--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/persistentstorage/sql/SQLite/func.c Fri Jan 22 11:06:30 2010 +0200
@@ -0,0 +1,1399 @@
+/*
+** 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 1.196 2008/07/28 19:34:53 drh Exp $
+*/
+#include "sqliteInt.h"
+#include <ctype.h>
+#include <stdlib.h>
+#include <assert.h>
+#include "vdbeInt.h"
+
+
+/*
+** Return the collating function associated with a function.
+*/
+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 = 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 ){
+ 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 unsigned char *z = sqlite3_value_text(argv[0]);
+ if( z==0 ) return;
+ len = 0;
+ while( *z ){
+ len++;
+ SQLITE_SKIP_UTF8(z);
+ }
+ 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 ){
+ if( (iVal<<1)==0 ){
+ sqlite3_result_error(context, "integer overflow", -1);
+ return;
+ }
+ iVal = -iVal;
+ }
+ 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;
+ sqlite3_result_double(context, rVal);
+ break;
+ }
+ }
+}
+
+/*
+** 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[].
+*/
+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]);
+ 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;
+ for(z2=z; *z2; len++){
+ SQLITE_SKIP_UTF8(z2);
+ }
+ }
+ p1 = sqlite3_value_int(argv[1]);
+ if( argc==3 ){
+ p2 = sqlite3_value_int(argv[2]);
+ }else{
+ p2 = sqlite3_context_db_handle(context)->aLimit[SQLITE_LIMIT_LENGTH];
+ }
+ if( p1<0 ){
+ p1 += len;
+ if( p1<0 ){
+ p2 += p1;
+ p1 = 0;
+ }
+ }else if( p1>0 ){
+ p1--;
+ }
+ if( p1+p2>len ){
+ p2 = len-p1;
+ }
+ if( p0type!=SQLITE_BLOB ){
+ while( *z && p1 ){
+ SQLITE_SKIP_UTF8(z);
+ p1--;
+ }
+ for(z2=z; *z2 && p2; p2--){
+ SQLITE_SKIP_UTF8(z2);
+ }
+ sqlite3_result_text(context, (char*)z, z2-z, SQLITE_TRANSIENT);
+ }else{
+ if( p2<0 ) p2 = 0;
+ sqlite3_result_blob(context, (char*)&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[500]; /* larger than the %f representation of the largest double */
+ 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( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
+ r = sqlite3_value_double(argv[0]);
+ sqlite3_snprintf(sizeof(zBuf),zBuf,"%.*f",n,r);
+ sqlite3AtoF(zBuf, &r);
+ sqlite3_result_double(context, r);
+}
+
+/*
+** Allocate nByte bytes of space using sqlite3_malloc(). If the
+** allocation fails, call sqlite3_result_error_nomem() to notify
+** the database handle that malloc() has failed.
+*/
+static void *contextMalloc(sqlite3_context *context, i64 nByte){
+ char *z;
+ if( nByte>sqlite3_context_db_handle(context)->aLimit[SQLITE_LIMIT_LENGTH] ){
+ sqlite3_result_error_toobig(context);
+ z = 0;
+ }else{
+ z = sqlite3Malloc(nByte);
+ if( !z && nByte>0 ){
+ 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;
+ if( argc<1 || SQLITE_NULL==sqlite3_value_type(argv[0]) ) return;
+ 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 ){
+ memcpy(z1, z2, n+1);
+ for(i=0; z1[i]; i++){
+ z1[i] = toupper(z1[i]);
+ }
+ sqlite3_result_text(context, z1, -1, sqlite3_free);
+ }
+ }
+}
+static void lowerFunc(sqlite3_context *context, int argc, sqlite3_value **argv){
+ char *z1;
+ const char *z2;
+ int i, n;
+ if( argc<1 || SQLITE_NULL==sqlite3_value_type(argv[0]) ) return;
+ 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 ){
+ memcpy(z1, z2, n+1);
+ for(i=0; z1[i]; i++){
+ z1[i] = tolower(z1[i]);
+ }
+ sqlite3_result_text(context, z1, -1, sqlite3_free);
+ }
+ }
+}
+
+/*
+** 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
+){
+ sqlite_int64 r;
+ sqlite3_randomness(sizeof(r), &r);
+ if( (r<<1)==0 ) r = 0; /* Prevent 0x8000.... as the result so that we */
+ /* can always do abs() of the result */
+ 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
+){
+ int n;
+ unsigned char *p;
+ assert( argc==1 );
+ n = sqlite3_value_int(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 arg,
+ sqlite3_value **argv
+){
+ sqlite3 *db = sqlite3_context_db_handle(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
+){
+ sqlite3 *db = sqlite3_context_db_handle(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
+){
+ sqlite3 *db = sqlite3_context_db_handle(context);
+ sqlite3_result_int(context, sqlite3_total_changes(db));
+}
+
+/*
+** A structure defining how to do GLOB-style comparisons.
+*/
+struct compareInfo {
+ u8 matchAll;
+ u8 matchOne;
+ u8 matchSet;
+ u8 noCase;
+};
+
+/*
+** For LIKE and GLOB matching on EBCDIC machines, assume that every
+** character is exactly one byte in size. Also, all characters are
+** able to participate in upper-case-to-lower-case mappings in EBCDIC
+** whereas only characters less than 0x80 do in ASCII.
+*/
+#if defined(SQLITE_EBCDIC)
+# define sqlite3Utf8Read(A,B,C) (*(A++))
+# define GlogUpperToLower(A) A = sqlite3UpperToLower[A]
+#else
+# define GlogUpperToLower(A) if( A<0x80 ){ A = sqlite3UpperToLower[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 };
+
+/*
+** Compare two UTF-8 strings for equality where the first string can
+** potentially be a "glob" expression. Return true (1) if they
+** are the same and false (0) if they are different.
+**
+** 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.
+**
+** This routine is usually quick, but can be N**2 in the worst case.
+**
+** Hints: to match '*' or '?', put them in "[]". Like this:
+**
+** abc[*]xyz Matches "abc*xyz" only
+*/
+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 */
+ const int esc /* The escape character */
+){
+ int c, c2;
+ int invert;
+ int seen;
+ u8 matchOne = pInfo->matchOne;
+ u8 matchAll = pInfo->matchAll;
+ u8 matchSet = pInfo->matchSet;
+ u8 noCase = pInfo->noCase;
+ int prevEscape = 0; /* True if the previous character was 'escape' */
+
+ while( (c = sqlite3Utf8Read(zPattern,0,&zPattern))!=0 ){
+ if( !prevEscape && c==matchAll ){
+ while( (c=sqlite3Utf8Read(zPattern,0,&zPattern)) == matchAll
+ || c == matchOne ){
+ if( c==matchOne && sqlite3Utf8Read(zString, 0, &zString)==0 ){
+ return 0;
+ }
+ }
+ if( c==0 ){
+ return 1;
+ }else if( c==esc ){
+ c = sqlite3Utf8Read(zPattern, 0, &zPattern);
+ if( c==0 ){
+ return 0;
+ }
+ }else if( c==matchSet ){
+ assert( esc==0 ); /* This is GLOB, not LIKE */
+ assert( matchSet<0x80 ); /* '[' is a single-byte character */
+ while( *zString && patternCompare(&zPattern[-1],zString,pInfo,esc)==0 ){
+ SQLITE_SKIP_UTF8(zString);
+ }
+ return *zString!=0;
+ }
+ while( (c2 = sqlite3Utf8Read(zString,0,&zString))!=0 ){
+ if( noCase ){
+ GlogUpperToLower(c2);
+ GlogUpperToLower(c);
+ while( c2 != 0 && c2 != c ){
+ c2 = sqlite3Utf8Read(zString, 0, &zString);
+ GlogUpperToLower(c2);
+ }
+ }else{
+ while( c2 != 0 && c2 != c ){
+ c2 = sqlite3Utf8Read(zString, 0, &zString);
+ }
+ }
+ if( c2==0 ) return 0;
+ if( patternCompare(zPattern,zString,pInfo,esc) ) return 1;
+ }
+ return 0;
+ }else if( !prevEscape && c==matchOne ){
+ if( sqlite3Utf8Read(zString, 0, &zString)==0 ){
+ return 0;
+ }
+ }else if( c==matchSet ){
+ int prior_c = 0;
+ assert( esc==0 ); /* This only occurs for GLOB, not LIKE */
+ seen = 0;
+ invert = 0;
+ c = sqlite3Utf8Read(zString, 0, &zString);
+ if( c==0 ) return 0;
+ c2 = sqlite3Utf8Read(zPattern, 0, &zPattern);
+ if( c2=='^' ){
+ invert = 1;
+ c2 = sqlite3Utf8Read(zPattern, 0, &zPattern);
+ }
+ if( c2==']' ){
+ if( c==']' ) seen = 1;
+ c2 = sqlite3Utf8Read(zPattern, 0, &zPattern);
+ }
+ while( c2 && c2!=']' ){
+ if( c2=='-' && zPattern[0]!=']' && zPattern[0]!=0 && prior_c>0 ){
+ c2 = sqlite3Utf8Read(zPattern, 0, &zPattern);
+ if( c>=prior_c && c<=c2 ) seen = 1;
+ prior_c = 0;
+ }else{
+ if( c==c2 ){
+ seen = 1;
+ }
+ prior_c = c2;
+ }
+ c2 = sqlite3Utf8Read(zPattern, 0, &zPattern);
+ }
+ if( c2==0 || (seen ^ invert)==0 ){
+ return 0;
+ }
+ }else if( esc==c && !prevEscape ){
+ prevEscape = 1;
+ }else{
+ c2 = sqlite3Utf8Read(zString, 0, &zString);
+ if( noCase ){
+ GlogUpperToLower(c);
+ GlogUpperToLower(c2);
+ }
+ if( c!=c2 ){
+ return 0;
+ }
+ prevEscape = 0;
+ }
+ }
+ return *zString==0;
+}
+
+/*
+** 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 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).
+**
+** 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;
+ int escape = 0;
+ sqlite3 *db = sqlite3_context_db_handle(context);
+
+ zB = sqlite3_value_text(argv[0]);
+ zA = sqlite3_value_text(argv[1]);
+
+ /* Limit the length of the LIKE or GLOB pattern to avoid problems
+ ** of deep recursion and N*N behavior in patternCompare().
+ */
+ if( sqlite3_value_bytes(argv[0]) >
+ db->aLimit[SQLITE_LIMIT_LIKE_PATTERN_LENGTH] ){
+ sqlite3_result_error(context, "LIKE or GLOB pattern too complex", -1);
+ return;
+ }
+ assert( zB==sqlite3_value_text(argv[0]) ); /* Encoding did not change */
+
+ 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, 0, &zEsc);
+ }
+ if( zA && zB ){
+ struct compareInfo *pInfo = sqlite3_user_data(context);
+#ifdef SQLITE_TEST
+ sqlite3_like_count++;
+#endif
+
+ sqlite3_result_int(context, patternCompare(zB, zA, pInfo, escape));
+ }
+}
+
+/*
+** 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);
+}
+
+/* Array for converting from half-bytes (nybbles) into ASCII hex
+** digits. */
+static const char hexdigits[] = {
+ '0', '1', '2', '3', '4', '5', '6', '7',
+ '8', '9', 'A', 'B', 'C', 'D', 'E', 'F'
+};
+
+/*
+** 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: {
+ char *zText = 0;
+ char const *zBlob = sqlite3_value_blob(argv[0]);
+ int nBlob = sqlite3_value_bytes(argv[0]);
+ assert( zBlob==sqlite3_value_blob(argv[0]) ); /* No encoding change */
+ zText = (char *)contextMalloc(context, (2*(i64)nBlob)+4);
+ if( zText ){
+ 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);
+ sqlite3_free(zText);
+ }
+ break;
+ }
+ case SQLITE_TEXT: {
+ int i,j;
+ u64 n;
+ const unsigned char *zArg = sqlite3_value_text(argv[0]);
+ char *z;
+
+ if( zArg==0 ) return;
+ for(i=0, n=0; zArg[i]; i++){ if( zArg[i]=='\'' ) n++; }
+ z = contextMalloc(context, ((i64)i)+((i64)n)+3);
+ if( z ){
+ 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, sqlite3_free);
+ }
+ }
+ }
+}
+
+/*
+** The hex() function. Interpret the argument as a blob. Return
+** a hexadecimal rendering as text.
+*/
+static void hexFunc(
+ sqlite3_context *context,
+ int argc,
+ sqlite3_value **argv
+){
+ int i, n;
+ const unsigned char *pBlob;
+ char *zHex, *z;
+ assert( argc==1 );
+ pBlob = sqlite3_value_blob(argv[0]);
+ n = sqlite3_value_bytes(argv[0]);
+ assert( pBlob==sqlite3_value_blob(argv[0]) ); /* No encoding change */
+ z = zHex = contextMalloc(context, ((i64)n)*2 + 1);
+ if( zHex ){
+ for(i=0; i<n; i++, pBlob++){
+ unsigned char c = *pBlob;
+ *(z++) = hexdigits[(c>>4)&0xf];
+ *(z++) = hexdigits[c&0xf];
+ }
+ *z = 0;
+ sqlite3_result_text(context, zHex, n*2, sqlite3_free);
+ }
+}
+
+/*
+** The zeroblob(N) function returns a zero-filled blob of size N bytes.
+*/
+static void zeroblobFunc(
+ sqlite3_context *context,
+ int argc,
+ sqlite3_value **argv
+){
+ i64 n;
+ assert( argc==1 );
+ n = sqlite3_value_int64(argv[0]);
+ if( n>SQLITE_MAX_LENGTH ){
+ sqlite3_result_error_toobig(context);
+ }else{
+ sqlite3_result_zeroblob(context, n);
+ }
+}
+
+/*
+** The replace() function. Three arguments are all strings: call
+** them A, B, and C. The result is also a string which is derived
+** from A by replacing every occurance of B with C. The match
+** must be exact. Collating sequences are not used.
+*/
+static void replaceFunc(
+ sqlite3_context *context,
+ int argc,
+ sqlite3_value **argv
+){
+ const unsigned char *zStr; /* The input string A */
+ const unsigned char *zPattern; /* The pattern string B */
+ const unsigned char *zRep; /* The replacement string C */
+ unsigned char *zOut; /* The output */
+ int nStr; /* Size of zStr */
+ int nPattern; /* Size of zPattern */
+ int nRep; /* Size of zRep */
+ i64 nOut; /* Maximum size of zOut */
+ int loopLimit; /* Last zStr[] that might match zPattern[] */
+ int i, j; /* Loop counters */
+
+ assert( argc==3 );
+ zStr = sqlite3_value_text(argv[0]);
+ if( zStr==0 ) return;
+ nStr = sqlite3_value_bytes(argv[0]);
+ assert( zStr==sqlite3_value_text(argv[0]) ); /* No encoding change */
+ zPattern = sqlite3_value_text(argv[1]);
+ if( zPattern==0 || zPattern[0]==0 ) return;
+ nPattern = sqlite3_value_bytes(argv[1]);
+ assert( zPattern==sqlite3_value_text(argv[1]) ); /* No encoding change */
+ zRep = sqlite3_value_text(argv[2]);
+ if( zRep==0 ) return;
+ nRep = sqlite3_value_bytes(argv[2]);
+ assert( zRep==sqlite3_value_text(argv[2]) );
+ nOut = nStr + 1;
+ assert( nOut<SQLITE_MAX_LENGTH );
+ zOut = contextMalloc(context, (i64)nOut);
+ if( zOut==0 ){
+ return;
+ }
+ loopLimit = nStr - nPattern;
+ for(i=j=0; i<=loopLimit; i++){
+ if( zStr[i]!=zPattern[0] || memcmp(&zStr[i], zPattern, nPattern) ){
+ zOut[j++] = zStr[i];
+ }else{
+ u8 *zOld;
+ sqlite3 *db = sqlite3_context_db_handle(context);
+ nOut += nRep - nPattern;
+ if( nOut>=db->aLimit[SQLITE_LIMIT_LENGTH] ){
+ sqlite3_result_error_toobig(context);
+ sqlite3DbFree(db, zOut);
+ return;
+ }
+ zOld = zOut;
+ zOut = sqlite3_realloc(zOut, (int)nOut);
+ if( zOut==0 ){
+ sqlite3_result_error_nomem(context);
+ sqlite3DbFree(db, zOld);
+ return;
+ }
+ memcpy(&zOut[j], zRep, nRep);
+ j += nRep;
+ i += nPattern-1;
+ }
+ }
+ assert( j+nStr-i+1==nOut );
+ memcpy(&zOut[j], &zStr[i], nStr-i);
+ j += nStr - i;
+ assert( j<=nOut );
+ zOut[j] = 0;
+ sqlite3_result_text(context, (char*)zOut, j, sqlite3_free);
+}
+
+/*
+** Implementation of the TRIM(), LTRIM(), and RTRIM() functions.
+** The userdata is 0x1 for left trim, 0x2 for right trim, 0x3 for both.
+*/
+static void trimFunc(
+ sqlite3_context *context,
+ int argc,
+ sqlite3_value **argv
+){
+ const unsigned char *zIn; /* Input string */
+ const unsigned char *zCharSet; /* Set of characters to trim */
+ int nIn; /* Number of bytes in input */
+ int flags; /* 1: trimleft 2: trimright 3: trim */
+ int i; /* Loop counter */
+ unsigned char *aLen; /* Length of each character in zCharSet */
+ unsigned char **azChar; /* Individual characters in zCharSet */
+ int nChar; /* Number of characters in zCharSet */
+
+ if( sqlite3_value_type(argv[0])==SQLITE_NULL ){
+ return;
+ }
+ zIn = sqlite3_value_text(argv[0]);
+ if( zIn==0 ) return;
+ nIn = sqlite3_value_bytes(argv[0]);
+ assert( zIn==sqlite3_value_text(argv[0]) );
+ if( argc==1 ){
+ static const unsigned char lenOne[] = { 1 };
+ static const unsigned char *azOne[] = { (u8*)" " };
+ nChar = 1;
+ aLen = (u8*)lenOne;
+ azChar = (unsigned char **)azOne;
+ zCharSet = 0;
+ }else if( (zCharSet = sqlite3_value_text(argv[1]))==0 ){
+ return;
+ }else{
+ const unsigned char *z;
+ for(z=zCharSet, nChar=0; *z; nChar++){
+ SQLITE_SKIP_UTF8(z);
+ }
+ if( nChar>0 ){
+ azChar = contextMalloc(context, ((i64)nChar)*(sizeof(char*)+1));
+ if( azChar==0 ){
+ return;
+ }
+ aLen = (unsigned char*)&azChar[nChar];
+ for(z=zCharSet, nChar=0; *z; nChar++){
+ azChar[nChar] = (unsigned char *)z;
+ SQLITE_SKIP_UTF8(z);
+ aLen[nChar] = z - azChar[nChar];
+ }
+ }
+ }
+ if( nChar>0 ){
+ flags = SQLITE_PTR_TO_INT(sqlite3_user_data(context));
+ if( flags & 1 ){
+ while( nIn>0 ){
+ int len;
+ for(i=0; i<nChar; i++){
+ len = aLen[i];
+ if( memcmp(zIn, azChar[i], len)==0 ) break;
+ }
+ if( i>=nChar ) break;
+ zIn += len;
+ nIn -= len;
+ }
+ }
+ if( flags & 2 ){
+ while( nIn>0 ){
+ int len;
+ for(i=0; i<nChar; i++){
+ len = aLen[i];
+ if( len<=nIn && memcmp(&zIn[nIn-len],azChar[i],len)==0 ) break;
+ }
+ if( i>=nChar ) break;
+ nIn -= len;
+ }
+ }
+ if( zCharSet ){
+ sqlite3_free(azChar);
+ }
+ }
+ sqlite3_result_text(context, (char*)zIn, nIn, SQLITE_TRANSIENT);
+}
+
+#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 u8 *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 = (u8*)sqlite3_value_text(argv[0]);
+ if( zIn==0 ) zIn = (u8*)"";
+ for(i=0; zIn[i] && !isalpha(zIn[i]); i++){}
+ if( zIn[i] ){
+ u8 prevcode = iCode[zIn[i]&0x7f];
+ zResult[0] = toupper(zIn[i]);
+ for(j=1; j<4 && zIn[i]; i++){
+ int code = iCode[zIn[i]&0x7f];
+ if( code>0 ){
+ if( code!=prevcode ){
+ prevcode = code;
+ zResult[j++] = code + '0';
+ }
+ }else{
+ prevcode = 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
+
+#ifndef SQLITE_OMIT_LOAD_EXTENSION
+/*
+** A function that loads a shared-library extension then returns NULL.
+*/
+static void loadExt(sqlite3_context *context, int argc, sqlite3_value **argv){
+ const char *zFile = (const char *)sqlite3_value_text(argv[0]);
+ const char *zProc;
+ sqlite3 *db = sqlite3_context_db_handle(context);
+ char *zErrMsg = 0;
+
+ if( argc==2 ){
+ zProc = (const char *)sqlite3_value_text(argv[1]);
+ }else{
+ zProc = 0;
+ }
+ if( zFile && sqlite3_load_extension(db, zFile, zProc, &zErrMsg) ){
+ sqlite3_result_error(context, zErrMsg, -1);
+ sqlite3_free(zErrMsg);
+ }
+}
+#endif
+
+
+/*
+** An instance of the following structure holds the context of a
+** sum() or avg() aggregate computation.
+*/
+typedef struct SumCtx SumCtx;
+struct SumCtx {
+ double rSum; /* Floating point sum */
+ i64 iSum; /* Integer sum */
+ i64 cnt; /* Number of elements summed */
+ u8 overflow; /* True if integer overflow seen */
+ u8 approx; /* True if non-integer value was input to the sum */
+};
+
+/*
+** Routines used to compute the sum, average, and total.
+**
+** The SUM() function follows the (broken) SQL standard which means
+** that it returns NULL if it sums over no inputs. TOTAL returns
+** 0.0 in that case. In addition, TOTAL always returns a float where
+** SUM might return an integer if it never encounters a floating point
+** value. TOTAL never fails, but SUM might through an exception if
+** it overflows an integer.
+*/
+static void sumStep(sqlite3_context *context, int argc, sqlite3_value **argv){
+ SumCtx *p;
+ int type;
+ assert( argc==1 );
+ p = sqlite3_aggregate_context(context, sizeof(*p));
+ type = sqlite3_value_numeric_type(argv[0]);
+ if( p && type!=SQLITE_NULL ){
+ p->cnt++;
+ if( type==SQLITE_INTEGER ){
+ i64 v = sqlite3_value_int64(argv[0]);
+ p->rSum += v;
+ if( (p->approx|p->overflow)==0 ){
+ i64 iNewSum = p->iSum + v;
+ int s1 = p->iSum >> (sizeof(i64)*8-1);
+ int s2 = v >> (sizeof(i64)*8-1);
+ int s3 = iNewSum >> (sizeof(i64)*8-1);
+ p->overflow = (s1&s2&~s3) | (~s1&~s2&s3);
+ p->iSum = iNewSum;
+ }
+ }else{
+ p->rSum += sqlite3_value_double(argv[0]);
+ p->approx = 1;
+ }
+ }
+}
+static void sumFinalize(sqlite3_context *context){
+ SumCtx *p;
+ p = sqlite3_aggregate_context(context, 0);
+ if( p && p->cnt>0 ){
+ if( p->overflow ){
+ sqlite3_result_error(context,"integer overflow",-1);
+ }else if( p->approx ){
+ sqlite3_result_double(context, p->rSum);
+ }else{
+ sqlite3_result_int64(context, p->iSum);
+ }
+ }
+}
+static void avgFinalize(sqlite3_context *context){
+ SumCtx *p;
+ p = sqlite3_aggregate_context(context, 0);
+ if( p && p->cnt>0 ){
+ sqlite3_result_double(context, p->rSum/(double)p->cnt);
+ }
+}
+static void totalFinalize(sqlite3_context *context){
+ SumCtx *p;
+ p = sqlite3_aggregate_context(context, 0);
+ sqlite3_result_double(context, p ? p->rSum : 0.0);
+}
+
+/*
+** The following structure keeps track of state information for the
+** count() aggregate function.
+*/
+typedef struct CountCtx CountCtx;
+struct CountCtx {
+ i64 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, 0);
+ sqlite3_result_int64(context, p ? p->n : 0);
+}
+
+/*
+** Routines to implement min() and max() aggregate functions.
+*/
+static void minmaxStep(sqlite3_context *context, int argc, sqlite3_value **argv){
+ Mem *pArg = (Mem *)argv[0];
+ Mem *pBest;
+
+ if( sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
+ pBest = (Mem *)sqlite3_aggregate_context(context, sizeof(*pBest));
+ if( !pBest ) return;
+
+ if( pBest->flags ){
+ int max;
+ int cmp;
+ 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)!=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, 0);
+ if( pRes ){
+ if( pRes->flags ){
+ sqlite3_result_value(context, pRes);
+ }
+ sqlite3VdbeMemRelease(pRes);
+ }
+}
+
+/*
+** group_concat(EXPR, ?SEPARATOR?)
+*/
+static void groupConcatStep(
+ sqlite3_context *context,
+ int argc,
+ sqlite3_value **argv
+){
+ const char *zVal;
+ StrAccum *pAccum;
+ const char *zSep;
+ int nVal, nSep, i;
+ if( argc==0 || sqlite3_value_type(argv[0])==SQLITE_NULL ) return;
+ pAccum = (StrAccum*)sqlite3_aggregate_context(context, sizeof(*pAccum));
+
+ if( pAccum ){
+ sqlite3 *db = sqlite3_context_db_handle(context);
+ pAccum->useMalloc = 1;
+ pAccum->mxAlloc = db->aLimit[SQLITE_LIMIT_LENGTH];
+ if( pAccum->nChar ){
+ if( argc>1 ){
+ zSep = (char*)sqlite3_value_text(argv[argc-1]);
+ nSep = sqlite3_value_bytes(argv[argc-1]);
+ }else{
+ zSep = ",";
+ nSep = 1;
+ }
+ sqlite3StrAccumAppend(pAccum, zSep, nSep);
+ }
+ i = 0;
+ do{
+ zVal = (char*)sqlite3_value_text(argv[i]);
+ nVal = sqlite3_value_bytes(argv[i]);
+ sqlite3StrAccumAppend(pAccum, zVal, nVal);
+ i++;
+ }while( i<argc-1 );
+ }
+}
+static void groupConcatFinalize(sqlite3_context *context){
+ StrAccum *pAccum;
+ pAccum = sqlite3_aggregate_context(context, 0);
+ if( pAccum ){
+ if( pAccum->tooBig ){
+ sqlite3_result_error_toobig(context);
+ }else if( pAccum->mallocFailed ){
+ sqlite3_result_error_nomem(context);
+ }else{
+ sqlite3_result_text(context, sqlite3StrAccumFinish(pAccum), -1,
+ sqlite3_free);
+ }
+ }
+}
+
+/*
+** 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(sqlite3 *db){
+ static const struct {
+ char *zName;
+ signed char nArg;
+ u8 argType; /* 1: 0, 2: 1, 3: 2,... N: N-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, 1, SQLITE_UTF8, 1, minmaxFunc },
+ { "max", 0, 1, SQLITE_UTF8, 1, 0 },
+ { "typeof", 1, 0, SQLITE_UTF8, 0, typeofFunc },
+ { "length", 1, 0, SQLITE_UTF8, 0, lengthFunc },
+ { "substr", 2, 0, SQLITE_UTF8, 0, substrFunc },
+ { "substr", 3, 0, SQLITE_UTF8, 0, substrFunc },
+ { "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 },
+ { "hex", 1, 0, SQLITE_UTF8, 0, hexFunc },
+ { "ifnull", 2, 0, SQLITE_UTF8, 1, ifnullFunc },
+ { "random", -1, 0, SQLITE_UTF8, 0, randomFunc },
+ { "randomblob", 1, 0, SQLITE_UTF8, 0, randomBlob },
+ { "nullif", 2, 0, SQLITE_UTF8, 1, nullifFunc },
+ { "sqlite_version", 0, 0, SQLITE_UTF8, 0, versionFunc},
+ { "quote", 1, 0, SQLITE_UTF8, 0, quoteFunc },
+ { "last_insert_rowid", 0, 0, SQLITE_UTF8, 0, last_insert_rowid },
+ { "changes", 0, 0, SQLITE_UTF8, 0, changes },
+ { "total_changes", 0, 0, SQLITE_UTF8, 0, total_changes },
+ { "replace", 3, 0, SQLITE_UTF8, 0, replaceFunc },
+ { "ltrim", 1, 1, SQLITE_UTF8, 0, trimFunc },
+ { "ltrim", 2, 1, SQLITE_UTF8, 0, trimFunc },
+ { "rtrim", 1, 2, SQLITE_UTF8, 0, trimFunc },
+ { "rtrim", 2, 2, SQLITE_UTF8, 0, trimFunc },
+ { "trim", 1, 3, SQLITE_UTF8, 0, trimFunc },
+ { "trim", 2, 3, SQLITE_UTF8, 0, trimFunc },
+ { "zeroblob", 1, 0, SQLITE_UTF8, 0, zeroblobFunc },
+#ifdef SQLITE_SOUNDEX
+ { "soundex", 1, 0, SQLITE_UTF8, 0, soundexFunc},
+#endif
+#ifndef SQLITE_OMIT_LOAD_EXTENSION
+ { "load_extension", 1, 0, SQLITE_UTF8, 0, loadExt },
+ { "load_extension", 2, 0, SQLITE_UTF8, 0, loadExt },
+#endif
+ };
+ static const 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, 1, 1, minmaxStep, minMaxFinalize },
+ { "sum", 1, 0, 0, sumStep, sumFinalize },
+ { "total", 1, 0, 0, sumStep, totalFinalize },
+ { "avg", 1, 0, 0, sumStep, avgFinalize },
+ { "count", 0, 0, 0, countStep, countFinalize },
+ { "count", 1, 0, 0, countStep, countFinalize },
+ { "group_concat", -1, 0, 0, groupConcatStep, groupConcatFinalize },
+ };
+ int i;
+
+ for(i=0; i<sizeof(aFuncs)/sizeof(aFuncs[0]); i++){
+ void *pArg;
+ u8 argType = aFuncs[i].argType;
+ pArg = SQLITE_INT_TO_PTR(argType);
+ sqlite3CreateFunc(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;
+ }
+ }
+ }
+#ifndef SQLITE_OMIT_ALTERTABLE
+ sqlite3AlterFunctions(db);
+#endif
+#ifndef SQLITE_OMIT_PARSER
+ sqlite3AttachFunctions(db);
+#endif
+ for(i=0; i<sizeof(aAggs)/sizeof(aAggs[0]); i++){
+ void *pArg = SQLITE_INT_TO_PTR(aAggs[i].argType);
+ sqlite3CreateFunc(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);
+ if( !db->mallocFailed ){
+ int rc = sqlite3_overload_function(db, "MATCH", 2);
+ assert( rc==SQLITE_NOMEM || rc==SQLITE_OK );
+ if( rc==SQLITE_NOMEM ){
+ db->mallocFailed = 1;
+ }
+ }
+#ifdef SQLITE_SSE
+ (void)sqlite3SseFunctions(db);
+#endif
+#ifdef SQLITE_CASE_SENSITIVE_LIKE
+ sqlite3RegisterLikeFunctions(db, 1);
+#else
+ sqlite3RegisterLikeFunctions(db, 0);
+#endif
+}
+
+/*
+** Set the LIKEOPT flag on the 2-argument function with the given name.
+*/
+static void setLikeOptFlag(sqlite3 *db, const char *zName, int flagVal){
+ FuncDef *pDef;
+ pDef = sqlite3FindFunction(db, zName, strlen(zName), 2, SQLITE_UTF8, 0);
+ if( pDef ){
+ pDef->flags = flagVal;
+ }
+}
+
+/*
+** Register the built-in LIKE and GLOB functions. The caseSensitive
+** parameter determines whether or not the LIKE operator is case
+** sensitive. GLOB is always case sensitive.
+*/
+void sqlite3RegisterLikeFunctions(sqlite3 *db, int caseSensitive){
+ struct compareInfo *pInfo;
+ if( caseSensitive ){
+ pInfo = (struct compareInfo*)&likeInfoAlt;
+ }else{
+ pInfo = (struct compareInfo*)&likeInfoNorm;
+ }
+ sqlite3CreateFunc(db, "like", 2, SQLITE_UTF8, pInfo, likeFunc, 0, 0);
+ sqlite3CreateFunc(db, "like", 3, SQLITE_UTF8, pInfo, likeFunc, 0, 0);
+ sqlite3CreateFunc(db, "glob", 2, SQLITE_UTF8,
+ (struct compareInfo*)&globInfo, likeFunc, 0,0);
+ setLikeOptFlag(db, "glob", SQLITE_FUNC_LIKE | SQLITE_FUNC_CASE);
+ setLikeOptFlag(db, "like",
+ caseSensitive ? (SQLITE_FUNC_LIKE | SQLITE_FUNC_CASE) : SQLITE_FUNC_LIKE);
+}
+
+/*
+** pExpr points to an expression which implements a function. If
+** it is appropriate to apply the LIKE optimization to that function
+** then set aWc[0] through aWc[2] to the wildcard characters and
+** return TRUE. If the function is not a LIKE-style function then
+** return FALSE.
+*/
+int sqlite3IsLikeFunction(sqlite3 *db, Expr *pExpr, int *pIsNocase, char *aWc){
+ FuncDef *pDef;
+ if( pExpr->op!=TK_FUNCTION || !pExpr->pList ){
+ return 0;
+ }
+ if( pExpr->pList->nExpr!=2 ){
+ return 0;
+ }
+ pDef = sqlite3FindFunction(db, (char*)pExpr->token.z, pExpr->token.n, 2,
+ SQLITE_UTF8, 0);
+ if( pDef==0 || (pDef->flags & SQLITE_FUNC_LIKE)==0 ){
+ return 0;
+ }
+
+ /* The memcpy() statement assumes that the wildcard characters are
+ ** the first three statements in the compareInfo structure. The
+ ** asserts() that follow verify that assumption
+ */
+ memcpy(aWc, pDef->pUserData, 3);
+ assert( (char*)&likeInfoAlt == (char*)&likeInfoAlt.matchAll );
+ assert( &((char*)&likeInfoAlt)[1] == (char*)&likeInfoAlt.matchOne );
+ assert( &((char*)&likeInfoAlt)[2] == (char*)&likeInfoAlt.matchSet );
+ *pIsNocase = (pDef->flags & SQLITE_FUNC_CASE)==0;
+ return 1;
+}