cpython/Modules/zlibmodule.c at main · 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

/* zlibmodule.c -- gzip-compatible data compression */

/* See http://zlib.net/ */

/* Windows users: read Python's PCbuild\readme.txt */

#ifndef Py_BUILD_CORE_BUILTIN

# define Py_BUILD_CORE_MODULE 1

#endif

#include "Python.h"

#include "pycore_pyatomic_ft_wrappers.h" // FT_ATOMIC_STORE_CHAR_RELAXED

#include "zlib.h"

#include "stdbool.h"

#include <stddef.h> // offsetof()

#if defined(ZLIB_VERNUM) && ZLIB_VERNUM < 0x1221

#error "At least zlib version 1.2.2.1 is required"

#endif

#if (SIZEOF_OFF_T == SIZEOF_SIZE_T)

# define convert_to_z_off_t PyLong_AsSsize_t

#elif (SIZEOF_OFF_T == SIZEOF_LONG_LONG)

# define convert_to_z_off_t PyLong_AsLongLong

#elif (SIZEOF_OFF_T == SIZEOF_LONG)

# define convert_to_z_off_t PyLong_AsLong

#else

# error off_t does not match either size_t, long, or long long!

#endif

// Blocks output buffer wrappers

#include "pycore_blocks_output_buffer.h"

#if OUTPUT_BUFFER_MAX_BLOCK_SIZE > UINT32_MAX

#error "The maximum block size accepted by zlib is UINT32_MAX."

#endif

/* On success, return value >= 0

On failure, return -1 */

static inline Py_ssize_t

OutputBuffer_InitAndGrow(_BlocksOutputBuffer *buffer, Py_ssize_t max_length,

Bytef **next_out, uint32_t *avail_out)

{

Py_ssize_t allocated;

allocated = _BlocksOutputBuffer_InitAndGrow(

buffer, max_length, (void**) next_out);

*avail_out = (uint32_t) allocated;

return allocated;

}

/* On success, return value >= 0

On failure, return -1 */

static inline Py_ssize_t

OutputBuffer_Grow(_BlocksOutputBuffer *buffer,

Bytef **next_out, uint32_t *avail_out)

{

Py_ssize_t allocated;

allocated = _BlocksOutputBuffer_Grow(

buffer, (void**) next_out, (Py_ssize_t) *avail_out);

*avail_out = (uint32_t) allocated;

return allocated;

}

static inline Py_ssize_t

OutputBuffer_GetDataSize(_BlocksOutputBuffer *buffer, uint32_t avail_out)

{

return _BlocksOutputBuffer_GetDataSize(buffer, (Py_ssize_t) avail_out);

}

static inline PyObject *

OutputBuffer_Finish(_BlocksOutputBuffer *buffer, uint32_t avail_out)

{

return _BlocksOutputBuffer_Finish(buffer, (Py_ssize_t) avail_out);

}

static inline void

OutputBuffer_OnError(_BlocksOutputBuffer *buffer)

{

_BlocksOutputBuffer_OnError(buffer);

}

/* The max buffer size accepted by zlib is UINT32_MAX, the initial buffer size

`init_size` may > it in 64-bit build. These wrapper functions maintain an

UINT32_MAX sliding window for the first block:

1. OutputBuffer_WindowInitWithSize()

2. OutputBuffer_WindowGrow()

3. OutputBuffer_WindowFinish()

4. OutputBuffer_WindowOnError()

==== is the sliding window:

1. ====------

^ next_posi, left_bytes is 6

2. ----====--

^ next_posi, left_bytes is 2

3. --------==

^ next_posi, left_bytes is 0 */

typedef struct {

Py_ssize_t left_bytes;

Bytef *next_posi;

} _Uint32Window;

/* Initialize the buffer with an initial buffer size.

On success, return value >= 0

On failure, return value < 0 */

static inline Py_ssize_t

OutputBuffer_WindowInitWithSize(_BlocksOutputBuffer *buffer, _Uint32Window *window,

Py_ssize_t init_size,

Bytef **next_out, uint32_t *avail_out)

{

Py_ssize_t allocated = _BlocksOutputBuffer_InitWithSize(

buffer, init_size, (void**) next_out);

if (allocated >= 0) {

// the UINT32_MAX sliding window

Py_ssize_t window_size = Py_MIN((size_t)allocated, UINT32_MAX);

*avail_out = (uint32_t) window_size;

window->left_bytes = allocated - window_size;

window->next_posi = *next_out + window_size;

}

return allocated;

}

/* Grow the buffer.

On success, return value >= 0

On failure, return value < 0 */

static inline Py_ssize_t

OutputBuffer_WindowGrow(_BlocksOutputBuffer *buffer, _Uint32Window *window,

Bytef **next_out, uint32_t *avail_out)

{

Py_ssize_t allocated;

/* ensure no gaps in the data.

if inlined, this check could be optimized away.*/

if (*avail_out != 0) {

PyErr_SetString(PyExc_SystemError,

"*avail_out != 0 in OutputBuffer_WindowGrow().");

return -1;

}

// slide the UINT32_MAX sliding window

if (window->left_bytes > 0) {

Py_ssize_t window_size = Py_MIN((size_t)window->left_bytes, UINT32_MAX);

*next_out = window->next_posi;

*avail_out = (uint32_t) window_size;

window->left_bytes -= window_size;

window->next_posi += window_size;

return window_size;

}

assert(window->left_bytes == 0);

// only the first block may > UINT32_MAX

allocated = _BlocksOutputBuffer_Grow(

buffer, (void**) next_out, (Py_ssize_t) *avail_out);

*avail_out = (uint32_t) allocated;

return allocated;

}

/* Finish the buffer.

On success, return a bytes object

On failure, return NULL */

static inline PyObject *

OutputBuffer_WindowFinish(_BlocksOutputBuffer *buffer, _Uint32Window *window,

uint32_t avail_out)

{

Py_ssize_t real_avail_out = (Py_ssize_t) avail_out + window->left_bytes;

return _BlocksOutputBuffer_Finish(buffer, real_avail_out);

}

static inline void

OutputBuffer_WindowOnError(_BlocksOutputBuffer *buffer, _Uint32Window *window)

{

_BlocksOutputBuffer_OnError(buffer);

}

/* The following parameters are copied from zutil.h, version 0.95 */

#define DEFLATED 8

#if MAX_MEM_LEVEL >= 8

# define DEF_MEM_LEVEL 8

#else

# define DEF_MEM_LEVEL MAX_MEM_LEVEL

#endif

/* Initial buffer size. */

#define DEF_BUF_SIZE (16*1024)

#define DEF_MAX_INITIAL_BUF_SIZE (16 * 1024 * 1024)

static PyModuleDef zlibmodule;

typedef struct {

PyTypeObject *Comptype;

PyTypeObject *Decomptype;

PyTypeObject *ZlibDecompressorType;

PyObject *ZlibError;

} zlibstate;

static inline zlibstate*

get_zlib_state(PyObject *module)

{

void *state = PyModule_GetState(module);

assert(state != NULL);

return (zlibstate *)state;

}

typedef struct

{

PyObject_HEAD

z_stream zst;

PyObject *unused_data;

PyObject *unconsumed_tail;

char eof;

bool is_initialised;

PyObject *zdict;

PyMutex mutex;

} compobject;

#define _compobject_CAST(op) ((compobject *)op)

static void

zlib_error(zlibstate *state, z_stream zst, int err, const char *msg)

{

const char *zmsg = Z_NULL;

/* In case of a version mismatch, zst.msg won't be initialized.

Check for this case first, before looking at zst.msg. */

if (err == Z_VERSION_ERROR)

zmsg = "library version mismatch";

if (zmsg == Z_NULL)

zmsg = zst.msg;

if (zmsg == Z_NULL) {

switch (err) {

case Z_BUF_ERROR:

zmsg = "incomplete or truncated stream";

break;

case Z_STREAM_ERROR:

zmsg = "inconsistent stream state";

break;

case Z_DATA_ERROR:

zmsg = "invalid input data";

break;

}

if (zmsg == Z_NULL)

PyErr_Format(state->ZlibError, "Error %d %s", err, msg);

else

PyErr_Format(state->ZlibError, "Error %d %s: %.200s", err, msg, zmsg);

}

/*[clinic input]

module zlib

class zlib.Compress "compobject *" "&Comptype"

class zlib.Decompress "compobject *" "&Decomptype"

[clinic start generated code]*/

/*[clinic end generated code: output=da39a3ee5e6b4b0d input=093935115c3e3158]*/

static compobject *

newcompobject(PyTypeObject *type)

{

compobject *self;

assert(type != NULL);

assert(type->tp_alloc != NULL);

self = _compobject_CAST(type->tp_alloc(type, 0));

if (self == NULL)

return NULL;

self->eof = 0;

self->is_initialised = 0;

self->zdict = NULL;

self->unused_data = Py_GetConstant(Py_CONSTANT_EMPTY_BYTES);

if (self->unused_data == NULL) {

Py_DECREF(self);

return NULL;

}

self->unconsumed_tail = Py_GetConstant(Py_CONSTANT_EMPTY_BYTES);

if (self->unconsumed_tail == NULL) {

Py_DECREF(self);

return NULL;

}

self->mutex = (PyMutex){0};

return self;

}

static void*

PyZlib_Malloc(voidpf ctx, uInt items, uInt size)

{

if (size != 0 && items > (size_t)PY_SSIZE_T_MAX / size)

return NULL;

/* PyMem_Malloc() cannot be used: the GIL is not held when

inflate() and deflate() are called */

return PyMem_RawMalloc((size_t)items * (size_t)size);

}

static void

PyZlib_Free(voidpf ctx, void *ptr)

{

PyMem_RawFree(ptr);

}

static void

arrange_input_buffer(z_stream *zst, Py_ssize_t *remains)

{

zst->avail_in = (uInt)Py_MIN((size_t)*remains, UINT_MAX);

*remains -= zst->avail_in;

}

/*[clinic input]

zlib.compress

data: Py_buffer

Binary data to be compressed.

level: int(c_default="Z_DEFAULT_COMPRESSION") = Z_DEFAULT_COMPRESSION

Compression level, in 0-9 or -1.

wbits: int(c_default="MAX_WBITS") = MAX_WBITS

The window buffer size and container format.

Returns a bytes object containing compressed data.

[clinic start generated code]*/

static PyObject *

zlib_compress_impl(PyObject *module, Py_buffer *data, int level, int wbits)

/*[clinic end generated code: output=46bd152fadd66df2 input=c4d06ee5782a7e3f]*/

{

PyObject *return_value;

int flush;

z_stream zst;

_BlocksOutputBuffer buffer = {.writer = NULL};

zlibstate *state = get_zlib_state(module);

Byte *ibuf = data->buf;

Py_ssize_t ibuflen = data->len;

if (OutputBuffer_InitAndGrow(&buffer, -1, &zst.next_out, &zst.avail_out) < 0) {

goto error;

}

zst.opaque = NULL;

zst.zalloc = PyZlib_Malloc;

zst.zfree = PyZlib_Free;

zst.next_in = ibuf;

int err = deflateInit2(&zst, level, DEFLATED, wbits, DEF_MEM_LEVEL,

Z_DEFAULT_STRATEGY);

switch (err) {

case Z_OK:

break;

case Z_MEM_ERROR:

PyErr_SetString(PyExc_MemoryError,

"Out of memory while compressing data");

goto error;

case Z_STREAM_ERROR:

PyErr_SetString(state->ZlibError, "Bad compression level");

goto error;

default:

deflateEnd(&zst);

zlib_error(state, zst, err, "while compressing data");

goto error;

}

do {

arrange_input_buffer(&zst, &ibuflen);

flush = ibuflen == 0 ? Z_FINISH : Z_NO_FLUSH;

do {

if (zst.avail_out == 0) {

if (OutputBuffer_Grow(&buffer, &zst.next_out, &zst.avail_out) < 0) {

deflateEnd(&zst);

goto error;

}

Py_BEGIN_ALLOW_THREADS

err = deflate(&zst, flush);

Py_END_ALLOW_THREADS

if (err == Z_STREAM_ERROR) {

deflateEnd(&zst);

zlib_error(state, zst, err, "while compressing data");

goto error;

}

} while (zst.avail_out == 0);

assert(zst.avail_in == 0);

} while (flush != Z_FINISH);

assert(err == Z_STREAM_END);

err = deflateEnd(&zst);

if (err == Z_OK) {

return_value = OutputBuffer_Finish(&buffer, zst.avail_out);

if (return_value == NULL) {

goto error;

}

return return_value;

}

else

zlib_error(state, zst, err, "while finishing compression");

error:

OutputBuffer_OnError(&buffer);

return NULL;

}

/*[clinic input]

zlib.decompress

data: Py_buffer

Compressed data.

wbits: int(c_default="MAX_WBITS") = MAX_WBITS

The window buffer size and container format.

bufsize: Py_ssize_t(c_default="DEF_BUF_SIZE", allow_negative=False) = DEF_BUF_SIZE

The initial output buffer size.

Returns a bytes object containing the uncompressed data.

[clinic start generated code]*/

static PyObject *

zlib_decompress_impl(PyObject *module, Py_buffer *data, int wbits,

Py_ssize_t bufsize)

/*[clinic end generated code: output=77c7e35111dc8c42 input=530077065b3a2233]*/

{

PyObject *return_value;

Byte *ibuf;

Py_ssize_t ibuflen;

int err, flush;

z_stream zst;

_BlocksOutputBuffer buffer = {.writer = NULL};

_Uint32Window window; // output buffer's UINT32_MAX sliding window

zlibstate *state = get_zlib_state(module);

if (bufsize == 0) {

bufsize = 1;

}

if (OutputBuffer_WindowInitWithSize(&buffer, &window, bufsize,

&zst.next_out, &zst.avail_out) < 0) {

goto error;

}

ibuf = data->buf;

ibuflen = data->len;

zst.opaque = NULL;

zst.zalloc = PyZlib_Malloc;

zst.zfree = PyZlib_Free;

zst.avail_in = 0;

zst.next_in = ibuf;

err = inflateInit2(&zst, wbits);

switch (err) {

case Z_OK:

break;

case Z_MEM_ERROR:

PyErr_SetString(PyExc_MemoryError,

"Out of memory while decompressing data");

goto error;

default:

inflateEnd(&zst);

zlib_error(state, zst, err, "while preparing to decompress data");

goto error;

}

do {

arrange_input_buffer(&zst, &ibuflen);

flush = ibuflen == 0 ? Z_FINISH : Z_NO_FLUSH;

do {

if (zst.avail_out == 0) {

if (OutputBuffer_WindowGrow(&buffer, &window,

&zst.next_out, &zst.avail_out) < 0) {

inflateEnd(&zst);

goto error;

}

Py_BEGIN_ALLOW_THREADS

err = inflate(&zst, flush);

Py_END_ALLOW_THREADS

switch (err) {

case Z_OK: _Py_FALLTHROUGH;

case Z_BUF_ERROR: _Py_FALLTHROUGH;

case Z_STREAM_END:

break;

case Z_MEM_ERROR:

inflateEnd(&zst);

PyErr_SetString(PyExc_MemoryError,

"Out of memory while decompressing data");

goto error;

default:

inflateEnd(&zst);

zlib_error(state, zst, err, "while decompressing data");

goto error;

}

} while (zst.avail_out == 0);

} while (err != Z_STREAM_END && ibuflen != 0);

if (err != Z_STREAM_END) {

inflateEnd(&zst);

zlib_error(state, zst, err, "while decompressing data");

goto error;

}

err = inflateEnd(&zst);

if (err != Z_OK) {

zlib_error(state, zst, err, "while finishing decompression");

goto error;

}

return_value = OutputBuffer_WindowFinish(&buffer, &window, zst.avail_out);

if (return_value != NULL) {

return return_value;

}

error:

OutputBuffer_WindowOnError(&buffer, &window);

return NULL;

}

/*[clinic input]

zlib.compressobj

level: int(c_default="Z_DEFAULT_COMPRESSION") = Z_DEFAULT_COMPRESSION

The compression level (an integer in the range 0-9 or -1; default is

currently equivalent to 6). Higher compression levels are slower,

but produce smaller results.

method: int(c_default="DEFLATED") = DEFLATED

The compression algorithm. If given, this must be DEFLATED.

wbits: int(c_default="MAX_WBITS") = MAX_WBITS

+9 to +15: The base-two logarithm of the window size. Include a zlib

container.

-9 to -15: Generate a raw stream.

+25 to +31: Include a gzip container.

memLevel: int(c_default="DEF_MEM_LEVEL") = DEF_MEM_LEVEL

Controls the amount of memory used for internal compression state.

Valid values range from 1 to 9. Higher values result in higher memory

usage, faster compression, and smaller output.

strategy: int(c_default="Z_DEFAULT_STRATEGY") = Z_DEFAULT_STRATEGY

Used to tune the compression algorithm. Possible values are

Z_DEFAULT_STRATEGY, Z_FILTERED, and Z_HUFFMAN_ONLY.

zdict: Py_buffer = NULL

The predefined compression dictionary - a sequence of bytes

containing subsequences that are likely to occur in the input data.

Return a compressor object.

[clinic start generated code]*/

static PyObject *

zlib_compressobj_impl(PyObject *module, int level, int method, int wbits,

int memLevel, int strategy, Py_buffer *zdict)

/*[clinic end generated code: output=8b5bed9c8fc3814d input=1a6f61d8a8885c0d]*/

{

zlibstate *state = get_zlib_state(module);

if (zdict->buf != NULL && (size_t)zdict->len > UINT_MAX) {

PyErr_SetString(PyExc_OverflowError,

"zdict length does not fit in an unsigned int");

return NULL;

}

compobject *self = newcompobject(state->Comptype);

if (self == NULL)

goto error;

self->zst.opaque = NULL;

self->zst.zalloc = PyZlib_Malloc;

self->zst.zfree = PyZlib_Free;

self->zst.next_in = NULL;

self->zst.avail_in = 0;

int err = deflateInit2(&self->zst, level, method, wbits, memLevel, strategy);

switch (err) {

case Z_OK:

self->is_initialised = 1;

if (zdict->buf == NULL) {

goto success;

} else {

err = deflateSetDictionary(&self->zst,

zdict->buf, (unsigned int)zdict->len);

switch (err) {

case Z_OK:

goto success;

case Z_STREAM_ERROR:

PyErr_SetString(PyExc_ValueError, "Invalid dictionary");

goto error;

default:

PyErr_SetString(PyExc_ValueError, "deflateSetDictionary()");

goto error;

}

case Z_MEM_ERROR:

PyErr_SetString(PyExc_MemoryError,

"Can't allocate memory for compression object");

goto error;

case Z_STREAM_ERROR:

PyErr_SetString(PyExc_ValueError, "Invalid initialization option");

goto error;

default:

zlib_error(state, self->zst, err, "while creating compression object");

goto error;

}

error:

Py_CLEAR(self);

success:

return (PyObject *)self;

}

static int

set_inflate_zdict(zlibstate *state, compobject *self)

{

Py_buffer zdict_buf;

if (PyObject_GetBuffer(self->zdict, &zdict_buf, PyBUF_SIMPLE) == -1) {

return -1;

}

if ((size_t)zdict_buf.len > UINT_MAX) {

PyErr_SetString(PyExc_OverflowError,

"zdict length does not fit in an unsigned int");

PyBuffer_Release(&zdict_buf);

return -1;

}

int err;

err = inflateSetDictionary(&self->zst,

zdict_buf.buf, (unsigned int)zdict_buf.len);

PyBuffer_Release(&zdict_buf);

if (err != Z_OK) {

zlib_error(state, self->zst, err, "while setting zdict");

return -1;

}

return 0;

}

/*[clinic input]

zlib.decompressobj

wbits: int(c_default="MAX_WBITS") = MAX_WBITS

The window buffer size and container format.

zdict: object(c_default="NULL") = b''

The predefined compression dictionary. This must be the same

dictionary as used by the compressor that produced the input data.

Return a decompressor object.

[clinic start generated code]*/

static PyObject *

zlib_decompressobj_impl(PyObject *module, int wbits, PyObject *zdict)

/*[clinic end generated code: output=3069b99994f36906 input=d3832b8511fc977b]*/

{

zlibstate *state = get_zlib_state(module);

if (zdict != NULL && !PyObject_CheckBuffer(zdict)) {

PyErr_SetString(PyExc_TypeError,

"zdict argument must support the buffer protocol");

return NULL;

}

compobject *self = newcompobject(state->Decomptype);

if (self == NULL)

return NULL;

self->zst.opaque = NULL;

self->zst.zalloc = PyZlib_Malloc;

self->zst.zfree = PyZlib_Free;

self->zst.next_in = NULL;

self->zst.avail_in = 0;

if (zdict != NULL) {

self->zdict = Py_NewRef(zdict);

}

int err = inflateInit2(&self->zst, wbits);

switch (err) {

case Z_OK:

self->is_initialised = 1;

if (self->zdict != NULL && wbits < 0) {

if (set_inflate_zdict(state, self) < 0) {

Py_DECREF(self);

return NULL;

}

return (PyObject *)self;

case Z_STREAM_ERROR:

Py_DECREF(self);

PyErr_SetString(PyExc_ValueError, "Invalid initialization option");

return NULL;

case Z_MEM_ERROR:

Py_DECREF(self);

PyErr_SetString(PyExc_MemoryError,

"Can't allocate memory for decompression object");

return NULL;

default:

zlib_error(state, self->zst, err, "while creating decompression object");

Py_DECREF(self);

return NULL;

}

static void

compobject_dealloc_impl(PyObject *op, int (*dealloc)(z_streamp))

{

PyTypeObject *type = Py_TYPE(op);

PyObject_GC_UnTrack(op);

compobject *self = _compobject_CAST(op);

assert(!PyMutex_IsLocked(&self->mutex));

if (self->is_initialised) {

(void)dealloc(&self->zst);

}

Py_XDECREF(self->unused_data);

Py_XDECREF(self->unconsumed_tail);

Py_XDECREF(self->zdict);

type->tp_free(self);

Py_DECREF(type);

}

static int

compobject_traverse(PyObject *op, visitproc visit, void *arg)

{

compobject *self = _compobject_CAST(op);

Py_VISIT(Py_TYPE(op));

Py_VISIT(self->zdict);

return 0;

}

static void

Comp_dealloc(PyObject *op)

{

compobject_dealloc_impl(op, &deflateEnd);

}

static void

Decomp_dealloc(PyObject *op)

{

compobject_dealloc_impl(op, &inflateEnd);

}

/*[clinic input]

zlib.Compress.compress

cls: defining_class

data: Py_buffer

Binary data to be compressed.

Returns a bytes object containing compressed data.

After calling this function, some of the input data may still

be stored in internal buffers for later processing.

Call the flush() method to clear these buffers.

[clinic start generated code]*/

static PyObject *

zlib_Compress_compress_impl(compobject *self, PyTypeObject *cls,

Py_buffer *data)

/*[clinic end generated code: output=6731b3f0ff357ca6 input=04d00f65ab01d260]*/

{

PyObject *return_value;

int err;

_BlocksOutputBuffer buffer = {.writer = NULL};

zlibstate *state = PyType_GetModuleState(cls);

PyMutex_Lock(&self->mutex);

self->zst.next_in = data->buf;

Py_ssize_t ibuflen = data->len;

if (OutputBuffer_InitAndGrow(&buffer, -1, &self->zst.next_out, &self->zst.avail_out) < 0) {

goto error;

}

do {

arrange_input_buffer(&self->zst, &ibuflen);

do {

if (self->zst.avail_out == 0) {

if (OutputBuffer_Grow(&buffer, &self->zst.next_out, &self->zst.avail_out) < 0) {

goto error;

}

Py_BEGIN_ALLOW_THREADS

err = deflate(&self->zst, Z_NO_FLUSH);

Py_END_ALLOW_THREADS

if (err == Z_STREAM_ERROR) {

zlib_error(state, self->zst, err, "while compressing data");

goto error;

}

} while (self->zst.avail_out == 0);

assert(self->zst.avail_in == 0);

} while (ibuflen != 0);

return_value = OutputBuffer_Finish(&buffer, self->zst.avail_out);

if (return_value != NULL) {

goto success;

}

error:

OutputBuffer_OnError(&buffer);

return_value = NULL;

success:

PyMutex_Unlock(&self->mutex);

return return_value;

}

/* Helper for objdecompress() and flush(). Saves any unconsumed input data in

self->unused_data or self->unconsumed_tail, as appropriate. */

static int

save_unconsumed_input(compobject *self, Py_buffer *data, int err)

{

if (err == Z_STREAM_END) {

/* The end of the compressed data has been reached. Store the leftover

input data in self->unused_data. */

if (self->zst.avail_in > 0) {

Py_ssize_t old_size = PyBytes_GET_SIZE(self->unused_data);

Py_ssize_t left_size;

left_size = (Byte *)data->buf + data->len - self->zst.next_in;

if (left_size > (PY_SSIZE_T_MAX - old_size)) {

PyErr_NoMemory();

return -1;

}

PyBytesWriter *writer = PyBytesWriter_Create(old_size + left_size);

if (writer == NULL) {

return -1;

}

char *new_data = PyBytesWriter_GetData(writer);

memcpy(new_data, PyBytes_AS_STRING(self->unused_data), old_size);

memcpy(new_data + old_size, self->zst.next_in, left_size);

PyObject *new_unused_data = PyBytesWriter_Finish(writer);

if (new_unused_data == NULL) {

return -1;

}

Py_SETREF(self->unused_data, new_unused_data);

self->zst.next_in += left_size;

self->zst.avail_in = 0;

}

if (self->zst.avail_in > 0 || PyBytes_GET_SIZE(self->unconsumed_tail)) {

/* This code handles two distinct cases:

1. Output limit was reached. Save leftover input in unconsumed_tail.

2. All input data was consumed. Clear unconsumed_tail. */

Py_ssize_t left_size = (Byte *)data->buf + data->len - self->zst.next_in;

PyObject *new_data = PyBytes_FromStringAndSize(

(char *)self->zst.next_in, left_size);

if (new_data == NULL)

return -1;

Py_SETREF(self->unconsumed_tail, new_data);

}

return 0;

}

/*[clinic input]

@permit_long_summary

zlib.Decompress.decompress

cls: defining_class

data: Py_buffer

The binary data to decompress.

max_length: Py_ssize_t(allow_negative=False) = 0

The maximum allowable length of the decompressed data.

Unconsumed input data will be stored in

the unconsumed_tail attribute.

Return a bytes object containing the decompressed version of the data.

After calling this function, some of the input data may still be

stored in internal buffers for later processing.

Call the flush() method to clear these buffers.

[clinic start generated code]*/

static PyObject *

zlib_Decompress_decompress_impl(compobject *self, PyTypeObject *cls,

Py_buffer *data, Py_ssize_t max_length)

/*[clinic end generated code: output=b024a93c2c922d57 input=9035027c9e4be7fd]*/

{

int err = Z_OK;

Py_ssize_t ibuflen;

PyObject *return_value;

_BlocksOutputBuffer buffer = {.writer = NULL};

PyObject *module = PyType_GetModule(cls);

if (module == NULL)

return NULL;

zlibstate *state = get_zlib_state(module);

if (max_length == 0) {

max_length = -1;

}

PyMutex_Lock(&self->mutex);

self->zst.next_in = data->buf;

ibuflen = data->len;

if (OutputBuffer_InitAndGrow(&buffer, max_length, &self->zst.next_out, &self->zst.avail_out) < 0) {

goto abort;

}

do {

arrange_input_buffer(&self->zst, &ibuflen);

do {

if (self->zst.avail_out == 0) {

if (OutputBuffer_GetDataSize(&buffer, self->zst.avail_out) == max_length) {

goto save;

}

if (OutputBuffer_Grow(&buffer, &self->zst.next_out, &self->zst.avail_out) < 0) {

goto abort;

}

Py_BEGIN_ALLOW_THREADS

err = inflate(&self->zst, Z_SYNC_FLUSH);

Py_END_ALLOW_THREADS

switch (err) {

case Z_OK: _Py_FALLTHROUGH;

case Z_BUF_ERROR: _Py_FALLTHROUGH;

case Z_STREAM_END:

break;

default:

if (err == Z_NEED_DICT && self->zdict != NULL) {

if (set_inflate_zdict(state, self) < 0) {

goto abort;

}

else

break;

}

goto save;

}

} while (self->zst.avail_out == 0 || err == Z_NEED_DICT);

} while (err != Z_STREAM_END && ibuflen != 0);

save:

if (save_unconsumed_input(self, data, err) < 0)

goto abort;

if (err == Z_STREAM_END) {

/* This is the logical place to call inflateEnd, but the old behaviour

of only calling it on flush() is preserved. */

FT_ATOMIC_STORE_CHAR_RELAXED(self->eof, 1);

} else if (err != Z_OK && err != Z_BUF_ERROR) {

/* We will only get Z_BUF_ERROR if the output buffer was full

but there wasn't more output when we tried again, so it is

not an error condition.

zlib_error(state, self->zst, err, "while decompressing data");

goto abort;

}

return_value = OutputBuffer_Finish(&buffer, self->zst.avail_out);

if (return_value != NULL) {

goto success;

}

abort:

OutputBuffer_OnError(&buffer);

return_value = NULL;

success:

PyMutex_Unlock(&self->mutex);

return return_value;

}

/*[clinic input]

zlib.Compress.flush

cls: defining_class

mode: int(c_default="Z_FINISH") = zlib.Z_FINISH

One of the constants Z_SYNC_FLUSH, Z_FULL_FLUSH, Z_FINISH.

If mode == Z_FINISH, the compressor object can no longer be

used after calling the flush() method. Otherwise, more data

can still be compressed.

Return a bytes object containing any remaining compressed data.

[clinic start generated code]*/

static PyObject *

zlib_Compress_flush_impl(compobject *self, PyTypeObject *cls, int mode)

/*[clinic end generated code: output=c7efd13efd62add2 input=286146e29442eb6c]*/

{

int err;

PyObject *return_value;

_BlocksOutputBuffer buffer = {.writer = NULL};

zlibstate *state = PyType_GetModuleState(cls);

/* Flushing with Z_NO_FLUSH is a no-op, so there's no point in

doing any work at all; just return an empty string. */

View remainder of file in raw view

cpython/Modules/zlibmodule.c at main · python/cpython · GitHub

Repository navigation

Expand file tree

Breadcrumbs

zlibmodule.c

Latest commit

History

Breadcrumbs

zlibmodule.c

File metadata and controls