diff options
Diffstat (limited to 'kopete/plugins/statistics/sqlite/func.c')
| -rw-r--r-- | kopete/plugins/statistics/sqlite/func.c | 1018 |
1 files changed, 1018 insertions, 0 deletions
diff --git a/kopete/plugins/statistics/sqlite/func.c b/kopete/plugins/statistics/sqlite/func.c new file mode 100644 index 00000000..f61bdae3 --- /dev/null +++ b/kopete/plugins/statistics/sqlite/func.c @@ -0,0 +1,1018 @@ +/* +** 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. +** +** $Id$ +*/ +#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 = 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 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){ + unsigned 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++){ + 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){ + unsigned 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++){ + 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 +){ + sqlite3 *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 +){ + sqlite3 *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 +){ + sqlite3 *db = sqlite3_user_data(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; +}; +static const struct compareInfo globInfo = { '*', '?', '[', 0 }; +static const struct compareInfo likeInfo = { '%', '_', 0, 1 }; + +/* +** X is a pointer to the first byte of a UTF-8 character. Increment +** X so that it points to the next character. This only works right +** if X points to a well-formed UTF-8 string. +*/ +#define sqliteNextChar(X) while( (0xc0&*++(X))==0x80 ){} +#define sqliteCharVal(X) sqlite3ReadUtf8(X) + + +/* +** 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 +*/ +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 */ +){ + register int c; + int invert; + int seen; + int c2; + u8 matchOne = pInfo->matchOne; + u8 matchAll = pInfo->matchAll; + u8 matchSet = pInfo->matchSet; + u8 noCase = pInfo->noCase; + + while( (c = *zPattern)!=0 ){ + if( c==matchAll ){ + while( (c=zPattern[1]) == matchAll || c == matchOne ){ + if( c==matchOne ){ + if( *zString==0 ) return 0; + sqliteNextChar(zString); + } + zPattern++; + } + if( c==0 ) return 1; + if( c==matchSet ){ + while( *zString && patternCompare(&zPattern[1],zString,pInfo)==0 ){ + sqliteNextChar(zString); + } + return *zString!=0; + }else{ + while( (c2 = *zString)!=0 ){ + if( noCase ){ + c2 = sqlite3UpperToLower[c2]; + c = sqlite3UpperToLower[c]; + while( c2 != 0 && c2 != c ){ c2 = sqlite3UpperToLower[*++zString]; } + }else{ + while( c2 != 0 && c2 != c ){ c2 = *++zString; } + } + if( c2==0 ) return 0; + if( patternCompare(&zPattern[1],zString,pInfo) ) return 1; + sqliteNextChar(zString); + } + return 0; + } + }else if( c==matchOne ){ + if( *zString==0 ) return 0; + sqliteNextChar(zString); + zPattern++; + }else if( c==matchSet ){ + int prior_c = 0; + seen = 0; + invert = 0; + c = sqliteCharVal(zString); + if( c==0 ) return 0; + c2 = *++zPattern; + if( c2=='^' ){ invert = 1; c2 = *++zPattern; } + if( c2==']' ){ + if( c==']' ) seen = 1; + c2 = *++zPattern; + } + while( (c2 = sqliteCharVal(zPattern))!=0 && c2!=']' ){ + if( c2=='-' && zPattern[1]!=']' && zPattern[1]!=0 && prior_c>0 ){ + zPattern++; + c2 = sqliteCharVal(zPattern); + if( c>=prior_c && c<=c2 ) seen = 1; + prior_c = 0; + }else if( c==c2 ){ + seen = 1; + prior_c = c2; + }else{ + prior_c = c2; + } + sqliteNextChar(zPattern); + } + if( c2==0 || (seen ^ invert)==0 ) return 0; + sqliteNextChar(zString); + zPattern++; + }else{ + if( noCase ){ + if( sqlite3UpperToLower[c] != sqlite3UpperToLower[*zString] ) return 0; + }else{ + if( c != *zString ) return 0; + } + zPattern++; + zString++; + } + } + return *zString==0; +} + + +/* +** 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, patternCompare(zA, zB, &likeInfo)); + } +} + +/* +** 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, patternCompare(zA, zB, &globInfo)); + } +} + +/* +** 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 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]); + 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; + sqlite3 *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){ + 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)==(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(sqlite3 *db){ + static const 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, 1, 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 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, 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); +} |