cpython/Modules/_io/stringio.c at 3.5 · python/cpython · GitHub

Repository navigation

History

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

203

204

205

206

207

208

209

210

211

212

213

214

215

216

217

218

219

220

221

222

223

224

225

226

227

228

229

230

231

232

233

234

235

236

237

238

239

240

241

242

243

244

245

246

247

248

249

250

251

252

253

254

255

256

257

258

259

260

261

262

263

264

265

266

267

268

269

270

271

272

273

274

275

276

277

278

279

280

281

282

283

284

285

286

287

288

289

290

291

292

293

294

295

296

297

298

299

300

301

302

303

304

305

306

307

308

309

310

311

312

313

314

315

316

317

318

319

320

321

322

323

324

325

326

327

328

329

330

331

332

333

334

335

336

337

338

339

340

341

342

343

344

345

346

347

348

349

350

351

352

353

354

355

356

357

358

359

360

361

362

363

364

365

366

367

368

369

370

371

372

373

374

375

376

377

378

379

380

381

382

383

384

385

386

387

388

389

390

391

392

393

394

395

396

397

398

399

400

401

402

403

404

405

406

407

408

409

410

411

412

413

414

415

416

417

418

419

420

421

422

423

424

425

426

427

428

429

430

431

432

433

434

435

436

437

438

439

440

441

442

443

444

445

446

447

448

449

450

451

452

453

454

455

456

457

458

459

460

461

462

463

464

465

466

467

468

469

470

471

472

473

474

475

476

477

478

479

480

481

482

483

484

485

486

487

488

489

490

491

492

493

494

495

496

497

498

499

500

501

502

503

504

505

506

507

508

509

510

511

512

513

514

515

516

517

518

519

520

521

522

523

524

525

526

527

528

529

530

531

532

533

534

535

536

537

538

539

540

541

542

543

544

545

546

547

548

549

550

551

552

553

554

555

556

557

558

559

560

561

562

563

564

565

566

567

568

569

570

571

572

573

574

575

576

577

578

579

580

581

582

583

584

585

586

587

588

589

590

591

592

593

594

595

596

597

598

599

600

601

602

603

604

605

606

607

608

609

610

611

612

613

614

615

616

617

618

619

620

621

622

623

624

625

626

627

628

629

630

631

632

633

634

635

636

637

638

639

640

641

642

643

644

645

646

647

648

649

650

651

652

653

654

655

656

657

658

659

660

661

662

663

664

665

666

667

668

669

670

671

672

673

674

675

676

677

678

679

680

681

682

683

684

685

686

687

688

689

690

691

692

693

694

695

696

697

698

699

700

701

702

703

704

705

706

707

708

709

710

711

712

713

714

715

716

717

718

719

720

721

722

723

724

725

726

727

728

729

730

731

732

733

734

735

736

737

738

739

740

741

742

743

744

745

746

747

748

749

750

751

752

753

754

755

756

757

758

759

760

761

762

763

764

765

766

767

768

769

770

771

772

773

774

775

776

777

778

779

780

781

782

783

784

785

786

787

788

789

790

791

792

793

794

795

796

797

798

799

800

801

802

803

804

805

806

807

808

809

810

811

812

813

814

815

816

817

818

819

820

821

822

823

824

825

826

827

828

829

830

831

832

833

834

835

836

837

838

839

840

841

842

843

844

845

846

847

848

849

850

851

852

853

854

855

856

857

858

859

860

861

862

863

864

865

866

867

868

869

870

871

872

873

874

875

876

877

878

879

880

881

882

883

884

885

886

887

888

889

890

891

892

893

894

895

896

897

898

899

900

901

902

903

904

905

906

907

908

909

910

911

912

913

914

915

916

917

918

919

920

921

922

923

924

925

926

927

928

929

930

931

932

933

934

935

936

937

938

939

940

941

942

943

944

945

946

947

948

949

950

951

952

953

954

955

956

957

958

959

960

961

962

963

964

965

966

967

968

969

970

971

972

973

974

975

976

977

978

979

980

981

982

983

984

985

986

987

988

989

990

991

992

993

994

995

996

997

998

999

1000

#define PY_SSIZE_T_CLEAN

#include "Python.h"

#include "structmember.h"

#include "accu.h"

#include "_iomodule.h"

/* Implementation note: the buffer is always at least one character longer

than the enclosed string, for proper functioning of _PyIO_find_line_ending.

#define STATE_REALIZED 1

#define STATE_ACCUMULATING 2

/*[clinic input]

module _io

class _io.StringIO "stringio *" "&PyStringIO_Type"

[clinic start generated code]*/

/*[clinic end generated code: output=da39a3ee5e6b4b0d input=c17bc0f42165cd7d]*/

typedef struct {

PyObject_HEAD

Py_UCS4 *buf;

Py_ssize_t pos;

Py_ssize_t string_size;

size_t buf_size;

/* The stringio object can be in two states: accumulating or realized.

In accumulating state, the internal buffer contains nothing and

the contents are given by the embedded _PyAccu structure.

In realized state, the internal buffer is meaningful and the

_PyAccu is destroyed.

int state;

_PyAccu accu;

char ok; /* initialized? */

char closed;

char readuniversal;

char readtranslate;

PyObject *decoder;

PyObject *readnl;

PyObject *writenl;

PyObject *dict;

PyObject *weakreflist;

} stringio;

static int _io_StringIO___init__(PyObject *self, PyObject *args, PyObject *kwargs);

#define CHECK_INITIALIZED(self) \

if (self->ok <= 0) { \

PyErr_SetString(PyExc_ValueError, \

"I/O operation on uninitialized object"); \

return NULL; \

}

#define CHECK_CLOSED(self) \

if (self->closed) { \

PyErr_SetString(PyExc_ValueError, \

"I/O operation on closed file"); \

return NULL; \

}

#define ENSURE_REALIZED(self) \

if (realize(self) < 0) { \

return NULL; \

}

/* Internal routine for changing the size, in terms of characters, of the

buffer of StringIO objects. The caller should ensure that the 'size'

argument is non-negative. Returns 0 on success, -1 otherwise. */

static int

resize_buffer(stringio *self, size_t size)

{

/* Here, unsigned types are used to avoid dealing with signed integer

overflow, which is undefined in C. */

size_t alloc = self->buf_size;

Py_UCS4 *new_buf = NULL;

assert(self->buf != NULL);

/* Reserve one more char for line ending detection. */

size = size + 1;

/* For simplicity, stay in the range of the signed type. Anyway, Python

doesn't allow strings to be longer than this. */

if (size > PY_SSIZE_T_MAX)

goto overflow;

if (size < alloc / 2) {

/* Major downsize; resize down to exact size. */

alloc = size + 1;

}

else if (size < alloc) {

/* Within allocated size; quick exit */

return 0;

}

else if (size <= alloc * 1.125) {

/* Moderate upsize; overallocate similar to list_resize() */

alloc = size + (size >> 3) + (size < 9 ? 3 : 6);

}

else {

/* Major upsize; resize up to exact size */

alloc = size + 1;

}

if (alloc > PY_SIZE_MAX / sizeof(Py_UCS4))

goto overflow;

new_buf = (Py_UCS4 *)PyMem_Realloc(self->buf, alloc * sizeof(Py_UCS4));

if (new_buf == NULL) {

PyErr_NoMemory();

return -1;

}

self->buf_size = alloc;

self->buf = new_buf;

return 0;

overflow:

PyErr_SetString(PyExc_OverflowError,

"new buffer size too large");

return -1;

}

static PyObject *

make_intermediate(stringio *self)

{

PyObject *intermediate = _PyAccu_Finish(&self->accu);

self->state = STATE_REALIZED;

if (intermediate == NULL)

return NULL;

if (_PyAccu_Init(&self->accu) ||

_PyAccu_Accumulate(&self->accu, intermediate)) {

Py_DECREF(intermediate);

return NULL;

}

self->state = STATE_ACCUMULATING;

return intermediate;

}

static int

realize(stringio *self)

{

Py_ssize_t len;

PyObject *intermediate;

if (self->state == STATE_REALIZED)

return 0;

assert(self->state == STATE_ACCUMULATING);

self->state = STATE_REALIZED;

intermediate = _PyAccu_Finish(&self->accu);

if (intermediate == NULL)

return -1;

/* Append the intermediate string to the internal buffer.

The length should be equal to the current cursor position.

len = PyUnicode_GET_LENGTH(intermediate);

if (resize_buffer(self, len) < 0) {

Py_DECREF(intermediate);

return -1;

}

if (!PyUnicode_AsUCS4(intermediate, self->buf, len, 0)) {

Py_DECREF(intermediate);

return -1;

}

Py_DECREF(intermediate);

return 0;

}

/* Internal routine for writing a whole PyUnicode object to the buffer of a

StringIO object. Returns 0 on success, or -1 on error. */

static Py_ssize_t

write_str(stringio *self, PyObject *obj)

{

Py_ssize_t len;

PyObject *decoded = NULL;

assert(self->buf != NULL);

assert(self->pos >= 0);

if (self->decoder != NULL) {

decoded = _PyIncrementalNewlineDecoder_decode(

self->decoder, obj, 1 /* always final */);

}

else {

decoded = obj;

Py_INCREF(decoded);

}

if (self->writenl) {

PyObject *translated = PyUnicode_Replace(

decoded, _PyIO_str_nl, self->writenl, -1);

Py_DECREF(decoded);

decoded = translated;

}

if (decoded == NULL)

return -1;

assert(PyUnicode_Check(decoded));

if (PyUnicode_READY(decoded)) {

Py_DECREF(decoded);

return -1;

}

len = PyUnicode_GET_LENGTH(decoded);

assert(len >= 0);

/* This overflow check is not strictly necessary. However, it avoids us to

deal with funky things like comparing an unsigned and a signed

integer. */

if (self->pos > PY_SSIZE_T_MAX - len) {

PyErr_SetString(PyExc_OverflowError,

"new position too large");

goto fail;

}

if (self->state == STATE_ACCUMULATING) {

if (self->string_size == self->pos) {

if (_PyAccu_Accumulate(&self->accu, decoded))

goto fail;

goto success;

}

if (realize(self))

goto fail;

}

if (self->pos + len > self->string_size) {

if (resize_buffer(self, self->pos + len) < 0)

goto fail;

}

if (self->pos > self->string_size) {

/* In case of overseek, pad with null bytes the buffer region between

the end of stream and the current position.

0 lo string_size hi

| |<---used--->|<----------available----------->|

| | <--to pad-->|<---to write---> |

0 buf position

memset(self->buf + self->string_size, '\0',

(self->pos - self->string_size) * sizeof(Py_UCS4));

}

/* Copy the data to the internal buffer, overwriting some of the

existing data if self->pos < self->string_size. */

if (!PyUnicode_AsUCS4(decoded,

self->buf + self->pos,

self->buf_size - self->pos,

0))

goto fail;

success:

/* Set the new length of the internal string if it has changed. */

self->pos += len;

if (self->string_size < self->pos)

self->string_size = self->pos;

Py_DECREF(decoded);

return 0;

fail:

Py_XDECREF(decoded);

return -1;

}

/*[clinic input]

_io.StringIO.getvalue

Retrieve the entire contents of the object.

[clinic start generated code]*/

static PyObject *

_io_StringIO_getvalue_impl(stringio *self)

/*[clinic end generated code: output=27b6a7bfeaebce01 input=d23cb81d6791cf88]*/

{

CHECK_INITIALIZED(self);

CHECK_CLOSED(self);

if (self->state == STATE_ACCUMULATING)

return make_intermediate(self);

return PyUnicode_FromKindAndData(PyUnicode_4BYTE_KIND, self->buf,

self->string_size);

}

/*[clinic input]

_io.StringIO.tell

Tell the current file position.

[clinic start generated code]*/

static PyObject *

_io_StringIO_tell_impl(stringio *self)

/*[clinic end generated code: output=2e87ac67b116c77b input=ec866ebaff02f405]*/

{

CHECK_INITIALIZED(self);

CHECK_CLOSED(self);

return PyLong_FromSsize_t(self->pos);

}

/*[clinic input]

_io.StringIO.read

size as arg: object = None

Read at most size characters, returned as a string.

If the argument is negative or omitted, read until EOF

is reached. Return an empty string at EOF.

[clinic start generated code]*/

static PyObject *

_io_StringIO_read_impl(stringio *self, PyObject *arg)

/*[clinic end generated code: output=3676864773746f68 input=9a319015f6f3965c]*/

{

Py_ssize_t size, n;

Py_UCS4 *output;

CHECK_INITIALIZED(self);

CHECK_CLOSED(self);

if (PyNumber_Check(arg)) {

size = PyNumber_AsSsize_t(arg, PyExc_OverflowError);

if (size == -1 && PyErr_Occurred())

return NULL;

}

else if (arg == Py_None) {

/* Read until EOF is reached, by default. */

size = -1;

}

else {

PyErr_Format(PyExc_TypeError, "integer argument expected, got '%s'",

Py_TYPE(arg)->tp_name);

return NULL;

}

/* adjust invalid sizes */

n = self->string_size - self->pos;

if (size < 0 || size > n) {

size = n;

if (size < 0)

size = 0;

}

/* Optimization for seek(0); read() */

if (self->state == STATE_ACCUMULATING && self->pos == 0 && size == n) {

PyObject *result = make_intermediate(self);

self->pos = self->string_size;

return result;

}

ENSURE_REALIZED(self);

output = self->buf + self->pos;

self->pos += size;

return PyUnicode_FromKindAndData(PyUnicode_4BYTE_KIND, output, size);

}

/* Internal helper, used by stringio_readline and stringio_iternext */

static PyObject *

_stringio_readline(stringio *self, Py_ssize_t limit)

{

Py_UCS4 *start, *end, old_char;

Py_ssize_t len, consumed;

/* In case of overseek, return the empty string */

if (self->pos >= self->string_size)

return PyUnicode_New(0, 0);

start = self->buf + self->pos;

if (limit < 0 || limit > self->string_size - self->pos)

limit = self->string_size - self->pos;

end = start + limit;

old_char = *end;

*end = '\0';

len = _PyIO_find_line_ending(

self->readtranslate, self->readuniversal, self->readnl,

PyUnicode_4BYTE_KIND, (char*)start, (char*)end, &consumed);

*end = old_char;

/* If we haven't found any line ending, we just return everything

(`consumed` is ignored). */

if (len < 0)

len = limit;

self->pos += len;

return PyUnicode_FromKindAndData(PyUnicode_4BYTE_KIND, start, len);

}

/*[clinic input]

_io.StringIO.readline

size as arg: object = None

Read until newline or EOF.

Returns an empty string if EOF is hit immediately.

[clinic start generated code]*/

static PyObject *

_io_StringIO_readline_impl(stringio *self, PyObject *arg)

/*[clinic end generated code: output=99fdcac03a3dee81 input=e0e0ed4042040176]*/

{

Py_ssize_t limit = -1;

CHECK_INITIALIZED(self);

CHECK_CLOSED(self);

ENSURE_REALIZED(self);

if (PyNumber_Check(arg)) {

limit = PyNumber_AsSsize_t(arg, PyExc_OverflowError);

if (limit == -1 && PyErr_Occurred())

return NULL;

}

else if (arg != Py_None) {

PyErr_Format(PyExc_TypeError, "integer argument expected, got '%s'",

Py_TYPE(arg)->tp_name);

return NULL;

}

return _stringio_readline(self, limit);

}

static PyObject *

stringio_iternext(stringio *self)

{

PyObject *line;

CHECK_INITIALIZED(self);

CHECK_CLOSED(self);

ENSURE_REALIZED(self);

if (Py_TYPE(self) == &PyStringIO_Type) {

/* Skip method call overhead for speed */

line = _stringio_readline(self, -1);

}

else {

/* XXX is subclassing StringIO really supported? */

line = PyObject_CallMethodObjArgs((PyObject *)self,

_PyIO_str_readline, NULL);

if (line && !PyUnicode_Check(line)) {

PyErr_Format(PyExc_IOError,

"readline() should have returned an str object, "

"not '%.200s'", Py_TYPE(line)->tp_name);

Py_DECREF(line);

return NULL;

}

if (line == NULL)

return NULL;

if (PyUnicode_GET_LENGTH(line) == 0) {

/* Reached EOF */

Py_DECREF(line);

return NULL;

}

return line;

}

/*[clinic input]

_io.StringIO.truncate

pos as arg: object = None

Truncate size to pos.

The pos argument defaults to the current file position, as

returned by tell(). The current file position is unchanged.

Returns the new absolute position.

[clinic start generated code]*/

static PyObject *

_io_StringIO_truncate_impl(stringio *self, PyObject *arg)

/*[clinic end generated code: output=6072439c2b01d306 input=748619a494ba53ad]*/

{

Py_ssize_t size;

CHECK_INITIALIZED(self);

CHECK_CLOSED(self);

if (PyNumber_Check(arg)) {

size = PyNumber_AsSsize_t(arg, PyExc_OverflowError);

if (size == -1 && PyErr_Occurred())

return NULL;

}

else if (arg == Py_None) {

/* Truncate to current position if no argument is passed. */

size = self->pos;

}

else {

PyErr_Format(PyExc_TypeError, "integer argument expected, got '%s'",

Py_TYPE(arg)->tp_name);

return NULL;

}

if (size < 0) {

PyErr_Format(PyExc_ValueError,

"Negative size value %zd", size);

return NULL;

}

if (size < self->string_size) {

ENSURE_REALIZED(self);

if (resize_buffer(self, size) < 0)

return NULL;

self->string_size = size;

}

return PyLong_FromSsize_t(size);

}

/*[clinic input]

_io.StringIO.seek

pos: Py_ssize_t

whence: int = 0

Change stream position.

Seek to character offset pos relative to position indicated by whence:

0 Start of stream (the default). pos should be >= 0;

1 Current position - pos must be 0;

2 End of stream - pos must be 0.

Returns the new absolute position.

[clinic start generated code]*/

static PyObject *

_io_StringIO_seek_impl(stringio *self, Py_ssize_t pos, int whence)

/*[clinic end generated code: output=e9e0ac9a8ae71c25 input=e3855b24e7cae06a]*/

{

CHECK_INITIALIZED(self);

CHECK_CLOSED(self);

if (whence != 0 && whence != 1 && whence != 2) {

PyErr_Format(PyExc_ValueError,

"Invalid whence (%i, should be 0, 1 or 2)", whence);

return NULL;

}

else if (pos < 0 && whence == 0) {

PyErr_Format(PyExc_ValueError,

"Negative seek position %zd", pos);

return NULL;

}

else if (whence != 0 && pos != 0) {

PyErr_SetString(PyExc_IOError,

"Can't do nonzero cur-relative seeks");

return NULL;

}

/* whence = 0: offset relative to beginning of the string.

whence = 1: no change to current position.

whence = 2: change position to end of file. */

if (whence == 1) {

pos = self->pos;

}

else if (whence == 2) {

pos = self->string_size;

}

self->pos = pos;

return PyLong_FromSsize_t(self->pos);

}

/*[clinic input]

_io.StringIO.write

s as obj: object

Write string to file.

Returns the number of characters written, which is always equal to

the length of the string.

[clinic start generated code]*/

static PyObject *

_io_StringIO_write(stringio *self, PyObject *obj)

/*[clinic end generated code: output=0deaba91a15b94da input=cf96f3b16586e669]*/

{

Py_ssize_t size;

CHECK_INITIALIZED(self);

if (!PyUnicode_Check(obj)) {

PyErr_Format(PyExc_TypeError, "string argument expected, got '%s'",

Py_TYPE(obj)->tp_name);

return NULL;

}

if (PyUnicode_READY(obj))

return NULL;

CHECK_CLOSED(self);

size = PyUnicode_GET_LENGTH(obj);

if (size > 0 && write_str(self, obj) < 0)

return NULL;

return PyLong_FromSsize_t(size);

}

/*[clinic input]

_io.StringIO.close

Close the IO object.

Attempting any further operation after the object is closed

will raise a ValueError.

This method has no effect if the file is already closed.

[clinic start generated code]*/

static PyObject *

_io_StringIO_close_impl(stringio *self)

/*[clinic end generated code: output=04399355cbe518f1 input=cbc10b45f35d6d46]*/

{

self->closed = 1;

/* Free up some memory */

if (resize_buffer(self, 0) < 0)

return NULL;

_PyAccu_Destroy(&self->accu);

Py_CLEAR(self->readnl);

Py_CLEAR(self->writenl);

Py_CLEAR(self->decoder);

Py_RETURN_NONE;

}

static int

stringio_traverse(stringio *self, visitproc visit, void *arg)

{

Py_VISIT(self->dict);

return 0;

}

static int

stringio_clear(stringio *self)

{

Py_CLEAR(self->dict);

return 0;

}

static void

stringio_dealloc(stringio *self)

{

_PyObject_GC_UNTRACK(self);

self->ok = 0;

if (self->buf) {

PyMem_Free(self->buf);

self->buf = NULL;

}

_PyAccu_Destroy(&self->accu);

Py_CLEAR(self->readnl);

Py_CLEAR(self->writenl);

Py_CLEAR(self->decoder);

Py_CLEAR(self->dict);

if (self->weakreflist != NULL)

PyObject_ClearWeakRefs((PyObject *) self);

Py_TYPE(self)->tp_free(self);

}

static PyObject *

stringio_new(PyTypeObject *type, PyObject *args, PyObject *kwds)

{

stringio *self;

assert(type != NULL && type->tp_alloc != NULL);

self = (stringio *)type->tp_alloc(type, 0);

if (self == NULL)

return NULL;

/* tp_alloc initializes all the fields to zero. So we don't have to

initialize them here. */

self->buf = (Py_UCS4 *)PyMem_Malloc(0);

if (self->buf == NULL) {

Py_DECREF(self);

return PyErr_NoMemory();

}

return (PyObject *)self;

}

/*[clinic input]

_io.StringIO.__init__

initial_value as value: object(c_default="NULL") = ''

newline as newline_obj: object(c_default="NULL") = '\n'

Text I/O implementation using an in-memory buffer.

The initial_value argument sets the value of object. The newline

argument is like the one of TextIOWrapper's constructor.

[clinic start generated code]*/

static int

_io_StringIO___init___impl(stringio *self, PyObject *value,

PyObject *newline_obj)

/*[clinic end generated code: output=a421ea023b22ef4e input=cee2d9181b2577a3]*/

{

char *newline = "\n";

Py_ssize_t value_len;

/* Parse the newline argument. We only want to allow unicode objects or

None. */

if (newline_obj == Py_None) {

newline = NULL;

}

else if (newline_obj) {

if (!PyUnicode_Check(newline_obj)) {

PyErr_Format(PyExc_TypeError,

"newline must be str or None, not %.200s",

Py_TYPE(newline_obj)->tp_name);

return -1;

}

newline = _PyUnicode_AsString(newline_obj);

if (newline == NULL)

return -1;

}

if (newline && newline[0] != '\0'

&& !(newline[0] == '\n' && newline[1] == '\0')

&& !(newline[0] == '\r' && newline[1] == '\0')

&& !(newline[0] == '\r' && newline[1] == '\n' && newline[2] == '\0')) {

PyErr_Format(PyExc_ValueError,

"illegal newline value: %R", newline_obj);

return -1;

}

if (value && value != Py_None && !PyUnicode_Check(value)) {

PyErr_Format(PyExc_TypeError,

"initial_value must be str or None, not %.200s",

Py_TYPE(value)->tp_name);

return -1;

}

self->ok = 0;

_PyAccu_Destroy(&self->accu);

Py_CLEAR(self->readnl);

Py_CLEAR(self->writenl);

Py_CLEAR(self->decoder);

assert((newline != NULL && newline_obj != Py_None) ||

(newline == NULL && newline_obj == Py_None));

if (newline) {

self->readnl = PyUnicode_FromString(newline);

if (self->readnl == NULL)

return -1;

}

self->readuniversal = (newline == NULL || newline[0] == '\0');

self->readtranslate = (newline == NULL);

/* If newline == "", we don't translate anything.

If newline == "\n" or newline == None, we translate to "\n", which is

a no-op.

(for newline == None, TextIOWrapper translates to os.linesep, but it

is pointless for StringIO)

if (newline != NULL && newline[0] == '\r') {

self->writenl = self->readnl;

Py_INCREF(self->writenl);

}

if (self->readuniversal) {

self->decoder = PyObject_CallFunction(

(PyObject *)&PyIncrementalNewlineDecoder_Type,

"Oi", Py_None, (int) self->readtranslate);

if (self->decoder == NULL)

return -1;

}

/* Now everything is set up, resize buffer to size of initial value,

and copy it */

self->string_size = 0;

if (value && value != Py_None)

value_len = PyUnicode_GetLength(value);

else

value_len = 0;

if (value_len > 0) {

/* This is a heuristic, for newline translation might change

the string length. */

if (resize_buffer(self, 0) < 0)

return -1;

self->state = STATE_REALIZED;

self->pos = 0;

if (write_str(self, value) < 0)

return -1;

}

else {

/* Empty stringio object, we can start by accumulating */

if (resize_buffer(self, 0) < 0)

return -1;

if (_PyAccu_Init(&self->accu))

return -1;

self->state = STATE_ACCUMULATING;

}

self->pos = 0;

self->closed = 0;

self->ok = 1;

return 0;

}

/* Properties and pseudo-properties */

/*[clinic input]

_io.StringIO.readable

Returns True if the IO object can be read.

[clinic start generated code]*/

static PyObject *

_io_StringIO_readable_impl(stringio *self)

/*[clinic end generated code: output=b19d44dd8b1ceb99 input=39ce068b224c21ad]*/

{

CHECK_INITIALIZED(self);

CHECK_CLOSED(self);

Py_RETURN_TRUE;

}

/*[clinic input]

_io.StringIO.writable

Returns True if the IO object can be written.

[clinic start generated code]*/

static PyObject *

_io_StringIO_writable_impl(stringio *self)

/*[clinic end generated code: output=13e4dd77187074ca input=7a691353aac38835]*/

{

CHECK_INITIALIZED(self);

CHECK_CLOSED(self);

Py_RETURN_TRUE;

}

/*[clinic input]

_io.StringIO.seekable

Returns True if the IO object can be seeked.

[clinic start generated code]*/

static PyObject *

_io_StringIO_seekable_impl(stringio *self)

/*[clinic end generated code: output=4d20b4641c756879 input=4c606d05b32952e6]*/

{

CHECK_INITIALIZED(self);

CHECK_CLOSED(self);

Py_RETURN_TRUE;

}

/* Pickling support.

The implementation of __getstate__ is similar to the one for BytesIO,

except that we also save the newline parameter. For __setstate__ and unlike

BytesIO, we call __init__ to restore the object's state. Doing so allows us

to avoid decoding the complex newline state while keeping the object

representation compact.

See comment in bytesio.c regarding why only pickle protocols and onward are

supported.

static PyObject *

stringio_getstate(stringio *self)

{

PyObject *initvalue = _io_StringIO_getvalue_impl(self);

PyObject *dict;

PyObject *state;

if (initvalue == NULL)

return NULL;

if (self->dict == NULL) {

Py_INCREF(Py_None);

dict = Py_None;

}

else {

dict = PyDict_Copy(self->dict);

if (dict == NULL)

return NULL;

}

state = Py_BuildValue("(OOnN)", initvalue,

self->readnl ? self->readnl : Py_None,

self->pos, dict);

Py_DECREF(initvalue);

return state;

}

static PyObject *

stringio_setstate(stringio *self, PyObject *state)

{

PyObject *initarg;

PyObject *position_obj;

PyObject *dict;

Py_ssize_t pos;

assert(state != NULL);

CHECK_CLOSED(self);

/* We allow the state tuple to be longer than 4, because we may need

someday to extend the object's state without breaking

backward-compatibility. */

if (!PyTuple_Check(state) || Py_SIZE(state) < 4) {

PyErr_Format(PyExc_TypeError,

"%.200s.__setstate__ argument should be 4-tuple, got %.200s",

Py_TYPE(self)->tp_name, Py_TYPE(state)->tp_name);

return NULL;

}

/* Initialize the object's state. */

initarg = PyTuple_GetSlice(state, 0, 2);

if (initarg == NULL)

return NULL;

if (_io_StringIO___init__((PyObject *)self, initarg, NULL) < 0) {

Py_DECREF(initarg);

return NULL;

}

Py_DECREF(initarg);

/* Restore the buffer state. Even if __init__ did initialize the buffer,

we have to initialize it again since __init__ may translate the

newlines in the initial_value string. We clearly do not want that

because the string value in the state tuple has already been translated

once by __init__. So we do not take any chance and replace object's

buffer completely. */

{

PyObject *item;

Py_UCS4 *buf;

Py_ssize_t bufsize;

item = PyTuple_GET_ITEM(state, 0);

buf = PyUnicode_AsUCS4Copy(item);

if (buf == NULL)

return NULL;

bufsize = PyUnicode_GET_LENGTH(item);

if (resize_buffer(self, bufsize) < 0) {

PyMem_Free(buf);

return NULL;

}

memcpy(self->buf, buf, bufsize * sizeof(Py_UCS4));

PyMem_Free(buf);

self->string_size = bufsize;

}

/* Set carefully the position value. Alternatively, we could use the seek

method instead of modifying self->pos directly to better protect the

object internal state against errneous (or malicious) inputs. */

position_obj = PyTuple_GET_ITEM(state, 2);

if (!PyLong_Check(position_obj)) {

PyErr_Format(PyExc_TypeError,

"third item of state must be an integer, got %.200s",

Py_TYPE(position_obj)->tp_name);

return NULL;

}

pos = PyLong_AsSsize_t(position_obj);

if (pos == -1 && PyErr_Occurred())

return NULL;

if (pos < 0) {

PyErr_SetString(PyExc_ValueError,

"position value cannot be negative");

return NULL;

}

self->pos = pos;

/* Set the dictionary of the instance variables. */

dict = PyTuple_GET_ITEM(state, 3);

if (dict != Py_None) {

if (!PyDict_Check(dict)) {

PyErr_Format(PyExc_TypeError,

"fourth item of state should be a dict, got a %.200s",

Py_TYPE(dict)->tp_name);

return NULL;

}

if (self->dict) {

/* Alternatively, we could replace the internal dictionary

completely. However, it seems more practical to just update it. */

if (PyDict_Update(self->dict, dict) < 0)

return NULL;

}

else {

Py_INCREF(dict);

self->dict = dict;

}

Py_RETURN_NONE;

}

static PyObject *

stringio_closed(stringio *self, void *context)

{

CHECK_INITIALIZED(self);

return PyBool_FromLong(self->closed);

}

static PyObject *

stringio_line_buffering(stringio *self, void *context)

{

CHECK_INITIALIZED(self);

CHECK_CLOSED(self);

Py_RETURN_FALSE;

}

View remainder of file in raw view

cpython/Modules/_io/stringio.c at 3.5 · python/cpython · GitHub

Repository navigation

Expand file tree

Breadcrumbs

stringio.c

Latest commit

History

Breadcrumbs

stringio.c

File metadata and controls