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3473 lines (3324 loc) · 106 KB
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3473 lines (3324 loc) · 106 KB
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/*
** 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;
if( z==0 ) return;
z0 = z;
while( 1 /*exit-by-break*/ ){
/* vvvvvv---- See tag-20260418-01 */
if( (u8)(z[0]-1)<(0x80-1) ){
z++;
}else if( z[0]==0 ){
break;
}else{
z++;
while( (z[0]&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);
n = str.nChar;
sqlite3_result_text(context, sqlite3StrAccumFinish(&str), n,
SQLITE_DYNAMIC);
}
}
/*
** 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 ){
for( ; p1>0; p1--){
/* vvvvvv---- See tag-20260418-01 */
if( (u8)(z[0]-1)<(0x80-1) ){
z++;
}else if( z[0]==0 ){
break;
}else{
do{ z++; }while( (z[0]&0xc0)==0x80 );
}
}
for(z2=z; p2>0; p2--){
/* vvvvvv---- See tag-20260418-01 */
if( (u8)(z2[0]-1)<(0x80-1) ){
z2++;
}else if( z2[0]==0 ){
break;
}else{
do{ z2++; }while( (z2[0]&0xc0)==0x80 );
}
}
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);
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