node/src/string_bytes.cc at v0.10 · cspotcode/node

History

632 lines (499 loc) · 16.4 KB

Raw

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

// Copyright Joyent, Inc. and other Node contributors.

// Permission is hereby granted, free of charge, to any person obtaining a

// copy of this software and associated documentation files (the

// "Software"), to deal in the Software without restriction, including

// without limitation the rights to use, copy, modify, merge, publish,

// distribute, sublicense, and/or sell copies of the Software, and to permit

// persons to whom the Software is furnished to do so, subject to the

// following conditions:

// The above copyright notice and this permission notice shall be included

// in all copies or substantial portions of the Software.

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS

// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN

// NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,

// DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR

// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE

// USE OR OTHER DEALINGS IN THE SOFTWARE.

#include "string_bytes.h"

#include <assert.h>

#include <string.h> // memcpy

#include <limits.h>

#include "node.h"

#include "node_buffer.h"

#include "v8.h"

namespace node {

using v8::Local;

using v8::Handle;

using v8::HandleScope;

using v8::Object;

using v8::String;

using v8::Value;

//// Base 64 ////

#define base64_encoded_size(size) ((size + 2 - ((size + 2) % 3)) / 3 * 4)

// Doesn't check for padding at the end. Can be 1-2 bytes over.

static inline size_t base64_decoded_size_fast(size_t size) {

size_t remainder = size % 4;

size = (size / 4) * 3;

if (remainder) {

if (size == 0 && remainder == 1) {

// special case: 1-byte input cannot be decoded

size = 0;

} else {

// non-padded input, add 1 or 2 extra bytes

size += 1 + (remainder == 3);

}

return size;

}

static inline size_t base64_decoded_size(const char* src, size_t size) {

if (size == 0)

return 0;

if (src[size - 1] == '=')

size--;

if (size > 0 && src[size - 1] == '=')

size--;

return base64_decoded_size_fast(size);

}

// supports regular and URL-safe base64

static const int unbase64_table[] =

{ -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -2, -1, -1, -2, -1, -1,

-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,

-2, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, 62, -1, 63,

52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1,

-1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,

15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, 63,

-1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,

41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1,

-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,

-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1

};

#define unbase64(x) unbase64_table[(uint8_t)(x)]

static inline size_t base64_decode(char *buf,

size_t len,

const char *src,

const size_t srcLen) {

char a, b, c, d;

char* dst = buf;

char* dstEnd = buf + len;

const char* srcEnd = src + srcLen;

while (src < srcEnd && dst < dstEnd) {

int remaining = srcEnd - src;

while (unbase64(*src) < 0 && src < srcEnd) src++, remaining--;

if (remaining == 0 || *src == '=') break;

a = unbase64(*src++);

while (unbase64(*src) < 0 && src < srcEnd) src++, remaining--;

if (remaining <= 1 || *src == '=') break;

b = unbase64(*src++);

*dst++ = (a << 2) | ((b & 0x30) >> 4);

if (dst == dstEnd) break;

while (unbase64(*src) < 0 && src < srcEnd) src++, remaining--;

if (remaining <= 2 || *src == '=') break;

c = unbase64(*src++);

*dst++ = ((b & 0x0F) << 4) | ((c & 0x3C) >> 2);

if (dst == dstEnd) break;

while (unbase64(*src) < 0 && src < srcEnd) src++, remaining--;

if (remaining <= 3 || *src == '=') break;

d = unbase64(*src++);

*dst++ = ((c & 0x03) << 6) | (d & 0x3F);

}

return dst - buf;

}

//// HEX ////

static inline unsigned hex2bin(char c) {

if (c >= '0' && c <= '9') return c - '0';

if (c >= 'A' && c <= 'F') return 10 + (c - 'A');

if (c >= 'a' && c <= 'f') return 10 + (c - 'a');

return static_cast<unsigned>(-1);

}

static inline size_t hex_decode(char *buf,

size_t len,

const char *src,

const size_t srcLen) {

size_t i;

for (i = 0; i < len && i * 2 + 1 < srcLen; ++i) {

unsigned a = hex2bin(src[i * 2 + 0]);

unsigned b = hex2bin(src[i * 2 + 1]);

if (!~a || !~b) return i;

buf[i] = a * 16 + b;

}

return i;

}

size_t StringBytes::Write(char* buf,

size_t buflen,

Handle<Value> val,

enum encoding encoding,

int* chars_written) {

HandleScope scope;

size_t len = 0;

bool is_buffer = Buffer::HasInstance(val);

// sometimes we use 'binary' when we mean 'buffer'

if (is_buffer && (encoding == BINARY || encoding == BUFFER)) {

// fast path, copy buffer data

Local<Object> valObj = Local<Object>::New(val.As<Object>());

const char* data = Buffer::Data(valObj);

size_t size = Buffer::Length(valObj);

size_t len = size < buflen ? size : buflen;

memcpy(buf, data, len);

return len;

}

Local<String> str = val->ToString();

int flags = String::NO_NULL_TERMINATION |

String::HINT_MANY_WRITES_EXPECTED;

switch (encoding) {

case ASCII:

len = str->WriteAscii(buf, 0, buflen, flags);

if (chars_written != NULL) {

*chars_written = len;

}

break;

case UTF8:

len = str->WriteUtf8(buf, buflen, chars_written, WRITE_UTF8_FLAGS);

break;

case UCS2:

len = str->Write(reinterpret_cast<uint16_t*>(buf), 0, buflen, flags);

if (chars_written != NULL) {

*chars_written = len;

}

len = len * sizeof(uint16_t);

break;

case BASE64: {

String::AsciiValue value(str);

len = base64_decode(buf, buflen, *value, value.length());

if (chars_written != NULL) {

*chars_written = len;

}

break;

}

case BINARY:

case BUFFER: {

// TODO(isaacs): THIS IS AWFUL!!!

uint16_t* twobytebuf = new uint16_t[buflen];

len = str->Write(twobytebuf, 0, buflen, flags);

for (size_t i = 0; i < buflen && i < len; i++) {

unsigned char *b = reinterpret_cast<unsigned char*>(&twobytebuf[i]);

buf[i] = b[0];

}

if (chars_written != NULL) {

*chars_written = len;

}

delete[] twobytebuf;

break;

}

case HEX: {

String::AsciiValue value(str);

len = hex_decode(buf, buflen, *value, value.length());

if (chars_written != NULL) {

*chars_written = len * 2;

}

break;

}

default:

assert(0 && "unknown encoding");

break;

}

return len;

}

bool StringBytes::IsValidString(Handle<String> string, enum encoding enc) {

if (enc == HEX && string->Length() % 2 != 0) return false;

// TODO(bnoordhuis) Add BASE64 check?

return true;

}

// Quick and dirty size calculation

// Will always be at least big enough, but may have some extra

// UTF8 can be as much as 3x the size, Base64 can have 1-2 extra bytes

size_t StringBytes::StorageSize(Handle<Value> val, enum encoding encoding) {

HandleScope scope;

size_t data_size = 0;

bool is_buffer = Buffer::HasInstance(val);

if (is_buffer && (encoding == BUFFER || encoding == BINARY)) {

return Buffer::Length(val);

}

Local<String> str = val->ToString();

switch (encoding) {

case BINARY:

case BUFFER:

case ASCII:

data_size = str->Length();

break;

case UTF8:

// A single UCS2 codepoint never takes up more than 3 utf8 bytes.

// It is an exercise for the caller to decide when a string is

// long enough to justify calling Size() instead of StorageSize()

// TODO(isaacs): MayContainNonAscii is deprecated in V8 3.19, remove

if (!str->MayContainNonAscii())

data_size = str->Length();

else

data_size = 3 * str->Length();

break;

case UCS2:

data_size = str->Length() * sizeof(uint16_t);

break;

case BASE64:

data_size = base64_decoded_size_fast(str->Length());

break;

case HEX:

assert(str->Length() % 2 == 0 && "invalid hex string length");

data_size = str->Length() / 2;

break;

default:

assert(0 && "unknown encoding");

break;

}

return data_size;

}

size_t StringBytes::Size(Handle<Value> val, enum encoding encoding) {

HandleScope scope;

size_t data_size = 0;

bool is_buffer = Buffer::HasInstance(val);

if (is_buffer && (encoding == BUFFER || encoding == BINARY)) {

return Buffer::Length(val);

}

Local<String> str = val->ToString();

switch (encoding) {

case BINARY:

case BUFFER:

case ASCII:

data_size = str->Length();

break;

case UTF8:

// TODO(isaacs): MayContainNonAscii is deprecated in V8 3.19, remove

if (!str->MayContainNonAscii())

data_size = str->Length();

else

data_size = str->Utf8Length();

break;

case UCS2:

data_size = str->Length() * sizeof(uint16_t);

break;

case BASE64: {

String::AsciiValue value(str);

data_size = base64_decoded_size(*value, value.length());

break;

}

case HEX:

data_size = str->Length() / 2;

break;

default:

assert(0 && "unknown encoding");

break;

}

return data_size;

}

static bool contains_non_ascii_slow(const char* buf, size_t len) {

for (size_t i = 0; i < len; ++i) {

if (buf[i] & 0x80) return true;

}

return false;

}

static bool contains_non_ascii(const char* src, size_t len) {

if (len < 16) {

return contains_non_ascii_slow(src, len);

}

const unsigned bytes_per_word = sizeof(void*);

const unsigned align_mask = bytes_per_word - 1;

const unsigned unaligned = reinterpret_cast<uintptr_t>(src) & align_mask;

if (unaligned > 0) {

const unsigned n = bytes_per_word - unaligned;

if (contains_non_ascii_slow(src, n)) return true;

src += n;

len -= n;

}

#if defined(__x86_64__) || defined(_WIN64)

const uintptr_t mask = 0x8080808080808080ll;

#else

const uintptr_t mask = 0x80808080l;

#endif

const uintptr_t* srcw = reinterpret_cast<const uintptr_t*>(src);

for (size_t i = 0, n = len / bytes_per_word; i < n; ++i) {

if (srcw[i] & mask) return true;

}

const unsigned remainder = len & align_mask;

if (remainder > 0) {

const size_t offset = len - remainder;

if (contains_non_ascii_slow(src + offset, remainder)) return true;

}

return false;

}

static void force_ascii_slow(const char* src, char* dst, size_t len) {

for (size_t i = 0; i < len; ++i) {

dst[i] = src[i] & 0x7f;

}

static void force_ascii(const char* src, char* dst, size_t len) {

if (len < 16) {

force_ascii_slow(src, dst, len);

return;

}

const unsigned bytes_per_word = sizeof(void*);

const unsigned align_mask = bytes_per_word - 1;

const unsigned src_unalign = reinterpret_cast<uintptr_t>(src) & align_mask;

const unsigned dst_unalign = reinterpret_cast<uintptr_t>(dst) & align_mask;

if (src_unalign > 0) {

if (src_unalign == dst_unalign) {

const unsigned unalign = bytes_per_word - src_unalign;

force_ascii_slow(src, dst, unalign);

src += unalign;

dst += unalign;

len -= src_unalign;

} else {

force_ascii_slow(src, dst, len);

return;

}

#if defined(__x86_64__) || defined(_WIN64)

const uintptr_t mask = ~0x8080808080808080ll;

#else

const uintptr_t mask = ~0x80808080l;

#endif

const uintptr_t* srcw = reinterpret_cast<const uintptr_t*>(src);

uintptr_t* dstw = reinterpret_cast<uintptr_t*>(dst);

for (size_t i = 0, n = len / bytes_per_word; i < n; ++i) {

dstw[i] = srcw[i] & mask;

}

const unsigned remainder = len & align_mask;

if (remainder > 0) {

const size_t offset = len - remainder;

force_ascii_slow(src + offset, dst + offset, remainder);

}

static size_t base64_encode(const char* src,

size_t slen,

char* dst,

size_t dlen) {

// We know how much we'll write, just make sure that there's space.

assert(dlen >= base64_encoded_size(slen) &&

"not enough space provided for base64 encode");

dlen = base64_encoded_size(slen);

unsigned a;

unsigned b;

unsigned c;

unsigned i;

unsigned k;

unsigned n;

static const char table[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"

"abcdefghijklmnopqrstuvwxyz"

"0123456789+/";

i = 0;

k = 0;

n = slen / 3 * 3;

while (i < n) {

a = src[i + 0] & 0xff;

b = src[i + 1] & 0xff;

c = src[i + 2] & 0xff;

dst[k + 0] = table[a >> 2];

dst[k + 1] = table[((a & 3) << 4) | (b >> 4)];

dst[k + 2] = table[((b & 0x0f) << 2) | (c >> 6)];

dst[k + 3] = table[c & 0x3f];

i += 3;

k += 4;

}

if (n != slen) {

switch (slen - n) {

case 1:

a = src[i + 0] & 0xff;

dst[k + 0] = table[a >> 2];

dst[k + 1] = table[(a & 3) << 4];

dst[k + 2] = '=';

dst[k + 3] = '=';

break;

case 2:

a = src[i + 0] & 0xff;

b = src[i + 1] & 0xff;

dst[k + 0] = table[a >> 2];

dst[k + 1] = table[((a & 3) << 4) | (b >> 4)];

dst[k + 2] = table[(b & 0x0f) << 2];

dst[k + 3] = '=';

break;

}

return dlen;

}

static size_t hex_encode(const char* src, size_t slen, char* dst, size_t dlen) {

// We know how much we'll write, just make sure that there's space.

assert(dlen >= slen * 2 &&

"not enough space provided for hex encode");

dlen = slen * 2;

for (uint32_t i = 0, k = 0; k < dlen; i += 1, k += 2) {

static const char hex[] = "0123456789abcdef";

uint8_t val = static_cast<uint8_t>(src[i]);

dst[k + 0] = hex[val >> 4];

dst[k + 1] = hex[val & 15];

}

return dlen;

}

Local<Value> StringBytes::Encode(const char* buf,

size_t buflen,

43EF enum encoding encoding) {

HandleScope scope;

assert(buflen <= Buffer::kMaxLength);

if (!buflen && encoding != BUFFER)

return scope.Close(String::Empty());

Local<String> val;

switch (encoding) {

case BUFFER:

return scope.Close(Buffer::New(buf, buflen)->handle_);

case ASCII:

if (contains_non_ascii(buf, buflen)) {

char* out = new char[buflen];

force_ascii(buf, out, buflen);

val = String::New(out, buflen);

delete[] out;

} else {

val = String::New(buf, buflen);

}

break;

case UTF8:

val = String::New(buf, buflen);

break;

case BINARY: {

// TODO(isaacs) use ExternalTwoByteString?

const unsigned char *cbuf = reinterpret_cast<const unsigned char*>(buf);

uint16_t * twobytebuf = new uint16_t[buflen];

for (size_t i = 0; i < buflen; i++) {

// XXX is the following line platform independent?

twobytebuf[i] = cbuf[i];

}

val = String::New(twobytebuf, buflen);

delete[] twobytebuf;

break;

}

case BASE64: {

size_t dlen = base64_encoded_size(buflen);

char* dst = new char[dlen];

size_t written = base64_encode(buf, buflen, dst, dlen);

assert(written == dlen);

val = String::New(dst, dlen);

delete[] dst;

break;

}

case UCS2: {

const uint16_t* data = reinterpret_cast<const uint16_t*>(buf);

val = String::New(data, buflen / 2);

break;

}

case HEX: {

size_t dlen = buflen * 2;

char* dst = new char[dlen];

size_t written = hex_encode(buf, buflen, dst, dlen);

assert(written == dlen);

val = String::New(dst, dlen);

delete[] dst;

break;

}

default:

assert(0 & 3441 ;& "unknown encoding");

break;

}

return scope.Close(val);

}

} // namespace node

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

FilesExpand file tree

string_bytes.cc

Latest commit

History

string_bytes.cc

File metadata and controls