Symaptic: os/persistentdata/persistentstorage/sql/SQLite364/func.c@bde4ae8d615e (annotated)

sl@0	1	/*
sl@0	2	** 2002 February 23
sl@0	3	**
sl@0	4	** The author disclaims copyright to this source code. In place of
sl@0	5	** a legal notice, here is a blessing:
sl@0	6	**
sl@0	7	** May you do good and not evil.
sl@0	8	** May you find forgiveness for yourself and forgive others.
sl@0	9	** May you share freely, never taking more than you give.
sl@0	10	**
sl@0	11	*************************************************************************
sl@0	12	** This file contains the C functions that implement various SQL
sl@0	13	** functions of SQLite.
sl@0	14	**
sl@0	15	** There is only one exported symbol in this file - the function
sl@0	16	** sqliteRegisterBuildinFunctions() found at the bottom of the file.
sl@0	17	** All other code has file scope.
sl@0	18	**
sl@0	19	** $Id: func.c,v 1.203 2008/09/03 17:11:16 drh Exp $
sl@0	20	*/
sl@0	21	#include "sqliteInt.h"
sl@0	22	#include <ctype.h>
sl@0	23	#include <stdlib.h>
sl@0	24	#include <assert.h>
sl@0	25	#include "vdbeInt.h"
sl@0	26
sl@0	27	/*
sl@0	28	** Return the collating function associated with a function.
sl@0	29	*/
sl@0	30	static CollSeq sqlite3GetFuncCollSeq(sqlite3_context context){
sl@0	31	return context->pColl;
sl@0	32	}
sl@0	33
sl@0	34	/*
sl@0	35	** Implementation of the non-aggregate min() and max() functions
sl@0	36	*/
sl@0	37	static void minmaxFunc(
sl@0	38	sqlite3_context *context,
sl@0	39	int argc,
sl@0	40	sqlite3_value **argv
sl@0	41	){
sl@0	42	int i;
sl@0	43	int mask; /* 0 for min() or 0xffffffff for max() */
sl@0	44	int iBest;
sl@0	45	CollSeq *pColl;
sl@0	46
sl@0	47	if( argc==0 ) return;
sl@0	48	mask = sqlite3_user_data(context)==0 ? 0 : -1;
sl@0	49	pColl = sqlite3GetFuncCollSeq(context);
sl@0	50	assert( pColl );
sl@0	51	assert( mask==-1 \|\| mask==0 );
sl@0	52	iBest = 0;
sl@0	53	if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
sl@0	54	for(i=1; i<argc; i++){
sl@0	55	if( sqlite3_value_type(argv[i])==SQLITE_NULL ) return;
sl@0	56	if( (sqlite3MemCompare(argv[iBest], argv[i], pColl)^mask)>=0 ){
sl@0	57	iBest = i;
sl@0	58	}
sl@0	59	}
sl@0	60	sqlite3_result_value(context, argv[iBest]);
sl@0	61	}
sl@0	62
sl@0	63	/*
sl@0	64	** Return the type of the argument.
sl@0	65	*/
sl@0	66	static void typeofFunc(
sl@0	67	sqlite3_context *context,
sl@0	68	int argc,
sl@0	69	sqlite3_value **argv
sl@0	70	){
sl@0	71	const char *z = 0;
sl@0	72	switch( sqlite3_value_type(argv[0]) ){
sl@0	73	case SQLITE_NULL: z = "null"; break;
sl@0	74	case SQLITE_INTEGER: z = "integer"; break;
sl@0	75	case SQLITE_TEXT: z = "text"; break;
sl@0	76	case SQLITE_FLOAT: z = "real"; break;
sl@0	77	case SQLITE_BLOB: z = "blob"; break;
sl@0	78	}
sl@0	79	sqlite3_result_text(context, z, -1, SQLITE_STATIC);
sl@0	80	}
sl@0	81
sl@0	82
sl@0	83	/*
sl@0	84	** Implementation of the length() function
sl@0	85	*/
sl@0	86	static void lengthFunc(
sl@0	87	sqlite3_context *context,
sl@0	88	int argc,
sl@0	89	sqlite3_value **argv
sl@0	90	){
sl@0	91	int len;
sl@0	92
sl@0	93	assert( argc==1 );
sl@0	94	switch( sqlite3_value_type(argv[0]) ){
sl@0	95	case SQLITE_BLOB:
sl@0	96	case SQLITE_INTEGER:
sl@0	97	case SQLITE_FLOAT: {
sl@0	98	sqlite3_result_int(context, sqlite3_value_bytes(argv[0]));
sl@0	99	break;
sl@0	100	}
sl@0	101	case SQLITE_TEXT: {
sl@0	102	const unsigned char *z = sqlite3_value_text(argv[0]);
sl@0	103	if( z==0 ) return;
sl@0	104	len = 0;
sl@0	105	while( *z ){
sl@0	106	len++;
sl@0	107	SQLITE_SKIP_UTF8(z);
sl@0	108	}
sl@0	109	sqlite3_result_int(context, len);
sl@0	110	break;
sl@0	111	}
sl@0	112	default: {
sl@0	113	sqlite3_result_null(context);
sl@0	114	break;
sl@0	115	}
sl@0	116	}
sl@0	117	}
sl@0	118
sl@0	119	/*
sl@0	120	** Implementation of the abs() function
sl@0	121	*/
sl@0	122	static void absFunc(sqlite3_context context, int argc, sqlite3_value *argv){
sl@0	123	assert( argc==1 );
sl@0	124	switch( sqlite3_value_type(argv[0]) ){
sl@0	125	case SQLITE_INTEGER: {
sl@0	126	i64 iVal = sqlite3_value_int64(argv[0]);
sl@0	127	if( iVal<0 ){
sl@0	128	if( (iVal<<1)==0 ){
sl@0	129	sqlite3_result_error(context, "integer overflow", -1);
sl@0	130	return;
sl@0	131	}
sl@0	132	iVal = -iVal;
sl@0	133	}
sl@0	134	sqlite3_result_int64(context, iVal);
sl@0	135	break;
sl@0	136	}
sl@0	137	case SQLITE_NULL: {
sl@0	138	sqlite3_result_null(context);
sl@0	139	break;
sl@0	140	}
sl@0	141	default: {
sl@0	142	double rVal = sqlite3_value_double(argv[0]);
sl@0	143	if( rVal<0 ) rVal = -rVal;
sl@0	144	sqlite3_result_double(context, rVal);
sl@0	145	break;
sl@0	146	}
sl@0	147	}
sl@0	148	}
sl@0	149
sl@0	150	/*
sl@0	151	** Implementation of the substr() function.
sl@0	152	**
sl@0	153	** substr(x,p1,p2) returns p2 characters of x[] beginning with p1.
sl@0	154	** p1 is 1-indexed. So substr(x,1,1) returns the first character
sl@0	155	** of x. If x is text, then we actually count UTF-8 characters.
sl@0	156	** If x is a blob, then we count bytes.
sl@0	157	**
sl@0	158	** If p1 is negative, then we begin abs(p1) from the end of x[].
sl@0	159	*/
sl@0	160	static void substrFunc(
sl@0	161	sqlite3_context *context,
sl@0	162	int argc,
sl@0	163	sqlite3_value **argv
sl@0	164	){
sl@0	165	const unsigned char *z;
sl@0	166	const unsigned char *z2;
sl@0	167	int len;
sl@0	168	int p0type;
sl@0	169	i64 p1, p2;
sl@0	170
sl@0	171	assert( argc==3 \|\| argc==2 );
sl@0	172	p0type = sqlite3_value_type(argv[0]);
sl@0	173	if( p0type==SQLITE_BLOB ){
sl@0	174	len = sqlite3_value_bytes(argv[0]);
sl@0	175	z = sqlite3_value_blob(argv[0]);
sl@0	176	if( z==0 ) return;
sl@0	177	assert( len==sqlite3_value_bytes(argv[0]) );
sl@0	178	}else{
sl@0	179	z = sqlite3_value_text(argv[0]);
sl@0	180	if( z==0 ) return;
sl@0	181	len = 0;
sl@0	182	for(z2=z; *z2; len++){
sl@0	183	SQLITE_SKIP_UTF8(z2);
sl@0	184	}
sl@0	185	}
sl@0	186	p1 = sqlite3_value_int(argv[1]);
sl@0	187	if( argc==3 ){
sl@0	188	p2 = sqlite3_value_int(argv[2]);
sl@0	189	}else{
sl@0	190	p2 = sqlite3_context_db_handle(context)->aLimit[SQLITE_LIMIT_LENGTH];
sl@0	191	}
sl@0	192	if( p1<0 ){
sl@0	193	p1 += len;
sl@0	194	if( p1<0 ){
sl@0	195	p2 += p1;
sl@0	196	p1 = 0;
sl@0	197	}
sl@0	198	}else if( p1>0 ){
sl@0	199	p1--;
sl@0	200	}
sl@0	201	if( p1+p2>len ){
sl@0	202	p2 = len-p1;
sl@0	203	}
sl@0	204	if( p0type!=SQLITE_BLOB ){
sl@0	205	while( *z && p1 ){
sl@0	206	SQLITE_SKIP_UTF8(z);
sl@0	207	p1--;
sl@0	208	}
sl@0	209	for(z2=z; *z2 && p2; p2--){
sl@0	210	SQLITE_SKIP_UTF8(z2);
sl@0	211	}
sl@0	212	sqlite3_result_text(context, (char*)z, z2-z, SQLITE_TRANSIENT);
sl@0	213	}else{
sl@0	214	if( p2<0 ) p2 = 0;
sl@0	215	sqlite3_result_blob(context, (char*)&z[p1], p2, SQLITE_TRANSIENT);
sl@0	216	}
sl@0	217	}
sl@0	218
sl@0	219	/*
sl@0	220	** Implementation of the round() function
sl@0	221	*/
sl@0	222	static void roundFunc(sqlite3_context context, int argc, sqlite3_value *argv){
sl@0	223	int n = 0;
sl@0	224	double r;
sl@0	225	char zBuf[500]; /* larger than the %f representation of the largest double */
sl@0	226	assert( argc==1 \|\| argc==2 );
sl@0	227	if( argc==2 ){
sl@0	228	if( SQLITE_NULL==sqlite3_value_type(argv[1]) ) return;
sl@0	229	n = sqlite3_value_int(argv[1]);
sl@0	230	if( n>30 ) n = 30;
sl@0	231	if( n<0 ) n = 0;
sl@0	232	}
sl@0	233	if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
sl@0	234	r = sqlite3_value_double(argv[0]);
sl@0	235	sqlite3_snprintf(sizeof(zBuf),zBuf,"%.*f",n,r);
sl@0	236	sqlite3AtoF(zBuf, &r);
sl@0	237	sqlite3_result_double(context, r);
sl@0	238	}
sl@0	239
sl@0	240	/*
sl@0	241	** Allocate nByte bytes of space using sqlite3_malloc(). If the
sl@0	242	** allocation fails, call sqlite3_result_error_nomem() to notify
sl@0	243	** the database handle that malloc() has failed.
sl@0	244	*/
sl@0	245	static void contextMalloc(sqlite3_context context, i64 nByte){
sl@0	246	char *z;
sl@0	247	if( nByte>sqlite3_context_db_handle(context)->aLimit[SQLITE_LIMIT_LENGTH] ){
sl@0	248	sqlite3_result_error_toobig(context);
sl@0	249	z = 0;
sl@0	250	}else{
sl@0	251	z = sqlite3Malloc(nByte);
sl@0	252	if( !z && nByte>0 ){
sl@0	253	sqlite3_result_error_nomem(context);
sl@0	254	}
sl@0	255	}
sl@0	256	return z;
sl@0	257	}
sl@0	258
sl@0	259	/*
sl@0	260	** Implementation of the upper() and lower() SQL functions.
sl@0	261	*/
sl@0	262	static void upperFunc(sqlite3_context context, int argc, sqlite3_value *argv){
sl@0	263	char *z1;
sl@0	264	const char *z2;
sl@0	265	int i, n;
sl@0	266	if( argc<1 \|\| SQLITE_NULL==sqlite3_value_type(argv[0]) ) return;
sl@0	267	z2 = (char*)sqlite3_value_text(argv[0]);
sl@0	268	n = sqlite3_value_bytes(argv[0]);
sl@0	269	/* Verify that the call to _bytes() does not invalidate the _text() pointer */
sl@0	270	assert( z2==(char*)sqlite3_value_text(argv[0]) );
sl@0	271	if( z2 ){
sl@0	272	z1 = contextMalloc(context, ((i64)n)+1);
sl@0	273	if( z1 ){
sl@0	274	memcpy(z1, z2, n+1);
sl@0	275	for(i=0; z1[i]; i++){
sl@0	276	z1[i] = toupper(z1[i]);
sl@0	277	}
sl@0	278	sqlite3_result_text(context, z1, -1, sqlite3_free);
sl@0	279	}
sl@0	280	}
sl@0	281	}
sl@0	282	static void lowerFunc(sqlite3_context context, int argc, sqlite3_value *argv){
sl@0	283	char *z1;
sl@0	284	const char *z2;
sl@0	285	int i, n;
sl@0	286	if( argc<1 \|\| SQLITE_NULL==sqlite3_value_type(argv[0]) ) return;
sl@0	287	z2 = (char*)sqlite3_value_text(argv[0]);
sl@0	288	n = sqlite3_value_bytes(argv[0]);
sl@0	289	/* Verify that the call to _bytes() does not invalidate the _text() pointer */
sl@0	290	assert( z2==(char*)sqlite3_value_text(argv[0]) );
sl@0	291	if( z2 ){
sl@0	292	z1 = contextMalloc(context, ((i64)n)+1);
sl@0	293	if( z1 ){
sl@0	294	memcpy(z1, z2, n+1);
sl@0	295	for(i=0; z1[i]; i++){
sl@0	296	z1[i] = tolower(z1[i]);
sl@0	297	}
sl@0	298	sqlite3_result_text(context, z1, -1, sqlite3_free);
sl@0	299	}
sl@0	300	}
sl@0	301	}
sl@0	302
sl@0	303	/*
sl@0	304	** Implementation of the IFNULL(), NVL(), and COALESCE() functions.
sl@0	305	** All three do the same thing. They return the first non-NULL
sl@0	306	** argument.
sl@0	307	*/
sl@0	308	static void ifnullFunc(
sl@0	309	sqlite3_context *context,
sl@0	310	int argc,
sl@0	311	sqlite3_value **argv
sl@0	312	){
sl@0	313	int i;
sl@0	314	for(i=0; i<argc; i++){
sl@0	315	if( SQLITE_NULL!=sqlite3_value_type(argv[i]) ){
sl@0	316	sqlite3_result_value(context, argv[i]);
sl@0	317	break;
sl@0	318	}
sl@0	319	}
sl@0	320	}
sl@0	321
sl@0	322	/*
sl@0	323	** Implementation of random(). Return a random integer.
sl@0	324	*/
sl@0	325	static void randomFunc(
sl@0	326	sqlite3_context *context,
sl@0	327	int argc,
sl@0	328	sqlite3_value **argv
sl@0	329	){
sl@0	330	sqlite_int64 r;
sl@0	331	sqlite3_randomness(sizeof(r), &r);
sl@0	332	if( (r<<1)==0 ) r = 0; /* Prevent 0x8000.... as the result so that we */
sl@0	333	/* can always do abs() of the result */
sl@0	334	sqlite3_result_int64(context, r);
sl@0	335	}
sl@0	336
sl@0	337	/*
sl@0	338	** Implementation of randomblob(N). Return a random blob
sl@0	339	** that is N bytes long.
sl@0	340	*/
sl@0	341	static void randomBlob(
sl@0	342	sqlite3_context *context,
sl@0	343	int argc,
sl@0	344	sqlite3_value **argv
sl@0	345	){
sl@0	346	int n;
sl@0	347	unsigned char *p;
sl@0	348	assert( argc==1 );
sl@0	349	n = sqlite3_value_int(argv[0]);
sl@0	350	if( n<1 ){
sl@0	351	n = 1;
sl@0	352	}
sl@0	353	p = contextMalloc(context, n);
sl@0	354	if( p ){
sl@0	355	sqlite3_randomness(n, p);
sl@0	356	sqlite3_result_blob(context, (char*)p, n, sqlite3_free);
sl@0	357	}
sl@0	358	}
sl@0	359
sl@0	360	/*
sl@0	361	** Implementation of the last_insert_rowid() SQL function. The return
sl@0	362	** value is the same as the sqlite3_last_insert_rowid() API function.
sl@0	363	*/
sl@0	364	static void last_insert_rowid(
sl@0	365	sqlite3_context *context,
sl@0	366	int arg,
sl@0	367	sqlite3_value **argv
sl@0	368	){
sl@0	369	sqlite3 *db = sqlite3_context_db_handle(context);
sl@0	370	sqlite3_result_int64(context, sqlite3_last_insert_rowid(db));
sl@0	371	}
sl@0	372
sl@0	373	/*
sl@0	374	** Implementation of the changes() SQL function. The return value is the
sl@0	375	** same as the sqlite3_changes() API function.
sl@0	376	*/
sl@0	377	static void changes(
sl@0	378	sqlite3_context *context,
sl@0	379	int arg,
sl@0	380	sqlite3_value **argv
sl@0	381	){
sl@0	382	sqlite3 *db = sqlite3_context_db_handle(context);
sl@0	383	sqlite3_result_int(context, sqlite3_changes(db));
sl@0	384	}
sl@0	385
sl@0	386	/*
sl@0	387	** Implementation of the total_changes() SQL function. The return value is
sl@0	388	** the same as the sqlite3_total_changes() API function.
sl@0	389	*/
sl@0	390	static void total_changes(
sl@0	391	sqlite3_context *context,
sl@0	392	int arg,
sl@0	393	sqlite3_value **argv
sl@0	394	){
sl@0	395	sqlite3 *db = sqlite3_context_db_handle(context);
sl@0	396	sqlite3_result_int(context, sqlite3_total_changes(db));
sl@0	397	}
sl@0	398
sl@0	399	/*
sl@0	400	** A structure defining how to do GLOB-style comparisons.
sl@0	401	*/
sl@0	402	struct compareInfo {
sl@0	403	u8 matchAll;
sl@0	404	u8 matchOne;
sl@0	405	u8 matchSet;
sl@0	406	u8 noCase;
sl@0	407	};
sl@0	408
sl@0	409	/*
sl@0	410	** For LIKE and GLOB matching on EBCDIC machines, assume that every
sl@0	411	** character is exactly one byte in size. Also, all characters are
sl@0	412	** able to participate in upper-case-to-lower-case mappings in EBCDIC
sl@0	413	** whereas only characters less than 0x80 do in ASCII.
sl@0	414	*/
sl@0	415	#if defined(SQLITE_EBCDIC)
sl@0	416	# define sqlite3Utf8Read(A,B,C) (*(A++))
sl@0	417	# define GlogUpperToLower(A) A = sqlite3UpperToLower[A]
sl@0	418	#else
sl@0	419	# define GlogUpperToLower(A) if( A<0x80 ){ A = sqlite3UpperToLower[A]; }
sl@0	420	#endif
sl@0	421
sl@0	422	static const struct compareInfo globInfo = { '*', '?', '[', 0 };
sl@0	423	/* The correct SQL-92 behavior is for the LIKE operator to ignore
sl@0	424	** case. Thus 'a' LIKE 'A' would be true. */
sl@0	425	static const struct compareInfo likeInfoNorm = { '%', '_', 0, 1 };
sl@0	426	/* If SQLITE_CASE_SENSITIVE_LIKE is defined, then the LIKE operator
sl@0	427	** is case sensitive causing 'a' LIKE 'A' to be false */
sl@0	428	static const struct compareInfo likeInfoAlt = { '%', '_', 0, 0 };
sl@0	429
sl@0	430	/*
sl@0	431	** Compare two UTF-8 strings for equality where the first string can
sl@0	432	** potentially be a "glob" expression. Return true (1) if they
sl@0	433	** are the same and false (0) if they are different.
sl@0	434	**
sl@0	435	** Globbing rules:
sl@0	436	**
sl@0	437	** '*' Matches any sequence of zero or more characters.
sl@0	438	**
sl@0	439	** '?' Matches exactly one character.
sl@0	440	**
sl@0	441	** [...] Matches one character from the enclosed list of
sl@0	442	** characters.
sl@0	443	**
sl@0	444	** [^...] Matches one character not in the enclosed list.
sl@0	445	**
sl@0	446	** With the [...] and [^...] matching, a ']' character can be included
sl@0	447	** in the list by making it the first character after '[' or '^'. A
sl@0	448	** range of characters can be specified using '-'. Example:
sl@0	449	** "[a-z]" matches any single lower-case letter. To match a '-', make
sl@0	450	** it the last character in the list.
sl@0	451	**
sl@0	452	This routine is usually quick, but can be N2 in the worst case.
sl@0	453	**
sl@0	454	** Hints: to match '*' or '?', put them in "[]". Like this:
sl@0	455	**
sl@0	456	** abc[]xyz Matches "abcxyz" only
sl@0	457	*/
sl@0	458	static int patternCompare(
sl@0	459	const u8 zPattern, / The glob pattern */
sl@0	460	const u8 zString, / The string to compare against the glob */
sl@0	461	const struct compareInfo pInfo, / Information about how to do the compare */
sl@0	462	const int esc /* The escape character */
sl@0	463	){
sl@0	464	int c, c2;
sl@0	465	int invert;
sl@0	466	int seen;
sl@0	467	u8 matchOne = pInfo->matchOne;
sl@0	468	u8 matchAll = pInfo->matchAll;
sl@0	469	u8 matchSet = pInfo->matchSet;
sl@0	470	u8 noCase = pInfo->noCase;
sl@0	471	int prevEscape = 0; /* True if the previous character was 'escape' */
sl@0	472
sl@0	473	while( (c = sqlite3Utf8Read(zPattern,0,&zPattern))!=0 ){
sl@0	474	if( !prevEscape && c==matchAll ){
sl@0	475	while( (c=sqlite3Utf8Read(zPattern,0,&zPattern)) == matchAll
sl@0	476	\|\| c == matchOne ){
sl@0	477	if( c==matchOne && sqlite3Utf8Read(zString, 0, &zString)==0 ){
sl@0	478	return 0;
sl@0	479	}
sl@0	480	}
sl@0	481	if( c==0 ){
sl@0	482	return 1;
sl@0	483	}else if( c==esc ){
sl@0	484	c = sqlite3Utf8Read(zPattern, 0, &zPattern);
sl@0	485	if( c==0 ){
sl@0	486	return 0;
sl@0	487	}
sl@0	488	}else if( c==matchSet ){
sl@0	489	assert( esc==0 ); /* This is GLOB, not LIKE */
sl@0	490	assert( matchSet<0x80 ); /* '[' is a single-byte character */
sl@0	491	while( *zString && patternCompare(&zPattern[-1],zString,pInfo,esc)==0 ){
sl@0	492	SQLITE_SKIP_UTF8(zString);
sl@0	493	}
sl@0	494	return *zString!=0;
sl@0	495	}
sl@0	496	while( (c2 = sqlite3Utf8Read(zString,0,&zString))!=0 ){
sl@0	497	if( noCase ){
sl@0	498	GlogUpperToLower(c2);
sl@0	499	GlogUpperToLower(c);
sl@0	500	while( c2 != 0 && c2 != c ){
sl@0	501	c2 = sqlite3Utf8Read(zString, 0, &zString);
sl@0	502	GlogUpperToLower(c2);
sl@0	503	}
sl@0	504	}else{
sl@0	505	while( c2 != 0 && c2 != c ){
sl@0	506	c2 = sqlite3Utf8Read(zString, 0, &zString);
sl@0	507	}
sl@0	508	}
sl@0	509	if( c2==0 ) return 0;
sl@0	510	if( patternCompare(zPattern,zString,pInfo,esc) ) return 1;
sl@0	511	}
sl@0	512	return 0;
sl@0	513	}else if( !prevEscape && c==matchOne ){
sl@0	514	if( sqlite3Utf8Read(zString, 0, &zString)==0 ){
sl@0	515	return 0;
sl@0	516	}
sl@0	517	}else if( c==matchSet ){
sl@0	518	int prior_c = 0;
sl@0	519	assert( esc==0 ); /* This only occurs for GLOB, not LIKE */
sl@0	520	seen = 0;
sl@0	521	invert = 0;
sl@0	522	c = sqlite3Utf8Read(zString, 0, &zString);
sl@0	523	if( c==0 ) return 0;
sl@0	524	c2 = sqlite3Utf8Read(zPattern, 0, &zPattern);
sl@0	525	if( c2=='^' ){
sl@0	526	invert = 1;
sl@0	527	c2 = sqlite3Utf8Read(zPattern, 0, &zPattern);
sl@0	528	}
sl@0	529	if( c2==']' ){
sl@0	530	if( c==']' ) seen = 1;
sl@0	531	c2 = sqlite3Utf8Read(zPattern, 0, &zPattern);
sl@0	532	}
sl@0	533	while( c2 && c2!=']' ){
sl@0	534	if( c2=='-' && zPattern[0]!=']' && zPattern[0]!=0 && prior_c>0 ){
sl@0	535	c2 = sqlite3Utf8Read(zPattern, 0, &zPattern);
sl@0	536	if( c>=prior_c && c<=c2 ) seen = 1;
sl@0	537	prior_c = 0;
sl@0	538	}else{
sl@0	539	if( c==c2 ){
sl@0	540	seen = 1;
sl@0	541	}
sl@0	542	prior_c = c2;
sl@0	543	}
sl@0	544	c2 = sqlite3Utf8Read(zPattern, 0, &zPattern);
sl@0	545	}
sl@0	546	if( c2==0 \|\| (seen ^ invert)==0 ){
sl@0	547	return 0;
sl@0	548	}
sl@0	549	}else if( esc==c && !prevEscape ){
sl@0	550	prevEscape = 1;
sl@0	551	}else{
sl@0	552	c2 = sqlite3Utf8Read(zString, 0, &zString);
sl@0	553	if( noCase ){
sl@0	554	GlogUpperToLower(c);
sl@0	555	GlogUpperToLower(c2);
sl@0	556	}
sl@0	557	if( c!=c2 ){
sl@0	558	return 0;
sl@0	559	}
sl@0	560	prevEscape = 0;
sl@0	561	}
sl@0	562	}
sl@0	563	return *zString==0;
sl@0	564	}
sl@0	565
sl@0	566	/*
sl@0	567	** Count the number of times that the LIKE operator (or GLOB which is
sl@0	568	** just a variation of LIKE) gets called. This is used for testing
sl@0	569	** only.
sl@0	570	*/
sl@0	571	#ifdef SQLITE_TEST
sl@0	572	int sqlite3_like_count = 0;
sl@0	573	#endif
sl@0	574
sl@0	575
sl@0	576	/*
sl@0	577	** Implementation of the like() SQL function. This function implements
sl@0	578	** the build-in LIKE operator. The first argument to the function is the
sl@0	579	** pattern and the second argument is the string. So, the SQL statements:
sl@0	580	**
sl@0	581	** A LIKE B
sl@0	582	**
sl@0	583	** is implemented as like(B,A).
sl@0	584	**
sl@0	585	** This same function (with a different compareInfo structure) computes
sl@0	586	** the GLOB operator.
sl@0	587	*/
sl@0	588	void likeFunc(
sl@0	589	sqlite3_context *context,
sl@0	590	int argc,
sl@0	591	sqlite3_value **argv
sl@0	592	){
sl@0	593	const unsigned char zA, zB;
sl@0	594	int escape = 0;
sl@0	595	sqlite3 *db = sqlite3_context_db_handle(context);
sl@0	596
sl@0	597	zB = sqlite3_value_text(argv[0]);
sl@0	598	zA = sqlite3_value_text(argv[1]);
sl@0	599
sl@0	600	/* Limit the length of the LIKE or GLOB pattern to avoid problems
sl@0	601	** of deep recursion and N*N behavior in patternCompare().
sl@0	602	*/
sl@0	603	if( sqlite3_value_bytes(argv[0]) >
sl@0	604	db->aLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH] ){
sl@0	605	sqlite3_result_error(context, "LIKE or GLOB pattern too complex", -1);
sl@0	606	return;
sl@0	607	}
sl@0	608	assert( zB==sqlite3_value_text(argv[0]) ); /* Encoding did not change */
sl@0	609
sl@0	610	if( argc==3 ){
sl@0	611	/* The escape character string must consist of a single UTF-8 character.
sl@0	612	** Otherwise, return an error.
sl@0	613	*/
sl@0	614	const unsigned char *zEsc = sqlite3_value_text(argv[2]);
sl@0	615	if( zEsc==0 ) return;
sl@0	616	if( sqlite3Utf8CharLen((char*)zEsc, -1)!=1 ){
sl@0	617	sqlite3_result_error(context,
sl@0	618	"ESCAPE expression must be a single character", -1);
sl@0	619	return;
sl@0	620	}
sl@0	621	escape = sqlite3Utf8Read(zEsc, 0, &zEsc);
sl@0	622	}
sl@0	623	if( zA && zB ){
sl@0	624	struct compareInfo *pInfo = sqlite3_user_data(context);
sl@0	625	#ifdef SQLITE_TEST
sl@0	626	sqlite3_like_count++;
sl@0	627	#endif
sl@0	628
sl@0	629	sqlite3_result_int(context, patternCompare(zB, zA, pInfo, escape));
sl@0	630	}
sl@0	631	}
sl@0	632
sl@0	633	/*
sl@0	634	** Implementation of the NULLIF(x,y) function. The result is the first
sl@0	635	** argument if the arguments are different. The result is NULL if the
sl@0	636	** arguments are equal to each other.
sl@0	637	*/
sl@0	638	static void nullifFunc(
sl@0	639	sqlite3_context *context,
sl@0	640	int argc,
sl@0	641	sqlite3_value **argv
sl@0	642	){
sl@0	643	CollSeq *pColl = sqlite3GetFuncCollSeq(context);
sl@0	644	if( sqlite3MemCompare(argv[0], argv[1], pColl)!=0 ){
sl@0	645	sqlite3_result_value(context, argv[0]);
sl@0	646	}
sl@0	647	}
sl@0	648
sl@0	649	/*
sl@0	650	** Implementation of the VERSION(*) function. The result is the version
sl@0	651	** of the SQLite library that is running.
sl@0	652	*/
sl@0	653	static void versionFunc(
sl@0	654	sqlite3_context *context,
sl@0	655	int argc,
sl@0	656	sqlite3_value **argv
sl@0	657	){
sl@0	658	sqlite3_result_text(context, sqlite3_version, -1, SQLITE_STATIC);
sl@0	659	}
sl@0	660
sl@0	661	/* Array for converting from half-bytes (nybbles) into ASCII hex
sl@0	662	** digits. */
sl@0	663	static const char hexdigits[] = {
sl@0	664	'0', '1', '2', '3', '4', '5', '6', '7',
sl@0	665	'8', '9', 'A', 'B', 'C', 'D', 'E', 'F'
sl@0	666	};
sl@0	667
sl@0	668	/*
sl@0	669	** EXPERIMENTAL - This is not an official function. The interface may
sl@0	670	** change. This function may disappear. Do not write code that depends
sl@0	671	** on this function.
sl@0	672	**
sl@0	673	** Implementation of the QUOTE() function. This function takes a single
sl@0	674	** argument. If the argument is numeric, the return value is the same as
sl@0	675	** the argument. If the argument is NULL, the return value is the string
sl@0	676	** "NULL". Otherwise, the argument is enclosed in single quotes with
sl@0	677	** single-quote escapes.
sl@0	678	*/
sl@0	679	static void quoteFunc(sqlite3_context context, int argc, sqlite3_value *argv){
sl@0	680	if( argc<1 ) return;
sl@0	681	switch( sqlite3_value_type(argv[0]) ){
sl@0	682	case SQLITE_NULL: {
sl@0	683	sqlite3_result_text(context, "NULL", 4, SQLITE_STATIC);
sl@0	684	break;
sl@0	685	}
sl@0	686	case SQLITE_INTEGER:
sl@0	687	case SQLITE_FLOAT: {
sl@0	688	sqlite3_result_value(context, argv[0]);
sl@0	689	break;
sl@0	690	}
sl@0	691	case SQLITE_BLOB: {
sl@0	692	char *zText = 0;
sl@0	693	char const *zBlob = sqlite3_value_blob(argv[0]);
sl@0	694	int nBlob = sqlite3_value_bytes(argv[0]);
sl@0	695	assert( zBlob==sqlite3_value_blob(argv[0]) ); /* No encoding change */
sl@0	696	zText = (char )contextMalloc(context, (2(i64)nBlob)+4);
sl@0	697	if( zText ){
sl@0	698	int i;
sl@0	699	for(i=0; i<nBlob; i++){
sl@0	700	zText[(i*2)+2] = hexdigits[(zBlob[i]>>4)&0x0F];
sl@0	701	zText[(i*2)+3] = hexdigits[(zBlob[i])&0x0F];
sl@0	702	}
sl@0	703	zText[(nBlob*2)+2] = '\'';
sl@0	704	zText[(nBlob*2)+3] = '\0';
sl@0	705	zText[0] = 'X';
sl@0	706	zText[1] = '\'';
sl@0	707	sqlite3_result_text(context, zText, -1, SQLITE_TRANSIENT);
sl@0	708	sqlite3_free(zText);
sl@0	709	}
sl@0	710	break;
sl@0	711	}
sl@0	712	case SQLITE_TEXT: {
sl@0	713	int i,j;
sl@0	714	u64 n;
sl@0	715	const unsigned char *zArg = sqlite3_value_text(argv[0]);
sl@0	716	char *z;
sl@0	717
sl@0	718	if( zArg==0 ) return;
sl@0	719	for(i=0, n=0; zArg[i]; i++){ if( zArg[i]=='\'' ) n++; }
sl@0	720	z = contextMalloc(context, ((i64)i)+((i64)n)+3);
sl@0	721	if( z ){
sl@0	722	z[0] = '\'';
sl@0	723	for(i=0, j=1; zArg[i]; i++){
sl@0	724	z[j++] = zArg[i];
sl@0	725	if( zArg[i]=='\'' ){
sl@0	726	z[j++] = '\'';
sl@0	727	}
sl@0	728	}
sl@0	729	z[j++] = '\'';
sl@0	730	z[j] = 0;
sl@0	731	sqlite3_result_text(context, z, j, sqlite3_free);
sl@0	732	}
sl@0	733	}
sl@0	734	}
sl@0	735	}
sl@0	736
sl@0	737	/*
sl@0	738	** The hex() function. Interpret the argument as a blob. Return
sl@0	739	** a hexadecimal rendering as text.
sl@0	740	*/
sl@0	741	static void hexFunc(
sl@0	742	sqlite3_context *context,
sl@0	743	int argc,
sl@0	744	sqlite3_value **argv
sl@0	745	){
sl@0	746	int i, n;
sl@0	747	const unsigned char *pBlob;
sl@0	748	char zHex, z;
sl@0	749	assert( argc==1 );
sl@0	750	pBlob = sqlite3_value_blob(argv[0]);
sl@0	751	n = sqlite3_value_bytes(argv[0]);
sl@0	752	assert( pBlob==sqlite3_value_blob(argv[0]) ); /* No encoding change */
sl@0	753	z = zHex = contextMalloc(context, ((i64)n)*2 + 1);
sl@0	754	if( zHex ){
sl@0	755	for(i=0; i<n; i++, pBlob++){
sl@0	756	unsigned char c = *pBlob;
sl@0	757	*(z++) = hexdigits[(c>>4)&0xf];
sl@0	758	*(z++) = hexdigits[c&0xf];
sl@0	759	}
sl@0	760	*z = 0;
sl@0	761	sqlite3_result_text(context, zHex, n*2, sqlite3_free);
sl@0	762	}
sl@0	763	}
sl@0	764
sl@0	765	/*
sl@0	766	** The zeroblob(N) function returns a zero-filled blob of size N bytes.
sl@0	767	*/
sl@0	768	static void zeroblobFunc(
sl@0	769	sqlite3_context *context,
sl@0	770	int argc,
sl@0	771	sqlite3_value **argv
sl@0	772	){
sl@0	773	i64 n;
sl@0	774	assert( argc==1 );
sl@0	775	n = sqlite3_value_int64(argv[0]);
sl@0	776	if( n>SQLITE_MAX_LENGTH ){
sl@0	777	sqlite3_result_error_toobig(context);
sl@0	778	}else{
sl@0	779	sqlite3_result_zeroblob(context, n);
sl@0	780	}
sl@0	781	}
sl@0	782
sl@0	783	/*
sl@0	784	** The replace() function. Three arguments are all strings: call
sl@0	785	** them A, B, and C. The result is also a string which is derived
sl@0	786	** from A by replacing every occurance of B with C. The match
sl@0	787	** must be exact. Collating sequences are not used.
sl@0	788	*/
sl@0	789	static void replaceFunc(
sl@0	790	sqlite3_context *context,
sl@0	791	int argc,
sl@0	792	sqlite3_value **argv
sl@0	793	){
sl@0	794	const unsigned char zStr; / The input string A */
sl@0	795	const unsigned char zPattern; / The pattern string B */
sl@0	796	const unsigned char zRep; / The replacement string C */
sl@0	797	unsigned char zOut; / The output */
sl@0	798	int nStr; /* Size of zStr */
sl@0	799	int nPattern; /* Size of zPattern */
sl@0	800	int nRep; /* Size of zRep */
sl@0	801	i64 nOut; /* Maximum size of zOut */
sl@0	802	int loopLimit; /* Last zStr[] that might match zPattern[] */
sl@0	803	int i, j; /* Loop counters */
sl@0	804
sl@0	805	assert( argc==3 );
sl@0	806	zStr = sqlite3_value_text(argv[0]);
sl@0	807	if( zStr==0 ) return;
sl@0	808	nStr = sqlite3_value_bytes(argv[0]);
sl@0	809	assert( zStr==sqlite3_value_text(argv[0]) ); /* No encoding change */
sl@0	810	zPattern = sqlite3_value_text(argv[1]);
sl@0	811	if( zPattern==0 \|\| zPattern[0]==0 ) return;
sl@0	812	nPattern = sqlite3_value_bytes(argv[1]);
sl@0	813	assert( zPattern==sqlite3_value_text(argv[1]) ); /* No encoding change */
sl@0	814	zRep = sqlite3_value_text(argv[2]);
sl@0	815	if( zRep==0 ) return;
sl@0	816	nRep = sqlite3_value_bytes(argv[2]);
sl@0	817	assert( zRep==sqlite3_value_text(argv[2]) );
sl@0	818	nOut = nStr + 1;
sl@0	819	assert( nOut<SQLITE_MAX_LENGTH );
sl@0	820	zOut = contextMalloc(context, (i64)nOut);
sl@0	821	if( zOut==0 ){
sl@0	822	return;
sl@0	823	}
sl@0	824	loopLimit = nStr - nPattern;
sl@0	825	for(i=j=0; i<=loopLimit; i++){
sl@0	826	if( zStr[i]!=zPattern[0] \|\| memcmp(&zStr[i], zPattern, nPattern) ){
sl@0	827	zOut[j++] = zStr[i];
sl@0	828	}else{
sl@0	829	u8 *zOld;
sl@0	830	sqlite3 *db = sqlite3_context_db_handle(context);
sl@0	831	nOut += nRep - nPattern;
sl@0	832	if( nOut>=db->aLimit[SQLITE_LIMIT_LENGTH] ){
sl@0	833	sqlite3_result_error_toobig(context);
sl@0	834	sqlite3DbFree(db, zOut);
sl@0	835	return;
sl@0	836	}
sl@0	837	zOld = zOut;
sl@0	838	zOut = sqlite3_realloc(zOut, (int)nOut);
sl@0	839	if( zOut==0 ){
sl@0	840	sqlite3_result_error_nomem(context);
sl@0	841	sqlite3DbFree(db, zOld);
sl@0	842	return;
sl@0	843	}
sl@0	844	memcpy(&zOut[j], zRep, nRep);
sl@0	845	j += nRep;
sl@0	846	i += nPattern-1;
sl@0	847	}
sl@0	848	}
sl@0	849	assert( j+nStr-i+1==nOut );
sl@0	850	memcpy(&zOut[j], &zStr[i], nStr-i);
sl@0	851	j += nStr - i;
sl@0	852	assert( j<=nOut );
sl@0	853	zOut[j] = 0;
sl@0	854	sqlite3_result_text(context, (char*)zOut, j, sqlite3_free);
sl@0	855	}
sl@0	856
sl@0	857	/*
sl@0	858	** Implementation of the TRIM(), LTRIM(), and RTRIM() functions.
sl@0	859	** The userdata is 0x1 for left trim, 0x2 for right trim, 0x3 for both.
sl@0	860	*/
sl@0	861	static void trimFunc(
sl@0	862	sqlite3_context *context,
sl@0	863	int argc,
sl@0	864	sqlite3_value **argv
sl@0	865	){
sl@0	866	const unsigned char zIn; / Input string */
sl@0	867	const unsigned char zCharSet; / Set of characters to trim */
sl@0	868	int nIn; /* Number of bytes in input */
sl@0	869	int flags; /* 1: trimleft 2: trimright 3: trim */
sl@0	870	int i; /* Loop counter */
sl@0	871	unsigned char aLen; / Length of each character in zCharSet */
sl@0	872	unsigned char *azChar; / Individual characters in zCharSet */
sl@0	873	int nChar; /* Number of characters in zCharSet */
sl@0	874
sl@0	875	if( sqlite3_value_type(argv[0])==SQLITE_NULL ){
sl@0	876	return;
sl@0	877	}
sl@0	878	zIn = sqlite3_value_text(argv[0]);
sl@0	879	if( zIn==0 ) return;
sl@0	880	nIn = sqlite3_value_bytes(argv[0]);
sl@0	881	assert( zIn==sqlite3_value_text(argv[0]) );
sl@0	882	if( argc==1 ){
sl@0	883	static const unsigned char lenOne[] = { 1 };
sl@0	884	static unsigned char * const azOne[] = { (u8*)" " };
sl@0	885	nChar = 1;
sl@0	886	aLen = (u8*)lenOne;
sl@0	887	azChar = (unsigned char **)azOne;
sl@0	888	zCharSet = 0;
sl@0	889	}else if( (zCharSet = sqlite3_value_text(argv[1]))==0 ){
sl@0	890	return;
sl@0	891	}else{
sl@0	892	const unsigned char *z;
sl@0	893	for(z=zCharSet, nChar=0; *z; nChar++){
sl@0	894	SQLITE_SKIP_UTF8(z);
sl@0	895	}
sl@0	896	if( nChar>0 ){
sl@0	897	azChar = contextMalloc(context, ((i64)nChar)(sizeof(char)+1));
sl@0	898	if( azChar==0 ){
sl@0	899	return;
sl@0	900	}
sl@0	901	aLen = (unsigned char*)&azChar[nChar];
sl@0	902	for(z=zCharSet, nChar=0; *z; nChar++){
sl@0	903	azChar[nChar] = (unsigned char *)z;
sl@0	904	SQLITE_SKIP_UTF8(z);
sl@0	905	aLen[nChar] = z - azChar[nChar];
sl@0	906	}
sl@0	907	}
sl@0	908	}
sl@0	909	if( nChar>0 ){
sl@0	910	flags = SQLITE_PTR_TO_INT(sqlite3_user_data(context));
sl@0	911	if( flags & 1 ){
sl@0	912	while( nIn>0 ){
sl@0	913	int len;
sl@0	914	for(i=0; i<nChar; i++){
sl@0	915	len = aLen[i];
sl@0	916	if( memcmp(zIn, azChar[i], len)==0 ) break;
sl@0	917	}
sl@0	918	if( i>=nChar ) break;
sl@0	919	zIn += len;
sl@0	920	nIn -= len;
sl@0	921	}
sl@0	922	}
sl@0	923	if( flags & 2 ){
sl@0	924	while( nIn>0 ){
sl@0	925	int len;
sl@0	926	for(i=0; i<nChar; i++){
sl@0	927	len = aLen[i];
sl@0	928	if( len<=nIn && memcmp(&zIn[nIn-len],azChar[i],len)==0 ) break;
sl@0	929	}
sl@0	930	if( i>=nChar ) break;
sl@0	931	nIn -= len;
sl@0	932	}
sl@0	933	}
sl@0	934	if( zCharSet ){
sl@0	935	sqlite3_free(azChar);
sl@0	936	}
sl@0	937	}
sl@0	938	sqlite3_result_text(context, (char*)zIn, nIn, SQLITE_TRANSIENT);
sl@0	939	}
sl@0	940
sl@0	941
sl@0	942	#ifdef SQLITE_SOUNDEX
sl@0	943	/*
sl@0	944	** Compute the soundex encoding of a word.
sl@0	945	*/
sl@0	946	static void soundexFunc(
sl@0	947	sqlite3_context *context,
sl@0	948	int argc,
sl@0	949	sqlite3_value **argv
sl@0	950	){
sl@0	951	char zResult[8];
sl@0	952	const u8 *zIn;
sl@0	953	int i, j;
sl@0	954	static const unsigned char iCode[] = {
sl@0	955	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
sl@0	956	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
sl@0	957	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
sl@0	958	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
sl@0	959	0, 0, 1, 2, 3, 0, 1, 2, 0, 0, 2, 2, 4, 5, 5, 0,
sl@0	960	1, 2, 6, 2, 3, 0, 1, 0, 2, 0, 2, 0, 0, 0, 0, 0,
sl@0	961	0, 0, 1, 2, 3, 0, 1, 2, 0, 0, 2, 2, 4, 5, 5, 0,
sl@0	962	1, 2, 6, 2, 3, 0, 1, 0, 2, 0, 2, 0, 0, 0, 0, 0,
sl@0	963	};
sl@0	964	assert( argc==1 );
sl@0	965	zIn = (u8*)sqlite3_value_text(argv[0]);
sl@0	966	if( zIn==0 ) zIn = (u8*)"";
sl@0	967	for(i=0; zIn[i] && !isalpha(zIn[i]); i++){}
sl@0	968	if( zIn[i] ){
sl@0	969	u8 prevcode = iCode[zIn[i]&0x7f];
sl@0	970	zResult[0] = toupper(zIn[i]);
sl@0	971	for(j=1; j<4 && zIn[i]; i++){
sl@0	972	int code = iCode[zIn[i]&0x7f];
sl@0	973	if( code>0 ){
sl@0	974	if( code!=prevcode ){
sl@0	975	prevcode = code;
sl@0	976	zResult[j++] = code + '0';
sl@0	977	}
sl@0	978	}else{
sl@0	979	prevcode = 0;
sl@0	980	}
sl@0	981	}
sl@0	982	while( j<4 ){
sl@0	983	zResult[j++] = '0';
sl@0	984	}
sl@0	985	zResult[j] = 0;
sl@0	986	sqlite3_result_text(context, zResult, 4, SQLITE_TRANSIENT);
sl@0	987	}else{
sl@0	988	sqlite3_result_text(context, "?000", 4, SQLITE_STATIC);
sl@0	989	}
sl@0	990	}
sl@0	991	#endif
sl@0	992
sl@0	993	#ifndef SQLITE_OMIT_LOAD_EXTENSION
sl@0	994	/*
sl@0	995	** A function that loads a shared-library extension then returns NULL.
sl@0	996	*/
sl@0	997	static void loadExt(sqlite3_context context, int argc, sqlite3_value *argv){
sl@0	998	const char zFile = (const char )sqlite3_value_text(argv[0]);
sl@0	999	const char *zProc;
sl@0	1000	sqlite3 *db = sqlite3_context_db_handle(context);
sl@0	1001	char *zErrMsg = 0;
sl@0	1002
sl@0	1003	if( argc==2 ){
sl@0	1004	zProc = (const char *)sqlite3_value_text(argv[1]);
sl@0	1005	}else{
sl@0	1006	zProc = 0;
sl@0	1007	}
sl@0	1008	if( zFile && sqlite3_load_extension(db, zFile, zProc, &zErrMsg) ){
sl@0	1009	sqlite3_result_error(context, zErrMsg, -1);
sl@0	1010	sqlite3_free(zErrMsg);
sl@0	1011	}
sl@0	1012	}
sl@0	1013	#endif
sl@0	1014
sl@0	1015
sl@0	1016	/*
sl@0	1017	** An instance of the following structure holds the context of a
sl@0	1018	** sum() or avg() aggregate computation.
sl@0	1019	*/
sl@0	1020	typedef struct SumCtx SumCtx;
sl@0	1021	struct SumCtx {
sl@0	1022	double rSum; /* Floating point sum */
sl@0	1023	i64 iSum; /* Integer sum */
sl@0	1024	i64 cnt; /* Number of elements summed */
sl@0	1025	u8 overflow; /* True if integer overflow seen */
sl@0	1026	u8 approx; /* True if non-integer value was input to the sum */
sl@0	1027	};
sl@0	1028
sl@0	1029	/*
sl@0	1030	** Routines used to compute the sum, average, and total.
sl@0	1031	**
sl@0	1032	** The SUM() function follows the (broken) SQL standard which means
sl@0	1033	** that it returns NULL if it sums over no inputs. TOTAL returns
sl@0	1034	** 0.0 in that case. In addition, TOTAL always returns a float where
sl@0	1035	** SUM might return an integer if it never encounters a floating point
sl@0	1036	** value. TOTAL never fails, but SUM might through an exception if
sl@0	1037	** it overflows an integer.
sl@0	1038	*/
sl@0	1039	static void sumStep(sqlite3_context context, int argc, sqlite3_value *argv){
sl@0	1040	SumCtx *p;
sl@0	1041	int type;
sl@0	1042	assert( argc==1 );
sl@0	1043	p = sqlite3_aggregate_context(context, sizeof(*p));
sl@0	1044	type = sqlite3_value_numeric_type(argv[0]);
sl@0	1045	if( p && type!=SQLITE_NULL ){
sl@0	1046	p->cnt++;
sl@0	1047	if( type==SQLITE_INTEGER ){
sl@0	1048	i64 v = sqlite3_value_int64(argv[0]);
sl@0	1049	p->rSum += v;
sl@0	1050	if( (p->approx\|p->overflow)==0 ){
sl@0	1051	i64 iNewSum = p->iSum + v;
sl@0	1052	int s1 = p->iSum >> (sizeof(i64)*8-1);
sl@0	1053	int s2 = v >> (sizeof(i64)*8-1);
sl@0	1054	int s3 = iNewSum >> (sizeof(i64)*8-1);
sl@0	1055	p->overflow = (s1&s2&~s3) \| (~s1&~s2&s3);
sl@0	1056	p->iSum = iNewSum;
sl@0	1057	}
sl@0	1058	}else{
sl@0	1059	p->rSum += sqlite3_value_double(argv[0]);
sl@0	1060	p->approx = 1;
sl@0	1061	}
sl@0	1062	}
sl@0	1063	}
sl@0	1064	static void sumFinalize(sqlite3_context *context){
sl@0	1065	SumCtx *p;
sl@0	1066	p = sqlite3_aggregate_context(context, 0);
sl@0	1067	if( p && p->cnt>0 ){
sl@0	1068	if( p->overflow ){
sl@0	1069	sqlite3_result_error(context,"integer overflow",-1);
sl@0	1070	}else if( p->approx ){
sl@0	1071	sqlite3_result_double(context, p->rSum);
sl@0	1072	}else{
sl@0	1073	sqlite3_result_int64(context, p->iSum);
sl@0	1074	}
sl@0	1075	}
sl@0	1076	}
sl@0	1077	static void avgFinalize(sqlite3_context *context){
sl@0	1078	SumCtx *p;
sl@0	1079	p = sqlite3_aggregate_context(context, 0);
sl@0	1080	if( p && p->cnt>0 ){
sl@0	1081	sqlite3_result_double(context, p->rSum/(double)p->cnt);
sl@0	1082	}
sl@0	1083	}
sl@0	1084	static void totalFinalize(sqlite3_context *context){
sl@0	1085	SumCtx *p;
sl@0	1086	p = sqlite3_aggregate_context(context, 0);
sl@0	1087	sqlite3_result_double(context, p ? p->rSum : 0.0);
sl@0	1088	}
sl@0	1089
sl@0	1090	/*
sl@0	1091	** The following structure keeps track of state information for the
sl@0	1092	** count() aggregate function.
sl@0	1093	*/
sl@0	1094	typedef struct CountCtx CountCtx;
sl@0	1095	struct CountCtx {
sl@0	1096	i64 n;
sl@0	1097	};
sl@0	1098
sl@0	1099	/*
sl@0	1100	** Routines to implement the count() aggregate function.
sl@0	1101	*/
sl@0	1102	static void countStep(sqlite3_context context, int argc, sqlite3_value *argv){
sl@0	1103	CountCtx *p;
sl@0	1104	p = sqlite3_aggregate_context(context, sizeof(*p));
sl@0	1105	if( (argc==0 \|\| SQLITE_NULL!=sqlite3_value_type(argv[0])) && p ){
sl@0	1106	p->n++;
sl@0	1107	}
sl@0	1108	}
sl@0	1109	static void countFinalize(sqlite3_context *context){
sl@0	1110	CountCtx *p;
sl@0	1111	p = sqlite3_aggregate_context(context, 0);
sl@0	1112	sqlite3_result_int64(context, p ? p->n : 0);
sl@0	1113	}
sl@0	1114
sl@0	1115	/*
sl@0	1116	** Routines to implement min() and max() aggregate functions.
sl@0	1117	*/
sl@0	1118	static void minmaxStep(sqlite3_context context, int argc, sqlite3_value *argv){
sl@0	1119	Mem pArg = (Mem )argv[0];
sl@0	1120	Mem *pBest;
sl@0	1121
sl@0	1122	if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
sl@0	1123	pBest = (Mem )sqlite3_aggregate_context(context, sizeof(pBest));
sl@0	1124	if( !pBest ) return;
sl@0	1125
sl@0	1126	if( pBest->flags ){
sl@0	1127	int max;
sl@0	1128	int cmp;
sl@0	1129	CollSeq *pColl = sqlite3GetFuncCollSeq(context);
sl@0	1130	/* This step function is used for both the min() and max() aggregates,
sl@0	1131	** the only difference between the two being that the sense of the
sl@0	1132	** comparison is inverted. For the max() aggregate, the
sl@0	1133	** sqlite3_user_data() function returns (void *)-1. For min() it
sl@0	1134	** returns (void )db, where db is the sqlite3 database pointer.
sl@0	1135	** Therefore the next statement sets variable 'max' to 1 for the max()
sl@0	1136	** aggregate, or 0 for min().
sl@0	1137	*/
sl@0	1138	max = sqlite3_user_data(context)!=0;
sl@0	1139	cmp = sqlite3MemCompare(pBest, pArg, pColl);
sl@0	1140	if( (max && cmp<0) \|\| (!max && cmp>0) ){
sl@0	1141	sqlite3VdbeMemCopy(pBest, pArg);
sl@0	1142	}
sl@0	1143	}else{
sl@0	1144	sqlite3VdbeMemCopy(pBest, pArg);
sl@0	1145	}
sl@0	1146	}
sl@0	1147	static void minMaxFinalize(sqlite3_context *context){
sl@0	1148	sqlite3_value *pRes;
sl@0	1149	pRes = (sqlite3_value *)sqlite3_aggregate_context(context, 0);
sl@0	1150	if( pRes ){
sl@0	1151	if( pRes->flags ){
sl@0	1152	sqlite3_result_value(context, pRes);
sl@0	1153	}
sl@0	1154	sqlite3VdbeMemRelease(pRes);
sl@0	1155	}
sl@0	1156	}
sl@0	1157
sl@0	1158	/*
sl@0	1159	** group_concat(EXPR, ?SEPARATOR?)
sl@0	1160	*/
sl@0	1161	static void groupConcatStep(
sl@0	1162	sqlite3_context *context,
sl@0	1163	int argc,
sl@0	1164	sqlite3_value **argv
sl@0	1165	){
sl@0	1166	const char *zVal;
sl@0	1167	StrAccum *pAccum;
sl@0	1168	const char *zSep;
sl@0	1169	int nVal, nSep, i;
sl@0	1170	if( argc==0 \|\| sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
sl@0	1171	pAccum = (StrAccum)sqlite3_aggregate_context(context, sizeof(pAccum));
sl@0	1172
sl@0	1173	if( pAccum ){
sl@0	1174	sqlite3 *db = sqlite3_context_db_handle(context);
sl@0	1175	pAccum->useMalloc = 1;
sl@0	1176	pAccum->mxAlloc = db->aLimit[SQLITE_LIMIT_LENGTH];
sl@0	1177	if( pAccum->nChar ){
sl@0	1178	if( argc>1 ){
sl@0	1179	zSep = (char*)sqlite3_value_text(argv[argc-1]);
sl@0	1180	nSep = sqlite3_value_bytes(argv[argc-1]);
sl@0	1181	}else{
sl@0	1182	zSep = ",";
sl@0	1183	nSep = 1;
sl@0	1184	}
sl@0	1185	sqlite3StrAccumAppend(pAccum, zSep, nSep);
sl@0	1186	}
sl@0	1187	i = 0;
sl@0	1188	do{
sl@0	1189	zVal = (char*)sqlite3_value_text(argv[i]);
sl@0	1190	nVal = sqlite3_value_bytes(argv[i]);
sl@0	1191	sqlite3StrAccumAppend(pAccum, zVal, nVal);
sl@0	1192	i++;
sl@0	1193	}while( i<argc-1 );
sl@0	1194	}
sl@0	1195	}
sl@0	1196	static void groupConcatFinalize(sqlite3_context *context){
sl@0	1197	StrAccum *pAccum;
sl@0	1198	pAccum = sqlite3_aggregate_context(context, 0);
sl@0	1199	if( pAccum ){
sl@0	1200	if( pAccum->tooBig ){
sl@0	1201	sqlite3_result_error_toobig(context);
sl@0	1202	}else if( pAccum->mallocFailed ){
sl@0	1203	sqlite3_result_error_nomem(context);
sl@0	1204	}else{
sl@0	1205	sqlite3_result_text(context, sqlite3StrAccumFinish(pAccum), -1,
sl@0	1206	sqlite3_free);
sl@0	1207	}
sl@0	1208	}
sl@0	1209	}
sl@0	1210
sl@0	1211	/*
sl@0	1212	** This function registered all of the above C functions as SQL
sl@0	1213	** functions. This should be the only routine in this file with
sl@0	1214	** external linkage.
sl@0	1215	*/
sl@0	1216	void sqlite3RegisterBuiltinFunctions(sqlite3 *db){
sl@0	1217	#ifndef SQLITE_OMIT_ALTERTABLE
sl@0	1218	sqlite3AlterFunctions(db);
sl@0	1219	#endif
sl@0	1220	#ifndef SQLITE_OMIT_PARSER
sl@0	1221	sqlite3AttachFunctions(db);
sl@0	1222	#endif
sl@0	1223	if( !db->mallocFailed ){
sl@0	1224	int rc = sqlite3_overload_function(db, "MATCH", 2);
sl@0	1225	assert( rc==SQLITE_NOMEM \|\| rc==SQLITE_OK );
sl@0	1226	if( rc==SQLITE_NOMEM ){
sl@0	1227	db->mallocFailed = 1;
sl@0	1228	}
sl@0	1229	}
sl@0	1230	#ifdef SQLITE_SSE
sl@0	1231	(void)sqlite3SseFunctions(db);
sl@0	1232	#endif
sl@0	1233	}
sl@0	1234
sl@0	1235	/*
sl@0	1236	** Set the LIKEOPT flag on the 2-argument function with the given name.
sl@0	1237	*/
sl@0	1238	static void setLikeOptFlag(sqlite3 db, const char zName, int flagVal){
sl@0	1239	FuncDef *pDef;
sl@0	1240	pDef = sqlite3FindFunction(db, zName, strlen(zName), 2, SQLITE_UTF8, 0);
sl@0	1241	if( pDef ){
sl@0	1242	pDef->flags = flagVal;
sl@0	1243	}
sl@0	1244	}
sl@0	1245
sl@0	1246	/*
sl@0	1247	** Register the built-in LIKE and GLOB functions. The caseSensitive
sl@0	1248	** parameter determines whether or not the LIKE operator is case
sl@0	1249	** sensitive. GLOB is always case sensitive.
sl@0	1250	*/
sl@0	1251	void sqlite3RegisterLikeFunctions(sqlite3 *db, int caseSensitive){
sl@0	1252	struct compareInfo *pInfo;
sl@0	1253	if( caseSensitive ){
sl@0	1254	pInfo = (struct compareInfo*)&likeInfoAlt;
sl@0	1255	}else{
sl@0	1256	pInfo = (struct compareInfo*)&likeInfoNorm;
sl@0	1257	}
sl@0	1258	sqlite3CreateFunc(db, "like", 2, SQLITE_UTF8, pInfo, likeFunc, 0, 0);
sl@0	1259	sqlite3CreateFunc(db, "like", 3, SQLITE_UTF8, pInfo, likeFunc, 0, 0);
sl@0	1260	sqlite3CreateFunc(db, "glob", 2, SQLITE_UTF8,
sl@0	1261	(struct compareInfo*)&globInfo, likeFunc, 0,0);
sl@0	1262	setLikeOptFlag(db, "glob", SQLITE_FUNC_LIKE \| SQLITE_FUNC_CASE);
sl@0	1263	setLikeOptFlag(db, "like",
sl@0	1264	caseSensitive ? (SQLITE_FUNC_LIKE \| SQLITE_FUNC_CASE) : SQLITE_FUNC_LIKE);
sl@0	1265	}
sl@0	1266
sl@0	1267	/*
sl@0	1268	** pExpr points to an expression which implements a function. If
sl@0	1269	** it is appropriate to apply the LIKE optimization to that function
sl@0	1270	** then set aWc[0] through aWc[2] to the wildcard characters and
sl@0	1271	** return TRUE. If the function is not a LIKE-style function then
sl@0	1272	** return FALSE.
sl@0	1273	*/
sl@0	1274	int sqlite3IsLikeFunction(sqlite3 db, Expr pExpr, int pIsNocase, char aWc){
sl@0	1275	FuncDef *pDef;
sl@0	1276	if( pExpr->op!=TK_FUNCTION \|\| !pExpr->pList ){
sl@0	1277	return 0;
sl@0	1278	}
sl@0	1279	if( pExpr->pList->nExpr!=2 ){
sl@0	1280	return 0;
sl@0	1281	}
sl@0	1282	pDef = sqlite3FindFunction(db, (char*)pExpr->token.z, pExpr->token.n, 2,
sl@0	1283	SQLITE_UTF8, 0);
sl@0	1284	if( pDef==0 \|\| (pDef->flags & SQLITE_FUNC_LIKE)==0 ){
sl@0	1285	return 0;
sl@0	1286	}
sl@0	1287
sl@0	1288	/* The memcpy() statement assumes that the wildcard characters are
sl@0	1289	** the first three statements in the compareInfo structure. The
sl@0	1290	** asserts() that follow verify that assumption
sl@0	1291	*/
sl@0	1292	memcpy(aWc, pDef->pUserData, 3);
sl@0	1293	assert( (char)&likeInfoAlt == (char)&likeInfoAlt.matchAll );
sl@0	1294	assert( &((char)&likeInfoAlt)[1] == (char)&likeInfoAlt.matchOne );
sl@0	1295	assert( &((char)&likeInfoAlt)[2] == (char)&likeInfoAlt.matchSet );
sl@0	1296	*pIsNocase = (pDef->flags & SQLITE_FUNC_CASE)==0;
sl@0	1297	return 1;
sl@0	1298	}
sl@0	1299
sl@0	1300	/*
sl@0	1301	** All all of the FuncDef structures in the aBuiltinFunc[] array above
sl@0	1302	** to the global function hash table. This occurs at start-time (as
sl@0	1303	** a consequence of calling sqlite3_initialize()).
sl@0	1304	**
sl@0	1305	** After this routine runs
sl@0	1306	*/
sl@0	1307	void sqlite3RegisterGlobalFunctions(void){
sl@0	1308	/*
sl@0	1309	** The following array holds FuncDef structures for all of the functions
sl@0	1310	** defined in this file.
sl@0	1311	**
sl@0	1312	** The array cannot be constant since changes are made to the
sl@0	1313	** FuncDef.pHash elements at start-time. The elements of this array
sl@0	1314	** are read-only after initialization is complete.
sl@0	1315	*/
sl@0	1316	static SQLITE_WSD FuncDef aBuiltinFunc[] = {
sl@0	1317	FUNCTION(ltrim, 1, 1, 0, trimFunc ),
sl@0	1318	FUNCTION(ltrim, 2, 1, 0, trimFunc ),
sl@0	1319	FUNCTION(rtrim, 1, 2, 0, trimFunc ),
sl@0	1320	FUNCTION(rtrim, 2, 2, 0, trimFunc ),
sl@0	1321	FUNCTION(trim, 1, 3, 0, trimFunc ),
sl@0	1322	FUNCTION(trim, 2, 3, 0, trimFunc ),
sl@0	1323	FUNCTION(min, -1, 0, 1, minmaxFunc ),
sl@0	1324	FUNCTION(min, 0, 0, 1, 0 ),
sl@0	1325	AGGREGATE(min, 1, 0, 1, minmaxStep, minMaxFinalize ),
sl@0	1326	FUNCTION(max, -1, 1, 1, minmaxFunc ),
sl@0	1327	FUNCTION(max, 0, 1, 1, 0 ),
sl@0	1328	AGGREGATE(max, 1, 1, 1, minmaxStep, minMaxFinalize ),
sl@0	1329	FUNCTION(typeof, 1, 0, 0, typeofFunc ),
sl@0	1330	FUNCTION(length, 1, 0, 0, lengthFunc ),
sl@0	1331	FUNCTION(substr, 2, 0, 0, substrFunc ),
sl@0	1332	FUNCTION(substr, 3, 0, 0, substrFunc ),
sl@0	1333	FUNCTION(abs, 1, 0, 0, absFunc ),
sl@0	1334	FUNCTION(round, 1, 0, 0, roundFunc ),
sl@0	1335	FUNCTION(round, 2, 0, 0, roundFunc ),
sl@0	1336	FUNCTION(upper, 1, 0, 0, upperFunc ),
sl@0	1337	FUNCTION(lower, 1, 0, 0, lowerFunc ),
sl@0	1338	FUNCTION(coalesce, 1, 0, 0, 0 ),
sl@0	1339	FUNCTION(coalesce, -1, 0, 0, ifnullFunc ),
sl@0	1340	FUNCTION(coalesce, 0, 0, 0, 0 ),
sl@0	1341	FUNCTION(hex, 1, 0, 0, hexFunc ),
sl@0	1342	FUNCTION(ifnull, 2, 0, 1, ifnullFunc ),
sl@0	1343	FUNCTION(random, -1, 0, 0, randomFunc ),
sl@0	1344	FUNCTION(randomblob, 1, 0, 0, randomBlob ),
sl@0	1345	FUNCTION(nullif, 2, 0, 1, nullifFunc ),
sl@0	1346	FUNCTION(sqlite_version, 0, 0, 0, versionFunc ),
sl@0	1347	FUNCTION(quote, 1, 0, 0, quoteFunc ),
sl@0	1348	FUNCTION(last_insert_rowid, 0, 0, 0, last_insert_rowid),
sl@0	1349	FUNCTION(changes, 0, 0, 0, changes ),
sl@0	1350	FUNCTION(total_changes, 0, 0, 0, total_changes ),
sl@0	1351	FUNCTION(replace, 3, 0, 0, replaceFunc ),
sl@0	1352	FUNCTION(zeroblob, 1, 0, 0, zeroblobFunc ),
sl@0	1353	#ifdef SQLITE_SOUNDEX
sl@0	1354	FUNCTION(soundex, 1, 0, 0, soundexFunc ),
sl@0	1355	#endif
sl@0	1356	#ifndef SQLITE_OMIT_LOAD_EXTENSION
sl@0	1357	FUNCTION(load_extension, 1, 0, 0, loadExt ),
sl@0	1358	FUNCTION(load_extension, 2, 0, 0, loadExt ),
sl@0	1359	#endif
sl@0	1360	AGGREGATE(sum, 1, 0, 0, sumStep, sumFinalize ),
sl@0	1361	AGGREGATE(total, 1, 0, 0, sumStep, totalFinalize ),
sl@0	1362	AGGREGATE(avg, 1, 0, 0, sumStep, avgFinalize ),
sl@0	1363	AGGREGATE(count, 0, 0, 0, countStep, countFinalize ),
sl@0	1364	AGGREGATE(count, 1, 0, 0, countStep, countFinalize ),
sl@0	1365	AGGREGATE(group_concat, -1, 0, 0, groupConcatStep, groupConcatFinalize),
sl@0	1366
sl@0	1367	LIKEFUNC(glob, 2, &globInfo, SQLITE_FUNC_LIKE\|SQLITE_FUNC_CASE),
sl@0	1368	#ifdef SQLITE_CASE_SENSITIVE_LIKE
sl@0	1369	LIKEFUNC(like, 2, &likeInfoAlt, SQLITE_FUNC_LIKE\|SQLITE_FUNC_CASE),
sl@0	1370	LIKEFUNC(like, 3, &likeInfoAlt, SQLITE_FUNC_LIKE\|SQLITE_FUNC_CASE),
sl@0	1371	#else
sl@0	1372	LIKEFUNC(like, 2, &likeInfoNorm, SQLITE_FUNC_LIKE),
sl@0	1373	LIKEFUNC(like, 3, &likeInfoNorm, SQLITE_FUNC_LIKE),
sl@0	1374	#endif
sl@0	1375	};
sl@0	1376
sl@0	1377	int i;
sl@0	1378	FuncDefHash *pHash = &GLOBAL(FuncDefHash, sqlite3GlobalFunctions);
sl@0	1379	FuncDef aFunc = (FuncDef)&GLOBAL(FuncDef, aBuiltinFunc);
sl@0	1380
sl@0	1381	for(i=0; i<ArraySize(aBuiltinFunc); i++){
sl@0	1382	sqlite3FuncDefInsert(pHash, &aFunc[i]);
sl@0	1383	}
sl@0	1384	sqlite3RegisterDateTimeFunctions();
sl@0	1385	}
sl@0	1386
sl@0	1387	int sqlite3RegisterInternalUtf8Like(sqlite3 *db){
sl@0	1388	int rc;
sl@0	1389	void pCtx = (void )&likeInfoNorm;
sl@0	1390	rc = sqlite3_create_function(db, "like", 2, SQLITE_UTF8, pCtx, likeFunc, 0, 0);
sl@0	1391	if( rc!=SQLITE_OK ) return rc;
sl@0	1392	rc = sqlite3_create_function(db, "like", 3, SQLITE_UTF8, pCtx, likeFunc, 0, 0);
sl@0	1393	if( rc!=SQLITE_OK ) return rc;
sl@0	1394	setLikeOptFlag(db, "like", SQLITE_FUNC_LIKE);
sl@0	1395	return SQLITE_OK;
sl@0	1396	}

author	sl@SLION-WIN7.fritz.box
	Fri, 15 Jun 2012 03:10:57 +0200
changeset 0	bde4ae8d615e
permissions	-rw-r--r--