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+/*
+This library will provide common mathematical and string functions in
+SQL queries using the operating system libraries or provided
+definitions. It includes the following functions:
+
+Math: acos, asin, atan, atn2, atan2, acosh, asinh, atanh, difference,
+degrees, radians, cos, sin, tan, cot, cosh, sinh, tanh, coth, exp,
+log, log10, power, sign, sqrt, square, ceil, floor, pi.
+
+String: replicate, charindex, leftstr, rightstr, ltrim, rtrim, trim,
+replace, reverse, proper, padl, padr, padc, strfilter.
+
+Aggregate: stdev, variance, mode, median, lower_quartile,
+upper_quartile.
+
+The string functions ltrim, rtrim, trim, replace are included in
+recent versions of SQLite and so by default do not build.
+
+Compilation instructions:
+ Compile this C source file into a dynamic library as follows:
+ * Linux:
+ gcc -fPIC -lm -shared extension-functions.c -o libsqlitefunctions.so
+ * Mac OS X:
+ gcc -fno-common -dynamiclib extension-functions.c -o libsqlitefunctions.dylib
+ (You may need to add flags
+ -I /opt/local/include/ -L/opt/local/lib -lsqlite3
+ if your sqlite3 is installed from Mac ports, or
+ -I /sw/include/ -L/sw/lib -lsqlite3
+ if installed with Fink.)
+ * Windows:
+ 1. Install MinGW (http://www.mingw.org/) and you will get the gcc
+ (gnu compiler collection)
+ 2. add the path to your path variable (isn't done during the
+ installation!)
+ 3. compile:
+ gcc -shared -I "path" -o libsqlitefunctions.so extension-functions.c
+ (path = path of sqlite3ext.h; i.e. C:\programs\sqlite)
+
+Usage instructions for applications calling the sqlite3 API functions:
+ In your application, call sqlite3_enable_load_extension(db,1) to
+ allow loading external libraries. Then load the library libsqlitefunctions
+ using sqlite3_load_extension; the third argument should be 0.
+ See http://www.sqlite.org/cvstrac/wiki?p=LoadableExtensions.
+ Select statements may now use these functions, as in
+ SELECT cos(radians(inclination)) FROM satsum WHERE satnum = 25544;
+
+Usage instructions for the sqlite3 program:
+ If the program is built so that loading extensions is permitted,
+ the following will work:
+ sqlite> SELECT load_extension('./libsqlitefunctions.so');
+ sqlite> select cos(radians(45));
+ 0.707106781186548
+ Note: Loading extensions is by default prohibited as a
+ security measure; see "Security Considerations" in
+ http://www.sqlite.org/cvstrac/wiki?p=LoadableExtensions.
+ If the sqlite3 program and library are built this
+ way, you cannot use these functions from the program, you
+ must write your own program using the sqlite3 API, and call
+ sqlite3_enable_load_extension as described above, or else
+ rebuilt the sqlite3 program to allow loadable extensions.
+
+Alterations:
+The instructions are for Linux, Mac OS X, and Windows; users of other
+OSes may need to modify this procedure. In particular, if your math
+library lacks one or more of the needed trig or log functions, comment
+out the appropriate HAVE_ #define at the top of file. If you do not
+wish to make a loadable module, comment out the define for
+COMPILE_SQLITE_EXTENSIONS_AS_LOADABLE_MODULE. If you are using a
+version of SQLite without the trim functions and replace, comment out
+the HAVE_TRIM #define.
+
+Liam Healy
+
+History:
+2010-01-06 Correct check for argc in squareFunc, and add Windows
+compilation instructions.
+2009-06-24 Correct check for argc in properFunc.
+2008-09-14 Add check that memory was actually allocated after
+sqlite3_malloc or sqlite3StrDup, call sqlite3_result_error_nomem if
+not. Thanks to Robert Simpson.
+2008-06-13 Change to instructions to indicate use of the math library
+and that program might work.
+2007-10-01 Minor clarification to instructions.
+2007-09-29 Compilation as loadable module is optional with
+COMPILE_SQLITE_EXTENSIONS_AS_LOADABLE_MODULE.
+2007-09-28 Use sqlite3_extension_init and macros
+SQLITE_EXTENSION_INIT1, SQLITE_EXTENSION_INIT2, so that it works with
+sqlite3_load_extension. Thanks to Eric Higashino and Joe Wilson.
+New instructions for Mac compilation.
+2007-09-17 With help from Joe Wilson and Nuno Luca, made use of
+external interfaces so that compilation is no longer dependent on
+SQLite source code. Merged source, header, and README into a single
+file. Added casts so that Mac will compile without warnings (unsigned
+and signed char).
+2007-09-05 Included some definitions from sqlite 3.3.13 so that this
+will continue to work in newer versions of sqlite. Completed
+description of functions available.
+2007-03-27 Revised description.
+2007-03-23 Small cleanup and a bug fix on the code. This was mainly
+letting errno flag errors encountered in the math library and checking
+the result, rather than pre-checking. This fixes a bug in power that
+would cause an error if any non-positive number was raised to any
+power.
+2007-02-07 posted by Mikey C to sqlite mailing list.
+Original code 2006 June 05 by relicoder.
+
+*/
+
+//#include "config.h"
+
+// #define COMPILE_SQLITE_EXTENSIONS_AS_LOADABLE_MODULE 1
+#define HAVE_ACOSH 1
+#define HAVE_ASINH 1
+#define HAVE_ATANH 1
+#define HAVE_SINH 1
+#define HAVE_COSH 1
+#define HAVE_TANH 1
+#define HAVE_LOG10 1
+#define HAVE_ISBLANK 1
+#define SQLITE_SOUNDEX 1
+#define HAVE_TRIM 1 /* LMH 2007-03-25 if sqlite has trim functions */
+
+#define __STDC_FORMAT_MACROS
+
+#ifdef COMPILE_SQLITE_EXTENSIONS_AS_LOADABLE_MODULE
+# include "sqlite3ext.h"
+SQLITE_EXTENSION_INIT1
+#else
+# include "sqlite3.h"
+#endif
+
+#include <ctype.h>
+/* relicoder */
+#include <assert.h>
+#include <errno.h> /* LMH 2007-03-25 */
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#ifndef _MAP_H_
+# define _MAP_H_
+
+# include <inttypes.h>
+# include <stdint.h>
+
+# include "sqlite-extension-func.hh"
+
+/*
+** Simple binary tree implementation to use in median, mode and quartile
+*calculations
+** Tree is not necessarily balanced. That would require something like red&black
+*trees of AVL
+*/
+
+typedef int (*cmp_func)(const void*, const void*);
+typedef void (*map_iterator)(void*, int64_t, void*);
+
+typedef struct node {
+ struct node* l;
+ struct node* r;
+ void* data;
+ int64_t count;
+} node;
+
+typedef struct map {
+ node* base;
+ cmp_func cmp;
+ short free;
+} map;
+
+/*
+** creates a map given a comparison function
+*/
+map map_make(cmp_func cmp);
+
+/*
+** inserts the element e into map m
+*/
+void map_insert(map* m, void* e);
+
+/*
+** executes function iter over all elements in the map, in key increasing order
+*/
+void map_iterate(map* m, map_iterator iter, void* p);
+
+/*
+** frees all memory used by a map
+*/
+void map_destroy(map* m);
+
+/*
+** compares 2 integers
+** to use with map_make
+*/
+int int_cmp(const void* a, const void* b);
+
+/*
+** compares 2 doubles
+** to use with map_make
+*/
+int double_cmp(const void* a, const void* b);
+
+#endif /* _MAP_H_ */
+
+typedef uint8_t u8;
+typedef uint16_t u16;
+typedef int64_t i64;
+
+static char*
+sqlite3StrDup(const char* z)
+{
+ char* res = (char*) sqlite3_malloc(strlen(z) + 1);
+ return strcpy(res, z);
+}
+
+/*
+** These are copied verbatim from fun.c so as to not have the names exported
+*/
+
+/* LMH from sqlite3 3.3.13 */
+/*
+** This table maps from the first byte of a UTF-8 character to the number
+** of trailing bytes expected. A value '4' indicates that the table key
+** is not a legal first byte for a UTF-8 character.
+*/
+static const u8 xtra_utf8_bytes[256] = {
+ /* 0xxxxxxx */
+ 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,
+ 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,
+
+ /* 10wwwwww */
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+
+ /* 110yyyyy */
+ 1,
+ 1,
+ 1,
+ 1,
+ 1,
+ 1,
+ 1,
+ 1,
+ 1,
+ 1,
+ 1,
+ 1,
+ 1,
+ 1,
+ 1,
+ 1,
+ 1,
+ 1,
+ 1,
+ 1,
+ 1,
+ 1,
+ 1,
+ 1,
+ 1,
+ 1,
+ 1,
+ 1,
+ 1,
+ 1,
+ 1,
+ 1,
+
+ /* 1110zzzz */
+ 2,
+ 2,
+ 2,
+ 2,
+ 2,
+ 2,
+ 2,
+ 2,
+ 2,
+ 2,
+ 2,
+ 2,
+ 2,
+ 2,
+ 2,
+ 2,
+
+ /* 11110yyy */
+ 3,
+ 3,
+ 3,
+ 3,
+ 3,
+ 3,
+ 3,
+ 3,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+ 4,
+};
+
+/*
+** This table maps from the number of trailing bytes in a UTF-8 character
+** to an integer constant that is effectively calculated for each character
+** read by a naive implementation of a UTF-8 character reader. The code
+** in the READ_UTF8 macro explains things best.
+*/
+static const int xtra_utf8_bits[] = {
+ 0,
+ 12416, /* (0xC0 << 6) + (0x80) */
+ 925824, /* (0xE0 << 12) + (0x80 << 6) + (0x80) */
+ 63447168 /* (0xF0 << 18) + (0x80 << 12) + (0x80 << 6) + 0x80 */
+};
+
+/*
+** If a UTF-8 character contains N bytes extra bytes (N bytes follow
+** the initial byte so that the total character length is N+1) then
+** masking the character with utf8_mask[N] must produce a non-zero
+** result. Otherwise, we have an (illegal) overlong encoding.
+*/
+static const unsigned long utf_mask[] = {
+ 0x00000000,
+ 0xffffff80,
+ 0xfffff800,
+ 0xffff0000,
+};
+
+/* LMH salvaged from sqlite3 3.3.13 source code src/utf.c */
+#define READ_UTF8(zIn, c) \
+ { \
+ int xtra; \
+ c = *(zIn)++; \
+ xtra = xtra_utf8_bytes[c]; \
+ switch (xtra) { \
+ case 4: \
+ c = (int) 0xFFFD; \
+ break; \
+ case 3: \
+ c = (c << 6) + *(zIn)++; \
+ case 2: \
+ c = (c << 6) + *(zIn)++; \
+ case 1: \
+ c = (c << 6) + *(zIn)++; \
+ c -= xtra_utf8_bits[xtra]; \
+ if ((utf_mask[xtra] & c) == 0 || (c & 0xFFFFF800) == 0xD800 \
+ || (c & 0xFFFFFFFE) == 0xFFFE) \
+ { \
+ c = 0xFFFD; \
+ } \
+ } \
+ }
+
+static int
+sqlite3ReadUtf8(const unsigned char* z)
+{
+ int c;
+ READ_UTF8(z, c);
+ return c;
+}
+
+#define SKIP_UTF8(zIn) \
+ { \
+ zIn += (xtra_utf8_bytes[*(u8*) zIn] + 1); \
+ }
+
+/*
+** pZ is a UTF-8 encoded unicode string. If nByte is less than zero,
+** return the number of unicode characters in pZ up to (but not including)
+** the first 0x00 byte. If nByte is not less than zero, return the
+** number of unicode characters in the first nByte of pZ (or up to
+** the first 0x00, whichever comes first).
+*/
+static int
+sqlite3Utf8CharLen(const char* z, int nByte)
+{
+ int r = 0;
+ const char* zTerm;
+ if (nByte >= 0) {
+ zTerm = &z[nByte];
+ } else {
+ zTerm = (const char*) (-1);
+ }
+ assert(z <= zTerm);
+ while (*z != 0 && z < zTerm) {
+ SKIP_UTF8(z);
+ r++;
+ }
+ return r;
+}
+
+/*
+** 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)
+
+/*
+** This is a macro that facilitates writting wrappers for math.h functions
+** it creates code for a function to use in SQlite that gets one numeric input
+** and returns a floating point value.
+**
+** Could have been implemented using pointers to functions but this way it's
+*inline
+** and thus more efficient. Lower * ranking though...
+**
+** Parameters:
+** name: function name to de defined (eg: sinFunc)
+** function: function defined in math.h to wrap (eg: sin)
+** domain: boolean condition that CAN'T happen in terms of the input
+*parameter rVal
+** (eg: rval<0 for sqrt)
+*/
+/* LMH 2007-03-25 Changed to use errno and remove domain; no pre-checking for
+ * errors. */
+#define GEN_MATH_WRAP_DOUBLE_1(name, function) \
+ static void name(sqlite3_context* context, int argc, sqlite3_value** argv) \
+ { \
+ double rVal = 0.0, val; \
+ assert(argc == 1); \
+ switch (sqlite3_value_type(argv[0])) { \
+ case SQLITE_NULL: { \
+ sqlite3_result_null(context); \
+ break; \
+ } \
+ default: { \
+ rVal = sqlite3_value_double(argv[0]); \
+ errno = 0; \
+ val = function(rVal); \
+ if (errno == 0) { \
+ sqlite3_result_double(context, val); \
+ } else { \
+ sqlite3_result_error(context, strerror(errno), errno); \
+ } \
+ break; \
+ } \
+ } \
+ }
+
+/*
+** Example of GEN_MATH_WRAP_DOUBLE_1 usage
+** this creates function sqrtFunc to wrap the math.h standard function
+*sqrt(x)=x^0.5
+*/
+GEN_MATH_WRAP_DOUBLE_1(sqrtFunc, sqrt)
+
+/* trignometric functions */
+GEN_MATH_WRAP_DOUBLE_1(acosFunc, acos)
+GEN_MATH_WRAP_DOUBLE_1(asinFunc, asin)
+GEN_MATH_WRAP_DOUBLE_1(atanFunc, atan)
+
+/*
+** Many of systems don't have inverse hyperbolic trig functions so this will
+*emulate
+** them on those systems in terms of log and sqrt (formulas are too trivial to
+*demand
+** written proof here)
+*/
+
+#ifndef HAVE_ACOSH
+static double
+acosh(double x)
+{
+ return log(x + sqrt(x * x - 1.0));
+}
+#endif
+
+GEN_MATH_WRAP_DOUBLE_1(acoshFunc, acosh)
+
+#ifndef HAVE_ASINH
+static double
+asinh(double x)
+{
+ return log(x + sqrt(x * x + 1.0));
+}
+#endif
+
+GEN_MATH_WRAP_DOUBLE_1(asinhFunc, asinh)
+
+#ifndef HAVE_ATANH
+static double
+atanh(double x)
+{
+ return (1.0 / 2.0) * log((1 + x) / (1 - x));
+}
+#endif
+
+GEN_MATH_WRAP_DOUBLE_1(atanhFunc, atanh)
+
+/*
+** math.h doesn't require cot (cotangent) so it's defined here
+*/
+static double
+cot(double x)
+{
+ return 1.0 / tan(x);
+}
+
+GEN_MATH_WRAP_DOUBLE_1(sinFunc, sin)
+GEN_MATH_WRAP_DOUBLE_1(cosFunc, cos)
+GEN_MATH_WRAP_DOUBLE_1(tanFunc, tan)
+GEN_MATH_WRAP_DOUBLE_1(cotFunc, cot)
+
+static double
+coth(double x)
+{
+ return 1.0 / tanh(x);
+}
+
+/*
+** Many systems don't have hyperbolic trigonometric functions so this will
+*emulate
+** them on those systems directly from the definition in terms of exp
+*/
+#ifndef HAVE_SINH
+static double
+sinh(double x)
+{
+ return (exp(x) - exp(-x)) / 2.0;
+}
+#endif
+
+GEN_MATH_WRAP_DOUBLE_1(sinhFunc, sinh)
+
+#ifndef HAVE_COSH
+static double
+cosh(double x)
+{
+ return (exp(x) + exp(-x)) / 2.0;
+}
+#endif
+
+GEN_MATH_WRAP_DOUBLE_1(coshFunc, cosh)
+
+#ifndef HAVE_TANH
+static double
+tanh(double x)
+{
+ return sinh(x) / cosh(x);
+}
+#endif
+
+GEN_MATH_WRAP_DOUBLE_1(tanhFunc, tanh)
+
+GEN_MATH_WRAP_DOUBLE_1(cothFunc, coth)
+
+/*
+** Some systems lack log in base 10. This will emulate it
+*/
+
+#ifndef HAVE_LOG10
+static double
+log10(double x)
+{
+ static double l10 = -1.0;
+ if (l10 < 0.0) {
+ l10 = log(10.0);
+ }
+ return log(x) / l10;
+}
+#endif
+
+GEN_MATH_WRAP_DOUBLE_1(logFunc, log)
+GEN_MATH_WRAP_DOUBLE_1(log10Func, log10)
+GEN_MATH_WRAP_DOUBLE_1(expFunc, exp)
+
+/*
+** Fallback for systems where math.h doesn't define M_PI
+*/
+#undef M_PI
+#ifndef M_PI
+/*
+** static double PI = acos(-1.0);
+** #define M_PI (PI)
+*/
+# define M_PI 3.14159265358979323846
+#endif
+
+/* Convert Degrees into Radians */
+static double
+deg2rad(double x)
+{
+ return x * M_PI / 180.0;
+}
+
+/* Convert Radians into Degrees */
+static double
+rad2deg(double x)
+{
+ return 180.0 * x / M_PI;
+}
+
+GEN_MATH_WRAP_DOUBLE_1(rad2degFunc, rad2deg)
+GEN_MATH_WRAP_DOUBLE_1(deg2radFunc, deg2rad)
+
+/* constant function that returns the value of PI=3.1415... */
+static void
+piFunc(sqlite3_context* context, int argc, sqlite3_value** argv)
+{
+ sqlite3_result_double(context, M_PI);
+}
+
+/*
+** Implements the sqrt function, it has the peculiarity of returning an integer
+*when the
+** the argument is an integer.
+** Since SQLite isn't strongly typed (almost untyped actually) this is a bit
+*pedantic
+*/
+static void
+squareFunc(sqlite3_context* context, int argc, sqlite3_value** argv)
+{
+ i64 iVal = 0;
+ double rVal = 0.0;
+ assert(argc == 1);
+ switch (sqlite3_value_type(argv[0])) {
+ case SQLITE_INTEGER: {
+ iVal = sqlite3_value_int64(argv[0]);
+ sqlite3_result_int64(context, iVal * iVal);
+ break;
+ }
+ case SQLITE_NULL: {
+ sqlite3_result_null(context);
+ break;
+ }
+ default: {
+ rVal = sqlite3_value_double(argv[0]);
+ sqlite3_result_double(context, rVal * rVal);
+ break;
+ }
+ }
+}
+
+/*
+** Wraps the pow math.h function
+** When both the base and the exponent are integers the result should be integer
+** (see sqrt just before this). Here the result is always double
+*/
+/* LMH 2007-03-25 Changed to use errno; no pre-checking for errors. Also
+ removes but that was present in the pre-checking that called
+ sqlite3_result_error on
+ a non-positive first argument, which is not always an error. */
+static void
+powerFunc(sqlite3_context* context, int argc, sqlite3_value** argv)
+{
+ double r1 = 0.0;
+ double r2 = 0.0;
+ double val;
+
+ assert(argc == 2);
+
+ if (sqlite3_value_type(argv[0]) == SQLITE_NULL
+ || sqlite3_value_type(argv[1]) == SQLITE_NULL)
+ {
+ sqlite3_result_null(context);
+ } else {
+ r1 = sqlite3_value_double(argv[0]);
+ r2 = sqlite3_value_double(argv[1]);
+ errno = 0;
+ val = pow(r1, r2);
+ if (errno == 0) {
+ sqlite3_result_double(context, val);
+ } else {
+ sqlite3_result_error(context, strerror(errno), errno);
+ }
+ }
+}
+
+/*
+** atan2 wrapper
+*/
+static void
+atn2Func(sqlite3_context* context, int argc, sqlite3_value** argv)
+{
+ double r1 = 0.0;
+ double r2 = 0.0;
+
+ assert(argc == 2);
+
+ if (sqlite3_value_type(argv[0]) == SQLITE_NULL
+ || sqlite3_value_type(argv[1]) == SQLITE_NULL)
+ {
+ sqlite3_result_null(context);
+ } else {
+ r1 = sqlite3_value_double(argv[0]);
+ r2 = sqlite3_value_double(argv[1]);
+ sqlite3_result_double(context, atan2(r1, r2));
+ }
+}
+
+/*
+** Implementation of the sign() function
+** return one of 3 possibilities +1,0 or -1 when the argument is respectively
+** positive, 0 or negative.
+** When the argument is NULL the result is also NULL (completly conventional)
+*/
+static void
+signFunc(sqlite3_context* context, int argc, sqlite3_value** argv)
+{
+ double rVal = 0.0;
+ i64 iVal = 0;
+ assert(argc == 1);
+ switch (sqlite3_value_type(argv[0])) {
+ case SQLITE_INTEGER: {
+ iVal = sqlite3_value_int64(argv[0]);
+ iVal = (iVal > 0) ? 1 : (iVal < 0) ? -1 : 0;
+ sqlite3_result_int64(context, iVal);
+ break;
+ }
+ case SQLITE_NULL: {
+ sqlite3_result_null(context);
+ break;
+ }
+ default: {
+ /* 2nd change below. Line for abs was: if( rVal<0 ) rVal = rVal *
+ * -1.0; */
+
+ rVal = sqlite3_value_double(argv[0]);
+ rVal = (rVal > 0) ? 1 : (rVal < 0) ? -1 : 0;
+ sqlite3_result_double(context, rVal);
+ break;
+ }
+ }
+}
+
+/*
+** smallest integer value not less than argument
+*/
+static void
+ceilFunc(sqlite3_context* context, int argc, sqlite3_value** argv)
+{
+ double rVal = 0.0;
+ assert(argc == 1);
+ switch (sqlite3_value_type(argv[0])) {
+ case SQLITE_INTEGER: {
+ i64 iVal = sqlite3_value_int64(argv[0]);
+ sqlite3_result_int64(context, iVal);
+ break;
+ }
+ case SQLITE_NULL: {
+ sqlite3_result_null(context);
+ break;
+ }
+ default: {
+ rVal = sqlite3_value_double(argv[0]);
+ sqlite3_result_int64(context, (i64) ceil(rVal));
+ break;
+ }
+ }
+}
+
+/*
+** largest integer value not greater than argument
+*/
+static void
+floorFunc(sqlite3_context* context, int argc, sqlite3_value** argv)
+{
+ double rVal = 0.0;
+ assert(argc == 1);
+ switch (sqlite3_value_type(argv[0])) {
+ case SQLITE_INTEGER: {
+ i64 iVal = sqlite3_value_int64(argv[0]);
+ sqlite3_result_int64(context, iVal);
+ break;
+ }
+ case SQLITE_NULL: {
+ sqlite3_result_null(context);
+ break;
+ }
+ default: {
+ rVal = sqlite3_value_double(argv[0]);
+ sqlite3_result_int64(context, (i64) floor(rVal));
+ break;
+ }
+ }
+}
+
+/*
+** Given a string (s) in the first argument and an integer (n) in the second
+*returns the
+** string that constains s contatenated n times
+*/
+static void
+replicateFunc(sqlite3_context* context, int argc, sqlite3_value** argv)
+{
+ static const char* EMPTY = "";
+ unsigned char* z; /* result string */
+ i64 iCount; /* times to repeat */
+ i64 nLen; /* length of the input string (no multibyte considerations) */
+ i64 nTLen; /* length of the result string (no multibyte considerations) */
+ i64 i = 0;
+
+ if (argc != 2 || SQLITE_NULL == sqlite3_value_type(argv[0]))
+ return;
+
+ iCount = sqlite3_value_int64(argv[1]);
+
+ if (iCount < 0) {
+ sqlite3_result_error(context, "domain error", -1);
+ return;
+ }
+
+ if (iCount == 0) {
+ sqlite3_result_text(context, EMPTY, 0, SQLITE_STATIC);
+ return;
+ }
+
+ nLen = sqlite3_value_bytes(argv[0]);
+ nTLen = nLen * iCount;
+ z = (unsigned char*) sqlite3_malloc(nTLen + 1);
+ if (!z) {
+ sqlite3_result_error_nomem(context);
+ if (z)
+ sqlite3_free(z);
+ return;
+ }
+ auto zo = sqlite3_value_text(argv[0]);
+
+ for (i = 0; i < iCount; ++i) {
+ strcpy((char*) (z + i * nLen), (char*) zo);
+ }
+
+ sqlite3_result_text(context, (char*) z, -1, sqlite3_free);
+}
+
+/*
+** Some systems (win32 among others) don't have an isblank function, this will
+*emulate it.
+** This function is not UFT-8 safe since it only analyses a byte character.
+*/
+#ifndef HAVE_ISBLANK
+int
+isblank(char c)
+{
+ return (' ' == c || '\t' == c);
+}
+#endif
+
+static void
+properFunc(sqlite3_context* context, int argc, sqlite3_value** argv)
+{
+ const unsigned char* z; /* input string */
+ unsigned char* zo; /* output string */
+ unsigned char* zt; /* iterator */
+ char r;
+ int c = 1;
+
+ assert(argc == 1);
+ if (SQLITE_NULL == sqlite3_value_type(argv[0])) {
+ sqlite3_result_null(context);
+ return;
+ }
+
+ z = sqlite3_value_text(argv[0]);
+ zo = (unsigned char*) sqlite3StrDup((char*) z);
+ if (!zo) {
+ sqlite3_result_error_nomem(context);
+ return;
+ }
+ zt = zo;
+
+ while ((r = *(z++)) != 0) {
+ if (isblank(r)) {
+ c = 1;
+ } else {
+ if (c == 1) {
+ r = toupper(r);
+ } else {
+ r = tolower(r);
+ }
+ c = 0;
+ }
+ *(zt++) = r;
+ }
+ *zt = '\0';
+
+ sqlite3_result_text(context, (char*) zo, -1, SQLITE_TRANSIENT);
+ sqlite3_free(zo);
+}
+
+/*
+** given an input string (s) and an integer (n) adds spaces at the begining of s
+** until it has a length of n characters.
+** When s has a length >=n it's a NOP
+** padl(NULL) = NULL
+*/
+static void
+padlFunc(sqlite3_context* context, int argc, sqlite3_value** argv)
+{
+ i64 ilen; /* length to pad to */
+ i64 zl; /* length of the input string (UTF-8 chars) */
+ int i = 0;
+ const char* zi; /* input string */
+ char* zo; /* output string */
+ char* zt;
+
+ assert(argc == 2);
+
+ if (sqlite3_value_type(argv[0]) == SQLITE_NULL) {
+ sqlite3_result_null(context);
+ } else {
+ zi = (char*) sqlite3_value_text(argv[0]);
+ ilen = sqlite3_value_int64(argv[1]);
+ /* check domain */
+ if (ilen < 0) {
+ sqlite3_result_error(context, "domain error", -1);
+ return;
+ }
+ zl = sqlite3Utf8CharLen(zi, -1);
+ if (zl >= ilen) {
+ /* string is longer than the requested pad length, return the same
+ * string (dup it) */
+ zo = sqlite3StrDup(zi);
+ if (!zo) {
+ sqlite3_result_error_nomem(context);
+ return;
+ }
+ sqlite3_result_text(context, zo, -1, SQLITE_TRANSIENT);
+ } else {
+ zo = (char*) sqlite3_malloc(strlen(zi) + ilen - zl + 1);
+ if (!zo) {
+ sqlite3_result_error_nomem(context);
+ return;
+ }
+ zt = zo;
+ for (i = 1; i + zl <= ilen; ++i) {
+ *(zt++) = ' ';
+ }
+ /* no need to take UTF-8 into consideration here */
+ strcpy(zt, zi);
+ }
+ sqlite3_result_text(context, zo, -1, SQLITE_TRANSIENT);
+ sqlite3_free(zo);
+ }
+}
+
+/*
+** given an input string (s) and an integer (n) appends spaces at the end of s
+** until it has a length of n characters.
+** When s has a length >=n it's a NOP
+** padl(NULL) = NULL
+*/
+static void
+padrFunc(sqlite3_context* context, int argc, sqlite3_value** argv)
+{
+ i64 ilen; /* length to pad to */
+ i64 zl; /* length of the input string (UTF-8 chars) */
+ i64 zll; /* length of the input string (bytes) */
+ int i = 0;
+ const char* zi; /* input string */
+ char* zo; /* output string */
+ char* zt;
+
+ assert(argc == 2);
+
+ if (sqlite3_value_type(argv[0]) == SQLITE_NULL) {
+ sqlite3_result_null(context);
+ } else {
+ zi = (char*) sqlite3_value_text(argv[0]);
+ ilen = sqlite3_value_int64(argv[1]);
+ /* check domain */
+ if (ilen < 0) {
+ sqlite3_result_error(context, "domain error", -1);
+ return;
+ }
+ zl = sqlite3Utf8CharLen(zi, -1);
+ if (zl >= ilen) {
+ /* string is longer than the requested pad length, return the same
+ * string (dup it) */
+ zo = sqlite3StrDup(zi);
+ if (!zo) {
+ sqlite3_result_error_nomem(context);
+ return;
+ }
+ sqlite3_result_text(context, zo, -1, SQLITE_TRANSIENT);
+ } else {
+ zll = strlen(zi);
+ zo = (char*) sqlite3_malloc(zll + ilen - zl + 1);
+ if (!zo) {
+ sqlite3_result_error_nomem(context);
+ return;
+ }
+ zt = strcpy(zo, zi) + zll;
+ for (i = 1; i + zl <= ilen; ++i) {
+ *(zt++) = ' ';
+ }
+ *zt = '\0';
+ }
+ sqlite3_result_text(context, zo, -1, SQLITE_TRANSIENT);
+ sqlite3_free(zo);
+ }
+}
+
+/*
+** given an input string (s) and an integer (n) appends spaces at the end of s
+** and adds spaces at the begining of s until it has a length of n characters.
+** Tries to add has many characters at the left as at the right.
+** When s has a length >=n it's a NOP
+** padl(NULL) = NULL
+*/
+static void
+padcFunc(sqlite3_context* context, int argc, sqlite3_value** argv)
+{
+ i64 ilen; /* length to pad to */
+ i64 zl; /* length of the input string (UTF-8 chars) */
+ i64 zll; /* length of the input string (bytes) */
+ int i = 0;
+ const char* zi; /* input string */
+ char* zo; /* output string */
+ char* zt;
+
+ assert(argc == 2);
+
+ if (sqlite3_value_type(argv[0]) == SQLITE_NULL) {
+ sqlite3_result_null(context);
+ } else {
+ zi = (char*) sqlite3_value_text(argv[0]);
+ ilen = sqlite3_value_int64(argv[1]);
+ /* check domain */
+ if (ilen < 0) {
+ sqlite3_result_error(context, "domain error", -1);
+ return;
+ }
+ zl = sqlite3Utf8CharLen(zi, -1);
+ if (zl >= ilen) {
+ /* string is longer than the requested pad length, return the same
+ * string (dup it) */
+ zo = sqlite3StrDup(zi);
+ if (!zo) {
+ sqlite3_result_error_nomem(context);
+ return;
+ }
+ sqlite3_result_text(context, zo, -1, SQLITE_TRANSIENT);
+ } else {
+ zll = strlen(zi);
+ zo = (char*) sqlite3_malloc(zll + ilen - zl + 1);
+ if (!zo) {
+ sqlite3_result_error_nomem(context);
+ return;
+ }
+ zt = zo;
+ for (i = 1; 2 * i + zl <= ilen; ++i) {
+ *(zt++) = ' ';
+ }
+ strcpy(zt, zi);
+ zt += zll;
+ for (; i + zl <= ilen; ++i) {
+ *(zt++) = ' ';
+ }
+ *zt = '\0';
+ }
+ sqlite3_result_text(context, zo, -1, SQLITE_TRANSIENT);
+ sqlite3_free(zo);
+ }
+}
+
+/*
+** given 2 string (s1,s2) returns the string s1 with the characters NOT in s2
+*removed
+** assumes strings are UTF-8 encoded
+*/
+static void
+strfilterFunc(sqlite3_context* context, int argc, sqlite3_value** argv)
+{
+ const char* zi1; /* first parameter string (searched string) */
+ const char* zi2; /* second parameter string (vcontains valid characters) */
+ const char* z1;
+ const char* z21;
+ const char* z22;
+ char* zo; /* output string */
+ char* zot;
+ int c1 = 0;
+ int c2 = 0;
+
+ assert(argc == 2);
+
+ if (sqlite3_value_type(argv[0]) == SQLITE_NULL
+ || sqlite3_value_type(argv[1]) == SQLITE_NULL)
+ {
+ sqlite3_result_null(context);
+ } else {
+ zi1 = (char*) sqlite3_value_text(argv[0]);
+ zi2 = (char*) sqlite3_value_text(argv[1]);
+ /*
+ ** maybe I could allocate less, but that would imply 2 passes, rather
+ *waste
+ ** (possibly) some memory
+ */
+ zo = (char*) sqlite3_malloc(strlen(zi1) + 1);
+ if (!zo) {
+ sqlite3_result_error_nomem(context);
+ return;
+ }
+ zot = zo;
+ z1 = zi1;
+ while ((c1 = sqliteCharVal((unsigned char*) z1)) != 0) {
+ z21 = zi2;
+ while ((c2 = sqliteCharVal((unsigned char*) z21)) != 0 && c2 != c1)
+ {
+ sqliteNextChar(z21);
+ }
+ if (c2 != 0) {
+ z22 = z21;
+ sqliteNextChar(z22);
+ strncpy(zot, z21, z22 - z21);
+ zot += z22 - z21;
+ }
+ sqliteNextChar(z1);
+ }
+ *zot = '\0';
+
+ sqlite3_result_text(context, zo, -1, SQLITE_TRANSIENT);
+ sqlite3_free(zo);
+ }
+}
+
+/*
+** Given a string z1, retutns the (0 based) index of it's first occurence
+** in z2 after the first s characters.
+** Returns -1 when there isn't a match.
+** updates p to point to the character where the match occured.
+** This is an auxiliary function.
+*/
+static int
+_substr(const char* z1, const char* z2, int s, const char** p)
+{
+ int c = 0;
+ int rVal = -1;
+ const char* zt1;
+ const char* zt2;
+ int c1, c2;
+
+ if ('\0' == *z1) {
+ return -1;
+ }
+
+ while ((sqliteCharVal((unsigned char*) z2) != 0) && (c++) < s) {
+ sqliteNextChar(z2);
+ }
+
+ c = 0;
+ while ((sqliteCharVal((unsigned char*) z2)) != 0) {
+ zt1 = z1;
+ zt2 = z2;
+
+ do {
+ c1 = sqliteCharVal((unsigned char*) zt1);
+ c2 = sqliteCharVal((unsigned char*) zt2);
+ if (c1 == 0) {
+ break;
+ }
+ if (c2 == 0) {
+ break;
+ }
+ sqliteNextChar(zt1);
+ sqliteNextChar(zt2);
+ } while (c1 == c2 && c1 != 0 && c2 != 0);
+
+ if (c1 == 0) {
+ rVal = c;
+ break;
+ }
+
+ sqliteNextChar(z2);
+ ++c;
+ }
+ if (p) {
+ *p = z2;
+ }
+ return rVal >= 0 ? rVal + s : rVal;
+}
+
+/*
+** given 2 input strings (s1,s2) and an integer (n) searches from the nth
+*character
+** for the string s1. Returns the position where the match occured.
+** Characters are counted from 1.
+** 0 is returned when no match occurs.
+*/
+
+static void
+charindexFunc(sqlite3_context* context, int argc, sqlite3_value** argv)
+{
+ const u8* z1; /* s1 string */
+ u8* z2; /* s2 string */
+ int s = 0;
+ int rVal = 0;
+
+ assert(argc == 3 || argc == 2);
+
+ if (SQLITE_NULL == sqlite3_value_type(argv[0])
+ || SQLITE_NULL == sqlite3_value_type(argv[1]))
+ {
+ sqlite3_result_null(context);
+ return;
+ }
+
+ z1 = sqlite3_value_text(argv[0]);
+ if (z1 == 0)
+ return;
+ z2 = (u8*) sqlite3_value_text(argv[1]);
+ if (argc == 3) {
+ s = sqlite3_value_int(argv[2]) - 1;
+ if (s < 0) {
+ s = 0;
+ }
+ } else {
+ s = 0;
+ }
+
+ rVal = _substr((char*) z1, (char*) z2, s, NULL);
+ sqlite3_result_int(context, rVal + 1);
+}
+
+/*
+** given a string (s) and an integer (n) returns the n leftmost (UTF-8)
+*characters
+** if the string has a length<=n or is NULL this function is NOP
+*/
+static void
+leftFunc(sqlite3_context* context, int argc, sqlite3_value** argv)
+{
+ int c = 0;
+ int cc = 0;
+ int l = 0;
+ const unsigned char* z; /* input string */
+ const unsigned char* zt;
+ unsigned char* rz; /* output string */
+
+ assert(argc == 2);
+
+ if (SQLITE_NULL == sqlite3_value_type(argv[0])
+ || SQLITE_NULL == sqlite3_value_type(argv[1]))
+ {
+ sqlite3_result_null(context);
+ return;
+ }
+
+ z = sqlite3_value_text(argv[0]);
+ l = sqlite3_value_int(argv[1]);
+ zt = z;
+
+ while (sqliteCharVal(zt) && c++ < l)
+ sqliteNextChar(zt);
+
+ cc = zt - z;
+
+ rz = (unsigned char*) sqlite3_malloc(zt - z + 1);
+ if (!rz) {
+ sqlite3_result_error_nomem(context);
+ return;
+ }
+ strncpy((char*) rz, (char*) z, zt - z);
+ *(rz + cc) = '\0';
+ sqlite3_result_text(context, (char*) rz, -1, SQLITE_TRANSIENT);
+ sqlite3_free(rz);
+}
+
+/*
+** given a string (s) and an integer (n) returns the n rightmost (UTF-8)
+*characters
+** if the string has a length<=n or is NULL this function is NOP
+*/
+static void
+rightFunc(sqlite3_context* context, int argc, sqlite3_value** argv)
+{
+ int l = 0;
+ int c = 0;
+ int cc = 0;
+ const char* z;
+ const char* zt;
+ const char* ze;
+ char* rz;
+
+ assert(argc == 2);
+
+ if (SQLITE_NULL == sqlite3_value_type(argv[0])
+ || SQLITE_NULL == sqlite3_value_type(argv[1]))
+ {
+ sqlite3_result_null(context);
+ return;
+ }
+
+ z = (char*) sqlite3_value_text(argv[0]);
+ l = sqlite3_value_int(argv[1]);
+ zt = z;
+
+ while (sqliteCharVal((unsigned char*) zt) != 0) {
+ sqliteNextChar(zt);
+ ++c;
+ }
+
+ ze = zt;
+ zt = z;
+
+ cc = c - l;
+ if (cc < 0)
+ cc = 0;
+
+ while (cc-- > 0) {
+ sqliteNextChar(zt);
+ }
+
+ rz = (char*) sqlite3_malloc(ze - zt + 1);
+ if (!rz) {
+ sqlite3_result_error_nomem(context);
+ return;
+ }
+ strcpy((char*) rz, (char*) (zt));
+ sqlite3_result_text(context, (char*) rz, -1, SQLITE_TRANSIENT);
+ sqlite3_free(rz);
+}
+
+#ifndef HAVE_TRIM
+/*
+** removes the whitespaces at the begining of a string.
+*/
+const char*
+ltrim(const char* s)
+{
+ while (*s == ' ')
+ ++s;
+ return s;
+}
+
+/*
+** removes the whitespaces at the end of a string.
+** !mutates the input string!
+*/
+void
+rtrim(char* s)
+{
+ char* ss = s + strlen(s) - 1;
+ while (ss >= s && *ss == ' ')
+ --ss;
+ *(ss + 1) = '\0';
+}
+
+/*
+** Removes the whitespace at the begining of a string
+*/
+static void
+ltrimFunc(sqlite3_context* context, int argc, sqlite3_value** argv)
+{
+ const char* z;
+
+ assert(argc == 1);
+
+ if (SQLITE_NULL == sqlite3_value_type(argv[0])) {
+ sqlite3_result_null(context);
+ return;
+ }
+ z = sqlite3_value_text(argv[0]);
+ sqlite3_result_text(context, ltrim(z), -1, SQLITE_TRANSIENT);
+}
+
+/*
+** Removes the whitespace at the end of a string
+*/
+static void
+rtrimFunc(sqlite3_context* context, int argc, sqlite3_value** argv)
+{
+ const char* z;
+ char* rz;
+ /* try not to change data in argv */
+
+ assert(argc == 1);
+
+ if (SQLITE_NULL == sqlite3_value_type(argv[0])) {
+ sqlite3_result_null(context);
+ return;
+ }
+ z = sqlite3_value_text(argv[0]);
+ rz = sqlite3StrDup(z);
+ rtrim(rz);
+ sqlite3_result_text(context, rz, -1, SQLITE_TRANSIENT);
+ sqlite3_free(rz);
+}
+
+/*
+** Removes the whitespace at the begining and end of a string
+*/
+static void
+trimFunc(sqlite3_context* context, int argc, sqlite3_value** argv)
+{
+ const char* z;
+ char* rz;
+ /* try not to change data in argv */
+
+ assert(argc == 1);
+
+ if (SQLITE_NULL == sqlite3_value_type(argv[0])) {
+ sqlite3_result_null(context);
+ return;
+ }
+ z = sqlite3_value_text(argv[0]);
+ rz = sqlite3StrDup(z);
+ rtrim(rz);
+ sqlite3_result_text(context, ltrim(rz), -1, SQLITE_TRANSIENT);
+ sqlite3_free(rz);
+}
+#endif
+
+/*
+** given a pointer to a string s1, the length of that string (l1), a new string
+*(s2)
+** and it's length (l2) appends s2 to s1.
+** All lengths in bytes.
+** This is just an auxiliary function
+*/
+// static void _append(char **s1, int l1, const char *s2, int l2){
+// *s1 = realloc(*s1, (l1+l2+1)*sizeof(char));
+// strncpy((*s1)+l1, s2, l2);
+// *(*(s1)+l1+l2) = '\0';
+// }
+
+#ifndef HAVE_TRIM
+
+/*
+** given strings s, s1 and s2 replaces occurrences of s1 in s by s2
+*/
+static void
+replaceFunc(sqlite3_context* context, int argc, sqlite3_value** argv)
+{
+ const char* z1; /* string s (first parameter) */
+ const char* z2; /* string s1 (second parameter) string to look for */
+ const char* z3; /* string s2 (third parameter) string to replace occurrences
+ of s1 with */
+ int lz1;
+ int lz2;
+ int lz3;
+ int lzo = 0;
+ char* zo = 0;
+ int ret = 0;
+ const char* zt1;
+ const char* zt2;
+
+ assert(3 == argc);
+
+ if (SQLITE_NULL == sqlite3_value_type(argv[0])) {
+ sqlite3_result_null(context);
+ return;
+ }
+
+ z1 = sqlite3_value_text(argv[0]);
+ z2 = sqlite3_value_text(argv[1]);
+ z3 = sqlite3_value_text(argv[2]);
+ /* handle possible null values */
+ if (0 == z2) {
+ z2 = "";
+ }
+ if (0 == z3) {
+ z3 = "";
+ }
+
+ lz1 = strlen(z1);
+ lz2 = strlen(z2);
+ lz3 = strlen(z3);
+
+# if 0
+ /* special case when z2 is empty (or null) nothing will be changed */
+ if( 0==lz2 ){
+ sqlite3_result_text(context, z1, -1, SQLITE_TRANSIENT);
+ return;
+ }
+# endif
+
+ zt1 = z1;
+ zt2 = z1;
+
+ while (1) {
+ ret = _substr(z2, zt1, 0, &zt2);
+
+ if (ret < 0)
+ break;
+
+ _append(&zo, lzo, zt1, zt2 - zt1);
+ lzo += zt2 - zt1;
+ _append(&zo, lzo, z3, lz3);
+ lzo += lz3;
+
+ zt1 = zt2 + lz2;
+ }
+ _append(&zo, lzo, zt1, lz1 - (zt1 - z1));
+ sqlite3_result_text(context, zo, -1, SQLITE_TRANSIENT);
+ sqlite3_free(zo);
+}
+#endif
+
+/*
+** given a string returns the same string but with the characters in reverse
+*order
+*/
+static void
+reverseFunc(sqlite3_context* context, int argc, sqlite3_value** argv)
+{
+ const char* z;
+ const char* zt;
+ char* rz;
+ char* rzt;
+ int l = 0;
+ int i = 0;
+
+ assert(1 == argc);
+
+ if (SQLITE_NULL == sqlite3_value_type(argv[0])) {
+ sqlite3_result_null(context);
+ return;
+ }
+ z = (char*) sqlite3_value_text(argv[0]);
+ l = strlen(z);
+ rz = (char*) sqlite3_malloc(l + 1);
+ if (!rz) {
+ sqlite3_result_error_nomem(context);
+ return;
+ }
+ rzt = rz + l;
+ *(rzt--) = '\0';
+
+ zt = z;
+ while (sqliteCharVal((unsigned char*) zt) != 0) {
+ z = zt;
+ sqliteNextChar(zt);
+ for (i = 1; zt - i >= z; ++i) {
+ *(rzt--) = *(zt - i);
+ }
+ }
+
+ sqlite3_result_text(context, rz, -1, SQLITE_TRANSIENT);
+ sqlite3_free(rz);
+}
+
+/*
+** An instance of the following structure holds the context of a
+** stdev() or variance() aggregate computation.
+** implementaion of
+*http://en.wikipedia.org/wiki/Algorithms_for_calculating_variance#Algorithm_II
+** less prone to rounding errors
+*/
+typedef struct StdevCtx StdevCtx;
+struct StdevCtx {
+ double rM;
+ double rS;
+ i64 cnt; /* number of elements */
+};
+
+/*
+** An instance of the following structure holds the context of a
+** mode() or median() aggregate computation.
+** Depends on structures defined in map.c (see map & map)
+** These aggregate functions only work for integers and floats although
+** they could be made to work for strings. This is usually considered
+*meaningless.
+** Only usuall order (for median), no use of collation functions (would this
+*even make sense?)
+*/
+typedef struct ModeCtx ModeCtx;
+struct ModeCtx {
+ i64 riM; /* integer value found so far */
+ double rdM; /* double value found so far */
+ i64 cnt; /* number of elements so far */
+ double pcnt; /* number of elements smaller than a percentile */
+ i64 mcnt; /* maximum number of occurrences (for mode) */
+ i64 mn; /* number of occurrences (for mode and percentiles) */
+ i64 is_double; /* whether the computation is being done for doubles (>0) or
+ integers (=0) */
+ map* m; /* map structure used for the computation */
+ int done; /* whether the answer has been found */
+};
+
+/*
+** called for each value received during a calculation of stdev or variance
+*/
+static void
+varianceStep(sqlite3_context* context, int argc, sqlite3_value** argv)
+{
+ StdevCtx* p;
+
+ double delta;
+ double x;
+
+ assert(argc == 1);
+ p = (StdevCtx*) sqlite3_aggregate_context(context, sizeof(*p));
+ /* only consider non-null values */
+ if (SQLITE_NULL != sqlite3_value_numeric_type(argv[0])) {
+ p->cnt++;
+ x = sqlite3_value_double(argv[0]);
+ delta = (x - p->rM);
+ p->rM += delta / p->cnt;
+ p->rS += delta * (x - p->rM);
+ }
+}
+
+/*
+** called for each value received during a calculation of mode of median
+*/
+static void
+modeStep(sqlite3_context* context, int argc, sqlite3_value** argv)
+{
+ ModeCtx* p;
+ i64 xi = 0;
+ double xd = 0.0;
+ i64* iptr;
+ double* dptr;
+ int type;
+
+ assert(argc == 1);
+ type = sqlite3_value_numeric_type(argv[0]);
+
+ if (type == SQLITE_NULL)
+ return;
+
+ p = (ModeCtx*) sqlite3_aggregate_context(context, sizeof(*p));
+
+ if (0 == (p->m)) {
+ p->m = (map*) calloc(1, sizeof(map));
+ if (type == SQLITE_INTEGER) {
+ /* map will be used for integers */
+ *(p->m) = map_make(int_cmp);
+ p->is_double = 0;
+ } else {
+ p->is_double = 1;
+ /* map will be used for doubles */
+ *(p->m) = map_make(double_cmp);
+ }
+ }
+
+ ++(p->cnt);
+
+ if (0 == p->is_double) {
+ xi = sqlite3_value_int64(argv[0]);
+ iptr = (i64*) calloc(1, sizeof(i64));
+ *iptr = xi;
+ map_insert(p->m, iptr);
+ } else {
+ xd = sqlite3_value_double(argv[0]);
+ dptr = (double*) calloc(1, sizeof(double));
+ *dptr = xd;
+ map_insert(p->m, dptr);
+ }
+}
+
+/*
+** Auxiliary function that iterates all elements in a map and finds the mode
+** (most frequent value)
+*/
+static void
+modeIterate(void* e, i64 c, void* pp)
+{
+ i64 ei;
+ double ed;
+ ModeCtx* p = (ModeCtx*) pp;
+
+ if (0 == p->is_double) {
+ ei = *(int*) (e);
+
+ if (p->mcnt == c) {
+ ++p->mn;
+ } else if (p->mcnt < c) {
+ p->riM = ei;
+ p->mcnt = c;
+ p->mn = 1;
+ }
+ } else {
+ ed = *(double*) (e);
+
+ if (p->mcnt == c) {
+ ++p->mn;
+ } else if (p->mcnt < c) {
+ p->rdM = ed;
+ p->mcnt = c;
+ p->mn = 1;
+ }
+ }
+}
+
+/*
+** Auxiliary function that iterates all elements in a map and finds the median
+** (the value such that the number of elements smaller is equal the number of
+** elements larger)
+*/
+static void
+medianIterate(void* e, i64 c, void* pp)
+{
+ i64 ei;
+ double ed;
+ double iL;
+ double iR;
+ int il;
+ int ir;
+ ModeCtx* p = (ModeCtx*) pp;
+
+ if (p->done > 0)
+ return;
+
+ iL = p->pcnt;
+ iR = p->cnt - p->pcnt;
+ il = p->mcnt + c;
+ ir = p->cnt - p->mcnt;
+
+ if (il >= iL) {
+ if (ir >= iR) {
+ ++p->mn;
+ if (0 == p->is_double) {
+ ei = *(int*) (e);
+ p->riM += ei;
+ } else {
+ ed = *(double*) (e);
+ p->rdM += ed;
+ }
+ } else {
+ p->done = 1;
+ }
+ }
+ p->mcnt += c;
+}
+
+/*
+** Returns the mode value
+*/
+static void
+modeFinalize(sqlite3_context* context)
+{
+ ModeCtx* p;
+ p = (ModeCtx*) sqlite3_aggregate_context(context, 0);
+ if (p && p->m) {
+ map_iterate(p->m, modeIterate, p);
+ map_destroy(p->m);
+ free(p->m);
+
+ if (1 == p->mn) {
+ if (0 == p->is_double)
+ sqlite3_result_int64(context, p->riM);
+ else
+ sqlite3_result_double(context, p->rdM);
+ }
+ }
+}
+
+/*
+** auxiliary function for percentiles
+*/
+static void
+_medianFinalize(sqlite3_context* context)
+{
+ ModeCtx* p;
+ p = (ModeCtx*) sqlite3_aggregate_context(context, 0);
+ if (p && p->m) {
+ p->done = 0;
+ map_iterate(p->m, medianIterate, p);
+ map_destroy(p->m);
+ free(p->m);
+
+ if (0 == p->is_double)
+ if (1 == p->mn)
+ sqlite3_result_int64(context, p->riM);
+ else
+ sqlite3_result_double(context, p->riM * 1.0 / p->mn);
+ else
+ sqlite3_result_double(context, p->rdM / p->mn);
+ }
+}
+
+/*
+** Returns the median value
+*/
+static void
+medianFinalize(sqlite3_context* context)
+{
+ ModeCtx* p;
+ p = (ModeCtx*) sqlite3_aggregate_context(context, 0);
+ if (p != 0) {
+ p->pcnt = (p->cnt) / 2.0;
+ _medianFinalize(context);
+ }
+}
+
+/*
+** Returns the lower_quartile value
+*/
+static void
+lower_quartileFinalize(sqlite3_context* context)
+{
+ ModeCtx* p;
+ p = (ModeCtx*) sqlite3_aggregate_context(context, 0);
+ if (p != 0) {
+ p->pcnt = (p->cnt) / 4.0;
+ _medianFinalize(context);
+ }
+}
+
+/*
+** Returns the upper_quartile value
+*/
+static void
+upper_quartileFinalize(sqlite3_context* context)
+{
+ ModeCtx* p;
+ p = (ModeCtx*) sqlite3_aggregate_context(context, 0);
+ if (p != 0) {
+ p->pcnt = (p->cnt) * 3 / 4.0;
+ _medianFinalize(context);
+ }
+}
+
+/*
+** Returns the stdev value
+*/
+static void
+stdevFinalize(sqlite3_context* context)
+{
+ StdevCtx* p;
+ p = (StdevCtx*) sqlite3_aggregate_context(context, 0);
+ if (p && p->cnt > 1) {
+ sqlite3_result_double(context, sqrt(p->rS / (p->cnt - 1)));
+ } else {
+ sqlite3_result_double(context, 0.0);
+ }
+}
+
+/*
+** Returns the variance value
+*/
+static void
+varianceFinalize(sqlite3_context* context)
+{
+ StdevCtx* p;
+ p = (StdevCtx*) sqlite3_aggregate_context(context, 0);
+ if (p && p->cnt > 1) {
+ sqlite3_result_double(context, p->rS / (p->cnt - 1));
+ } else {
+ sqlite3_result_double(context, 0.0);
+ }
+}
+
+#ifdef SQLITE_SOUNDEX
+
+/* relicoder factored code */
+/*
+** Calculates the soundex value of a string
+*/
+
+static void
+soundex(const u8* zIn, char* zResult)
+{
+ 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,
+ };
+
+ 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;
+ } else {
+ strcpy(zResult, "?000");
+ }
+}
+
+/*
+** computes the number of different characters between the soundex value fo 2
+*strings
+*/
+static void
+differenceFunc(sqlite3_context* context, int argc, sqlite3_value** argv)
+{
+ char zResult1[8];
+ char zResult2[8];
+ char* zR1 = zResult1;
+ char* zR2 = zResult2;
+ int rVal = 0;
+ int i = 0;
+ const u8* zIn1;
+ const u8* zIn2;
+
+ assert(argc == 2);
+
+ if (sqlite3_value_type(argv[0]) == SQLITE_NULL
+ || sqlite3_value_type(argv[1]) == SQLITE_NULL)
+ {
+ sqlite3_result_null(context);
+ return;
+ }
+
+ zIn1 = (u8*) sqlite3_value_text(argv[0]);
+ zIn2 = (u8*) sqlite3_value_text(argv[1]);
+
+ soundex(zIn1, zR1);
+ soundex(zIn2, zR2);
+
+ for (i = 0; i < 4; ++i) {
+ if (sqliteCharVal((unsigned char*) zR1)
+ == sqliteCharVal((unsigned char*) zR2))
+ ++rVal;
+ sqliteNextChar(zR1);
+ sqliteNextChar(zR2);
+ }
+ sqlite3_result_int(context, rVal);
+}
+#endif
+
+/*
+** This function registered all of the above C functions as SQL
+** functions. This should be the only routine in this file with
+** external linkage.
+*/
+int
+common_extension_functions(struct FuncDef** basic_funcs,
+ struct FuncDefAgg** agg_funcs)
+{
+ static struct FuncDef aFuncs[] = {
+ /* math.h */
+ {
+ "acos",
+ 1,
+ SQLITE_UTF8,
+ 0,
+ acosFunc,
+ help_text("acos")
+ .sql_function()
+ .with_summary("Returns the arccosine of a number, in radians")
+ .with_parameter(
+ {"num", "A cosine value that is between -1 and 1"})
+ .with_tags({"math"})
+ .with_example(
+ {"To get the arccosine of 0.2", "SELECT acos(0.2)"}),
+ },
+ {
+ "asin",
+ 1,
+ SQLITE_UTF8,
+ 0,
+ asinFunc,
+ help_text("asin")
+ .sql_function()
+ .with_summary("Returns the arcsine of a number, in radians")
+ .with_parameter(
+ {"num", "A sine value that is between -1 and 1"})
+ .with_tags({"math"})
+ .with_example(
+ {"To get the arcsine of 0.2", "SELECT asin(0.2)"}),
+ },
+ {
+ "atan",
+ 1,
+ SQLITE_UTF8,
+ 0,
+ atanFunc,
+ help_text("atan")
+ .sql_function()
+ .with_summary("Returns the arctangent of a number, in radians")
+ .with_parameter({"num", "The number"})
+ .with_tags({"math"})
+ .with_example(
+ {"To get the arctangent of 0.2", "SELECT atan(0.2)"}),
+ },
+ {
+ "atn2",
+ 2,
+ SQLITE_UTF8,
+ 0,
+ atn2Func,
+ help_text("atn2")
+ .sql_function()
+ .with_summary("Returns the angle in the plane between the "
+ "positive X axis "
+ "and the ray from (0, 0) to the point (x, y)")
+ .with_parameter({"y", "The y coordinate of the point"})
+ .with_parameter({"x", "The x coordinate of the point"})
+ .with_tags({"math"})
+ .with_example({
+ "To get the angle, in degrees, for the point at (5, 5)",
+ "SELECT degrees(atn2(5, 5))",
+ }),
+ },
+ /* XXX alias */
+ {
+ "atan2",
+ 2,
+ SQLITE_UTF8,
+ 0,
+ atn2Func,
+ help_text("atan2")
+ .sql_function()
+ .with_summary("Returns the angle in the plane between the "
+ "positive X axis "
+ "and the ray from (0, 0) to the point (x, y)")
+ .with_parameter({"y", "The y coordinate of the point"})
+ .with_parameter({"x", "The x coordinate of the point"})
+ .with_tags({"math"})
+ .with_example({
+ "To get the angle, in degrees, for the point at (5, 5)",
+ "SELECT degrees(atan2(5, 5))",
+ }),
+ },
+ {
+ "acosh",
+ 1,
+ SQLITE_UTF8,
+ 0,
+ acoshFunc,
+ help_text("acosh")
+ .sql_function()
+ .with_summary("Returns the hyperbolic arccosine of a number")
+ .with_parameter({"num", "A number that is one or more"})
+ .with_tags({"math"})
+ .with_example({
+ "To get the hyperbolic arccosine of 1.2",
+ "SELECT acosh(1.2)",
+ }),
+ },
+ {
+ "asinh",
+ 1,
+ SQLITE_UTF8,
+ 0,
+ asinhFunc,
+ help_text("asinh")
+ .sql_function()
+ .with_summary("Returns the hyperbolic arcsine of a number")
+ .with_parameter({"num", "The number"})
+ .with_tags({"math"})
+ .with_example({
+ "To get the hyperbolic arcsine of 0.2",
+ "SELECT asinh(0.2)",
+ }),
+ },
+ {
+ "atanh",
+ 1,
+ SQLITE_UTF8,
+ 0,
+ atanhFunc,
+ help_text("atanh")
+ .sql_function()
+ .with_summary("Returns the hyperbolic arctangent of a number")
+ .with_parameter({"num", "The number"})
+ .with_tags({"math"})
+ .with_example({
+ "To get the hyperbolic arctangent of 0.2",
+ "SELECT atanh(0.2)",
+ }),
+ },
+
+ {"difference", 2, SQLITE_UTF8, 0, differenceFunc},
+ {
+ "degrees",
+ 1,
+ SQLITE_UTF8,
+ 0,
+ rad2degFunc,
+ help_text("degrees")
+ .sql_function()
+ .with_summary("Converts radians to degrees")
+ .with_parameter(
+ {"radians", "The radians value to convert to degrees"})
+ .with_tags({"math"})
+ .with_example(
+ {"To convert PI to degrees", "SELECT degrees(pi())"}),
+ },
+ {
+ "radians",
+ 1,
+ SQLITE_UTF8,
+ 0,
+ deg2radFunc,
+ help_text("radians")
+ .sql_function()
+ .with_summary("Converts degrees to radians")
+ .with_parameter(
+ {"degrees", "The degrees value to convert to radians"})
+ .with_tags({"math"})
+ .with_example({
+ "To convert 180 degrees to radians",
+ "SELECT radians(180)",
+ }),
+ },
+
+ {"cos", 1, SQLITE_UTF8, 0, cosFunc},
+ {"sin", 1, SQLITE_UTF8, 0, sinFunc},
+ {"tan", 1, SQLITE_UTF8, 0, tanFunc},
+ {"cot", 1, SQLITE_UTF8, 0, cotFunc},
+ {"cosh", 1, SQLITE_UTF8, 0, coshFunc},
+ {"sinh", 1, SQLITE_UTF8, 0, sinhFunc},
+ {"tanh", 1, SQLITE_UTF8, 0, tanhFunc},
+ {"coth", 1, SQLITE_UTF8, 0, cothFunc},
+
+ {
+ "exp",
+ 1,
+ SQLITE_UTF8,
+ 0,
+ expFunc,
+ help_text("exp")
+ .sql_function()
+ .with_summary("Returns the value of e raised to the power of x")
+ .with_parameter({"x", "The exponent"})
+ .with_tags({"math"})
+ .with_example({"To raise e to 2", "SELECT exp(2)"}),
+ },
+ {
+ "log",
+ 1,
+ SQLITE_UTF8,
+ 0,
+ logFunc,
+ help_text("log")
+ .sql_function()
+ .with_summary("Returns the natural logarithm of x")
+ .with_parameter({"x", "The number"})
+ .with_tags({"math"})
+ .with_example(
+ {"To get the natual logarithm of 8", "SELECT log(8)"}),
+ },
+ {
+ "log10",
+ 1,
+ SQLITE_UTF8,
+ 0,
+ log10Func,
+ help_text("log10")
+ .sql_function()
+ .with_summary("Returns the base-10 logarithm of X")
+ .with_parameter({"x", "The number"})
+ .with_tags({"math"})
+ .with_example(
+ {"To get the logarithm of 100", "SELECT log10(100)"}),
+ },
+ {
+ "power",
+ 2,
+ SQLITE_UTF8,
+ 0,
+ powerFunc,
+ help_text("power")
+ .sql_function()
+ .with_summary("Returns the base to the given exponent")
+ .with_parameter({"base", "The base number"})
+ .with_parameter({"exp", "The exponent"})
+ .with_tags({"math"})
+ .with_example({
+ "To raise two to the power of three",
+ "SELECT power(2, 3)",
+ }),
+ },
+ {
+ "sign",
+ 1,
+ SQLITE_UTF8,
+ 0,
+ signFunc,
+ help_text("sign")
+ .sql_function()
+ .with_summary(
+ "Returns the sign of the given number as -1, 0, or 1")
+ .with_parameter({"num", "The number"})
+ .with_tags({"math"})
+ .with_example({"To get the sign of 10", "SELECT sign(10)"})
+ .with_example({"To get the sign of 0", "SELECT sign(0)"})
+ .with_example({"To get the sign of -10", "SELECT sign(-10)"}),
+ },
+ {"sqrt", 1, SQLITE_UTF8, 0, sqrtFunc},
+ {
+ "square",
+ 1,
+ SQLITE_UTF8,
+ 0,
+ squareFunc,
+ help_text("square")
+ .sql_function()
+ .with_summary("Returns the square of the argument")
+ .with_parameter({"num", "The number to square"})
+ .with_tags({"math"})
+ .with_example({"To get the square of two", "SELECT square(2)"}),
+ },
+
+ {
+ "ceil",
+ 1,
+ SQLITE_UTF8,
+ 0,
+ ceilFunc,
+ help_text("ceil")
+ .sql_function()
+ .with_summary(
+ "Returns the smallest integer that is not less than "
+ "the argument")
+ .with_parameter({"num", "The number to raise to the ceiling"})
+ .with_tags({"math"})
+ .with_example(
+ {"To get the ceiling of 1.23", "SELECT ceil(1.23)"}),
+ },
+ {
+ "floor",
+ 1,
+ SQLITE_UTF8,
+ 0,
+ floorFunc,
+ help_text("floor")
+ .sql_function()
+ .with_summary("Returns the largest integer that is not greater "
+ "than the argument")
+ .with_parameter({"num", "The number to lower to the floor"})
+ .with_tags({"math"})
+ .with_example(
+ {"To get the floor of 1.23", "SELECT floor(1.23)"}),
+ },
+
+ {
+ "pi",
+ 0,
+ SQLITE_UTF8,
+ 1,
+ piFunc,
+ help_text("pi")
+ .sql_function()
+ .with_summary("Returns the value of PI")
+ .with_tags({"math"})
+ .with_example({"To get the value of PI", "SELECT pi()"}),
+ },
+
+ /* string */
+ {
+ "replicate",
+ 2,
+ SQLITE_UTF8,
+ 0,
+ replicateFunc,
+ help_text("replicate")
+ .sql_function()
+ .with_summary("Returns the given string concatenated N times.")
+ .with_parameter({"str", "The string to replicate."})
+ .with_parameter(
+ {"N", "The number of times to replicate the string."})
+ .with_tags({"string"})
+ .with_example({
+ "To repeat the string 'abc' three times",
+ "SELECT replicate('abc', 3)",
+ }),
+ },
+ {"charindex", 2, SQLITE_UTF8, 0, charindexFunc},
+ {
+ "charindex",
+ 3,
+ SQLITE_UTF8,
+ 0,
+ charindexFunc,
+ help_text("charindex")
+ .sql_function()
+ .with_summary("Finds the first occurrence of the needle within "
+ "the haystack "
+ "and returns the number of prior characters plus "
+ "1, or 0 if Y "
+ "is nowhere found within X")
+ .with_parameter(
+ {"needle", "The string to look for in the haystack"})
+ .with_parameter({"haystack", "The string to search within"})
+ .with_parameter(help_text("start",
+ "The one-based index within the "
+ "haystack to start the search")
+ .optional())
+ .with_tags({"string"})
+ .with_example({
+ "To search for the string 'abc' within 'abcabc' "
+ "and starting at position 2",
+ "SELECT charindex('abc', 'abcabc', 2)",
+ })
+ .with_example({
+ "To search for the string 'abc' within 'abcdef' "
+ "and starting at position 2",
+ "SELECT charindex('abc', 'abcdef', 2)",
+ }),
+ },
+ {
+ "leftstr",
+ 2,
+ SQLITE_UTF8,
+ 0,
+ leftFunc,
+ help_text("leftstr")
+ .sql_function()
+ .with_summary(
+ "Returns the N leftmost (UTF-8) characters in the "
+ "given string.")
+ .with_parameter({"str", "The string to return subset."})
+ .with_parameter(
+ {"N",
+ "The number of characters from the left side of "
+ "the string to return."})
+ .with_tags({"string"})
+ .with_example({
+ "To get the first character of the string 'abc'",
+ "SELECT leftstr('abc', 1)",
+ })
+ .with_example({
+ "To get the first ten characters of a string, "
+ "regardless of size",
+ "SELECT leftstr('abc', 10)",
+ }),
+ },
+ {
+ "rightstr",
+ 2,
+ SQLITE_UTF8,
+ 0,
+ rightFunc,
+ help_text("rightstr")
+ .sql_function()
+ .with_summary(
+ "Returns the N rightmost (UTF-8) characters in the "
+ "given string.")
+ .with_parameter({"str", "The string to return subset."})
+ .with_parameter(
+ {"N",
+ "The number of characters from the right side of "
+ "the string to return."})
+ .with_tags({"string"})
+ .with_example({
+ "To get the last character of the string 'abc'",
+ "SELECT rightstr('abc', 1)",
+ })
+ .with_example({
+ "To get the last ten characters of a string, "
+ "regardless of size",
+ "SELECT rightstr('abc', 10)",
+ }),
+ },
+#ifndef HAVE_TRIM
+ {"ltrim", 1, SQLITE_UTF8, 0, ltrimFunc},
+ {"rtrim", 1, SQLITE_UTF8, 0, rtrimFunc},
+ {"trim", 1, SQLITE_UTF8, 0, trimFunc},
+ {"replace", 3, SQLITE_UTF8, 0, replaceFunc},
+#endif
+ {
+ "reverse",
+ 1,
+ SQLITE_UTF8,
+ 0,
+ reverseFunc,
+ help_text("reverse")
+ .sql_function()
+ .with_summary("Returns the reverse of the given string.")
+ .with_parameter({"str", "The string to reverse."})
+ .with_tags({"string"})
+ .with_example(
+ {"To reverse the string 'abc'", "SELECT reverse('abc')"}),
+ },
+ {
+ "proper",
+ 1,
+ SQLITE_UTF8,
+ 0,
+ properFunc,
+ help_text("proper")
+ .sql_function()
+ .with_summary("Capitalize the first character of words in the "
+ "given string")
+ .with_parameter({"str", "The string to capitalize."})
+ .with_tags({"string"})
+ .with_example({
+ "To capitalize the words in the string 'hello, world!'",
+ "SELECT proper('hello, world!')",
+ }),
+ },
+ {
+ "padl",
+ 2,
+ SQLITE_UTF8,
+ 0,
+ padlFunc,
+ help_text("padl")
+ .sql_function()
+ .with_summary(
+ "Pad the given string with leading spaces until it "
+ "reaches the desired length")
+ .with_parameter({"str", "The string to pad"})
+ .with_parameter(
+ {"len", "The minimum desired length of the output string"})
+ .with_tags({"string"})
+ .with_example(
+ {"To pad the string 'abc' to a length of six characters",
+ "SELECT padl('abc', 6)"})
+ .with_example({
+ "To pad the string 'abcdef' to a length of four "
+ "characters",
+ "SELECT padl('abcdef', 4)",
+ }),
+ },
+ {
+ "padr",
+ 2,
+ SQLITE_UTF8,
+ 0,
+ padrFunc,
+ help_text("padr")
+ .sql_function()
+ .with_summary(
+ "Pad the given string with trailing spaces until it "
+ "reaches the desired length")
+ .with_parameter({"str", "The string to pad"})
+ .with_parameter(
+ {"len", "The minimum desired length of the output string"})
+ .with_tags({"string"})
+ .with_example(
+ {"To pad the string 'abc' to a length of six characters",
+ "SELECT padr('abc', 6) || 'def'"})
+ .with_example({
+ "To pad the string 'abcdef' to a length of four characters",
+ "SELECT padr('abcdef', 4) || 'ghi'",
+ }),
+ },
+ {
+ "padc",
+ 2,
+ SQLITE_UTF8,
+ 0,
+ padcFunc,
+ help_text("padc")
+ .sql_function()
+ .with_summary(
+ "Pad the given string with enough spaces to make it "
+ "centered within the given length")
+ .with_parameter({"str", "The string to pad"})
+ .with_parameter(
+ {"len", "The minimum desired length of the output string"})
+ .with_tags({"string"})
+ .with_example(
+ {"To pad the string 'abc' to a length of six characters",
+ "SELECT padc('abc', 6) || 'def'"})
+ .with_example({
+ "To pad the string 'abcdef' to a length of "
+ "eight characters",
+ "SELECT padc('abcdef', 8) || 'ghi'",
+ }),
+ },
+ {
+ "strfilter",
+ 2,
+ SQLITE_UTF8,
+ 0,
+ strfilterFunc,
+ help_text("strfilter")
+ .sql_function()
+ .with_summary(
+ "Returns the source string with only the characters "
+ "given in the second parameter")
+ .with_parameter({"source", "The string to filter"})
+ .with_parameter(
+ {"include", "The characters to include in the result"})
+ .with_tags({"string"})
+ .with_example({
+ "To get the 'b', 'c', and 'd' characters from the "
+ "string 'abcabc'",
+ "SELECT strfilter('abcabc', 'bcd')",
+ }),
+ },
+
+ {nullptr},
+ };
+
+ /* Aggregate functions */
+ static struct FuncDefAgg aAggs[] = {
+ {"stdev", 1, 0, varianceStep, stdevFinalize},
+ {"stddev", 1, 0, varianceStep, stdevFinalize},
+ {"variance", 1, 0, varianceStep, varianceFinalize},
+ {"mode", 1, 0, modeStep, modeFinalize},
+ {"median", 1, 0, modeStep, medianFinalize},
+ {"lower_quartile", 1, 0, modeStep, lower_quartileFinalize},
+ {"upper_quartile", 1, 0, modeStep, upper_quartileFinalize},
+
+ {nullptr},
+ };
+
+ *basic_funcs = aFuncs;
+ *agg_funcs = aAggs;
+
+ return SQLITE_OK;
+}
+
+#ifdef COMPILE_SQLITE_EXTENSIONS_AS_LOADABLE_MODULE
+int
+sqlite3_extension_init(sqlite3* db,
+ char** pzErrMsg,
+ const sqlite3_api_routines* pApi)
+{
+ SQLITE_EXTENSION_INIT2(pApi);
+ RegisterExtensionFunctions(db);
+ return 0;
+}
+#endif /* COMPILE_SQLITE_EXTENSIONS_AS_LOADABLE_MODULE */
+
+map
+map_make(cmp_func cmp)
+{
+ map r;
+ r.cmp = cmp;
+ r.base = 0;
+ r.free = 0;
+
+ return r;
+}
+
+void*
+xcalloc(size_t nmemb, size_t size, const char* s)
+{
+ void* ret = calloc(nmemb, size);
+ return ret;
+}
+
+static void
+xfree(void* p)
+{
+ free(p);
+}
+
+void
+node_insert(node** n, cmp_func cmp, void* e)
+{
+ int c;
+ node* nn;
+ if (*n == 0) {
+ nn = (node*) xcalloc(1, sizeof(node), "for node");
+ nn->data = e;
+ nn->count = 1;
+ *n = nn;
+ } else {
+ c = cmp((*n)->data, e);
+ if (0 == c) {
+ ++((*n)->count);
+ xfree(e);
+ } else if (c > 0) {
+ /* put it right here */
+ node_insert(&((*n)->l), cmp, e);
+ } else {
+ node_insert(&((*n)->r), cmp, e);
+ }
+ }
+}
+
+void
+map_insert(map* m, void* e)
+{
+ node_insert(&(m->base), m->cmp, e);
+}
+
+void
+node_iterate(node* n, map_iterator iter, void* p)
+{
+ if (n) {
+ if (n->l)
+ node_iterate(n->l, iter, p);
+ iter(n->data, n->count, p);
+ if (n->r)
+ node_iterate(n->r, iter, p);
+ }
+}
+
+void
+map_iterate(map* m, map_iterator iter, void* p)
+{
+ node_iterate(m->base, iter, p);
+}
+
+void
+node_destroy(node* n)
+{
+ if (0 != n) {
+ xfree(n->data);
+ if (n->l)
+ node_destroy(n->l);
+ if (n->r)
+ node_destroy(n->r);
+
+ xfree(n);
+ }
+}
+
+void
+map_destroy(map* m)
+{
+ node_destroy(m->base);
+}
+
+int
+int_cmp(const void* a, const void* b)
+{
+ int64_t aa = *(int64_t*) (a);
+ int64_t bb = *(int64_t*) (b);
+ /* printf("cmp %d <=> %d\n",aa,bb); */
+ if (aa == bb)
+ return 0;
+ else if (aa < bb)
+ return -1;
+ else
+ return 1;
+}
+
+int
+double_cmp(const void* a, const void* b)
+{
+ double aa = *(double*) (a);
+ double bb = *(double*) (b);
+ /* printf("cmp %d <=> %d\n",aa,bb); */
+ if (aa == bb)
+ return 0;
+ else if (aa < bb)
+ return -1;
+ else
+ return 1;
+}
+
+void
+print_elem(void* e, int64_t c, void* p)
+{
+ int ee = *(int*) (e);
+ printf("%d => %" PRId64 "\n", ee, c);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-15 15:13:20 +0000