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f46188911d103c4a1f0e9f182783c5f1ec39294b
sqlite/src/func.c
danielk1977 f46188911d More coverage testing. (CVS 1754) 
FossilOrigin-Name: 332921041040b343b6b568685ff55d21a624f502
2004-06-28 13:09:11 +00:00

1120 lines
32 KiB
C
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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 functions that implement various SQL
** functions of SQLite.
**
** There is only one exported symbol in this file - the function
** sqliteRegisterBuildinFunctions() found at the bottom of the file.
** All other code has file scope.
**
** $Id: func.c,v 1.77 2004/06/28 13:09:11 danielk1977 Exp $
*/
#include <ctype.h>
#include <math.h>
#include <stdlib.h>
#include <assert.h>
#include "sqliteInt.h"
#include "vdbeInt.h"
#include "os.h"
static CollSeq *sqlite3GetFuncCollSeq(sqlite3_context *context){
return context->pColl;
}
/*
** 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;
if( argc==0 ) return;
mask = (int)sqlite3_user_data(context);
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 ){
iBest = i;
}
}
sqlite3_result_value(context, argv[iBest]);
}
/*
** Return the type of the argument.
*/
static void typeofFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
const char *z = 0;
switch( sqlite3_value_type(argv[0]) ){
case SQLITE_NULL: z = "null"; break;
case SQLITE_INTEGER: z = "integer"; break;
case SQLITE_TEXT: z = "text"; break;
case SQLITE_FLOAT: z = "real"; break;
case SQLITE_BLOB: z = "blob"; break;
}
sqlite3_result_text(context, z, -1, SQLITE_STATIC);
}
/*
** Implementation of the length() function
*/
static void lengthFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
int len;
assert( argc==1 );
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 char *z = sqlite3_value_text(argv[0]);
for(len=0; *z; z++){ if( (0xc0&*z)!=0x80 ) len++; }
sqlite3_result_int(context, len);
break;
}
default: {
sqlite3_result_null(context);
break;
}
}
}
/*
** Implementation of the abs() function
*/
static void absFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
assert( argc==1 );
switch( sqlite3_value_type(argv[0]) ){
case SQLITE_INTEGER: {
i64 iVal = sqlite3_value_int64(argv[0]);
if( iVal<0 ) iVal = iVal * -1;
sqlite3_result_int64(context, iVal);
break;
}
case SQLITE_NULL: {
sqlite3_result_null(context);
break;
}
default: {
double rVal = sqlite3_value_double(argv[0]);
if( rVal<0 ) rVal = rVal * -1.0;
sqlite3_result_double(context, rVal);
break;
}
}
}
/*
** Implementation of the substr() function
*/
static void substrFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
const char *z;
const char *z2;
int i;
int p1, p2, len;
assert( argc==3 );
z = sqlite3_value_text(argv[0]);
if( z==0 ) return;
p1 = sqlite3_value_int(argv[1]);
p2 = sqlite3_value_int(argv[2]);
for(len=0, z2=z; *z2; z2++){ if( (0xc0&*z2)!=0x80 ) len++; }
if( p1<0 ){
p1 += len;
if( p1<0 ){
p2 += p1;
p1 = 0;
}
}else if( p1>0 ){
p1--;
}
if( p1+p2>len ){
p2 = len-p1;
}
for(i=0; i<p1 && z[i]; i++){
if( (z[i]&0xc0)==0x80 ) p1++;
}
while( z[i] && (z[i]&0xc0)==0x80 ){ i++; p1++; }
for(; i<p1+p2 && z[i]; i++){
if( (z[i]&0xc0)==0x80 ) p2++;
}
while( z[i] && (z[i]&0xc0)==0x80 ){ i++; p2++; }
if( p2<0 ) p2 = 0;
sqlite3_result_text(context, &z[p1], p2, SQLITE_TRANSIENT);
}
/*
** Implementation of the round() function
*/
static void roundFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
int n = 0;
double r;
char zBuf[100];
assert( argc==1 || argc==2 );
if( argc==2 ){
if( SQLITE_NULL==sqlite3_value_type(argv[1]) ) return;
n = sqlite3_value_int(argv[1]);
if( n>30 ) n = 30;
if( n<0 ) n = 0;
}
if( SQLITE_NULL==sqlite3_value_type(argv[0]) ) return;
r = sqlite3_value_double(argv[0]);
sprintf(zBuf,"%.*f",n,r);
sqlite3_result_text(context, zBuf, -1, SQLITE_TRANSIENT);
}
/*
** Implementation of the upper() and lower() SQL functions.
*/
static void upperFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
char *z;
int i;
if( argc<1 || SQLITE_NULL==sqlite3_value_type(argv[0]) ) return;
z = sqliteMalloc(sqlite3_value_bytes(argv[0])+1);
if( z==0 ) return;
strcpy(z, sqlite3_value_text(argv[0]));
for(i=0; z[i]; i++){
if( islower(z[i]) ) z[i] = toupper(z[i]);
}
sqlite3_result_text(context, z, -1, SQLITE_TRANSIENT);
sqliteFree(z);
}
static void lowerFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
char *z;
int i;
if( argc<1 || SQLITE_NULL==sqlite3_value_type(argv[0]) ) return;
z = sqliteMalloc(sqlite3_value_bytes(argv[0])+1);
if( z==0 ) return;
strcpy(z, sqlite3_value_text(argv[0]));
for(i=0; z[i]; i++){
if( isupper(z[i]) ) z[i] = tolower(z[i]);
}
sqlite3_result_text(context, z, -1, SQLITE_TRANSIENT);
sqliteFree(z);
}
/*
** Implementation of the IFNULL(), NVL(), and COALESCE() functions.
** All three do the same thing. They return the first non-NULL
** argument.
*/
static void ifnullFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
int i;
for(i=0; i<argc; i++){
if( SQLITE_NULL!=sqlite3_value_type(argv[i]) ){
sqlite3_result_value(context, argv[i]);
break;
}
}
}
/*
** Implementation of random(). Return a random integer.
*/
static void randomFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
int r;
sqlite3Randomness(sizeof(r), &r);
sqlite3_result_int(context, r);
}
/*
** 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 arg,
sqlite3_value **argv
){
sqlite *db = sqlite3_user_data(context);
sqlite3_result_int64(context, sqlite3_last_insert_rowid(db));
}
/*
** Implementation of the changes() SQL function. The return value is the
** same as the sqlite3_changes() API function.
*/
static void changes(
sqlite3_context *context,
int arg,
sqlite3_value **argv
){
sqlite *db = sqlite3_user_data(context);
sqlite3_result_int(context, sqlite3_changes(db));
}
/*
** Implementation of the total_changes() SQL function. The return value is
** the same as the sqlite3_total_changes() API function.
*/
static void total_changes(
sqlite3_context *context,
int arg,
sqlite3_value **argv
){
sqlite *db = sqlite3_user_data(context);
sqlite3_result_int(context, sqlite3_total_changes(db));
}
#if 0
/*
** A LIKE pattern compiles to an instance of the following structure. Refer
** to the comment for compileLike() function for details.
*/
struct LikePattern {
int nState;
struct LikeState {
int val; /* Unicode codepoint or -1 for any char i.e. '_' */
int failstate; /* State to jump to if next char is not val */
} aState[1];
};
typedef struct LikePattern LikePattern;
void deleteLike(void *pLike){
sqliteFree(pLike);
}
/* #define TRACE_LIKE */
#if defined(TRACE_LIKE) && !defined(NDEBUG)
char *dumpLike(LikePattern *pLike){
int i;
int k = 0;
char *zBuf = (char *)sqliteMalloc(pLike->nState*40);
k += sprintf(&zBuf[k], "%d states - ", pLike->nState);
for(i=0; i<pLike->nState; i++){
k += sprintf(&zBuf[k], " %d:(%d, %d)", i, pLike->aState[i].val,
pLike->aState[i].failstate);
}
return zBuf;
}
#endif
/*
** This function compiles an SQL 'LIKE' pattern into a state machine,
** represented by a LikePattern structure.
**
** Each state of the state-machine has two attributes, 'val' and
** 'failstate'. The val attribute is either the value of a unicode
** codepoint, or -1, indicating a '_' wildcard (match any single
** character). The failstate is either the number of another state
** or -1, indicating jump to 'no match'.
**
** To see if a string matches a pattern the pattern is
** compiled to a state machine that is executed according to the algorithm
** below. The string is assumed to be terminated by a 'NUL' character
** (unicode codepoint 0).
**
** 1 S = 0
** 2 DO
** 3 C = <Next character from input string>
** 4 IF( C matches <State S val> )
** 5 S = S+1
** 6 ELSE IF( S != <State S failstate> )
** 7 S = <State S failstate>
** 8 <Rewind Input string 1 character>
** 9 WHILE( (C != NUL) AND (S != FAILED) )
** 10
** 11 IF( S == <number of states> )
** 12 RETURN MATCH
** 13 ELSE
** 14 RETURN NO-MATCH
**
** In practice there is a small optimization to avoid the <Rewind>
** operation in line 8 of the description above.
**
** For example, the following pattern, 'X%ABabc%_Y' is compiled to
** the state machine below.
**
** State Val FailState
** -------------------------------
** 0 120 (x) -1 (NO MATCH)
** 1 97 (a) 1
** 2 98 (b) 1
** 3 97 (a) 1
** 4 98 (b) 2
** 5 99 (c) 3
** 6 -1 (_) 6
** 7 121 (y) 7
** 8 0 (NUL) 7
**
** The algorithms implemented to compile and execute the state machine were
** first presented in "Fast pattern matching in strings", Knuth, Morris and
** Pratt, 1977.
**
*/
LikePattern *compileLike(sqlite3_value *pPattern, u8 enc){
LikePattern *pLike;
struct LikeState *aState;
int pc_state = -1; /* State number of previous '%' wild card */
int n = 0;
int c;
int offset = 0;
const char *zLike;
if( enc==SQLITE_UTF8 ){
zLike = sqlite3_value_text(pPattern);
n = sqlite3_value_bytes(pPattern) + 1;
}else{
zLike = sqlite3_value_text16(pPattern);
n = sqlite3_value_bytes16(pPattern)/2 + 1;
}
pLike = (LikePattern *)
sqliteMalloc(sizeof(LikePattern)+n*sizeof(struct LikeState));
aState = pLike->aState;
n = 0;
do {
c = sqlite3ReadUniChar(zLike, &offset, &enc, 1);
if( c==95 ){ /* A '_' wildcard */
aState[n].val = -1;
n++;
}else if( c==37 ){ /* A '%' wildcard */
aState[n].failstate = n;
pc_state = n;
}else{ /* A regular character */
aState[n].val = c;
assert( pc_state<=n );
if( pc_state<0 ){
aState[n].failstate = -1;
}else if( pc_state==n ){
if( c ){
aState[n].failstate = pc_state;
}else{
aState[n].failstate = -2;
}
}else{
int k = pLike->aState[n-1].failstate;
while( k>pc_state && aState[k+1].val!=-1 && aState[k+1].val!=c ){
k = aState[k].failstate;
}
if( k!=pc_state && aState[k+1].val==c ){
assert( k==pc_state );
k++;
}
aState[n].failstate = k;
}
n++;
}
}while( c );
pLike->nState = n;
#if defined(TRACE_LIKE) && !defined(NDEBUG)
{
char *zCompiled = dumpLike(pLike);
printf("Pattern=\"%s\" Compiled=\"%s\"\n", zPattern, zCompiled);
sqliteFree(zCompiled);
}
#endif
return pLike;
}
/*
** Implementation of the like() SQL function. This function implements
** the build-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).
**
** If the pointer retrieved by via a call to sqlite3_user_data() is
** not NULL, then this function uses UTF-16. Otherwise UTF-8.
*/
static void likeFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
register int c;
u8 enc;
int offset = 0;
const unsigned char *zString;
LikePattern *pLike = sqlite3_get_auxdata(context, 0);
struct LikeState *aState;
register struct LikeState *pState;
/* If either argument is NULL, the result is NULL */
if( sqlite3_value_type(argv[1])==SQLITE_NULL ||
sqlite3_value_type(argv[0])==SQLITE_NULL ){
return;
}
/* If the user-data pointer is NULL, use UTF-8. Otherwise UTF-16. */
if( sqlite3_user_data(context) ){
enc = SQLITE_UTF16NATIVE;
zString = (const unsigned char *)sqlite3_value_text16(argv[1]);
assert(0);
}else{
enc = SQLITE_UTF8;
zString = sqlite3_value_text(argv[1]);
}
/* If the LIKE pattern has not been compiled, compile it now. */
if( !pLike ){
pLike = compileLike(argv[0], enc);
if( !pLike ){
sqlite3_result_error(context, "out of memory", -1);
return;
}
sqlite3_set_auxdata(context, 0, pLike, deleteLike);
}
aState = pLike->aState;
pState = aState;
do {
if( enc==SQLITE_UTF8 ){
c = zString[offset++];
if( c&0x80 ){
offset--;
c = sqlite3ReadUniChar(zString, &offset, &enc, 1);
}
}else{
c = sqlite3ReadUniChar(zString, &offset, &enc, 1);
}
skip_read:
#if defined(TRACE_LIKE) && !defined(NDEBUG)
printf("State=%d:(%d, %d) Input=%d\n",
(aState - pState), pState->val, pState->failstate, c);
#endif
if( pState->val==-1 || pState->val==c ){
pState++;
}else{
struct LikeState *pFailState = &aState[pState->failstate];
if( pState!=pFailState ){
pState = pFailState;
if( c && pState>=aState ) goto skip_read;
}
}
}while( c && pState>=aState );
if( (pState-aState)==pLike->nState || (pState-aState)<-1 ){
sqlite3_result_int(context, 1);
}else{
sqlite3_result_int(context, 0);
}
}
#endif
/*
** Implementation of the like() SQL function. This function implements
** the build-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).
**
** If the pointer retrieved by via a call to sqlite3_user_data() is
** not NULL, then this function uses UTF-16. Otherwise UTF-8.
*/
static void likeFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
const unsigned char *zA = sqlite3_value_text(argv[0]);
const unsigned char *zB = sqlite3_value_text(argv[1]);
if( zA && zB ){
sqlite3_result_int(context, sqlite3utf8LikeCompare(zA, zB));
}
}
/*
** Implementation of the glob() SQL function. This function implements
** the build-in GLOB operator. The first argument to the function is the
** string and the second argument is the pattern. So, the SQL statements:
**
** A GLOB B
**
** is implemented as glob(A,B).
*/
static void globFunc(sqlite3_context *context, int arg, sqlite3_value **argv){
const unsigned char *zA = sqlite3_value_text(argv[0]);
const unsigned char *zB = sqlite3_value_text(argv[1]);
if( zA && zB ){
sqlite3_result_int(context, sqlite3GlobCompare(zA, zB));
}
}
/*
** 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 argc,
sqlite3_value **argv
){
CollSeq *pColl = sqlite3GetFuncCollSeq(context);
if( sqlite3MemCompare(argv[0], argv[1], pColl)!=0 ){
sqlite3_result_value(context, argv[0]);
}
}
/*
** Implementation of the VERSION(*) function. The result is the version
** of the SQLite library that is running.
*/
static void versionFunc(
sqlite3_context *context,
int argc,
sqlite3_value **argv
){
sqlite3_result_text(context, sqlite3_version, -1, SQLITE_STATIC);
}
/*
** EXPERIMENTAL - This is not an official function. The interface may
** change. This function may disappear. Do not write code that depends
** on this function.
**
** Implementation of the QUOTE() function. This function takes a single
** argument. If the argument is numeric, the return value is the same as
** the argument. If the argument is NULL, the return value is the string
** "NULL". Otherwise, the argument is enclosed in single quotes with
** single-quote escapes.
*/
static void quoteFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
if( argc<1 ) return;
switch( sqlite3_value_type(argv[0]) ){
case SQLITE_NULL: {
sqlite3_result_text(context, "NULL", 4, SQLITE_STATIC);
break;
}
case SQLITE_INTEGER:
case SQLITE_FLOAT: {
sqlite3_result_value(context, argv[0]);
break;
}
case SQLITE_BLOB: {
static const char hexdigits[] = {
'0', '1', '2', '3', '4', '5', '6', '7',
'8', '9', 'A', 'B', 'C', 'D', 'E', 'F'
};
char *zText = 0;
int nBlob = sqlite3_value_bytes(argv[0]);
char const *zBlob = sqlite3_value_blob(argv[0]);
zText = (char *)sqliteMalloc((2*nBlob)+4);
if( !zText ){
sqlite3_result_error(context, "out of memory", -1);
}else{
int i;
for(i=0; i<nBlob; i++){
zText[(i*2)+2] = hexdigits[(zBlob[i]>>4)&0x0F];
zText[(i*2)+3] = hexdigits[(zBlob[i])&0x0F];
}
zText[(nBlob*2)+2] = '\'';
zText[(nBlob*2)+3] = '\0';
zText[0] = 'X';
zText[1] = '\'';
sqlite3_result_text(context, zText, -1, SQLITE_TRANSIENT);
sqliteFree(zText);
}
break;
}
case SQLITE_TEXT: {
int i,j,n;
const char *zArg = sqlite3_value_text(argv[0]);
char *z;
for(i=n=0; zArg[i]; i++){ if( zArg[i]=='\'' ) n++; }
z = sqliteMalloc( i+n+3 );
if( z==0 ) return;
z[0] = '\'';
for(i=0, j=1; zArg[i]; i++){
z[j++] = zArg[i];
if( zArg[i]=='\'' ){
z[j++] = '\'';
}
}
z[j++] = '\'';
z[j] = 0;
sqlite3_result_text(context, z, j, SQLITE_TRANSIENT);
sqliteFree(z);
}
}
}
#ifdef SQLITE_SOUNDEX
/*
** Compute the soundex encoding of a word.
*/
static void soundexFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
char zResult[8];
const char *zIn;
int i, j;
static const unsigned char iCode[] = {
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 1, 2, 3, 0, 1, 2, 0, 0, 2, 2, 4, 5, 5, 0,
1, 2, 6, 2, 3, 0, 1, 0, 2, 0, 2, 0, 0, 0, 0, 0,
0, 0, 1, 2, 3, 0, 1, 2, 0, 0, 2, 2, 4, 5, 5, 0,
1, 2, 6, 2, 3, 0, 1, 0, 2, 0, 2, 0, 0, 0, 0, 0,
};
assert( argc==1 );
zIn = sqlite3_value_text(argv[0]);
for(i=0; zIn[i] && !isalpha(zIn[i]); i++){}
if( zIn[i] ){
zResult[0] = toupper(zIn[i]);
for(j=1; j<4 && zIn[i]; i++){
int code = iCode[zIn[i]&0x7f];
if( code>0 ){
zResult[j++] = code + '0';
}
}
while( j<4 ){
zResult[j++] = '0';
}
zResult[j] = 0;
sqlite3_result_text(context, zResult, 4, SQLITE_TRANSIENT);
}else{
sqlite3_result_text(context, "?000", 4, SQLITE_STATIC);
}
}
#endif
#ifdef SQLITE_TEST
/*
** This function generates a string of random characters. Used for
** generating test data.
*/
static void randStr(sqlite3_context *context, int argc, sqlite3_value **argv){
static const unsigned char zSrc[] =
"abcdefghijklmnopqrstuvwxyz"
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"0123456789"
".-!,:*^+=_|?/<> ";
int iMin, iMax, n, r, i;
unsigned char zBuf[1000];
if( argc>=1 ){
iMin = sqlite3_value_int(argv[0]);
if( iMin<0 ) iMin = 0;
if( iMin>=sizeof(zBuf) ) iMin = sizeof(zBuf)-1;
}else{
iMin = 1;
}
if( argc>=2 ){
iMax = sqlite3_value_int(argv[1]);
if( iMax<iMin ) iMax = iMin;
if( iMax>=sizeof(zBuf) ) iMax = sizeof(zBuf)-1;
}else{
iMax = 50;
}
n = iMin;
if( iMax>iMin ){
sqlite3Randomness(sizeof(r), &r);
r &= 0x7fffffff;
n += r%(iMax + 1 - iMin);
}
assert( n<sizeof(zBuf) );
sqlite3Randomness(n, zBuf);
for(i=0; i<n; i++){
zBuf[i] = zSrc[zBuf[i]%(sizeof(zSrc)-1)];
}
zBuf[n] = 0;
sqlite3_result_text(context, zBuf, n, SQLITE_TRANSIENT);
}
#endif /* SQLITE_TEST */
#ifdef SQLITE_TEST
/*
** The following two SQL functions are used to test returning a text
** result with a destructor. Function 'test_destructor' takes one argument
** and returns the same argument interpreted as TEXT. A destructor is
** passed with the sqlite3_result_text() call.
**
** SQL function 'test_destructor_count' returns the number of outstanding
** allocations made by 'test_destructor';
**
** WARNING: Not threadsafe.
*/
static int test_destructor_count_var = 0;
static void destructor(void *p){
char *zVal = (char *)p;
assert(zVal);
zVal--;
sqliteFree(zVal);
test_destructor_count_var--;
}
static void test_destructor(
sqlite3_context *pCtx,
int nArg,
sqlite3_value **argv
){
char *zVal;
int len;
sqlite *db = sqlite3_user_data(pCtx);
test_destructor_count_var++;
assert( nArg==1 );
if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
len = sqlite3ValueBytes(argv[0], db->enc);
zVal = sqliteMalloc(len+3);
zVal[len] = 0;
zVal[len-1] = 0;
assert( zVal );
zVal++;
memcpy(zVal, sqlite3ValueText(argv[0], db->enc), len);
if( db->enc==SQLITE_UTF8 ){
sqlite3_result_text(pCtx, zVal, -1, destructor);
}else if( db->enc==SQLITE_UTF16LE ){
sqlite3_result_text16le(pCtx, zVal, -1, destructor);
}else{
sqlite3_result_text16be(pCtx, zVal, -1, destructor);
}
}
static void test_destructor_count(
sqlite3_context *pCtx,
int nArg,
sqlite3_value **argv
){
sqlite3_result_int(pCtx, test_destructor_count_var);
}
#endif /* SQLITE_TEST */
#ifdef SQLITE_TEST
/*
** Routines for testing the sqlite3_get_auxdata() and sqlite3_set_auxdata()
** interface.
**
** The test_auxdata() SQL function attempts to register each of its arguments
** as auxiliary data. If there are no prior registrations of aux data for
** that argument (meaning the argument is not a constant or this is its first
** call) then the result for that argument is 0. If there is a prior
** registration, the result for that argument is 1. The overall result
** is the individual argument results separated by spaces.
*/
static void free_test_auxdata(void *p) {sqliteFree(p);}
static void test_auxdata(
sqlite3_context *pCtx,
int nArg,
sqlite3_value **argv
){
int i;
char *zRet = sqliteMalloc(nArg*2);
if( !zRet ) return;
for(i=0; i<nArg; i++){
char const *z = sqlite3_value_text(argv[i]);
if( z ){
char *zAux = sqlite3_get_auxdata(pCtx, i);
if( zAux ){
zRet[i*2] = '1';
if( strcmp(zAux, z) ){
sqlite3_result_error(pCtx, "Auxilary data corruption", -1);
return;
}
}else{
zRet[i*2] = '0';
zAux = sqliteStrDup(z);
sqlite3_set_auxdata(pCtx, i, zAux, free_test_auxdata);
}
zRet[i*2+1] = ' ';
}
}
sqlite3_result_text(pCtx, zRet, 2*nArg-1, free_test_auxdata);
}
#endif /* SQLITE_TEST */
/*
** An instance of the following structure holds the context of a
** sum() or avg() aggregate computation.
*/
typedef struct SumCtx SumCtx;
struct SumCtx {
double sum; /* Sum of terms */
int cnt; /* Number of elements summed */
};
/*
** Routines used to compute the sum or average.
*/
static void sumStep(sqlite3_context *context, int argc, sqlite3_value **argv){
SumCtx *p;
if( argc<1 ) return;
p = sqlite3_aggregate_context(context, sizeof(*p));
if( p && SQLITE_NULL!=sqlite3_value_type(argv[0]) ){
p->sum += sqlite3_value_double(argv[0]);
p->cnt++;
}
}
static void sumFinalize(sqlite3_context *context){
SumCtx *p;
p = sqlite3_aggregate_context(context, sizeof(*p));
sqlite3_result_double(context, p ? p->sum : 0.0);
}
static void avgFinalize(sqlite3_context *context){
SumCtx *p;
p = sqlite3_aggregate_context(context, sizeof(*p));
if( p && p->cnt>0 ){
sqlite3_result_double(context, p->sum/(double)p->cnt);
}
}
/*
** An instance of the following structure holds the context of a
** variance or standard deviation computation.
*/
typedef struct StdDevCtx StdDevCtx;
struct StdDevCtx {
double sum; /* Sum of terms */
double sum2; /* Sum of the squares of terms */
int cnt; /* Number of terms counted */
};
#if 0 /* Omit because math library is required */
/*
** Routines used to compute the standard deviation as an aggregate.
*/
static void stdDevStep(sqlite3_context *context, int argc, const char **argv){
StdDevCtx *p;
double x;
if( argc<1 ) return;
p = sqlite3_aggregate_context(context, sizeof(*p));
if( p && argv[0] ){
x = sqlite3AtoF(argv[0], 0);
p->sum += x;
p->sum2 += x*x;
p->cnt++;
}
}
static void stdDevFinalize(sqlite3_context *context){
double rN = sqlite3_aggregate_count(context);
StdDevCtx *p = sqlite3_aggregate_context(context, sizeof(*p));
if( p && p->cnt>1 ){
double rCnt = cnt;
sqlite3_set_result_double(context,
sqrt((p->sum2 - p->sum*p->sum/rCnt)/(rCnt-1.0)));
}
}
#endif
/*
** The following structure keeps track of state information for the
** count() aggregate function.
*/
typedef struct CountCtx CountCtx;
struct CountCtx {
int n;
};
/*
** Routines to implement the count() aggregate function.
*/
static void countStep(sqlite3_context *context, int argc, sqlite3_value **argv){
CountCtx *p;
p = sqlite3_aggregate_context(context, sizeof(*p));
if( (argc==0 || SQLITE_NULL!=sqlite3_value_type(argv[0])) && p ){
p->n++;
}
}
static void countFinalize(sqlite3_context *context){
CountCtx *p;
p = sqlite3_aggregate_context(context, sizeof(*p));
sqlite3_result_int(context, p ? p->n : 0);
}
/*
** This function tracks state information for the min() and max()
** aggregate functions.
*/
typedef struct MinMaxCtx MinMaxCtx;
struct MinMaxCtx {
char *z; /* The best so far */
char zBuf[28]; /* Space that can be used for storage */
};
/*
** Routines to implement min() and max() aggregate functions.
*/
static void minmaxStep(sqlite3_context *context, int argc, sqlite3_value **argv){
int max = 0;
int cmp = 0;
Mem *pArg = (Mem *)argv[0];
Mem *pBest = (Mem *)sqlite3_aggregate_context(context, sizeof(*pBest));
if( !pBest ) return;
if( pBest->flags ){
CollSeq *pColl = sqlite3GetFuncCollSeq(context);
/* This step function is used for both the min() and max() aggregates,
** the only difference between the two being that the sense of the
** comparison is inverted. For the max() aggregate, the
** sqlite3_user_data() function returns (void *)-1. For min() it
** returns (void *)db, where db is the sqlite3* database pointer.
** Therefore the next statement sets variable 'max' to 1 for the max()
** aggregate, or 0 for min().
*/
max = ((sqlite3_user_data(context)==(void *)-1)?1:0);
cmp = sqlite3MemCompare(pBest, pArg, pColl);
if( (max && cmp<0) || (!max && cmp>0) ){
sqlite3VdbeMemCopy(pBest, pArg);
}
}else{
sqlite3VdbeMemCopy(pBest, pArg);
}
}
static void minMaxFinalize(sqlite3_context *context){
sqlite3_value *pRes;
pRes = (sqlite3_value *)sqlite3_aggregate_context(context, sizeof(Mem));
if( pRes->flags ){
sqlite3_result_value(context, pRes);
}
sqlite3VdbeMemRelease(pRes);
}
/*
** This function registered all of the above C functions as SQL
** functions. This should be the only routine in this file with
** external linkage.
*/
void sqlite3RegisterBuiltinFunctions(sqlite *db){
static struct {
char *zName;
signed char nArg;
u8 argType; /* 0: none. 1: db 2: (-1) */
u8 eTextRep; /* 1: UTF-16. 0: UTF-8 */
u8 needCollSeq;
void (*xFunc)(sqlite3_context*,int,sqlite3_value **);
} aFuncs[] = {
{ "min", -1, 0, SQLITE_UTF8, 1, minmaxFunc },
{ "min", 0, 0, SQLITE_UTF8, 1, 0 },
{ "max", -1, 2, SQLITE_UTF8, 1, minmaxFunc },
{ "max", 0, 2, SQLITE_UTF8, 1, 0 },
{ "typeof", 1, 0, SQLITE_UTF8, 0, typeofFunc },
{ "length", 1, 0, SQLITE_UTF8, 0, lengthFunc },
{ "substr", 3, 0, SQLITE_UTF8, 0, substrFunc },
{ "substr", 3, 0, SQLITE_UTF16LE, 0, sqlite3utf16Substr },
{ "abs", 1, 0, SQLITE_UTF8, 0, absFunc },
{ "round", 1, 0, SQLITE_UTF8, 0, roundFunc },
{ "round", 2, 0, SQLITE_UTF8, 0, roundFunc },
{ "upper", 1, 0, SQLITE_UTF8, 0, upperFunc },
{ "lower", 1, 0, SQLITE_UTF8, 0, lowerFunc },
{ "coalesce", -1, 0, SQLITE_UTF8, 0, ifnullFunc },
{ "coalesce", 0, 0, SQLITE_UTF8, 0, 0 },
{ "coalesce", 1, 0, SQLITE_UTF8, 0, 0 },
{ "ifnull", 2, 0, SQLITE_UTF8, 1, ifnullFunc },
{ "random", -1, 0, SQLITE_UTF8, 0, randomFunc },
{ "like", 2, 0, SQLITE_UTF8, 0, likeFunc },
{ "glob", 2, 0, SQLITE_UTF8, 0, globFunc },
{ "nullif", 2, 0, SQLITE_UTF8, 0, nullifFunc },
{ "sqlite_version", 0, 0, SQLITE_UTF8, 0, versionFunc},
{ "quote", 1, 0, SQLITE_UTF8, 0, quoteFunc },
{ "last_insert_rowid", 0, 1, SQLITE_UTF8, 0, last_insert_rowid },
{ "changes", 0, 1, SQLITE_UTF8, 0, changes },
{ "total_changes", 0, 1, SQLITE_UTF8, 0, total_changes },
#ifdef SQLITE_SOUNDEX
{ "soundex", 1, 0, SQLITE_UTF8, 0, soundexFunc},
#endif
#ifdef SQLITE_TEST
{ "randstr", 2, 0, SQLITE_UTF8, 0, randStr },
{ "test_destructor", 1, 1, SQLITE_UTF8, 0, test_destructor},
{ "test_destructor_count", 0, 0, SQLITE_UTF8, 0, test_destructor_count},
{ "test_auxdata", -1, 0, SQLITE_UTF8, 0, test_auxdata},
#endif
};
static struct {
char *zName;
signed char nArg;
u8 argType;
u8 needCollSeq;
void (*xStep)(sqlite3_context*,int,sqlite3_value**);
void (*xFinalize)(sqlite3_context*);
} aAggs[] = {
{ "min", 1, 0, 1, minmaxStep, minMaxFinalize },
{ "max", 1, 2, 1, minmaxStep, minMaxFinalize },
{ "sum", 1, 0, 0, sumStep, sumFinalize },
{ "avg", 1, 0, 0, sumStep, avgFinalize },
{ "count", 0, 0, 0, countStep, countFinalize },
{ "count", 1, 0, 0, countStep, countFinalize },
#if 0
{ "stddev", 1, 0, stdDevStep, stdDevFinalize },
#endif
};
int i;
for(i=0; i<sizeof(aFuncs)/sizeof(aFuncs[0]); i++){
void *pArg = 0;
switch( aFuncs[i].argType ){
case 1: pArg = db; break;
case 2: pArg = (void *)(-1); break;
}
sqlite3_create_function(db, aFuncs[i].zName, aFuncs[i].nArg,
aFuncs[i].eTextRep, pArg, aFuncs[i].xFunc, 0, 0);
if( aFuncs[i].needCollSeq ){
FuncDef *pFunc = sqlite3FindFunction(db, aFuncs[i].zName,
strlen(aFuncs[i].zName), aFuncs[i].nArg, aFuncs[i].eTextRep, 0);
if( pFunc && aFuncs[i].needCollSeq ){
pFunc->needCollSeq = 1;
}
}
}
for(i=0; i<sizeof(aAggs)/sizeof(aAggs[0]); i++){
void *pArg = 0;
switch( aAggs[i].argType ){
case 1: pArg = db; break;
case 2: pArg = (void *)(-1); break;
}
sqlite3_create_function(db, aAggs[i].zName, aAggs[i].nArg, SQLITE_UTF8,
pArg, 0, aAggs[i].xStep, aAggs[i].xFinalize);
if( aAggs[i].needCollSeq ){
FuncDef *pFunc = sqlite3FindFunction( db, aAggs[i].zName,
strlen(aAggs[i].zName), aAggs[i].nArg, SQLITE_UTF8, 0);
if( pFunc && aAggs[i].needCollSeq ){
pFunc->needCollSeq = 1;
}
}
}
sqlite3RegisterDateTimeFunctions(db);
}
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