/*
** This file contains a standalone program used to generate C code that
** implements a static hash table to store the definitions of built-in
** SQL functions in SQLite.
*/
#include <stdio.h>
#include <string.h>
#include <assert.h>
/*
** The SQLite source file "func.c" is included below.
**
** By defining the 4 macros and typedef below before including "func.c",
** most of the code is excluded. What is left is an array of constant
** strings, aBuiltinFunc[], containing the names of SQLite's built-in
** SQL functions. i.e.:
**
** const char aBuiltinFunc[] = { "like", "glob", "min", "max" ... };
**
** The data from aBuiltinFunc[] is used by this program to create the
** static hash table.
*/
#define CREATE_BUILTIN_HASHTABLE 1
#define FUNCTION(zName,w,x,y,z) #zName
#define AGGREGATE(zName,v,w,x,y,z) #zName
#define LIKEFUNC(zName,x,y,z) #zName
#define FuncDef const char *
#include "func.c"
/* The number of buckets in the static hash table. */
#define HASHSIZE 127
typedef unsigned char u8;
/* An array to map all upper-case characters into their corresponding
** lower-case character.
*/
static const u8 sqlite3UpperToLower[] = {
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17,
18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53,
54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 97, 98, 99,100,101,102,103,
104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,
122, 91, 92, 93, 94, 95, 96, 97, 98, 99,100,101,102,103,104,105,106,107,
108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,
126,127,128,129,130,131,132,133,134,135,136,137,138,139,140,141,142,143,
144,145,146,147,148,149,150,151,152,153,154,155,156,157,158,159,160,161,
162,163,164,165,166,167,168,169,170,171,172,173,174,175,176,177,178,179,
180,181,182,183,184,185,186,187,188,189,190,191,192,193,194,195,196,197,
198,199,200,201,202,203,204,205,206,207,208,209,210,211,212,213,214,215,
216,217,218,219,220,221,222,223,224,225,226,227,228,229,230,231,232,233,
234,235,236,237,238,239,240,241,242,243,244,245,246,247,248,249,250,251,
252,253,254,255
};
#define UpperToLower sqlite3UpperToLower
int sqlite3StrICmp(const char *zLeft, const char *zRight){
register unsigned char *a, *b;
a = (unsigned char *)zLeft;
b = (unsigned char *)zRight;
while( *a!=0 && UpperToLower[*a]==UpperToLower[*b]){ a++; b++; }
return UpperToLower[*a] - UpperToLower[*b];
}
static int hashstring(const char *zName){
int ii;
unsigned int iKey = 0;
for(ii=0; zName[ii]; ii++){
iKey = (iKey<<3) + (u8)sqlite3UpperToLower[(u8)zName[ii]];
}
iKey = iKey%HASHSIZE;
return iKey;
}
static void printarray(const char *zName, u8 *aArray, int nArray){
int ii;
printf(" static u8 %s[%d] = {", zName, nArray);
for(ii=0; ii<nArray; ii++){
if( (ii%16)==0 ){
printf("\n ");
}
printf("%2d, ", aArray[ii]);
}
printf("\n };\n");
}
int main(int argc, char **argv){
int nFunc; /* Number of entries in the aBuiltinFunc array */
u8 anFunc[256];
u8 aHash[HASHSIZE];
u8 aNext[256];
int ii;
int iHead;
nFunc = (sizeof(aBuiltinFunc)/sizeof(const char *));
assert(nFunc<256);
memset(aHash, (unsigned char)nFunc, sizeof(aHash));
memset(aNext, (unsigned char)nFunc, sizeof(aNext));
memset(anFunc, 0, sizeof(anFunc));
iHead = -1;
for(ii=0; ii<nFunc; ii++){
int iHash;
if( iHead>=0 && 0==sqlite3StrICmp(aBuiltinFunc[ii], aBuiltinFunc[iHead]) ){
anFunc[iHead]++;
continue;
}else{
/* The routine generated by this program assumes that if there are
** two or more entries in the aBuiltinFunc[] array with the same
** name (i.e. two versions of the "max" function), then they must
** be stored in adjacent slots. The following block detects the
** problem if this is not the case.
*/
int jj;
for(jj=0; jj<ii; jj++){
if( 0==sqlite3StrICmp(aBuiltinFunc[ii], aBuiltinFunc[jj]) ){
fprintf(stderr, "Error in func.c\n");
return -1;
}
}
iHead = ii;
anFunc[iHead] = 1;
}
iHash = hashstring(aBuiltinFunc[ii]);
if( aHash[iHash]!=nFunc ){
int iNext = aHash[iHash];
while( aNext[iNext]!=nFunc ){
iNext = aNext[iNext];
}
aNext[iNext] = ii;
}else{
aHash[iHash] = ii;
}
}
printf(
"/******* Automatically Generated code - do not edit **************/\n"
"int sqlite3GetBuiltinFunction(\n"
" const char *zName, \n"
" int nName, \n"
" FuncDef **paFunc\n"
"){\n"
);
printarray("aHash", aHash, HASHSIZE);
printarray("anFunc", anFunc, nFunc);
printarray("aNext", aNext, nFunc);
printf(" FuncDef *pNoFunc = &aBuiltinFunc[%d];\n", nFunc);
printf(
" unsigned int iKey = 0; /* Hash of case-insensitive string zName. */\n"
" int ii;\n"
" FuncDef *pFunc;\n"
"\n"
);
printf(
" assert( (sizeof(aBuiltinFunc)/sizeof(aBuiltinFunc[0]))==%d );\n", nFunc
);
printf(
" /* Generate the hash of zName */\n"
" for(ii=0; ii<nName; ii++){\n"
" iKey = (iKey<<3) + (u8)sqlite3UpperToLower[(u8)zName[ii]];\n"
" }\n"
" iKey = iKey%%127;\n"
"\n"
" pFunc = &aBuiltinFunc[iKey = aHash[iKey]];\n"
" while( pFunc!=pNoFunc && sqlite3StrNICmp(pFunc->zName, zName, nName) ){\n"
" pFunc = &aBuiltinFunc[iKey = aNext[iKey]];\n"
" }\n"
"\n"
" *paFunc = pFunc;\n"
" return anFunc[iKey];\n"
"}\n"
);
return 0;
}