sqlcipher/src/func.c at sqlite-release · sqlcipher/sqlcipher · GitHub

History

3469 lines (3322 loc) · 106 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

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

** 2002 February 23

** The author disclaims copyright to this source code. In place of

** a legal notice, here is a blessing:

** May you do good and not evil.

** May you find forgiveness for yourself and forgive others.

** May you share freely, never taking more than you give.

*************************************************************************

** This file contains the C-language implementations for many of the SQL

** functions of SQLite. (Some function, and in particular the date and

** time functions, are implemented separately.)

#include "sqliteInt.h"

#include <stdlib.h>

#include <assert.h>

#ifndef SQLITE_OMIT_FLOATING_POINT

#include <math.h>

#endif

#include "vdbeInt.h"

** Return the collating function associated with a function.

static CollSeq *sqlite3GetFuncCollSeq(sqlite3_context *context){

VdbeOp *pOp;

assert( context->pVdbe!=0 );

pOp = &context->pVdbe->aOp[context->iOp-1];

assert( pOp->opcode==OP_CollSeq );

assert( pOp->p4type==P4_COLLSEQ );

return pOp->p4.pColl;

}

** Indicate that the accumulator load should be skipped on this

** iteration of the aggregate loop.

static void sqlite3SkipAccumulatorLoad(sqlite3_context *context){

assert( context->isError<=0 );

context->isError = -1;

context->skipFlag = 1;

}

** Implementation of the non-aggregate min() and max() functions

static void minmaxFunc(

sqlite3_context *context,

int argc,

sqlite3_value **argv

){

int i;

int mask; /* 0 for min() or 0xffffffff for max() */

int iBest;

CollSeq *pColl;

assert( argc>1 );

mask = sqlite3_user_data(context)==0 ? 0 : -1;

pColl = sqlite3GetFuncCollSeq(context);

assert( pColl );

assert( mask==-1 || mask==0 );

iBest = 0;

if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;

for(i=1; i<argc; i++){

if( sqlite3_value_type(argv[i])==SQLITE_NULL ) return;

if( (sqlite3MemCompare(argv[iBest], argv[i], pColl)^mask)>=0 ){

testcase( mask==0 );

iBest = i;

}

sqlite3_result_value(context, argv[iBest]);

}

** Return the type of the argument.

static void typeofFunc(

sqlite3_context *context,

int NotUsed,

sqlite3_value **argv

){

static const char *azType[] = { "integer", "real", "text", "blob", "null" };

int i = sqlite3_value_type(argv[0]) - 1;

UNUSED_PARAMETER(NotUsed);

assert( i>=0 && i<ArraySize(azType) );

assert( SQLITE_INTEGER==1 );

assert( SQLITE_FLOAT==2 );

assert( SQLITE_TEXT==3 );

assert( SQLITE_BLOB==4 );

assert( SQLITE_NULL==5 );

/* EVIDENCE-OF: R-01470-60482 The sqlite3_value_type(V) interface returns

** the datatype code for the initial datatype of the sqlite3_value object

** V. The returned value is one of SQLITE_INTEGER, SQLITE_FLOAT,

** SQLITE_TEXT, SQLITE_BLOB, or SQLITE_NULL. */

sqlite3_result_text(context, azType[i], -1, SQLITE_STATIC);

}

/* subtype(X)

** Return the subtype of X

static void subtypeFunc(

sqlite3_context *context,

int argc,

sqlite3_value **argv

){

UNUSED_PARAMETER(argc);

sqlite3_result_int(context, sqlite3_value_subtype(argv[0]));

}

** Implementation of the length() function

static void lengthFunc(

sqlite3_context *context,

int argc,

sqlite3_value **argv

){

assert( argc==1 );

UNUSED_PARAMETER(argc);

switch( sqlite3_value_type(argv[0]) ){

case SQLITE_BLOB:

case SQLITE_INTEGER:

case SQLITE_FLOAT: {

sqlite3_result_int(context, sqlite3_value_bytes(argv[0]));

break;

}

case SQLITE_TEXT: {

const unsigned char *z = sqlite3_value_text(argv[0]);

const unsigned char *z0;

unsigned char c;

if( z==0 ) return;

z0 = z;

while( (c = *z)!=0 ){

z++;

if( c>=0xc0 ){

while( (*z & 0xc0)==0x80 ){ z++; z0++; }

}

sqlite3_result_int(context, (int)(z-z0));

break;

}

default: {

sqlite3_result_null(context);

break;

}

** Implementation of the octet_length() function

static void bytelengthFunc(

sqlite3_context *context,

int argc,

sqlite3_value **argv

){

assert( argc==1 );

UNUSED_PARAMETER(argc);

switch( sqlite3_value_type(argv[0]) ){

case SQLITE_BLOB: {

sqlite3_result_int(context, sqlite3_value_bytes(argv[0]));

break;

}

case SQLITE_INTEGER:

case SQLITE_FLOAT: {

i64 m = sqlite3_context_db_handle(context)->enc<=SQLITE_UTF8 ? 1 : 2;

sqlite3_result_int64(context, sqlite3_value_bytes(argv[0])*m);

break;

}

case SQLITE_TEXT: {

if( sqlite3_value_encoding(argv[0])<=SQLITE_UTF8 ){

sqlite3_result_int(context, sqlite3_value_bytes(argv[0]));

}else{

sqlite3_result_int(context, sqlite3_value_bytes16(argv[0]));

}

break;

}

default: {

sqlite3_result_null(context);

break;

}

** Implementation of the abs() function.

** IMP: R-23979-26855 The abs(X) function returns the absolute value of

** the numeric argument X.

static void absFunc(sqlite3_context *context, int argc, sqlite3_value **argv){

assert( argc==1 );

UNUSED_PARAMETER(argc);

switch( sqlite3_value_type(argv[0]) ){

case SQLITE_INTEGER: {

i64 iVal = sqlite3_value_int64(argv[0]);

if( iVal<0 ){

if( iVal==SMALLEST_INT64 ){

/* IMP: R-31676-45509 If X is the integer -9223372036854775808

** then abs(X) throws an integer overflow error since there is no

** equivalent positive 64-bit two complement value. */

sqlite3_result_error(context, "integer overflow", -1);

return;

}

iVal = -iVal;

}

sqlite3_result_int64(context, iVal);

break;

}

case SQLITE_NULL: {

/* IMP: R-37434-19929 Abs(X) returns NULL if X is NULL. */

sqlite3_result_null(context);

break;

}

default: {

/* Because sqlite3_value_double() returns 0.0 if the argument is not

** something that can be converted into a number, we have:

** IMP: R-01992-00519 Abs(X) returns 0.0 if X is a string or blob

** that cannot be converted to a numeric value.

double rVal = sqlite3_value_double(argv[0]);

if( rVal<0 ) rVal = -rVal;

sqlite3_result_double(context, rVal);

break;

}

** Implementation of the instr() function.

** instr(haystack,needle) finds the first occurrence of needle

** in haystack and returns the number of previous characters plus 1,

** or 0 if needle does not occur within haystack.

** If both haystack and needle are BLOBs, then the result is one more than

** the number of bytes in haystack prior to the first occurrence of needle,

** or 0 if needle never occurs in haystack.

static void instrFunc(

sqlite3_context *context,

int argc,

sqlite3_value **argv

){

const unsigned char *zHaystack;

const unsigned char *zNeedle;

int nHaystack;

int nNeedle;

int typeHaystack, typeNeedle;

int N = 1;

int isText;

unsigned char firstChar;

sqlite3_value *pC1 = 0;

sqlite3_value *pC2 = 0;

UNUSED_PARAMETER(argc);

typeHaystack = sqlite3_value_type(argv[0]);

typeNeedle = sqlite3_value_type(argv[1]);

if( typeHaystack==SQLITE_NULL || typeNeedle==SQLITE_NULL ) return;

nHaystack = sqlite3_value_bytes(argv[0]);

nNeedle = sqlite3_value_bytes(argv[1]);

if( nNeedle>0 ){

if( typeHaystack==SQLITE_BLOB && typeNeedle==SQLITE_BLOB ){

zHaystack = sqlite3_value_blob(argv[0]);

zNeedle = sqlite3_value_blob(argv[1]);

isText = 0;

}else if( typeHaystack!=SQLITE_BLOB && typeNeedle!=SQLITE_BLOB ){

zHaystack = sqlite3_value_text(argv[0]);

zNeedle = sqlite3_value_text(argv[1]);

isText = 1;

}else{

pC1 = sqlite3_value_dup(argv[0]);

zHaystack = sqlite3_value_text(pC1);

if( zHaystack==0 ) goto endInstrOOM;

nHaystack = sqlite3_value_bytes(pC1);

pC2 = sqlite3_value_dup(argv[1]);

zNeedle = sqlite3_value_text(pC2);

if( zNeedle==0 ) goto endInstrOOM;

nNeedle = sqlite3_value_bytes(pC2);

isText = 1;

}

if( zNeedle==0 || (nHaystack && zHaystack==0) ) goto endInstrOOM;

firstChar = zNeedle[0];

while( nNeedle<=nHaystack

&& (zHaystack[0]!=firstChar || memcmp(zHaystack, zNeedle, nNeedle)!=0)

){

N++;

do{

nHaystack--;

zHaystack++;

}while( isText && (zHaystack[0]&0xc0)==0x80 );

}

if( nNeedle>nHaystack ) N = 0;

}

sqlite3_result_int(context, N);

endInstr:

sqlite3_value_free(pC1);

sqlite3_value_free(pC2);

return;

endInstrOOM:

sqlite3_result_error_nomem(context);

goto endInstr;

}

** Implementation of the printf() (a.k.a. format()) SQL function.

static void printfFunc(

sqlite3_context *context,

int argc,

sqlite3_value **argv

){

PrintfArguments x;

StrAccum str;

const char *zFormat;

int n;

sqlite3 *db = sqlite3_context_db_handle(context);

if( argc>=1 && (zFormat = (const char*)sqlite3_value_text(argv[0]))!=0 ){

x.nArg = argc-1;

x.nUsed = 0;

x.apArg = argv+1;

sqlite3StrAccumInit(&str, db, 0, 0, db->aLimit[SQLITE_LIMIT_LENGTH]);

str.printfFlags = SQLITE_PRINTF_SQLFUNC;

sqlite3_str_appendf(&str, zFormat, &x);

if( str.accError==SQLITE_OK ){

n = str.nChar;

sqlite3_result_text(context, sqlite3StrAccumFinish(&str), n,

SQLITE_DYNAMIC);

}else{

if( str.accError==SQLITE_NOMEM ){

sqlite3_result_error_nomem(context);

}else{

sqlite3_result_error_toobig(context);

}

sqlite3_str_reset(&str);

}

** Implementation of the substr() function.

** substr(x,p1,p2) returns p2 characters of x[] beginning with p1.

** p1 is 1-indexed. So substr(x,1,1) returns the first character

** of x. If x is text, then we actually count UTF-8 characters.

** If x is a blob, then we count bytes.

** If p1 is negative, then we begin abs(p1) from the end of x[].

** If p2 is negative, return the p2 characters preceding p1.

static void substrFunc(

sqlite3_context *context,

int argc,

sqlite3_value **argv

){

const unsigned char *z;

const unsigned char *z2;

int len;

int p0type;

i64 p1, p2;

assert( argc==3 || argc==2 );

p0type = sqlite3_value_type(argv[0]);

p1 = sqlite3_value_int64(argv[1]);

if( p0type==SQLITE_BLOB ){

len = sqlite3_value_bytes(argv[0]);

z = sqlite3_value_blob(argv[0]);

if( z==0 ) return;

assert( len==sqlite3_value_bytes(argv[0]) );

}else{

z = sqlite3_value_text(argv[0]);

if( z==0 ) return;

len = 0;

if( p1<0 ){

for(z2=z; *z2; len++){

SQLITE_SKIP_UTF8(z2);

}

if( argc==3 ){

p2 = sqlite3_value_int64(argv[2]);

if( p2==0 && sqlite3_value_type(argv[2])==SQLITE_NULL ) return;

}else{

p2 = sqlite3_context_db_handle(context)->aLimit[SQLITE_LIMIT_LENGTH];

}

if( p1==0 ){

#ifdef SQLITE_SUBSTR_COMPATIBILITY

/* If SUBSTR_COMPATIBILITY is defined then substr(X,0,N) work the same as

** as substr(X,1,N) - it returns the first N characters of X. This

** is essentially a back-out of the bug-fix in check-in [5fc125d362df4b8]

** from 2009-02-02 for compatibility of applications that exploited the

** old buggy behavior. */

p1 = 1; /* <rdar://problem/6778339> */

#endif

if( sqlite3_value_type(argv[1])==SQLITE_NULL ) return;

}

if( p1<0 ){

p1 += len;

if( p1<0 ){

if( p2<0 ){

p2 = 0;

}else{

p2 += p1;

}

p1 = 0;

}

}else if( p1>0 ){

p1--;

}else if( p2>0 ){

p2--;

}

if( p2<0 ){

if( p2<-p1 ){

p2 = p1;

}else{

p2 = -p2;

}

p1 -= p2;

}

assert( p1>=0 && p2>=0 );

if( p0type!=SQLITE_BLOB ){

while( *z && p1 ){

SQLITE_SKIP_UTF8(z);

p1--;

}

for(z2=z; *z2 && p2; p2--){

SQLITE_SKIP_UTF8(z2);

}

sqlite3_result_text64(context, (char*)z, z2-z, SQLITE_TRANSIENT,

SQLITE_UTF8);

}else{

if( p1>=len ){

p1 = p2 = 0;

}else if( p2>len-p1 ){

p2 = len-p1;

assert( p2>0 );

}

sqlite3_result_blob64(context, (char*)&z[p1], (u64)p2, SQLITE_TRANSIENT);

}

** Implementation of the round() function

#ifndef SQLITE_OMIT_FLOATING_POINT

static void roundFunc(sqlite3_context *context, int argc, sqlite3_value **argv){

i64 n = 0;

double r;

char *zBuf;

assert( argc==1 || argc==2 );

if( argc==2 ){

if( SQLITE_NULL==sqlite3_value_type(argv[1]) ) return;

n = sqlite3_value_int64(argv[1]);

if( n>30 ) n = 30;

if( n<0 ) n = 0;

}

if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;

r = sqlite3_value_double(argv[0]);

/* If Y==0 and X will fit in a 64-bit int,

** handle the rounding directly,

** otherwise use printf.

if( r<-4503599627370496.0 || r>+4503599627370496.0 ){

/* The value has no fractional part so there is nothing to round */

}else if( n==0 ){

r = (double)((sqlite_int64)(r+(r<0?-0.5:+0.5)));

}else{

zBuf = sqlite3_mprintf("%!.*f",(int)n,r);

if( zBuf==0 ){

sqlite3_result_error_nomem(context);

return;

}

sqlite3AtoF(zBuf, &r);

sqlite3_free(zBuf);

}

sqlite3_result_double(context, r);

}

#endif

** Allocate nByte bytes of space using sqlite3Malloc(). If the

** allocation fails, call sqlite3_result_error_nomem() to notify

** the database handle that malloc() has failed and return NULL.

** If nByte is larger than the maximum string or blob length, then

** raise an SQLITE_TOOBIG exception and return NULL.

static void *contextMalloc(sqlite3_context *context, i64 nByte){

char *z;

sqlite3 *db = sqlite3_context_db_handle(context);

assert( nByte>0 );

testcase( nByte==db->aLimit[SQLITE_LIMIT_LENGTH] );

testcase( nByte==(i64)db->aLimit[SQLITE_LIMIT_LENGTH]+1 );

if( nByte>db->aLimit[SQLITE_LIMIT_LENGTH] ){

sqlite3_result_error_toobig(context);

z = 0;

}else{

z = sqlite3Malloc(nByte);

if( !z ){

sqlite3_result_error_nomem(context);

}

return z;

}

** Implementation of the upper() and lower() SQL functions.

static void upperFunc(sqlite3_context *context, int argc, sqlite3_value **argv){

char *z1;

const char *z2;

int i, n;

UNUSED_PARAMETER(argc);

z2 = (char*)sqlite3_value_text(argv[0]);

n = sqlite3_value_bytes(argv[0]);

/* Verify that the call to _bytes() does not invalidate the _text() pointer */

assert( z2==(char*)sqlite3_value_text(argv[0]) );

if( z2 ){

z1 = contextMalloc(context, ((i64)n)+1);

if( z1 ){

for(i=0; i<n; i++){

z1[i] = (char)sqlite3Toupper(z2[i]);

}

sqlite3_result_text(context, z1, n, sqlite3_free);

}

static void lowerFunc(sqlite3_context *context, int argc, sqlite3_value **argv){

char *z1;

const char *z2;

int i, n;

UNUSED_PARAMETER(argc);

z2 = (char*)sqlite3_value_text(argv[0]);

n = sqlite3_value_bytes(argv[0]);

/* Verify that the call to _bytes() does not invalidate the _text() pointer */

assert( z2==(char*)sqlite3_value_text(argv[0]) );

if( z2 ){

z1 = contextMalloc(context, ((i64)n)+1);

if( z1 ){

for(i=0; i<n; i++){

z1[i] = sqlite3Tolower(z2[i]);

}

sqlite3_result_text(context, z1, n, sqlite3_free);

}

** Some functions like COALESCE() and IFNULL() and UNLIKELY() are implemented

** as VDBE code so that unused argument values do not have to be computed.

** However, we still need some kind of function implementation for this

** routines in the function table. The noopFunc macro provides this.

** noopFunc will never be called so it doesn't matter what the implementation

** is. We might as well use the "version()" function as a substitute.

#define noopFunc versionFunc /* Substitute function - never called */

** Implementation of random(). Return a random integer.

static void randomFunc(

sqlite3_context *context,

int NotUsed,

sqlite3_value **NotUsed2

){

sqlite_int64 r;

UNUSED_PARAMETER2(NotUsed, NotUsed2);

sqlite3_randomness(sizeof(r), &r);

if( r<0 ){

/* We need to prevent a random number of 0x8000000000000000

** (or -9223372036854775808) since when you do abs() of that

** number of you get the same value back again. To do this

** in a way that is testable, mask the sign bit off of negative

** values, resulting in a positive value. Then take the

** 2s complement of that positive value. The end result can

** therefore be no less than -9223372036854775807.

r = -(r & LARGEST_INT64);

}

sqlite3_result_int64(context, r);

}

** Implementation of randomblob(N). Return a random blob

** that is N bytes long.

static void randomBlob(

sqlite3_context *context,

int argc,

sqlite3_value **argv

){

sqlite3_int64 n;

unsigned char *p;

assert( argc==1 );

UNUSED_PARAMETER(argc);

n = sqlite3_value_int64(argv[0]);

if( n<1 ){

n = 1;

}

p = contextMalloc(context, n);

if( p ){

sqlite3_randomness(n, p);

sqlite3_result_blob(context, (char*)p, n, sqlite3_free);

}

** Implementation of the last_insert_rowid() SQL function. The return

** value is the same as the sqlite3_last_insert_rowid() API function.

static void last_insert_rowid(

sqlite3_context *context,

int NotUsed,

sqlite3_value **NotUsed2

){

sqlite3 *db = sqlite3_context_db_handle(context);

UNUSED_PARAMETER2(NotUsed, NotUsed2);

/* IMP: R-51513-12026 The last_insert_rowid() SQL function is a

** wrapper around the sqlite3_last_insert_rowid() C/C++ interface

** function. */

sqlite3_result_int64(context, sqlite3_last_insert_rowid(db));

}

** Implementation of the changes() SQL function.

** IMP: R-32760-32347 The changes() SQL function is a wrapper

** around the sqlite3_changes64() C/C++ function and hence follows the

** same rules for counting changes.

static void changes(

sqlite3_context *context,

int NotUsed,

sqlite3_value **NotUsed2

){

sqlite3 *db = sqlite3_context_db_handle(context);

UNUSED_PARAMETER2(NotUsed, NotUsed2);

sqlite3_result_int64(context, sqlite3_changes64(db));

}

** Implementation of the total_changes() SQL function. The return value is

** the same as the sqlite3_total_changes64() API function.

static void total_changes(

sqlite3_context *context,

int NotUsed,

sqlite3_value **NotUsed2

){

sqlite3 *db = sqlite3_context_db_handle(context);

UNUSED_PARAMETER2(NotUsed, NotUsed2);

/* IMP: R-11217-42568 This function is a wrapper around the

** sqlite3_total_changes64() C/C++ interface. */

sqlite3_result_int64(context, sqlite3_total_changes64(db));

}

** A structure defining how to do GLOB-style comparisons.

struct compareInfo {

u8 matchAll; /* "*" or "%" */

u8 matchOne; /* "?" or "_" */

u8 matchSet; /* "[" or 0 */

u8 noCase; /* true to ignore case differences */

};

** For LIKE and GLOB matching on EBCDIC machines, assume that every

** character is exactly one byte in size. Also, provide the Utf8Read()

** macro for fast reading of the next character in the common case where

** the next character is ASCII.

#if defined(SQLITE_EBCDIC)

# define sqlite3Utf8Read(A) (*((*A)++))

# define Utf8Read(A) (*(A++))

#else

# define Utf8Read(A) (A[0]<0x80?*(A++):sqlite3Utf8Read(&A))

#endif

static const struct compareInfo globInfo = { '*', '?', '[', 0 };

/* The correct SQL-92 behavior is for the LIKE operator to ignore

** case. Thus 'a' LIKE 'A' would be true. */

static const struct compareInfo likeInfoNorm = { '%', '_', 0, 1 };

/* If SQLITE_CASE_SENSITIVE_LIKE is defined, then the LIKE operator

** is case sensitive causing 'a' LIKE 'A' to be false */

static const struct compareInfo likeInfoAlt = { '%', '_', 0, 0 };

** Possible error returns from patternMatch()

#define SQLITE_MATCH 0

#define SQLITE_NOMATCH 1

#define SQLITE_NOWILDCARDMATCH 2

** Compare two UTF-8 strings for equality where the first string is

** a GLOB or LIKE expression. Return values:

** SQLITE_MATCH: Match

** SQLITE_NOMATCH: No match

** SQLITE_NOWILDCARDMATCH: No match in spite of having * or % wildcards.

** Globbing rules:

** '*' Matches any sequence of zero or more characters.

** '?' Matches exactly one character.

** [...] Matches one character from the enclosed list of

** characters.

** [^...] Matches one character not in the enclosed list.

** With the [...] and [^...] matching, a ']' character can be included

** in the list by making it the first character after '[' or '^'. A

** range of characters can be specified using '-'. Example:

** "[a-z]" matches any single lower-case letter. To match a '-', make

** it the last character in the list.

** Like matching rules:

** '%' Matches any sequence of zero or more characters

*** '_' Matches any one character

** Ec Where E is the "esc" character and c is any other

** character, including '%', '_', and esc, match exactly c.

** The comments within this routine usually assume glob matching.

** This routine is usually quick, but can be N**2 in the worst case.

static int patternCompare(

const u8 *zPattern, /* The glob pattern */

const u8 *zString, /* The string to compare against the glob */

const struct compareInfo *pInfo, /* Information about how to do the compare */

u32 matchOther /* The escape char (LIKE) or '[' (GLOB) */

){

u32 c, c2; /* Next pattern and input string chars */

u32 matchOne = pInfo->matchOne; /* "?" or "_" */

u32 matchAll = pInfo->matchAll; /* "*" or "%" */

u8 noCase = pInfo->noCase; /* True if uppercase==lowercase */

const u8 *zEscaped = 0; /* One past the last escaped input char */

while( (c = Utf8Read(zPattern))!=0 ){

if( c==matchAll ){ /* Match "*" */

/* Skip over multiple "*" characters in the pattern. If there

** are also "?" characters, skip those as well, but consume a

** single character of the input string for each "?" skipped */

while( (c=Utf8Read(zPattern)) == matchAll

|| (c == matchOne && matchOne!=0) ){

if( c==matchOne && sqlite3Utf8Read(&zString)==0 ){

return SQLITE_NOWILDCARDMATCH;

}

if( c==0 ){

return SQLITE_MATCH; /* "*" at the end of the pattern matches */

}else if( c==matchOther ){

if( pInfo->matchSet==0 ){

c = sqlite3Utf8Read(&zPattern);

if( c==0 ) return SQLITE_NOWILDCARDMATCH;

}else{

/* "[...]" immediately follows the "*". We have to do a slow

** recursive search in this case, but it is an unusual case. */

assert( matchOther<0x80 ); /* '[' is a single-byte character */

while( *zString ){

int bMatch = patternCompare(&zPattern[-1],zString,pInfo,matchOther);

if( bMatch!=SQLITE_NOMATCH ) return bMatch;

SQLITE_SKIP_UTF8(zString);

}

return SQLITE_NOWILDCARDMATCH;

}

/* At this point variable c contains the first character of the

** pattern string past the "*". Search in the input string for the

** first matching character and recursively continue the match from

** that point.

** For a case-insensitive search, set variable cx to be the same as

** c but in the other case and search the input string for either

** c or cx.

if( c<0x80 ){

char zStop[3];

int bMatch;

if( noCase ){

zStop[0] = sqlite3Toupper(c);

zStop[1] = sqlite3Tolower(c);

zStop[2] = 0;

}else{

zStop[0] = c;

zStop[1] = 0;

}

while(1){

zString += strcspn((const char*)zString, zStop);

if( zString[0]==0 ) break;

zString++;

bMatch = patternCompare(zPattern,zString,pInfo,matchOther);

if( bMatch!=SQLITE_NOMATCH ) return bMatch;

}

}else{

int bMatch;

while( (c2 = Utf8Read(zString))!=0 ){

if( c2!=c ) continue;

bMatch = patternCompare(zPattern,zString,pInfo,matchOther);

if( bMatch!=SQLITE_NOMATCH ) return bMatch;

}

return SQLITE_NOWILDCARDMATCH;

}

if( c==matchOther ){

if( pInfo->matchSet==0 ){

c = sqlite3Utf8Read(&zPattern);

if( c==0 ) return SQLITE_NOMATCH;

zEscaped = zPattern;

}else{

u32 prior_c = 0;

int seen = 0;

int invert = 0;

c = sqlite3Utf8Read(&zString);

if( c==0 ) return SQLITE_NOMATCH;

c2 = sqlite3Utf8Read(&zPattern);

if( c2=='^' ){

invert = 1;

c2 = sqlite3Utf8Read(&zPattern);

}

if( c2==']' ){

if( c==']' ) seen = 1;

c2 = sqlite3Utf8Read(&zPattern);

}

while( c2 && c2!=']' ){

if( c2=='-' && zPattern[0]!=']' && zPattern[0]!=0 && prior_c>0 ){

c2 = sqlite3Utf8Read(&zPattern);

if( c>=prior_c && c<=c2 ) seen = 1;

prior_c = 0;

}else{

if( c==c2 ){

seen = 1;

}

prior_c = c2;

}

c2 = sqlite3Utf8Read(&zPattern);

}

if( c2==0 || (seen ^ invert)==0 ){

return SQLITE_NOMATCH;

}

continue;

}

c2 = Utf8Read(zString);

if( c==c2 ) continue;

if( noCase && sqlite3Tolower(c)==sqlite3Tolower(c2) && c<0x80 && c2<0x80 ){

continue;

}

if( c==matchOne && zPattern!=zEscaped && c2!=0 ) continue;

return SQLITE_NOMATCH;

}

return *zString==0 ? SQLITE_MATCH : SQLITE_NOMATCH;

}

** The sqlite3_strglob() interface. Return 0 on a match (like strcmp()) and

** non-zero if there is no match.

int sqlite3_strglob(const char *zGlobPattern, const char *zString){

if( zString==0 ){

return zGlobPattern!=0;

}else if( zGlobPattern==0 ){

return 1;

}else {

return patternCompare((u8*)zGlobPattern, (u8*)zString, &globInfo, '[');

}

** The sqlite3_strlike() interface. Return 0 on a match and non-zero for

** a miss - like strcmp().

int sqlite3_strlike(const char *zPattern, const char *zStr, unsigned int esc){

if( zStr==0 ){

return zPattern!=0;

}else if( zPattern==0 ){

return 1;

}else{

return patternCompare((u8*)zPattern, (u8*)zStr, &likeInfoNorm, esc);

}

** Count the number of times that the LIKE operator (or GLOB which is

** just a variation of LIKE) gets called. This is used for testing

** only.

#ifdef SQLITE_TEST

int sqlite3_like_count = 0;

#endif

** Implementation of the like() SQL function. This function implements

** the built-in LIKE operator. The first argument to the function is the

** pattern and the second argument is the string. So, the SQL statements:

** A LIKE B

** is implemented as like(B,A).

** This same function (with a different compareInfo structure) computes

** the GLOB operator.

static void likeFunc(

sqlite3_context *context,

int argc,

sqlite3_value **argv

){

const unsigned char *zA, *zB;

u32 escape;

int nPat;

sqlite3 *db = sqlite3_context_db_handle(context);

struct compareInfo *pInfo = sqlite3_user_data(context);

struct compareInfo backupInfo;

#ifdef SQLITE_LIKE_DOESNT_MATCH_BLOBS

if( sqlite3_value_type(argv[0])==SQLITE_BLOB

|| sqlite3_value_type(argv[1])==SQLITE_BLOB

){

#ifdef SQLITE_TEST

sqlite3_like_count++;

#endif

sqlite3_result_int(context, 0);

return;

}

#endif

/* Limit the length of the LIKE or GLOB pattern to avoid problems

** of deep recursion and N*N behavior in patternCompare().

nPat = sqlite3_value_bytes(argv[0]);

testcase( nPat==db->aLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH] );

testcase( nPat==db->aLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]+1 );

if( nPat > db->aLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH] ){

sqlite3_result_error(context, "LIKE or GLOB pattern too complex", -1);

return;

}

if( argc==3 ){

/* The escape character string must consist of a single UTF-8 character.

** Otherwise, return an error.

const unsigned char *zEsc = sqlite3_value_text(argv[2]);

if( zEsc==0 ) return;

if( sqlite3Utf8CharLen((char*)zEsc, -1)!=1 ){

sqlite3_result_error(context,

"ESCAPE expression must be a single character", -1);

return;

}

escape = sqlite3Utf8Read(&zEsc);

if( escape==pInfo->matchAll || escape==pInfo->matchOne ){

memcpy(&backupInfo, pInfo, sizeof(backupInfo));

pInfo = &backupInfo;

if( escape==pInfo->matchAll ) pInfo->matchAll = 0;

if( escape==pInfo->matchOne ) pInfo->matchOne = 0;

}

}else{

escape = pInfo->matchSet;

}

zB = sqlite3_value_text(argv[0]);

zA = sqlite3_value_text(argv[1]);

if( zA && zB ){

#ifdef SQLITE_TEST

sqlite3_like_count++;

#endif

sqlite3_result_int(context,

patternCompare(zB, zA, pInfo, escape)==SQLITE_MATCH);

}

** Implementation of the NULLIF(x,y) function. The result is the first

** argument if the arguments are different. The result is NULL if the

** arguments are equal to each other.

static void nullifFunc(

sqlite3_context *context,

int NotUsed,

sqlite3_value **argv

){

CollSeq *pColl = sqlite3GetFuncCollSeq(context);

UNUSED_PARAMETER(NotUsed);

if( sqlite3MemCompare(argv[0], argv[1], pColl)!=0 ){

sqlite3_result_value(context, argv[0]);

}

** Implementation of the sqlite_version() function. The result is the version

View remainder of file in raw view

sqlcipher/src/func.c at sqlite-release · sqlcipher/sqlcipher · GitHub

Uh oh!

Expand file tree

Breadcrumbs

func.c

Latest commit

History

Breadcrumbs

func.c

File metadata and controls