors == NULL) {
215         self->errors = PyUnicode_FromString("strict");
216         if (self->errors == NULL)
217             return -1;
218     }
219     else {
220         Py_INCREF(errors);
221         self->errors = errors;
222     }
223 
224     self->translate = translate;
225     self->seennl = 0;
226     self->pendingcr = 0;
227 
228     return 0;
229 }
230 
231 static void
incrementalnewlinedecoder_dealloc(nldecoder_object * self)232 incrementalnewlinedecoder_dealloc(nldecoder_object *self)
233 {
234     Py_CLEAR(self->decoder);
235     Py_CLEAR(self->errors);
236     Py_TYPE(self)->tp_free((PyObject *)self);
237 }
238 
239 static int
check_decoded(PyObject * decoded)240 check_decoded(PyObject *decoded)
241 {
242     if (decoded == NULL)
243         return -1;
244     if (!PyUnicode_Check(decoded)) {
245         PyErr_Format(PyExc_TypeError,
246                      "decoder should return a string result, not '%.200s'",
247                      Py_TYPE(decoded)->tp_name);
248         Py_DECREF(decoded);
249         return -1;
250     }
251     return 0;
252 }
253 
254 #define SEEN_CR   1
255 #define SEEN_LF   2
256 #define SEEN_CRLF 4
257 #define SEEN_ALL (SEEN_CR | SEEN_LF | SEEN_CRLF)
258 
259 PyObject *
_PyIncrementalNewlineDecoder_decode(PyObject * _self,PyObject * input,int final)260 _PyIncrementalNewlineDecoder_decode(PyObject *_self,
261                                     PyObject *input, int final)
262 {
263     PyObject *output;
264     Py_ssize_t output_len;
265     nldecoder_object *self = (nldecoder_object *) _self;
266 
267     if (self->decoder == NULL) {
268         PyErr_SetString(PyExc_ValueError,
269                         "IncrementalNewlineDecoder.__init__ not called");
270         return NULL;
271     }
272 
273     /* decode input (with the eventual \r from a previous pass) */
274     if (self->decoder != Py_None) {
275         output = PyObject_CallMethodObjArgs(self->decoder,
276             _PyIO_str_decode, input, final ? Py_True : Py_False, NULL);
277     }
278     else {
279         output = input;
280         Py_INCREF(output);
281     }
282 
283     if (check_decoded(output) < 0)
284         return NULL;
285 
286     output_len = PyUnicode_GET_SIZE(output);
287     if (self->pendingcr && (final || output_len > 0)) {
288         Py_UNICODE *out;
289         PyObject *modified = PyUnicode_FromUnicode(NULL, output_len + 1);
290         if (modified == NULL)
291             goto error;
292         out = PyUnicode_AS_UNICODE(modified);
293         out[0] = '\r';
294         memcpy(out + 1, PyUnicode_AS_UNICODE(output),
295                output_len * sizeof(Py_UNICODE));
296         Py_DECREF(output);
297         output = modified;
298         self->pendingcr = 0;
299         output_len++;
300     }
301 
302     /* retain last \r even when not translating data:
303      * then readline() is sure to get \r\n in one pass
304      */
305     if (!final) {
306         if (output_len > 0
307             && PyUnicode_AS_UNICODE(output)[output_len - 1] == '\r') {
308 
309             if (Py_REFCNT(output) == 1) {
310                 if (PyUnicode_Resize(&output, output_len - 1) < 0)
311                     goto error;
312             }
313             else {
314                 PyObject *modified = PyUnicode_FromUnicode(
315                     PyUnicode_AS_UNICODE(output),
316                     output_len - 1);
317                 if (modified == NULL)
318                     goto error;
319                 Py_DECREF(output);
320                 output = modified;
321             }
322             self->pendingcr = 1;
323         }
324     }
325 
326     /* Record which newlines are read and do newline translation if desired,
327        all in one pass. */
328     {
329         Py_UNICODE *in_str;
330         Py_ssize_t len;
331         int seennl = self->seennl;
332         int only_lf = 0;
333 
334         in_str = PyUnicode_AS_UNICODE(output);
335         len = PyUnicode_GET_SIZE(output);
336 
337         if (len == 0)
338             return output;
339 
340         /* If, up to now, newlines are consistently \n, do a quick check
341            for the \r *byte* with the libc's optimized memchr.
342            */
343         if (seennl == SEEN_LF || seennl == 0) {
344             only_lf = (memchr(in_str, '\r', len * sizeof(Py_UNICODE)) == NULL);
345         }
346 
347         if (only_lf) {
348             /* If not already seen, quick scan for a possible "\n" character.
349                (there's nothing else to be done, even when in translation mode)
350             */
351             if (seennl == 0 &&
352                 memchr(in_str, '\n', len * sizeof(Py_UNICODE)) != NULL) {
353                 Py_UNICODE *s, *end;
354                 s = in_str;
355                 end = in_str + len;
356                 for (;;) {
357                     Py_UNICODE c;
358                     /* Fast loop for non-control characters */
359                     while (*s > '\n')
360                         s++;
361                     c = *s++;
362                     if (c == '\n') {
363                         seennl |= SEEN_LF;
364                         break;
365                     }
366                     if (s > end)
367                         break;
368                 }
369             }
370             /* Finished: we have scanned for newlines, and none of them
371                need translating */
372         }
373         else if (!self->translate) {
374             Py_UNICODE *s, *end;
375             /* We have already seen all newline types, no need to scan again */
376             if (seennl == SEEN_ALL)
377                 goto endscan;
378             s = in_str;
379             end = in_str + len;
380             for (;;) {
381                 Py_UNICODE c;
382                 /* Fast loop for non-control characters */
383                 while (*s > '\r')
384                     s++;
385                 c = *s++;
386                 if (c == '\n')
387                     seennl |= SEEN_LF;
388                 else if (c == '\r') {
389                     if (*s == '\n') {
390                         seennl |= SEEN_CRLF;
391                         s++;
392                     }
393                     else
394                         seennl |= SEEN_CR;
395                 }
396                 if (s > end)
397                     break;
398                 if (seennl == SEEN_ALL)
399                     break;
400             }
401         endscan:
402             ;
403         }
404         else {
405             PyObject *translated = NULL;
406             Py_UNICODE *out_str;
407             Py_UNICODE *in, *out, *end;
408             if (Py_REFCNT(output) != 1) {
409                 /* We could try to optimize this so that we only do a copy
410                    when there is something to translate. On the other hand,
411                    most decoders should only output non-shared strings, i.e.
412                    translation is done in place. */
413                 translated = PyUnicode_FromUnicode(NULL, len);
414                 if (translated == NULL)
415                     goto error;
416                 assert(Py_REFCNT(translated) == 1);
417                 memcpy(PyUnicode_AS_UNICODE(translated),
418                        PyUnicode_AS_UNICODE(output),
419                        len * sizeof(Py_UNICODE));
420             }
421             else {
422                 translated = output;
423             }
424             out_str = PyUnicode_AS_UNICODE(translated);
425             in = in_str;
426             out = out_str;
427             end = in_str + len;
428             for (;;) {
429                 Py_UNICODE c;
430                 /* Fast loop for non-control characters */
431                 while ((c = *in++) > '\r')
432                     *out++ = c;
433                 if (c == '\n') {
434                     *out++ = c;
435                     seennl |= SEEN_LF;
436                     continue;
437                 }
438                 if (c == '\r') {
439                     if (*in == '\n') {
440                         in++;
441                         seennl |= SEEN_CRLF;
442                     }
443                     else
444                         seennl |= SEEN_CR;
445                     *out++ = '\n';
446                     continue;
447                 }
448                 if (in > end)
449                     break;
450                 *out++ = c;
451             }
452             if (translated != output) {
453                 Py_DECREF(output);
454                 output = translated;
455             }
456             if (out - out_str != len) {
457                 if (PyUnicode_Resize(&output, out - out_str) < 0)
458                     goto error;
459             }
460         }
461         self->seennl |= seennl;
462     }
463 
464     return output;
465 
466   error:
467     Py_DECREF(output);
468     return NULL;
469 }
470 
471 static PyObject *
incrementalnewlinedecoder_decode(nldecoder_object * self,PyObject * args,PyObject * kwds)472 incrementalnewlinedecoder_decode(nldecoder_object *self,
473                                  PyObject *args, PyObject *kwds)
474 {
475     char *kwlist[] = {"input", "final", NULL};
476     PyObject *input;
477     int final = 0;
478 
479     if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|i:IncrementalNewlineDecoder",
480                                      kwlist, &input, &final))
481         return NULL;
482     return _PyIncrementalNewlineDecoder_decode((PyObject *) self, input, final);
483 }
484 
485 static PyObject *
incrementalnewlinedecoder_getstate(nldecoder_object * self,PyObject * args)486 incrementalnewlinedecoder_getstate(nldecoder_object *self, PyObject *args)
487 {
488     PyObject *buffer;
489     unsigned PY_LONG_LONG flag;
490 
491     if (self->decoder != Py_None) {
492         PyObject *state = PyObject_CallMethodObjArgs(self->decoder,
493            _PyIO_str_getstate, NULL);
494         if (state == NULL)
495             return NULL;
496         if (!PyArg_Parse(state, "(OK)", &buffer, &flag)) {
497             Py_DECREF(state);
498             return NULL;
499         }
500         Py_INCREF(buffer);
501         Py_DECREF(state);
502     }
503     else {
504         buffer = PyBytes_FromString("");
505         flag = 0;
506     }
507     flag <<= 1;
508     if (self->pendingcr)
509         flag |= 1;
510     return Py_BuildValue("NK", buffer, flag);
511 }
512 
513 static PyObject *
incrementalnewlinedecoder_setstate(nldecoder_object * self,PyObject * state)514 incrementalnewlinedecoder_setstate(nldecoder_object *self, PyObject *state)
515 {
516     PyObject *buffer;
517     unsigned PY_LONG_LONG flag;
518 
519     if (!PyArg_Parse(state, "(OK)", &buffer, &flag))
520         return NULL;
521 
522     self->pendingcr = (int) flag & 1;
523     flag >>= 1;
524 
525     if (self->decoder != Py_None)
526         return PyObject_CallMethod(self->decoder,
527                                    "setstate", "((OK))", buffer, flag);
528     else
529         Py_RETURN_NONE;
530 }
531 
532 static PyObject *
incrementalnewlinedecoder_reset(nldecoder_object * self,PyObject * args)533 incrementalnewlinedecoder_reset(nldecoder_object *self, PyObject *args)
534 {
535     self->seennl = 0;
536     self->pendingcr = 0;
537     if (self->decoder != Py_None)
538         return PyObject_CallMethodObjArgs(self->decoder, _PyIO_str_reset, NULL);
539     else
540         Py_RETURN_NONE;
541 }
542 
543 static PyObject *
incrementalnewlinedecoder_newlines_get(nldecoder_object * self,void * context)544 incrementalnewlinedecoder_newlines_get(nldecoder_object *self, void *context)
545 {
546     switch (self->seennl) {
547     case SEEN_CR:
548         return PyUnicode_FromString("\r");
549     case SEEN_LF:
550         return PyUnicode_FromString("\n");
551     case SEEN_CRLF:
552         return PyUnicode_FromString("\r\n");
553     case SEEN_CR | SEEN_LF:
554         return Py_BuildValue("ss", "\r", "\n");
555     case SEEN_CR | SEEN_CRLF:
556         return Py_BuildValue("ss", "\r", "\r\n");
557     case SEEN_LF | SEEN_CRLF:
558         return Py_BuildValue("ss", "\n", "\r\n");
559     case SEEN_CR | SEEN_LF | SEEN_CRLF:
560         return Py_BuildValue("sss", "\r", "\n", "\r\n");
561     default:
562         Py_RETURN_NONE;
563    }
564 
565 }
566 
567 
568 static PyMethodDef incrementalnewlinedecoder_methods[] = {
569     {"decode", (PyCFunction)incrementalnewlinedecoder_decode, METH_VARARGS|METH_KEYWORDS},
570     {"getstate", (PyCFunction)incrementalnewlinedecoder_getstate, METH_NOARGS},
571     {"setstate", (PyCFunction)incrementalnewlinedecoder_setstate, METH_O},
572     {"reset", (PyCFunction)incrementalnewlinedecoder_reset, METH_NOARGS},
573     {NULL}
574 };
575 
576 static PyGetSetDef incrementalnewlinedecoder_getset[] = {
577     {"newlines", (getter)incrementalnewlinedecoder_newlines_get, NULL, NULL},
578     {NULL}
579 };
580 
581 PyTypeObject PyIncrementalNewlineDecoder_Type = {
582     PyVarObject_HEAD_INIT(NULL, 0)
583     "_io.IncrementalNewlineDecoder", /*tp_name*/
584     sizeof(nldecoder_object), /*tp_basicsize*/
585     0,                          /*tp_itemsize*/
586     (destructor)incrementalnewlinedecoder_dealloc, /*tp_dealloc*/
587     0,                          /*tp_print*/
588     0,                          /*tp_getattr*/
589     0,                          /*tp_setattr*/
590     0,                          /*tp_compare */
591     0,                          /*tp_repr*/
592     0,                          /*tp_as_number*/
593     0,                          /*tp_as_sequence*/
594     0,                          /*tp_as_mapping*/
595     0,                          /*tp_hash */
596     0,                          /*tp_call*/
597     0,                          /*tp_str*/
598     0,                          /*tp_getattro*/
599     0,                          /*tp_setattro*/
600     0,                          /*tp_as_buffer*/
601     Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE,  /*tp_flags*/
602     incrementalnewlinedecoder_doc,          /* tp_doc */
603     0,                          /* tp_traverse */
604     0,                          /* tp_clear */
605     0,                          /* tp_richcompare */
606     0,                          /*tp_weaklistoffset*/
607     0,                          /* tp_iter */
608     0,                          /* tp_iternext */
609     incrementalnewlinedecoder_methods, /* tp_methods */
610     0,                          /* tp_members */
611     incrementalnewlinedecoder_getset, /* tp_getset */
612     0,                          /* tp_base */
613     0,                          /* tp_dict */
614     0,                          /* tp_descr_get */
615     0,                          /* tp_descr_set */
616     0,                          /* tp_dictoffset */
617     (initproc)incrementalnewlinedecoder_init, /* tp_init */
618     0,                          /* tp_alloc */
619     PyType_GenericNew,          /* tp_new */
620 };
621 
622 
623 /* TextIOWrapper */
624 
625 PyDoc_STRVAR(textiowrapper_doc,
626     "Character and line based layer over a BufferedIOBase object, buffer.\n"
627     "\n"
628     "encoding gives the name of the encoding that the stream will be\n"
629     "decoded or encoded with. It defaults to locale.getpreferredencoding.\n"
630     "\n"
631     "errors determines the strictness of encoding and decoding (see the\n"
632     "codecs.register) and defaults to \"strict\".\n"
633     "\n"
634     "newline controls how line endings are handled. It can be None, '',\n"
635     "'\\n', '\\r', and '\\r\\n'.  It works as follows:\n"
636     "\n"
637     "* On input, if newline is None, universal newlines mode is\n"
638     "  enabled. Lines in the input can end in '\\n', '\\r', or '\\r\\n', and\n"
639     "  these are translated into '\\n' before being returned to the\n"
640     "  caller. If it is '', universal newline mode is enabled, but line\n"
641     "  endings are returned to the caller untranslated. If it has any of\n"
642     "  the other legal values, input lines are only terminated by the given\n"
643     "  string, and the line ending is returned to the caller untranslated.\n"
644     "\n"
645     "* On output, if newline is None, any '\\n' characters written are\n"
646     "  translated to the system default line separator, os.linesep. If\n"
647     "  newline is '', no translation takes place. If newline is any of the\n"
648     "  other legal values, any '\\n' characters written are translated to\n"
649     "  the given string.\n"
650     "\n"
651     "If line_buffering is True, a call to flush is implied when a call to\n"
652     "write contains a newline character."
653     );
654 
655 typedef PyObject *
656         (*encodefunc_t)(PyObject *, PyObject *);
657 
658 typedef struct
659 {
660     PyObject_HEAD
661     int ok; /* initialized? */
662     int detached;
663     Py_ssize_t chunk_size;
664     PyObject *buffer;
665     PyObject *encoding;
666     PyObject *encoder;
667     PyObject *decoder;
668     PyObject *readnl;
669     PyObject *errors;
670     const char *writenl; /* utf-8 encoded, NULL stands for \n */
671     char line_buffering;
672     char readuniversal;
673     char readtranslate;
674     char writetranslate;
675     char seekable;
676     char telling;
677     /* Specialized encoding func (see below) */
678     encodefunc_t encodefunc;
679     /* Whether or not it's the start of the stream */
680     char encoding_start_of_stream;
681 
682     /* Reads and writes are internally buffered in order to speed things up.
683        However, any read will first flush the write buffer if itsn't empty.
684 
685        Please also note that text to be written is first encoded before being
686        buffered. This is necessary so that encoding errors are immediately
687        reported to the caller, but it unfortunately means that the
688        IncrementalEncoder (whose encode() method is always written in Python)
689        becomes a bottleneck for small writes.
690     */
691     PyObject *decoded_chars;       /* buffer for text returned from decoder */
692     Py_ssize_t decoded_chars_used; /* offset into _decoded_chars for read() */
693     PyObject *pending_bytes;       /* list of bytes objects waiting to be
694                                       written, or NULL */
695     Py_ssize_t pending_bytes_count;
696     PyObject *snapshot;
697     /* snapshot is either None, or a tuple (dec_flags, next_input) where
698      * dec_flags is the second (integer) item of the decoder state and
699      * next_input is the chunk of input bytes that comes next after the
700      * snapshot point.  We use this to reconstruct decoder states in tell().
701      */
702 
703     /* Cache raw object if it's a FileIO object */
704     PyObject *raw;
705 
706     PyObject *weakreflist;
707     PyObject *dict;
708 } textio;
709 
710 
711 /* A couple of specialized cases in order to bypass the slow incremental
712    encoding methods for the most popular encodings. */
713 
714 static PyObject *
ascii_encode(textio * self,PyObject * text)715 ascii_encode(textio *self, PyObject *text)
716 {
717     return PyUnicode_EncodeASCII(PyUnicode_AS_UNICODE(text),
718                                  PyUnicode_GET_SIZE(text),
719                                  PyBytes_AS_STRING(self->errors));
720 }
721 
722 static PyObject *
utf16be_encode(textio * self,PyObject * text)723 utf16be_encode(textio *self, PyObject *text)
724 {
725     return PyUnicode_EncodeUTF16(PyUnicode_AS_UNICODE(text),
726                                  PyUnicode_GET_SIZE(text),
727                                  PyBytes_AS_STRING(self->errors), 1);
728 }
729 
730 static PyObject *
utf16le_encode(textio * self,PyObject * text)731 utf16le_encode(textio *self, PyObject *text)
732 {
733     return PyUnicode_EncodeUTF16(PyUnicode_AS_UNICODE(text),
734                                  PyUnicode_GET_SIZE(text),
735                                  PyBytes_AS_STRING(self->errors), -1);
736 }
737 
738 static PyObject *
utf16_encode(textio * self,PyObject * text)739 utf16_encode(textio *self, PyObject *text)
740 {
741     if (!self->encoding_start_of_stream) {
742         /* Skip the BOM and use native byte ordering */
743 #if defined(WORDS_BIGENDIAN)
744         return utf16be_encode(self, text);
745 #else
746         return utf16le_encode(self, text);
747 #endif
748     }
749     return PyUnicode_EncodeUTF16(PyUnicode_AS_UNICODE(text),
750                                  PyUnicode_GET_SIZE(text),
751                                  PyBytes_AS_STRING(self->errors), 0);
752 }
753 
754 static PyObject *
utf32be_encode(textio * self,PyObject * text)755 utf32be_encode(textio *self, PyObject *text)
756 {
757     return PyUnicode_EncodeUTF32(PyUnicode_AS_UNICODE(text),
758                                  PyUnicode_GET_SIZE(text),
759                                  PyBytes_AS_STRING(self->errors), 1);
760 }
761 
762 static PyObject *
utf32le_encode(textio * self,PyObject * text)763 utf32le_encode(textio *self, PyObject *text)
764 {
765     return PyUnicode_EncodeUTF32(PyUnicode_AS_UNICODE(text),
766                                  PyUnicode_GET_SIZE(text),
767                                  PyBytes_AS_STRING(self->errors), -1);
768 }
769 
770 static PyObject *
utf32_encode(textio * self,PyObject * text)771 utf32_encode(textio *self, PyObject *text)
772 {
773     if (!self->encoding_start_of_stream) {
774         /* Skip the BOM and use native byte ordering */
775 #if defined(WORDS_BIGENDIAN)
776         return utf32be_encode(self, text);
777 #else
778         return utf32le_encode(self, text);
779 #endif
780     }
781     return PyUnicode_EncodeUTF32(PyUnicode_AS_UNICODE(text),
782                                  PyUnicode_GET_SIZE(text),
783                                  PyBytes_AS_STRING(self->errors), 0);
784 }
785 
786 static PyObject *
utf8_encode(textio * self,PyObject * text)787 utf8_encode(textio *self, PyObject *text)
788 {
789     return PyUnicode_EncodeUTF8(PyUnicode_AS_UNICODE(text),
790                                 PyUnicode_GET_SIZE(text),
791                                 PyBytes_AS_STRING(self->errors));
792 }
793 
794 static PyObject *
latin1_encode(textio * self,PyObject * text)795 latin1_encode(textio *self, PyObject *text)
796 {
797     return PyUnicode_EncodeLatin1(PyUnicode_AS_UNICODE(text),
798                                   PyUnicode_GET_SIZE(text),
799                                   PyBytes_AS_STRING(self->errors));
800 }
801 
802 /* Map normalized encoding names onto the specialized encoding funcs */
803 
804 typedef struct {
805     const char *name;
806     encodefunc_t encodefunc;
807 } encodefuncentry;
808 
809 static encodefuncentry encodefuncs[] = {
810     {"ascii",       (encodefunc_t) ascii_encode},
811     {"iso8859-1",   (encodefunc_t) latin1_encode},
812     {"utf-8",       (encodefunc_t) utf8_encode},
813     {"utf-16-be",   (encodefunc_t) utf16be_encode},
814     {"utf-16-le",   (encodefunc_t) utf16le_encode},
815     {"utf-16",      (encodefunc_t) utf16_encode},
816     {"utf-32-be",   (encodefunc_t) utf32be_encode},
817     {"utf-32-le",   (encodefunc_t) utf32le_encode},
818     {"utf-32",      (encodefunc_t) utf32_encode},
819     {NULL, NULL}
820 };
821 
822 
823 static int
textiowrapper_init(textio * self,PyObject * args,PyObject * kwds)824 textiowrapper_init(textio *self, PyObject *args, PyObject *kwds)
825 {
826     char *kwlist[] = {"buffer", "encoding", "errors",
827                       "newline", "line_buffering",
828                       NULL};
829     PyObject *buffer, *raw, *codec_info = NULL;
830     char *encoding = NULL;
831     char *errors = NULL;
832     char *newline = NULL;
833     int line_buffering = 0;
834 
835     PyObject *res;
836     int r;
837 
838     self->ok = 0;
839     self->detached = 0;
840     if (!PyArg_ParseTupleAndKeywords(args, kwds, "O|zzzi:fileio",
841                                      kwlist, &buffer, &encoding, &errors,
842                                      &newline, &line_buffering))
843         return -1;
844 
845     if (newline && newline[0] != '\0'
846         && !(newline[0] == '\n' && newline[1] == '\0')
847         && !(newline[0] == '\r' && newline[1] == '\0')
848         && !(newline[0] == '\r' && newline[1] == '\n' && newline[2] == '\0')) {
849         PyErr_Format(PyExc_ValueError,
850                      "illegal newline value: %s", newline);
851         return -1;
852     }
853 
854     Py_CLEAR(self->buffer);
855     Py_CLEAR(self->encoding);
856     Py_CLEAR(self->encoder);
857     Py_CLEAR(self->decoder);
858     Py_CLEAR(self->readnl);
859     Py_CLEAR(self->decoded_chars);
860     Py_CLEAR(self->pending_bytes);
861     Py_CLEAR(self->snapshot);
862     Py_CLEAR(self->errors);
863     Py_CLEAR(self->raw);
864     self->decoded_chars_used = 0;
865     self->pending_bytes_count = 0;
866     self->encodefunc = NULL;
867     self->writenl = NULL;
868 
869     if (encoding == NULL && self->encoding == NULL) {
870         if (_PyIO_locale_module == NULL) {
871             _PyIO_locale_module = PyImport_ImportModule("locale");
872             if (_PyIO_locale_module == NULL)
873                 goto catch_ImportError;
874             else
875                 goto use_locale;
876         }
877         else {
878           use_locale:
879             self->encoding = PyObject_CallMethod(
880                 _PyIO_locale_module, "getpreferredencoding", NULL);
881             if (self->encoding == NULL) {
882               catch_ImportError:
883                 /*
884                  Importing locale can raise an ImportError because of
885                  _functools, and locale.getpreferredencoding can raise an
886                  ImportError if _locale is not available.  These will happen
887                  during module building.
888                 */
889                 if (PyErr_ExceptionMatches(PyExc_ImportError)) {
890                     PyErr_Clear();
891                     self->encoding = PyString_FromString("ascii");
892                 }
893                 else
894                     goto error;
895             }
896             else if (!PyString_Check(self->encoding))
897                 Py_CLEAR(self->encoding);
898         }
899     }
900     if (self->encoding != NULL)
901         encoding = PyString_AsString(self->encoding);
902     else if (encoding != NULL) {
903         self->encoding = PyString_FromString(encoding);
904         if (self->encoding == NULL)
905             goto error;
906     }
907     else {
908         PyErr_SetString(PyExc_IOError,
909                         "could not determine default encoding");
910     }
911 
912     /* Check we have been asked for a real text encoding */
913     codec_info = _PyCodec_LookupTextEncoding(encoding, "codecs.open()");
914     if (codec_info == NULL) {
915         Py_CLEAR(self->encoding);
916         goto error;
917     }
918 
919     /* XXX: Failures beyond this point have the potential to leak elements
920      * of the partially constructed object (like self->encoding)
921      */
922 
923     if (errors == NULL)
924         errors = "strict";
925     self->errors = PyBytes_FromString(errors);
926     if (self->errors == NULL)
927         goto error;
928 
929     self->chunk_size = 8192;
930     self->readuniversal = (newline == NULL || newline[0] == '\0');
931     self->line_buffering = line_buffering;
932     self->readtranslate = (newline == NULL);
933     if (newline) {
934         self->readnl = PyString_FromString(newline);
935         if (self->readnl == NULL)
936             goto error;
937     }
938     self->writetranslate = (newline == NULL || newline[0] != '\0');
939     if (!self->readuniversal && self->writetranslate) {
940         self->writenl = PyString_AsString(self->readnl);
941         if (!strcmp(self->writenl, "\n"))
942             self->writenl = NULL;
943     }
944 #ifdef MS_WINDOWS
945     else
946         self->writenl = "\r\n";
947 #endif
948 
949     /* Build the decoder object */
950     res = PyObject_CallMethod(buffer, "readable", NULL);
951     if (res == NULL)
952         goto error;
953     r = PyObject_IsTrue(res);
954     Py_DECREF(res);
955     if (r == -1)
956         goto error;
957     if (r == 1) {
958         self->decoder = _PyCodecInfo_GetIncrementalDecoder(codec_info,
959                                                            errors);
960         if (self->decoder == NULL)
961             goto error;
962 
963         if (self->readuniversal) {
964             PyObject *incrementalDecoder = PyObject_CallFunction(
965                 (PyObject *)&PyIncrementalNewlineDecoder_Type,
966                 "Oi", self->decoder, (int)self->readtranslate);
967             if (incrementalDecoder == NULL)
968                 goto error;
969             Py_XSETREF(self->decoder, incrementalDecoder);
970         }
971     }
972 
973     /* Build the encoder object */
974     res = PyObject_CallMethod(buffer, "writable", NULL);
975     if (res == NULL)
976         goto error;
977     r = PyObject_IsTrue(res);
978     Py_DECREF(res);
979     if (r == -1)
980         goto error;
981     if (r == 1) {
982         self->encoder = _PyCodecInfo_GetIncrementalEncoder(codec_info,
983                                                            errors);
984         if (self->encoder == NULL)
985             goto error;
986         /* Get the normalized named of the codec */
987         res = PyObject_GetAttrString(codec_info, "name");
988         if (res == NULL) {
989             if (PyErr_ExceptionMatches(PyExc_AttributeError))
990                 PyErr_Clear();
991             else
992                 goto error;
993         }
994         else if (PyString_Check(res)) {
995             encodefuncentry *e = encodefuncs;
996             while (e->name != NULL) {
997                 if (!strcmp(PyString_AS_STRING(res), e->name)) {
998                     self->encodefunc = e->encodefunc;
999                     break;
1000                 }
1001                 e++;
1002             }
1003         }
1004         Py_XDECREF(res);
1005     }
1006 
1007     /* Finished sorting out the codec details */
1008     Py_DECREF(codec_info);
1009 
1010     self->buffer = buffer;
1011     Py_INCREF(buffer);
1012 
1013     if (Py_TYPE(buffer) == &PyBufferedReader_Type ||
1014         Py_TYPE(buffer) == &PyBufferedWriter_Type ||
1015         Py_TYPE(buffer) == &PyBufferedRandom_Type) {
1016         raw = PyObject_GetAttrString(buffer, "raw");
1017         /* Cache the raw FileIO object to speed up 'closed' checks */
1018         if (raw == NULL) {
1019             if (PyErr_ExceptionMatches(PyExc_AttributeError))
1020                 PyErr_Clear();
1021             else
1022                 goto error;
1023         }
1024         else if (Py_TYPE(raw) == &PyFileIO_Type)
1025             self->raw = raw;
1026         else
1027             Py_DECREF(raw);
1028     }
1029 
1030     res = PyObject_CallMethod(buffer, "seekable", NULL);
1031     if (res == NULL)
1032         goto error;
1033     r = PyObject_IsTrue(res);
1034     Py_DECREF(res);
1035     if (r < 0)
1036         goto error;
1037     self->seekable = self->telling = r;
1038 
1039     self->encoding_start_of_stream = 0;
1040     if (self->seekable && self->encoder) {
1041         PyObject *cookieObj;
1042         int cmp;
1043 
1044         self->encoding_start_of_stream = 1;
1045 
1046         cookieObj = PyObject_CallMethodObjArgs(buffer, _PyIO_str_tell, NULL);
1047         if (cookieObj == NULL)
1048             goto error;
1049 
1050         cmp = PyObject_RichCompareBool(cookieObj, _PyIO_zero, Py_EQ);
1051         Py_DECREF(cookieObj);
1052         if (cmp < 0) {
1053             goto error;
1054         }
1055 
1056         if (cmp == 0) {
1057             self->encoding_start_of_stream = 0;
1058             res = PyObject_CallMethodObjArgs(self->encoder, _PyIO_str_setstate,
1059                                              _PyIO_zero, NULL);
1060             if (res == NULL)
1061                 goto error;
1062             Py_DECREF(res);
1063         }
1064     }
1065 
1066     self->ok = 1;
1067     return 0;
1068 
1069   error:
1070     Py_XDECREF(codec_info);
1071     return -1;
1072 }
1073 
1074 static void
_textiowrapper_clear(textio * self)1075 _textiowrapper_clear(textio *self)
1076 {
1077     self->ok = 0;
1078     Py_CLEAR(self->buffer);
1079     Py_CLEAR(self->encoding);
1080     Py_CLEAR(self->encoder);
1081     Py_CLEAR(self->decoder);
1082     Py_CLEAR(self->readnl);
1083     Py_CLEAR(self->decoded_chars);
1084     Py_CLEAR(self->pending_bytes);
1085     Py_CLEAR(self->snapshot);
1086     Py_CLEAR(self->errors);
1087     Py_CLEAR(self->raw);
1088 
1089     Py_CLEAR(self->dict);
1090 }
1091 
1092 static void
textiowrapper_dealloc(textio * self)1093 textiowrapper_dealloc(textio *self)
1094 {
1095     if (self->ok && _PyIOBase_finalize((PyObject *) self) < 0)
1096         return;
1097     _PyObject_GC_UNTRACK(self);
1098     if (self->weakreflist != NULL)
1099         PyObject_ClearWeakRefs((PyObject *)self);
1100     _textiowrapper_clear(self);
1101     Py_TYPE(self)->tp_free((PyObject *)self);
1102 }
1103 
1104 static int
textiowrapper_traverse(textio * self,visitproc visit,void * arg)1105 textiowrapper_traverse(textio *self, visitproc visit, void *arg)
1106 {
1107     Py_VISIT(self->buffer);
1108     Py_VISIT(self->encoding);
1109     Py_VISIT(self->encoder);
1110     Py_VISIT(self->decoder);
1111     Py_VISIT(self->readnl);
1112     Py_VISIT(self->decoded_chars);
1113     Py_VISIT(self->pending_bytes);
1114     Py_VISIT(self->snapshot);
1115     Py_VISIT(self->errors);
1116     Py_VISIT(self->raw);
1117 
1118     Py_VISIT(self->dict);
1119     return 0;
1120 }
1121 
1122 static int
textiowrapper_clear(textio * self)1123 textiowrapper_clear(textio *self)
1124 {
1125     if (self->ok && _PyIOBase_finalize((PyObject *) self) < 0)
1126         return -1;
1127     _textiowrapper_clear(self);
1128     return 0;
1129 }
1130 
1131 static PyObject *
1132 textiowrapper_closed_get(textio *self, void *context);
1133 
1134 /* This macro takes some shortcuts to make the common case faster. */
1135 #define CHECK_CLOSED(self) \
1136     do { \
1137         int r; \
1138         PyObject *_res; \
1139         if (Py_TYPE(self) == &PyTextIOWrapper_Type) { \
1140             if (self->raw != NULL) \
1141                 r = _PyFileIO_closed(self->raw); \
1142             else { \
1143                 _res = textiowrapper_closed_get(self, NULL); \
1144                 if (_res == NULL) \
1145                     return NULL; \
1146                 r = PyObject_IsTrue(_res); \
1147                 Py_DECREF(_res); \
1148                 if (r < 0) \
1149                     return NULL; \
1150             } \
1151             if (r > 0) { \
1152                 PyErr_SetString(PyExc_ValueError, \
1153                                 "I/O operation on closed file."); \
1154                 return NULL; \
1155             } \
1156         } \
1157         else if (_PyIOBase_check_closed((PyObject *)self, Py_True) == NULL) \
1158             return NULL; \
1159     } while (0)
1160 
1161 #define CHECK_INITIALIZED(self) \
1162     if (self->ok <= 0) { \
1163         PyErr_SetString(PyExc_ValueError, \
1164             "I/O operation on uninitialized object"); \
1165         return NULL; \
1166     }
1167 
1168 #define CHECK_ATTACHED(self) \
1169     CHECK_INITIALIZED(self); \
1170     if (self->detached) { \
1171         PyErr_SetString(PyExc_ValueError, \
1172              "underlying buffer has been detached"); \
1173         return NULL; \
1174     }
1175 
1176 #define CHECK_ATTACHED_INT(self) \
1177     if (self->ok <= 0) { \
1178         PyErr_SetString(PyExc_ValueError, \
1179             "I/O operation on uninitialized object"); \
1180         return -1; \
1181     } else if (self->detached) { \
1182         PyErr_SetString(PyExc_ValueError, \
1183              "underlying buffer has been detached"); \
1184         return -1; \
1185     }
1186 
1187 
1188 static PyObject *
textiowrapper_detach(textio * self)1189 textiowrapper_detach(textio *self)
1190 {
1191     PyObject *buffer, *res;
1192     CHECK_ATTACHED(self);
1193     res = PyObject_CallMethodObjArgs((PyObject *)self, _PyIO_str_flush, NULL);
1194     if (res == NULL)
1195         return NULL;
1196     Py_DECREF(res);
1197     buffer = self->buffer;
1198     self->buffer = NULL;
1199     self->detached = 1;
1200     return buffer;
1201 }
1202 
1203 Py_LOCAL_INLINE(const Py_UNICODE *)
findchar(const Py_UNICODE * s,Py_ssize_t size,Py_UNICODE ch)1204 findchar(const Py_UNICODE *s, Py_ssize_t size, Py_UNICODE ch)
1205 {
1206     /* like wcschr, but doesn't stop at NULL characters */
1207     while (size-- > 0) {
1208         if (*s == ch)
1209             return s;
1210         s++;
1211     }
1212     return NULL;
1213 }
1214 
1215 /* Flush the internal write buffer. This doesn't explicitly flush the
1216    underlying buffered object, though. */
1217 static int
_textiowrapper_writeflush(textio * self)1218 _textiowrapper_writeflush(textio *self)
1219 {
1220     PyObject *pending, *b, *ret;
1221 
1222     if (self->pending_bytes == NULL)
1223         return 0;
1224 
1225     pending = self->pending_bytes;
1226     Py_INCREF(pending);
1227     self->pending_bytes_count = 0;
1228     Py_CLEAR(self->pending_bytes);
1229 
1230     b = _PyBytes_Join(_PyIO_empty_bytes, pending);
1231     Py_DECREF(pending);
1232     if (b == NULL)
1233         return -1;
1234     ret = NULL;
1235     do {
1236         ret = PyObject_CallMethodObjArgs(self->buffer,
1237                                          _PyIO_str_write, b, NULL);
1238     } while (ret == NULL && _PyIO_trap_eintr());
1239     Py_DECREF(b);
1240     if (ret == NULL)
1241         return -1;
1242     Py_DECREF(ret);
1243     return 0;
1244 }
1245 
1246 static PyObject *
textiowrapper_write(textio * self,PyObject * args)1247 textiowrapper_write(textio *self, PyObject *args)
1248 {
1249     PyObject *ret;
1250     PyObject *text; /* owned reference */
1251     PyObject *b;
1252     Py_ssize_t textlen;
1253     int haslf = 0;
1254     int needflush = 0;
1255 
1256     CHECK_ATTACHED(self);
1257 
1258     if (!PyArg_ParseTuple(args, "U:write", &text)) {
1259         return NULL;
1260     }
1261 
1262     CHECK_CLOSED(self);
1263 
1264     if (self->encoder == NULL) {
1265         PyErr_SetString(PyExc_IOError, "not writable");
1266         return NULL;
1267     }
1268 
1269     Py_INCREF(text);
1270 
1271     textlen = PyUnicode_GetSize(text);
1272 
1273     if ((self->writetranslate && self->writenl != NULL) || self->line_buffering)
1274         if (findchar(PyUnicode_AS_UNICODE(text),
1275                      PyUnicode_GET_SIZE(text), '\n'))
1276             haslf = 1;
1277 
1278     if (haslf && self->writetranslate && self->writenl != NULL) {
1279         PyObject *newtext = PyObject_CallMethod(
1280             text, "replace", "ss", "\n", self->writenl);
1281         Py_DECREF(text);
1282         if (newtext == NULL)
1283             return NULL;
1284         text = newtext;
1285     }
1286 
1287     if (self->line_buffering &&
1288         (haslf ||
1289          findchar(PyUnicode_AS_UNICODE(text),
1290                   PyUnicode_GET_SIZE(text), '\r')))
1291         needflush = 1;
1292 
1293     /* XXX What if we were just reading? */
1294     if (self->encodefunc != NULL) {
1295         b = (*self->encodefunc)((PyObject *) self, text);
1296         self->encoding_start_of_stream = 0;
1297     }
1298     else
1299         b = PyObject_CallMethodObjArgs(self->encoder,
1300                                        _PyIO_str_encode, text, NULL);
1301     Py_DECREF(text);
1302     if (b == NULL)
1303         return NULL;
1304 
1305     if (self->pending_bytes == NULL) {
1306         self->pending_bytes = PyList_New(0);
1307         if (self->pending_bytes == NULL) {
1308             Py_DECREF(b);
1309             return NULL;
1310         }
1311         self->pending_bytes_count = 0;
1312     }
1313     if (PyList_Append(self->pending_bytes, b) < 0) {
1314         Py_DECREF(b);
1315         return NULL;
1316     }
1317     self->pending_bytes_count += PyBytes_GET_SIZE(b);
1318     Py_DECREF(b);
1319     if (self->pending_bytes_count > self->chunk_size || needflush) {
1320         if (_textiowrapper_writeflush(self) < 0)
1321             return NULL;
1322     }
1323 
1324     if (needflush) {
1325         ret = PyObject_CallMethodObjArgs(self->buffer, _PyIO_str_flush, NULL);
1326         if (ret == NULL)
1327             return NULL;
1328         Py_DECREF(ret);
1329     }
1330 
1331     Py_CLEAR(self->snapshot);
1332 
1333     if (self->decoder) {
1334         ret = PyObject_CallMethod(self->decoder, "reset", NULL);
1335         if (ret == NULL)
1336             return NULL;
1337         Py_DECREF(ret);
1338     }
1339 
1340     return PyLong_FromSsize_t(textlen);
1341 }
1342 
1343 /* Steal a reference to chars and store it in the decoded_char buffer;
1344  */
1345 static void
textiowrapper_set_decoded_chars(textio * self,PyObject * chars)1346 textiowrapper_set_decoded_chars(textio *self, PyObject *chars)
1347 {
1348     Py_XSETREF(self->decoded_chars, chars);
1349     self->decoded_chars_used = 0;
1350 }
1351 
1352 static PyObject *
textiowrapper_get_decoded_chars(textio * self,Py_ssize_t n)1353 textiowrapper_get_decoded_chars(textio *self, Py_ssize_t n)
1354 {
1355     PyObject *chars;
1356     Py_ssize_t avail;
1357 
1358     if (self->decoded_chars == NULL)
1359         return PyUnicode_FromStringAndSize(NULL, 0);
1360 
1361     avail = (PyUnicode_GET_SIZE(self->decoded_chars)
1362              - self->decoded_chars_used);
1363 
1364     assert(avail >= 0);
1365 
1366     if (n < 0 || n > avail)
1367         n = avail;
1368 
1369     if (self->decoded_chars_used > 0 || n < avail) {
1370         chars = PyUnicode_FromUnicode(
1371             PyUnicode_AS_UNICODE(self->decoded_chars)
1372             + self->decoded_chars_used, n);
1373         if (chars == NULL)
1374             return NULL;
1375     }
1376     else {
1377         chars = self->decoded_chars;
1378         Py_INCREF(chars);
1379     }
1380 
1381     self->decoded_chars_used += n;
1382     return chars;
1383 }
1384 
1385 /* Read and decode the next chunk of data from the BufferedReader.
1386  */
1387 static int
textiowrapper_read_chunk(textio * self)1388 textiowrapper_read_chunk(textio *self)
1389 {
1390     PyObject *dec_buffer = NULL;
1391     PyObject *dec_flags = NULL;
1392     PyObject *input_chunk = NULL;
1393     PyObject *decoded_chars, *chunk_size;
1394     int eof;
1395 
1396     /* The return value is True unless EOF was reached.  The decoded string is
1397      * placed in self._decoded_chars (replacing its previous value).  The
1398      * entire input chunk is sent to the decoder, though some of it may remain
1399      * buffered in the decoder, yet to be converted.
1400      */
1401 
1402     if (self->decoder == NULL) {
1403         PyErr_SetString(PyExc_IOError, "not readable");
1404         return -1;
1405     }
1406 
1407     if (self->telling) {
1408         /* To prepare for tell(), we need to snapshot a point in the file
1409          * where the decoder's input buffer is empty.
1410          */
1411 
1412         PyObject *state = PyObject_CallMethodObjArgs(self->decoder,
1413                                                      _PyIO_str_getstate, NULL);
1414         if (state == NULL)
1415             return -1;
1416         /* Given this, we know there was a valid snapshot point
1417          * len(dec_buffer) bytes ago with decoder state (b'', dec_flags).
1418          */
1419         if (PyArg_Parse(state, "(OO)", &dec_buffer, &dec_flags) < 0) {
1420             Py_DECREF(state);
1421             return -1;
1422         }
1423         Py_INCREF(dec_buffer);
1424         Py_INCREF(dec_flags);
1425         Py_DECREF(state);
1426     }
1427 
1428     /* Read a chunk, decode it, and put the result in self._decoded_chars. */
1429     chunk_size = PyLong_FromSsize_t(self->chunk_size);
1430     if (chunk_size == NULL)
1431         goto fail;
1432     input_chunk = PyObject_CallMethodObjArgs(self->buffer,
1433         _PyIO_str_read1, chunk_size, NULL);
1434     Py_DECREF(chunk_size);
1435     if (input_chunk == NULL)
1436         goto fail;
1437     if (!PyBytes_Check(input_chunk)) {
1438         PyErr_Format(PyExc_TypeError,
1439                      "underlying read1() should have returned a bytes object, "
1440                      "not '%.200s'", Py_TYPE(input_chunk)->tp_name);
1441         goto fail;
1442     }
1443 
1444     eof = (PyBytes_Size(input_chunk) == 0);
1445 
1446     if (Py_TYPE(self->decoder) == &PyIncrementalNewlineDecoder_Type) {
1447         decoded_chars = _PyIncrementalNewlineDecoder_decode(
1448             self->decoder, input_chunk, eof);
1449     }
1450     else {
1451         decoded_chars = PyObject_CallMethodObjArgs(self->decoder,
1452             _PyIO_str_decode, input_chunk, eof ? Py_True : Py_False, NULL);
1453     }
1454 
1455     if (check_decoded(decoded_chars) < 0)
1456         goto fail;
1457     textiowrapper_set_decoded_chars(self, decoded_chars);
1458     if (PyUnicode_GET_SIZE(decoded_chars) > 0)
1459         eof = 0;
1460 
1461     if (self->telling) {
1462         /* At the snapshot point, len(dec_buffer) bytes before the read, the
1463          * next input to be decoded is dec_buffer + input_chunk.
1464          */
1465         PyObject *next_input = PyNumber_Add(dec_buffer, input_chunk);
1466         if (next_input == NULL)
1467             goto fail;
1468         if (!PyBytes_Check(next_input)) {
1469             PyErr_Format(PyExc_TypeError,
1470                          "decoder getstate() should have returned a bytes "
1471                          "object, not '%.200s'",
1472                          Py_TYPE(next_input)->tp_name);
1473             Py_DECREF(next_input);
1474             goto fail;
1475         }
1476         Py_DECREF(dec_buffer);
1477         Py_XSETREF(self->snapshot, Py_BuildValue("NN", dec_flags, next_input));
1478     }
1479     Py_DECREF(input_chunk);
1480 
1481     return (eof == 0);
1482 
1483   fail:
1484     Py_XDECREF(dec_buffer);
1485     Py_XDECREF(dec_flags);
1486     Py_XDECREF(input_chunk);
1487     return -1;
1488 }
1489 
1490 static PyObject *
textiowrapper_read(textio * self,PyObject * args)1491 textiowrapper_read(textio *self, PyObject *args)
1492 {
1493     Py_ssize_t n = -1;
1494     PyObject *result = NULL, *chunks = NULL;
1495 
1496     CHECK_ATTACHED(self);
1497 
1498     if (!PyArg_ParseTuple(args, "|O&:read", &_PyIO_ConvertSsize_t, &n))
1499         return NULL;
1500 
1501     CHECK_CLOSED(self);
1502 
1503     if (self->decoder == NULL) {
1504         PyErr_SetString(PyExc_IOError, "not readable");
1505         return NULL;
1506     }
1507 
1508     if (_textiowrapper_writeflush(self) < 0)
1509         return NULL;
1510 
1511     if (n < 0) {
1512         /* Read everything */
1513         PyObject *bytes = PyObject_CallMethod(self->buffer, "read", NULL);
1514         PyObject *decoded, *final;
1515         if (bytes == NULL)
1516             goto fail;
1517         decoded = PyObject_CallMethodObjArgs(self->decoder, _PyIO_str_decode,
1518                                              bytes, Py_True, NULL);
1519         Py_DECREF(bytes);
1520         if (check_decoded(decoded) < 0)
1521             goto fail;
1522 
1523         result = textiowrapper_get_decoded_chars(self, -1);
1524 
1525         if (result == NULL) {
1526             Py_DECREF(decoded);
1527             return NULL;
1528         }
1529 
1530         final = PyUnicode_Concat(result, decoded);
1531         Py_DECREF(result);
1532         Py_DECREF(decoded);
1533         if (final == NULL)
1534             goto fail;
1535 
1536         Py_CLEAR(self->snapshot);
1537         return final;
1538     }
1539     else {
1540         int res = 1;
1541         Py_ssize_t remaining = n;
1542 
1543         result = textiowrapper_get_decoded_chars(self, n);
1544         if (result == NULL)
1545             goto fail;
1546         remaining -= PyUnicode_GET_SIZE(result);
1547 
1548         /* Keep reading chunks until we have n characters to return */
1549         while (remaining > 0) {
1550             res = textiowrapper_read_chunk(self);
1551             if (res < 0) {
1552                 /* NOTE: PyErr_SetFromErrno() calls PyErr_CheckSignals()
1553                    when EINTR occurs so we needn't do it ourselves. */
1554                 if (_PyIO_trap_eintr()) {
1555                     continue;
1556                 }
1557                 goto fail;
1558             }
1559             if (res == 0)  /* EOF */
1560                 break;
1561             if (chunks == NULL) {
1562                 chunks = PyList_New(0);
1563                 if (chunks == NULL)
1564                     goto fail;
1565             }
1566             if (PyList_Append(chunks, result) < 0)
1567                 goto fail;
1568             Py_DECREF(result);
1569             result = textiowrapper_get_decoded_chars(self, remaining);
1570             if (result == NULL)
1571                 goto fail;
1572             remaining -= PyUnicode_GET_SIZE(result);
1573         }
1574         if (chunks != NULL) {
1575             if (result != NULL && PyList_Append(chunks, result) < 0)
1576                 goto fail;
1577             Py_XSETREF(result, PyUnicode_Join(_PyIO_empty_str, chunks));
1578             if (result == NULL)
1579                 goto fail;
1580             Py_CLEAR(chunks);
1581         }
1582         return result;
1583     }
1584   fail:
1585     Py_XDECREF(result);
1586     Py_XDECREF(chunks);
1587     return NULL;
1588 }
1589 
1590 
1591 /* NOTE: `end` must point to the real end of the Py_UNICODE storage,
1592    that is to the NUL character. Otherwise the function will produce
1593    incorrect results. */
1594 static Py_UNICODE *
find_control_char(Py_UNICODE * start,Py_UNICODE * end,Py_UNICODE ch)1595 find_control_char(Py_UNICODE *start, Py_UNICODE *end, Py_UNICODE ch)
1596 {
1597     Py_UNICODE *s = start;
1598     for (;;) {
1599         while (*s > ch)
1600             s++;
1601         if (*s == ch)
1602             return s;
1603         if (s == end)
1604             return NULL;
1605         s++;
1606     }
1607 }
1608 
1609 Py_ssize_t
_PyIO_find_line_ending(int translated,int universal,PyObject * readnl,Py_UNICODE * start,Py_UNICODE * end,Py_ssize_t * consumed)1610 _PyIO_find_line_ending(
1611     int translated, int universal, PyObject *readnl,
1612     Py_UNICODE *start, Py_UNICODE *end, Py_ssize_t *consumed)
1613 {
1614     Py_ssize_t len = end - start;
1615 
1616     if (translated) {
1617         /* Newlines are already translated, only search for \n */
1618         Py_UNICODE *pos = find_control_char(start, end, '\n');
1619         if (pos != NULL)
1620             return pos - start + 1;
1621         else {
1622             *consumed = len;
1623             return -1;
1624         }
1625     }
1626     else if (universal) {
1627         /* Universal newline search. Find any of \r, \r\n, \n
1628          * The decoder ensures that \r\n are not split in two pieces
1629          */
1630         Py_UNICODE *s = start;
1631         for (;;) {
1632             Py_UNICODE ch;
1633             /* Fast path for non-control chars. The loop always ends
1634                since the Py_UNICODE storage is NUL-terminated. */
1635             while (*s > '\r')
1636                 s++;
1637             if (s >= end) {
1638                 *consumed = len;
1639                 return -1;
1640             }
1641             ch = *s++;
1642             if (ch == '\n')
1643                 return s - start;
1644             if (ch == '\r') {
1645                 if (*s == '\n')
1646                     return s - start + 1;
1647                 else
1648                     return s - start;
1649             }
1650         }
1651     }
1652     else {
1653         /* Non-universal mode. */
1654         Py_ssize_t readnl_len = PyString_GET_SIZE(readnl);
1655         unsigned char *nl = (unsigned char *) PyString_AS_STRING(readnl);
1656         if (readnl_len == 1) {
1657             Py_UNICODE *pos = find_control_char(start, end, nl[0]);
1658             if (pos != NULL)
1659                 return pos - start + 1;
1660             *consumed = len;
1661             return -1;
1662         }
1663         else {
1664             Py_UNICODE *s = start;
1665             Py_UNICODE *e = end - readnl_len + 1;
1666             Py_UNICODE *pos;
1667             if (e < s)
1668                 e = s;
1669             while (s < e) {
1670                 Py_ssize_t i;
1671                 Py_UNICODE *pos = find_control_char(s, end, nl[0]);
1672                 if (pos == NULL || pos >= e)
1673                     break;
1674                 for (i = 1; i < readnl_len; i++) {
1675                     if (pos[i] != nl[i])
1676                         break;
1677                 }
1678                 if (i == readnl_len)
1679                     return pos - start + readnl_len;
1680                 s = pos + 1;
1681             }
1682             pos = find_control_char(e, end, nl[0]);
1683             if (pos == NULL)
1684                 *consumed = len;
1685             else
1686                 *consumed = pos - start;
1687             return -1;
1688         }
1689     }
1690 }
1691 
1692 static PyObject *
_textiowrapper_readline(textio * self,Py_ssize_t limit)1693 _textiowrapper_readline(textio *self, Py_ssize_t limit)
1694 {
1695     PyObject *line = NULL, *chunks = NULL, *remaining = NULL;
1696     Py_ssize_t start, endpos, chunked, offset_to_buffer;
1697     int res;
1698 
1699     CHECK_CLOSED(self);
1700 
1701     if (_textiowrapper_writeflush(self) < 0)
1702         return NULL;
1703 
1704     chunked = 0;
1705 
1706     while (1) {
1707         Py_UNICODE *ptr;
1708         Py_ssize_t line_len;
1709         Py_ssize_t consumed = 0;
1710 
1711         /* First, get some data if necessary */
1712         res = 1;
1713         while (!self->decoded_chars ||
1714                !PyUnicode_GET_SIZE(self->decoded_chars)) {
1715             res = textiowrapper_read_chunk(self);
1716             if (res < 0) {
1717                 /* NOTE: PyErr_SetFromErrno() calls PyErr_CheckSignals()
1718                    when EINTR occurs so we needn't do it ourselves. */
1719                 if (_PyIO_trap_eintr()) {
1720                     continue;
1721                 }
1722                 goto error;
1723             }
1724             if (res == 0)
1725                 break;
1726         }
1727         if (res == 0) {
1728             /* end of file */
1729             textiowrapper_set_decoded_chars(self, NULL);
1730             Py_CLEAR(self->snapshot);
1731             start = endpos = offset_to_buffer = 0;
1732             break;
1733         }
1734 
1735         if (remaining == NULL) {
1736             line = self->decoded_chars;
1737             start = self->decoded_chars_used;
1738             offset_to_buffer = 0;
1739             Py_INCREF(line);
1740         }
1741         else {
1742             assert(self->decoded_chars_used == 0);
1743             line = PyUnicode_Concat(remaining, self->decoded_chars);
1744             start = 0;
1745             offset_to_buffer = PyUnicode_GET_SIZE(remaining);
1746             Py_CLEAR(remaining);
1747             if (line == NULL)
1748                 goto error;
1749         }
1750 
1751         ptr = PyUnicode_AS_UNICODE(line);
1752         line_len = PyUnicode_GET_SIZE(line);
1753 
1754         endpos = _PyIO_find_line_ending(
1755             self->readtranslate, self->readuniversal, self->readnl,
1756             ptr + start, ptr + line_len, &consumed);
1757         if (endpos >= 0) {
1758             endpos += start;
1759             if (limit >= 0 && (endpos - start) + chunked >= limit)
1760                 endpos = start + limit - chunked;
1761             break;
1762         }
1763 
1764         /* We can put aside up to `endpos` */
1765         endpos = consumed + start;
1766         if (limit >= 0 && (endpos - start) + chunked >= limit) {
1767             /* Didn't find line ending, but reached length limit */
1768             endpos = start + limit - chunked;
1769             break;
1770         }
1771 
1772         if (endpos > start) {
1773             /* No line ending seen yet - put aside current data */
1774             PyObject *s;
1775             if (chunks == NULL) {
1776                 chunks = PyList_New(0);
1777                 if (chunks == NULL)
1778                     goto error;
1779             }
1780             s = PyUnicode_FromUnicode(ptr + start, endpos - start);
1781             if (s == NULL)
1782                 goto error;
1783             if (PyList_Append(chunks, s) < 0) {
1784                 Py_DECREF(s);
1785                 goto error;
1786             }
1787             chunked += PyUnicode_GET_SIZE(s);
1788             Py_DECREF(s);
1789         }
1790         /* There may be some remaining bytes we'll have to prepend to the
1791            next chunk of data */
1792         if (endpos < line_len) {
1793             remaining = PyUnicode_FromUnicode(
1794                     ptr + endpos, line_len - endpos);
1795             if (remaining == NULL)
1796                 goto error;
1797         }
1798         Py_CLEAR(line);
1799         /* We have consumed the buffer */
1800         textiowrapper_set_decoded_chars(self, NULL);
1801     }
1802 
1803     if (line != NULL) {
1804         /* Our line ends in the current buffer */
1805         self->decoded_chars_used = endpos - offset_to_buffer;
1806         if (start > 0 || endpos < PyUnicode_GET_SIZE(line)) {
1807             if (start == 0 && Py_REFCNT(line) == 1) {
1808                 if (PyUnicode_Resize(&line, endpos) < 0)
1809                     goto error;
1810             }
1811             else {
1812                 PyObject *s = PyUnicode_FromUnicode(
1813                         PyUnicode_AS_UNICODE(line) + start, endpos - start);
1814                 Py_CLEAR(line);
1815                 if (s == NULL)
1816                     goto error;
1817                 line = s;
1818             }
1819         }
1820     }
1821     if (remaining != NULL) {
1822         if (chunks == NULL) {
1823             chunks = PyList_New(0);
1824             if (chunks == NULL)
1825                 goto error;
1826         }
1827         if (PyList_Append(chunks, remaining) < 0)
1828             goto error;
1829         Py_CLEAR(remaining);
1830     }
1831     if (chunks != NULL) {
1832         if (line != NULL && PyList_Append(chunks, line) < 0)
1833             goto error;
1834         Py_XSETREF(line, PyUnicode_Join(_PyIO_empty_str, chunks));
1835         if (line == NULL)
1836             goto error;
1837         Py_DECREF(chunks);
1838     }
1839     if (line == NULL)
1840         line = PyUnicode_FromStringAndSize(NULL, 0);
1841 
1842     return line;
1843 
1844   error:
1845     Py_XDECREF(chunks);
1846     Py_XDECREF(remaining);
1847     Py_XDECREF(line);
1848     return NULL;
1849 }
1850 
1851 static PyObject *
textiowrapper_readline(textio * self,PyObject * args)1852 textiowrapper_readline(textio *self, PyObject *args)
1853 {
1854     PyObject *limitobj = NULL;
1855     Py_ssize_t limit = -1;
1856 
1857     CHECK_ATTACHED(self);
1858     if (!PyArg_ParseTuple(args, "|O:readline", &limitobj)) {
1859         return NULL;
1860     }
1861     if (limitobj) {
1862         if (!PyNumber_Check(limitobj)) {
1863             PyErr_Format(PyExc_TypeError,
1864                          "integer argument expected, got '%.200s'",
1865                          Py_TYPE(limitobj)->tp_name);
1866             return NULL;
1867         }
1868         limit = PyNumber_AsSsize_t(limitobj, PyExc_OverflowError);
1869         if (limit == -1 && PyErr_Occurred())
1870             return NULL;
1871     }
1872     return _textiowrapper_readline(self, limit);
1873 }
1874 
1875 /* Seek and Tell */
1876 
1877 typedef struct {
1878     Py_off_t start_pos;
1879     int dec_flags;
1880     int bytes_to_feed;
1881     int chars_to_skip;
1882     char need_eof;
1883 } cookie_type;
1884 
1885 /*
1886    To speed up cookie packing/unpacking, we store the fields in a temporary
1887    string and call _PyLong_FromByteArray() or _PyLong_AsByteArray (resp.).
1888    The following macros define at which offsets in the intermediary byte
1889    string the various CookieStruct fields will be stored.
1890  */
1891 
1892 #define COOKIE_BUF_LEN      (sizeof(Py_off_t) + 3 * sizeof(int) + sizeof(char))
1893 
1894 #if defined(WORDS_BIGENDIAN)
1895 
1896 # define IS_LITTLE_ENDIAN   0
1897 
1898 /* We want the least significant byte of start_pos to also be the least
1899    significant byte of the cookie, which means that in big-endian mode we
1900    must copy the fields in reverse order. */
1901 
1902 # define OFF_START_POS      (sizeof(char) + 3 * sizeof(int))
1903 # define OFF_DEC_FLAGS      (sizeof(char) + 2 * sizeof(int))
1904 # define OFF_BYTES_TO_FEED  (sizeof(char) + sizeof(int))
1905 # define OFF_CHARS_TO_SKIP  (sizeof(char))
1906 # define OFF_NEED_EOF       0
1907 
1908 #else
1909 
1910 # define IS_LITTLE_ENDIAN   1
1911 
1912 /* Little-endian mode: the least significant byte of start_pos will
1913    naturally end up the least significant byte of the cookie. */
1914 
1915 # define OFF_START_POS      0
1916 # define OFF_DEC_FLAGS      (sizeof(Py_off_t))
1917 # define OFF_BYTES_TO_FEED  (sizeof(Py_off_t) + sizeof(int))
1918 # define OFF_CHARS_TO_SKIP  (sizeof(Py_off_t) + 2 * sizeof(int))
1919 # define OFF_NEED_EOF       (sizeof(Py_off_t) + 3 * sizeof(int))
1920 
1921 #endif
1922 
1923 static int
textiowrapper_parse_cookie(cookie_type * cookie,PyObject * cookieObj)1924 textiowrapper_parse_cookie(cookie_type *cookie, PyObject *cookieObj)
1925 {
1926     unsigned char buffer[COOKIE_BUF_LEN];
1927     PyLongObject *cookieLong = (PyLongObject *)PyNumber_Long(cookieObj);
1928     if (cookieLong == NULL)
1929         return -1;
1930 
1931     if (_PyLong_AsByteArray(cookieLong, buffer, sizeof(buffer),
1932                             IS_LITTLE_ENDIAN, 0) < 0) {
1933         Py_DECREF(cookieLong);
1934         return -1;
1935     }
1936     Py_DECREF(cookieLong);
1937 
1938     memcpy(&cookie->start_pos, buffer + OFF_START_POS, sizeof(cookie->start_pos));
1939     memcpy(&cookie->dec_flags, buffer + OFF_DEC_FLAGS, sizeof(cookie->dec_flags));
1940     memcpy(&cookie->bytes_to_feed, buffer + OFF_BYTES_TO_FEED, sizeof(cookie->bytes_to_feed));
1941     memcpy(&cookie->chars_to_skip, buffer + OFF_CHARS_TO_SKIP, sizeof(cookie->chars_to_skip));
1942     memcpy(&cookie->need_eof, buffer + OFF_NEED_EOF, sizeof(cookie->need_eof));
1943 
1944     return 0;
1945 }
1946 
1947 static PyObject *
textiowrapper_build_cookie(cookie_type * cookie)1948 textiowrapper_build_cookie(cookie_type *cookie)
1949 {
1950     unsigned char buffer[COOKIE_BUF_LEN];
1951 
1952     memcpy(buffer + OFF_START_POS, &cookie->start_pos, sizeof(cookie->start_pos));
1953     memcpy(buffer + OFF_DEC_FLAGS, &cookie->dec_flags, sizeof(cookie->dec_flags));
1954     memcpy(buffer + OFF_BYTES_TO_FEED, &cookie->bytes_to_feed, sizeof(cookie->bytes_to_feed));
1955     memcpy(buffer + OFF_CHARS_TO_SKIP, &cookie->chars_to_skip, sizeof(cookie->chars_to_skip));
1956     memcpy(buffer + OFF_NEED_EOF, &cookie->need_eof, sizeof(cookie->need_eof));
1957 
1958     return _PyLong_FromByteArray(buffer, sizeof(buffer), IS_LITTLE_ENDIAN, 0);
1959 }
1960 #undef IS_LITTLE_ENDIAN
1961 
1962 static int
_textiowrapper_decoder_setstate(textio * self,cookie_type * cookie)1963 _textiowrapper_decoder_setstate(textio *self, cookie_type *cookie)
1964 {
1965     PyObject *res;
1966     /* When seeking to the start of the stream, we call decoder.reset()
1967        rather than decoder.getstate().
1968        This is for a few decoders such as utf-16 for which the state value
1969        at start is not (b"", 0) but e.g. (b"", 2) (meaning, in the case of
1970        utf-16, that we are expecting a BOM).
1971     */
1972     if (cookie->start_pos == 0 && cookie->dec_flags == 0)
1973         res = PyObject_CallMethodObjArgs(self->decoder, _PyIO_str_reset, NULL);
1974     else
1975         res = PyObject_CallMethod(self->decoder, "setstate",
1976                                   "((si))", "", cookie->dec_flags);
1977     if (res == NULL)
1978         return -1;
1979     Py_DECREF(res);
1980     return 0;
1981 }
1982 
1983 static int
_textiowrapper_encoder_setstate(textio * self,cookie_type * cookie)1984 _textiowrapper_encoder_setstate(textio *self, cookie_type *cookie)
1985 {
1986     PyObject *res;
1987     /* Same as _textiowrapper_decoder_setstate() above. */
1988     if (cookie->start_pos == 0 && cookie->dec_flags == 0) {
1989         res = PyObject_CallMethodObjArgs(self->encoder, _PyIO_str_reset, NULL);
1990         self->encoding_start_of_stream = 1;
1991     }
1992     else {
1993         res = PyObject_CallMethodObjArgs(self->encoder, _PyIO_str_setstate,
1994                                          _PyIO_zero, NULL);
1995         self->encoding_start_of_stream = 0;
1996     }
1997     if (res == NULL)
1998         return -1;
1999     Py_DECREF(res);
2000     return 0;
2001 }
2002 
2003 static PyObject *
textiowrapper_seek(textio * self,PyObject * args)2004 textiowrapper_seek(textio *self, PyObject *args)
2005 {
2006     PyObject *cookieObj, *posobj;
2007     cookie_type cookie;
2008     int whence = 0;
2009     PyObject *res;
2010     int cmp;
2011 
2012     CHECK_ATTACHED(self);
2013 
2014     if (!PyArg_ParseTuple(args, "O|i:seek", &cookieObj, &whence))
2015         return NULL;
2016     CHECK_CLOSED(self);
2017 
2018     Py_INCREF(cookieObj);
2019 
2020     if (!self->seekable) {
2021         PyErr_SetString(PyExc_IOError,
2022                         "underlying stream is not seekable");
2023         goto fail;
2024     }
2025 
2026     if (whence == 1) {
2027         /* seek relative to current position */
2028         cmp = PyObject_RichCompareBool(cookieObj, _PyIO_zero, Py_EQ);
2029         if (cmp < 0)
2030             goto fail;
2031 
2032         if (cmp == 0) {
2033             PyErr_SetString(PyExc_IOError,
2034                             "can't do nonzero cur-relative seeks");
2035             goto fail;
2036         }
2037 
2038         /* Seeking to the current position should attempt to
2039          * sync the underlying buffer with the current position.
2040          */
2041         Py_DECREF(cookieObj);
2042         cookieObj = PyObject_CallMethod((PyObject *)self, "tell", NULL);
2043         if (cookieObj == NULL)
2044             goto fail;
2045     }
2046     else if (whence == 2) {
2047         /* seek relative to end of file */
2048 
2049         cmp = PyObject_RichCompareBool(cookieObj, _PyIO_zero, Py_EQ);
2050         if (cmp < 0)
2051             goto fail;
2052 
2053         if (cmp == 0) {
2054             PyErr_SetString(PyExc_IOError,
2055                             "can't do nonzero end-relative seeks");
2056             goto fail;
2057         }
2058 
2059         res = PyObject_CallMethod((PyObject *)self, "flush", NULL);
2060         if (res == NULL)
2061             goto fail;
2062         Py_DECREF(res);
2063 
2064         textiowrapper_set_decoded_chars(self, NULL);
2065         Py_CLEAR(self->snapshot);
2066         if (self->decoder) {
2067             res = PyObject_CallMethod(self->decoder, "reset", NULL);
2068             if (res == NULL)
2069                 goto fail;
2070             Py_DECREF(res);
2071         }
2072 
2073         res = PyObject_CallMethod(self->buffer, "seek", "ii", 0, 2);
2074         Py_XDECREF(cookieObj);
2075         return res;
2076     }
2077     else if (whence != 0) {
2078         PyErr_Format(PyExc_ValueError,
2079                      "invalid whence (%d, should be 0, 1 or 2)", whence);
2080         goto fail;
2081     }
2082 
2083     cmp = PyObject_RichCompareBool(cookieObj, _PyIO_zero, Py_LT);
2084     if (cmp < 0)
2085         goto fail;
2086 
2087     if (cmp == 1) {
2088         PyObject *repr = PyObject_Repr(cookieObj);
2089         if (repr != NULL) {
2090             PyErr_Format(PyExc_ValueError,
2091                          "negative seek position %s",
2092                          PyString_AS_STRING(repr));
2093             Py_DECREF(repr);
2094         }
2095         goto fail;
2096     }
2097 
2098     res = PyObject_CallMethodObjArgs((PyObject *)self, _PyIO_str_flush, NULL);
2099     if (res == NULL)
2100         goto fail;
2101     Py_DECREF(res);
2102 
2103     /* The strategy of seek() is to go back to the safe start point
2104      * and replay the effect of read(chars_to_skip) from there.
2105      */
2106     if (textiowrapper_parse_cookie(&cookie, cookieObj) < 0)
2107         goto fail;
2108 
2109     /* Seek back to the safe start point. */
2110     posobj = PyLong_FromOff_t(cookie.start_pos);
2111     if (posobj == NULL)
2112         goto fail;
2113     res = PyObject_CallMethodObjArgs(self->buffer,
2114                                      _PyIO_str_seek, posobj, NULL);
2115     Py_DECREF(posobj);
2116     if (res == NULL)
2117         goto fail;
2118     Py_DECREF(res);
2119 
2120     textiowrapper_set_decoded_chars(self, NULL);
2121     Py_CLEAR(self->snapshot);
2122 
2123     /* Restore the decoder to its state from the safe start point. */
2124     if (self->decoder) {
2125         if (_textiowrapper_decoder_setstate(self, &cookie) < 0)
2126             goto fail;
2127     }
2128 
2129     if (cookie.chars_to_skip) {
2130         /* Just like _read_chunk, feed the decoder and save a snapshot. */
2131         PyObject *input_chunk = PyObject_CallMethod(
2132             self->buffer, "read", "i", cookie.bytes_to_feed);
2133         PyObject *decoded;
2134 
2135         if (input_chunk == NULL)
2136             goto fail;
2137 
2138         if (!PyBytes_Check(input_chunk)) {
2139             PyErr_Format(PyExc_TypeError,
2140                          "underlying read() should have returned a bytes "
2141                          "object, not '%.200s'",
2142                          Py_TYPE(input_chunk)->tp_name);
2143             Py_DECREF(input_chunk);
2144             goto fail;
2145         }
2146 
2147         self->snapshot = Py_BuildValue("iN", cookie.dec_flags, input_chunk);
2148         if (self->snapshot == NULL) {
2149             Py_DECREF(input_chunk);
2150             goto fail;
2151         }
2152 
2153         decoded = PyObject_CallMethod(self->decoder, "decode",
2154                                       "Oi", input_chunk, (int)cookie.need_eof);
2155 
2156         if (check_decoded(decoded) < 0)
2157             goto fail;
2158 
2159         textiowrapper_set_decoded_chars(self, decoded);
2160 
2161         /* Skip chars_to_skip of the decoded characters. */
2162         if (PyUnicode_GetSize(self->decoded_chars) < cookie.chars_to_skip) {
2163             PyErr_SetString(PyExc_IOError, "can't restore logical file position");
2164             goto fail;
2165         }
2166         self->decoded_chars_used = cookie.chars_to_skip;
2167     }
2168     else {
2169         self->snapshot = Py_BuildValue("is", cookie.dec_flags, "");
2170         if (self->snapshot == NULL)
2171             goto fail;
2172     }
2173 
2174     /* Finally, reset the encoder (merely useful for proper BOM handling) */
2175     if (self->encoder) {
2176         if (_textiowrapper_encoder_setstate(self, &cookie) < 0)
2177             goto fail;
2178     }
2179     return cookieObj;
2180   fail:
2181     Py_XDECREF(cookieObj);
2182     return NULL;
2183 
2184 }
2185 
2186 static PyObject *
textiowrapper_tell(textio * self,PyObject * args)2187 textiowrapper_tell(textio *self, PyObject *args)
2188 {
2189     PyObject *res;
2190     PyObject *posobj = NULL;
2191     cookie_type cookie = {0,0,0,0,0};
2192     PyObject *next_input;
2193     Py_ssize_t chars_to_skip, chars_decoded;
2194     PyObject *saved_state = NULL;
2195     char *input, *input_end;
2196 
2197     CHECK_ATTACHED(self);
2198     CHECK_CLOSED(self);
2199 
2200     if (!self->seekable) {
2201         PyErr_SetString(PyExc_IOError,
2202                         "underlying stream is not seekable");
2203         goto fail;
2204     }
2205     if (!self->telling) {
2206         PyErr_SetString(PyExc_IOError,
2207                         "telling position disabled by next() call");
2208         goto fail;
2209     }
2210 
2211     if (_textiowrapper_writeflush(self) < 0)
2212         return NULL;
2213     res = PyObject_CallMethod((PyObject *)self, "flush", NULL);
2214     if (res == NULL)
2215         goto fail;
2216     Py_DECREF(res);
2217 
2218     posobj = PyObject_CallMethod(self->buffer, "tell", NULL);
2219     if (posobj == NULL)
2220         goto fail;
2221 
2222     if (self->decoder == NULL || self->snapshot == NULL) {
2223         assert (self->decoded_chars == NULL || PyUnicode_GetSize(self->decoded_chars) == 0);
2224         return posobj;
2225     }
2226 
2227 #if defined(HAVE_LARGEFILE_SUPPORT)
2228     cookie.start_pos = PyLong_AsLongLong(posobj);
2229 #else
2230     cookie.start_pos = PyLong_AsLong(posobj);
2231 #endif
2232     if (PyErr_Occurred())
2233         goto fail;
2234 
2235     /* Skip backward to the snapshot point (see _read_chunk). */
2236     if (!PyArg_Parse(self->snapshot, "(iO)", &cookie.dec_flags, &next_input))
2237         goto fail;
2238 
2239     assert (PyBytes_Check(next_input));
2240 
2241     cookie.start_pos -= PyBytes_GET_SIZE(next_input);
2242 
2243     /* How many decoded characters have been used up since the snapshot? */
2244     if (self->decoded_chars_used == 0)  {
2245         /* We haven't moved from the snapshot point. */
2246         Py_DECREF(posobj);
2247         return textiowrapper_build_cookie(&cookie);
2248     }
2249 
2250     chars_to_skip = self->decoded_chars_used;
2251 
2252     /* Starting from the snapshot position, we will walk the decoder
2253      * forward until it gives us enough decoded characters.
2254      */
2255     saved_state = PyObject_CallMethodObjArgs(self->decoder,
2256                                              _PyIO_str_getstate, NULL);
2257     if (saved_state == NULL)
2258         goto fail;
2259 
2260     /* Note our initial start point. */
2261     if (_textiowrapper_decoder_setstate(self, &cookie) < 0)
2262         goto fail;
2263 
2264     /* Feed the decoder one byte at a time.  As we go, note the
2265      * nearest "safe start point" before the current location
2266      * (a point where the decoder has nothing buffered, so seek()
2267      * can safely start from there and advance to this location).
2268      */
2269     chars_decoded = 0;
2270     input = PyBytes_AS_STRING(next_input);
2271     input_end = input + PyBytes_GET_SIZE(next_input);
2272     while (input < input_end) {
2273         PyObject *state;
2274         char *dec_buffer;
2275         Py_ssize_t dec_buffer_len;
2276         int dec_flags;
2277 
2278         PyObject *decoded = PyObject_CallMethod(
2279             self->decoder, "decode", "s#", input, (Py_ssize_t)1);
2280         if (check_decoded(decoded) < 0)
2281             goto fail;
2282         chars_decoded += PyUnicode_GET_SIZE(decoded);
2283         Py_DECREF(decoded);
2284 
2285         cookie.bytes_to_feed += 1;
2286 
2287         state = PyObject_CallMethodObjArgs(self->decoder,
2288                                            _PyIO_str_getstate, NULL);
2289         if (state == NULL)
2290             goto fail;
2291         if (!PyArg_Parse(state, "(s#i)", &dec_buffer, &dec_buffer_len, &dec_flags)) {
2292             Py_DECREF(state);
2293             goto fail;
2294         }
2295         Py_DECREF(state);
2296 
2297         if (dec_buffer_len == 0 && chars_decoded <= chars_to_skip) {
2298             /* Decoder buffer is empty, so this is a safe start point. */
2299             cookie.start_pos += cookie.bytes_to_feed;
2300             chars_to_skip -= chars_decoded;
2301             cookie.dec_flags = dec_flags;
2302             cookie.bytes_to_feed = 0;
2303             chars_decoded = 0;
2304         }
2305         if (chars_decoded >= chars_to_skip)
2306             break;
2307         input++;
2308     }
2309     if (input == input_end) {
2310         /* We didn't get enough decoded data; signal EOF to get more. */
2311         PyObject *decoded = PyObject_CallMethod(
2312             self->decoder, "decode", "si", "", /* final = */ 1);
2313         if (check_decoded(decoded) < 0)
2314             goto fail;
2315         chars_decoded += PyUnicode_GET_SIZE(decoded);
2316         Py_DECREF(decoded);
2317         cookie.need_eof = 1;
2318 
2319         if (chars_decoded < chars_to_skip) {
2320             PyErr_SetString(PyExc_IOError,
2321                             "can't reconstruct logical file position");
2322             goto fail;
2323         }
2324     }
2325 
2326     /* finally */
2327     Py_XDECREF(posobj);
2328     res = PyObject_CallMethod(self->decoder, "setstate", "(O)", saved_state);
2329     Py_DECREF(saved_state);
2330     if (res == NULL)
2331         return NULL;
2332     Py_DECREF(res);
2333 
2334     /* The returned cookie corresponds to the last safe start point. */
2335     cookie.chars_to_skip = Py_SAFE_DOWNCAST(chars_to_skip, Py_ssize_t, int);
2336     return textiowrapper_build_cookie(&cookie);
2337 
2338   fail:
2339     Py_XDECREF(posobj);
2340     if (saved_state) {
2341         PyObject *type, *value, *traceback;
2342         PyErr_Fetch(&type, &value, &traceback);
2343 
2344         res = PyObject_CallMethod(self->decoder, "setstate", "(O)", saved_state);
2345         _PyErr_ReplaceException(type, value, traceback);
2346         Py_DECREF(saved_state);
2347         Py_XDECREF(res);
2348     }
2349     return NULL;
2350 }
2351 
2352 static PyObject *
textiowrapper_truncate(textio * self,PyObject * args)2353 textiowrapper_truncate(textio *self, PyObject *args)
2354 {
2355     PyObject *pos = Py_None;
2356     PyObject *res;
2357 
2358     CHECK_ATTACHED(self)
2359     if (!PyArg_ParseTuple(args, "|O:truncate", &pos)) {
2360         return NULL;
2361     }
2362 
2363     res = PyObject_CallMethodObjArgs((PyObject *) self, _PyIO_str_flush, NULL);
2364     if (res == NULL)
2365         return NULL;
2366     Py_DECREF(res);
2367 
2368     return PyObject_CallMethodObjArgs(self->buffer, _PyIO_str_truncate, pos, NULL);
2369 }
2370 
2371 static PyObject *
textiowrapper_repr(textio * self)2372 textiowrapper_repr(textio *self)
2373 {
2374     PyObject *nameobj, *res;
2375     PyObject *namerepr = NULL, *encrepr = NULL;
2376 
2377     CHECK_INITIALIZED(self);
2378 
2379     nameobj = PyObject_GetAttrString((PyObject *) self, "name");
2380     if (nameobj == NULL) {
2381         if (PyErr_ExceptionMatches(PyExc_Exception))
2382             PyErr_Clear();
2383         else
2384             goto error;
2385         encrepr = PyObject_Repr(self->encoding);
2386         res = PyString_FromFormat("<_io.TextIOWrapper encoding=%s>",
2387                                    PyString_AS_STRING(encrepr));
2388     }
2389     else {
2390         encrepr = PyObject_Repr(self->encoding);
2391         namerepr = PyObject_Repr(nameobj);
2392         res = PyString_FromFormat("<_io.TextIOWrapper name=%s encoding=%s>",
2393                                    PyString_AS_STRING(namerepr),
2394                                    PyString_AS_STRING(encrepr));
2395         Py_DECREF(nameobj);
2396     }
2397     Py_XDECREF(namerepr);
2398     Py_XDECREF(encrepr);
2399     return res;
2400 
2401 error:
2402     Py_XDECREF(namerepr);
2403     Py_XDECREF(encrepr);
2404     return NULL;
2405 }
2406 
2407 
2408 /* Inquiries */
2409 
2410 static PyObject *
textiowrapper_fileno(textio * self,PyObject * args)2411 textiowrapper_fileno(textio *self, PyObject *args)
2412 {
2413     CHECK_ATTACHED(self);
2414     return PyObject_CallMethod(self->buffer, "fileno", NULL);
2415 }
2416 
2417 static PyObject *
textiowrapper_seekable(textio * self,PyObject * args)2418 textiowrapper_seekable(textio *self, PyObject *args)
2419 {
2420     CHECK_ATTACHED(self);
2421     return PyObject_CallMethod(self->buffer, "seekable", NULL);
2422 }
2423 
2424 static PyObject *
textiowrapper_readable(textio * self,PyObject * args)2425 textiowrapper_readable(textio *self, PyObject *args)
2426 {
2427     CHECK_ATTACHED(self);
2428     return PyObject_CallMethod(self->buffer, "readable", NULL);
2429 }
2430 
2431 static PyObject *
textiowrapper_writable(textio * self,PyObject * args)2432 textiowrapper_writable(textio *self, PyObject *args)
2433 {
2434     CHECK_ATTACHED(self);
2435     return PyObject_CallMethod(self->buffer, "writable", NULL);
2436 }
2437 
2438 static PyObject *
textiowrapper_isatty(textio * self,PyObject * args)2439 textiowrapper_isatty(textio *self, PyObject *args)
2440 {
2441     CHECK_ATTACHED(self);
2442     return PyObject_CallMethod(self->buffer, "isatty", NULL);
2443 }
2444 
2445 static PyObject *
textiowrapper_flush(textio * self,PyObject * args)2446 textiowrapper_flush(textio *self, PyObject *args)
2447 {
2448     CHECK_ATTACHED(self);
2449     CHECK_CLOSED(self);
2450     self->telling = self->seekable;
2451     if (_textiowrapper_writeflush(self) < 0)
2452         return NULL;
2453     return PyObject_CallMethod(self->buffer, "flush", NULL);
2454 }
2455 
2456 static PyObject *
textiowrapper_close(textio * self,PyObject * args)2457 textiowrapper_close(textio *self, PyObject *args)
2458 {
2459     PyObject *res;
2460     int r;
2461     CHECK_ATTACHED(self);
2462 
2463     res = textiowrapper_closed_get(self, NULL);
2464     if (res == NULL)
2465         return NULL;
2466     r = PyObject_IsTrue(res);
2467     Py_DECREF(res);
2468     if (r < 0)
2469         return NULL;
2470 
2471     if (r > 0) {
2472         Py_RETURN_NONE; /* stream already closed */
2473     }
2474     else {
2475         PyObject *exc = NULL, *val, *tb;
2476         res = PyObject_CallMethod((PyObject *)self, "flush", NULL);
2477         if (res == NULL)
2478             PyErr_Fetch(&exc, &val, &tb);
2479         else
2480             Py_DECREF(res);
2481 
2482         res = PyObject_CallMethod(self->buffer, "close", NULL);
2483         if (exc != NULL) {
2484             _PyErr_ReplaceException(exc, val, tb);
2485             Py_CLEAR(res);
2486         }
2487         return res;
2488     }
2489 }
2490 
2491 static PyObject *
textiowrapper_iternext(textio * self)2492 textiowrapper_iternext(textio *self)
2493 {
2494     PyObject *line;
2495 
2496     CHECK_ATTACHED(self);
2497 
2498     self->telling = 0;
2499     if (Py_TYPE(self) == &PyTextIOWrapper_Type) {
2500         /* Skip method call overhead for speed */
2501         line = _textiowrapper_readline(self, -1);
2502     }
2503     else {
2504         line = PyObject_CallMethodObjArgs((PyObject *)self,
2505                                            _PyIO_str_readline, NULL);
2506         if (line && !PyUnicode_Check(line)) {
2507             PyErr_Format(PyExc_IOError,
2508                          "readline() should have returned an str object, "
2509                          "not '%.200s'", Py_TYPE(line)->tp_name);
2510             Py_DECREF(line);
2511             return NULL;
2512         }
2513     }
2514 
2515     if (line == NULL)
2516         return NULL;
2517 
2518     if (PyUnicode_GET_SIZE(line) == 0) {
2519         /* Reached EOF or would have blocked */
2520         Py_DECREF(line);
2521         Py_CLEAR(self->snapshot);
2522         self->telling = self->seekable;
2523         return NULL;
2524     }
2525 
2526     return line;
2527 }
2528 
2529 static PyObject *
textiowrapper_name_get(textio * self,void * context)2530 textiowrapper_name_get(textio *self, void *context)
2531 {
2532     CHECK_ATTACHED(self);
2533     return PyObject_GetAttrString(self->buffer, "name");
2534 }
2535 
2536 static PyObject *
textiowrapper_closed_get(textio * self,void * context)2537 textiowrapper_closed_get(textio *self, void *context)
2538 {
2539     CHECK_ATTACHED(self);
2540     return PyObject_GetAttr(self->buffer, _PyIO_str_closed);
2541 }
2542 
2543 static PyObject *
textiowrapper_newlines_get(textio * self,void * context)2544 textiowrapper_newlines_get(textio *self, void *context)
2545 {
2546     PyObject *res;
2547     CHECK_ATTACHED(self);
2548     if (self->decoder == NULL)
2549         Py_RETURN_NONE;
2550     res = PyObject_GetAttr(self->decoder, _PyIO_str_newlines);
2551     if (res == NULL) {
2552         if (PyErr_ExceptionMatches(PyExc_AttributeError)) {
2553             PyErr_Clear();
2554             Py_RETURN_NONE;
2555         }
2556         else {
2557             return NULL;
2558         }
2559     }
2560     return res;
2561 }
2562 
2563 static PyObject *
textiowrapper_errors_get(textio * self,void * context)2564 textiowrapper_errors_get(textio *self, void *context)
2565 {
2566     CHECK_INITIALIZED(self);
2567     Py_INCREF(self->errors);
2568     return self->errors;
2569 }
2570 
2571 static PyObject *
textiowrapper_chunk_size_get(textio * self,void * context)2572 textiowrapper_chunk_size_get(textio *self, void *context)
2573 {
2574     CHECK_ATTACHED(self);
2575     return PyLong_FromSsize_t(self->chunk_size);
2576 }
2577 
2578 static int
textiowrapper_chunk_size_set(textio * self,PyObject * arg,void * context)2579 textiowrapper_chunk_size_set(textio *self, PyObject *arg, void *context)
2580 {
2581     Py_ssize_t n;
2582     CHECK_ATTACHED_INT(self);
2583     n = PyNumber_AsSsize_t(arg, PyExc_TypeError);
2584     if (n == -1 && PyErr_Occurred())
2585         return -1;
2586     if (n <= 0) {
2587         PyErr_SetString(PyExc_ValueError,
2588                         "a strictly positive integer is required");
2589         return -1;
2590     }
2591     self->chunk_size = n;
2592     return 0;
2593 }
2594 
2595 static PyMethodDef textiowrapper_methods[] = {
2596     {"detach", (PyCFunction)textiowrapper_detach, METH_NOARGS},
2597     {"write", (PyCFunction)textiowrapper_write, METH_VARARGS},
2598     {"read", (PyCFunction)textiowrapper_read, METH_VARARGS},
2599     {"readline", (PyCFunction)textiowrapper_readline, METH_VARARGS},
2600     {"flush", (PyCFunction)textiowrapper_flush, METH_NOARGS},
2601     {"close", (PyCFunction)textiowrapper_close, METH_NOARGS},
2602 
2603     {"fileno", (PyCFunction)textiowrapper_fileno, METH_NOARGS},
2604     {"seekable", (PyCFunction)textiowrapper_seekable, METH_NOARGS},
2605     {"readable", (PyCFunction)textiowrapper_readable, METH_NOARGS},
2606     {"writable", (PyCFunction)textiowrapper_writable, METH_NOARGS},
2607     {"isatty", (PyCFunction)textiowrapper_isatty, METH_NOARGS},
2608 
2609     {"seek", (PyCFunction)textiowrapper_seek, METH_VARARGS},
2610     {"tell", (PyCFunction)textiowrapper_tell, METH_NOARGS},
2611     {"truncate", (PyCFunction)textiowrapper_truncate, METH_VARARGS},
2612     {NULL, NULL}
2613 };
2614 
2615 static PyMemberDef textiowrapper_members[] = {
2616     {"encoding", T_OBJECT, offsetof(textio, encoding), READONLY},
2617     {"buffer", T_OBJECT, offsetof(textio, buffer), READONLY},
2618     {"line_buffering", T_BOOL, offsetof(textio, line_buffering), READONLY},
2619     {NULL}
2620 };
2621 
2622 static PyGetSetDef textiowrapper_getset[] = {
2623     {"name", (getter)textiowrapper_name_get, NULL, NULL},
2624     {"closed", (getter)textiowrapper_closed_get, NULL, NULL},
2625 /*    {"mode", (getter)TextIOWrapper_mode_get, NULL, NULL},
2626 */
2627     {"newlines", (getter)textiowrapper_newlines_get, NULL, NULL},
2628     {"errors", (getter)textiowrapper_errors_get, NULL, NULL},
2629     {"_CHUNK_SIZE", (getter)textiowrapper_chunk_size_get,
2630                     (setter)textiowrapper_chunk_size_set, NULL},
2631     {NULL}
2632 };
2633 
2634 PyTypeObject PyTextIOWrapper_Type = {
2635     PyVarObject_HEAD_INIT(NULL, 0)
2636     "_io.TextIOWrapper",        /*tp_name*/
2637     sizeof(textio), /*tp_basicsize*/
2638     0,                          /*tp_itemsize*/
2639     (destructor)textiowrapper_dealloc, /*tp_dealloc*/
2640     0,                          /*tp_print*/
2641     0,                          /*tp_getattr*/
2642     0,                          /*tps_etattr*/
2643     0,                          /*tp_compare */
2644     (reprfunc)textiowrapper_repr,/*tp_repr*/
2645     0,                          /*tp_as_number*/
2646     0,                          /*tp_as_sequence*/
2647     0,                          /*tp_as_mapping*/
2648     0,                          /*tp_hash */
2649     0,                          /*tp_call*/
2650     0,                          /*tp_str*/
2651     0,                          /*tp_getattro*/
2652     0,                          /*tp_setattro*/
2653     0,                          /*tp_as_buffer*/
2654     Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE
2655             | Py_TPFLAGS_HAVE_GC, /*tp_flags*/
2656     textiowrapper_doc,          /* tp_doc */
2657     (traverseproc)textiowrapper_traverse, /* tp_traverse */
2658     (inquiry)textiowrapper_clear, /* tp_clear */
2659     0,                          /* tp_richcompare */
2660     offsetof(textio, weakreflist), /*tp_weaklistoffset*/
2661     0,                          /* tp_iter */
2662     (iternextfunc)textiowrapper_iternext, /* tp_iternext */
2663     textiowrapper_methods,      /* tp_methods */
2664     textiowrapper_members,      /* tp_members */
2665     textiowrapper_getset,       /* tp_getset */
2666     0,                          /* tp_base */
2667     0,                          /* tp_dict */
2668     0,                          /* tp_descr_get */
2669     0,                          /* tp_descr_set */
2670     offsetof(textio, dict), /*tp_dictoffset*/
2671     (initproc)textiowrapper_init, /* tp_init */
2672     0,                          /* tp_alloc */
2673     PyType_GenericNew,          /* tp_new */
2674 };
2675