/* Copyright (C) 2000 MySQL AB & MySQL Finland AB & TCX DataKonsult AB This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ /* The idea of presented algorithm see in "The Art of Computer Programming" by Donald E. Knuth Volume 3 "Sorting and searching" (chapter 6.3 "Digital searching" - name and number of chapter is back translation from Russian edition :)) as illustration of data structures, imagine next table: static SYMBOL symbols[] = { { "ADD", SYM(ADD),0,0}, { "AND", SYM(AND),0,0}, { "DAY", SYM(DAY_SYM),0,0}, }; for this structure, presented program generate next searching-structure: +-----------+-+-+-+ | len |1|2|3| +-----------+-+-+-+ |first_char |0|0|a| |last_char |0|0|d| |link |0|0|+| | V +----------+-+-+-+--+ | 1 char|a|b|c|d | +----------+-+-+-+--+ |first_char|b|0|0|0 | |last_char |n|0|0|-1| |link |+|0|0|+ | | | | V | symbols[2] ( "DAY" ) V +----------+--+-+-+-+-+-+-+-+-+-+--+ | 2 char|d |e|f|j|h|i|j|k|l|m|n | +----------+--+-+-+-+-+-+-+-+-+-+--+ |first_char|0 |0|0|0|0|0|0|0|0|0|0 | |last_char |-1|0|0|0|0|0|0|0|0|0|-1| |link |+ |0|0|0|0|0|0|0|0|0|+ | | | V V symbols[0] ( "ADD" ) symbols[1] ( "AND" ) for optimization, link is the 16-bit index in 'symbols' or 'sql_functions' or search-array.. So, we can read full search-structure as 32-bit word TODO: 1. use instead to_upper_lex, special array (substitute chars) without skip codes.. 2. try use reverse order of comparing.. */ #define NO_YACC_SYMBOLS #include "my_global.h" #include "my_sys.h" #include "m_string.h" #ifndef __GNU_LIBRARY__ #define __GNU_LIBRARY__ // Skip warnings in getopt.h #endif #include <my_getopt.h> #include "mysql_version.h" #include "lex.h" static struct my_option my_long_options[] = { {"help", '?', "Display help and exit", 0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0}, {"version", 'V', "Output version information and exit", 0, 0, 0, GET_NO_ARG, NO_ARG, 0, 0, 0, 0, 0, 0}, }; struct hash_lex_struct { char first_char; char last_char; union{ hash_lex_struct *char_tails; int iresult; }; int ithis; }; hash_lex_struct *get_hash_struct_by_len(hash_lex_struct **root_by_len, int len, int *max_len) { if (*max_len<len){ *root_by_len= (hash_lex_struct *)realloc((char*)*root_by_len, sizeof(hash_lex_struct)*len); hash_lex_struct *cur, *end= *root_by_len + len; for (cur= *root_by_len + *max_len; cur<end; cur++) cur->first_char= 0; *max_len= len; } return (*root_by_len)+(len-1); } void insert_into_hash(hash_lex_struct *root, const char *name, int len_from_begin, int index, int function) { hash_lex_struct *end, *cur, *tails; if (!root->first_char){ root->first_char= -1; root->iresult= index; return; } if (root->first_char==-1){ int index2= root->iresult; const char *name2= (index2<0 ? sql_functions[-index2-1] : symbols[index2]).name + len_from_begin; root->first_char= name2[0]; root->last_char= root->first_char; tails= (hash_lex_struct*)malloc(sizeof(hash_lex_struct)); root->char_tails= tails; tails->first_char= -1; tails->iresult= index2; } size_t real_size= (root->last_char-root->first_char+1); if (root->first_char>(*name)){ size_t new_size= root->last_char-(*name)+1; if (new_size<real_size) printf("error!!!!\n"); tails= root->char_tails; tails= (hash_lex_struct*)realloc((char*)tails, sizeof(hash_lex_struct)*new_size); root->char_tails= tails; memmove(tails+(new_size-real_size),tails,real_size*sizeof(hash_lex_struct)); end= tails + new_size - real_size; for (cur= tails; cur<end; cur++) cur->first_char= 0; root->first_char= (*name); } if (root->last_char<(*name)){ size_t new_size= (*name)-root->first_char+1; if (new_size<real_size) printf("error!!!!\n"); tails= root->char_tails; tails= (hash_lex_struct*)realloc((char*)tails, sizeof(hash_lex_struct)*new_size); root->char_tails= tails; end= tails + new_size; for (cur= tails+real_size; cur<end; cur++) cur->first_char= 0; root->last_char= (*name); } insert_into_hash (root->char_tails+(*name)-root->first_char, name+1,len_from_begin+1,index,function); } hash_lex_struct *root_by_len= 0; int max_len=0; hash_lex_struct *root_by_len2= 0; int max_len2=0; void insert_symbols() { size_t i= 0; SYMBOL *cur; for (cur= symbols; i<array_elements(symbols); cur++, i++){ hash_lex_struct *root= get_hash_struct_by_len(&root_by_len,cur->length,&max_len); insert_into_hash(root,cur->name,0,i,0); } } void insert_sql_functions() { size_t i= 0; SYMBOL *cur; for (cur= sql_functions; i<array_elements(sql_functions); cur++, i++){ hash_lex_struct *root= get_hash_struct_by_len(&root_by_len,cur->length,&max_len); insert_into_hash(root,cur->name,0,-i-1,1); } } void generate_find_structs() { root_by_len= 0; max_len=0; size_t i; SYMBOL *cur, *end= symbols + array_elements(symbols); for (cur= symbols; cur < end; cur++) cur->length=(uchar) strlen(cur->name); end= sql_functions + array_elements(sql_functions); for (cur= sql_functions; cur<end; cur++) cur->length=(uchar) strlen(cur->name); insert_symbols(); root_by_len2= root_by_len; max_len2= max_len; root_by_len= 0; max_len= 0; insert_symbols(); insert_sql_functions(); } char *hash_map= 0; int size_hash_map= 0; void add_struct_to_map(hash_lex_struct *st) { st->ithis= size_hash_map/4; size_hash_map+= 4; hash_map= (char*)realloc((char*)hash_map,size_hash_map); hash_map[size_hash_map-4]= st->first_char==-1 ? 0 : st->first_char; hash_map[size_hash_map-3]= st->first_char==-1 || st->first_char==0 ? 0 : st->last_char; if (st->first_char==-1) { hash_map[size_hash_map-2]= ((unsigned int)(int16)st->iresult)&255; hash_map[size_hash_map-1]= ((unsigned int)(int16)st->iresult)>>8; } else if (st->first_char==0) { hash_map[size_hash_map-2]= ((unsigned int)(int16)array_elements(symbols))&255; hash_map[size_hash_map-1]= ((unsigned int)(int16)array_elements(symbols))>>8; } }; void add_structs_to_map(hash_lex_struct *st, int len) { hash_lex_struct *cur, *end= st+len; for (cur= st; cur<end; cur++) add_struct_to_map(cur); for (cur= st; cur<end; cur++) if (cur->first_char && cur->first_char!=-1) add_structs_to_map(cur->char_tails,cur->last_char-cur->first_char+1); } void set_links(hash_lex_struct *st, int len) { hash_lex_struct *cur, *end= st+len; for (cur= st; cur<end; cur++) if (cur->first_char!=0 && cur->first_char!=-1){ int ilink= cur->char_tails->ithis; hash_map[cur->ithis*4+2]= ilink%256; hash_map[cur->ithis*4+3]= ilink/256; set_links(cur->char_tails,cur->last_char-cur->first_char+1); } } void print_hash_map(const char *name) { printf("uchar %s[%d]= {\n",name,size_hash_map); char *cur; int i; for (i=0, cur= hash_map; i<size_hash_map; i++, cur++){ switch(i%4){ case 0: case 1: if (!*cur) printf("0, "); else printf("\'%c\', ",*cur); break; case 2: printf("%u, ",(uint)(uchar)*cur); break; case 3: printf("%u,\n",(uint)(uchar)*cur); break; } } printf("};\n"); } void print_find_structs() { add_structs_to_map(root_by_len,max_len); set_links(root_by_len,max_len); print_hash_map("sql_functions_map"); hash_map= 0; size_hash_map= 0; printf("\n"); add_structs_to_map(root_by_len2,max_len2); set_links(root_by_len2,max_len2); print_hash_map("symbols_map"); } static void usage(int version) { printf("%s Ver 3.5 Distrib %s, for %s (%s)\n", my_progname, MYSQL_SERVER_VERSION, SYSTEM_TYPE, MACHINE_TYPE); if (version) return; puts("Copyright (C) 2001 MySQL AB, by VVA and Monty"); puts("This software comes with ABSOLUTELY NO WARRANTY. This is free software,\n\ and you are welcome to modify and redistribute it under the GPL license\n"); puts("This program generates a perfect hashing function for the sql_lex.cc"); printf("Usage: %s [OPTIONS]\n\n", my_progname); my_print_help(my_long_options); } static my_bool get_one_option(int optid, const struct my_option *opt __attribute__((unused)), char *argument __attribute__((unused))) { switch(optid) { case 'V': usage(1); exit(0); case 'I': case '?': usage(0); exit(0); } return 0; } static int get_options(int argc, char **argv) { int ho_error; if ((ho_error=handle_options(&argc, &argv, my_long_options, get_one_option))) exit(ho_error); if (argc >= 1) { usage(0); exit(1); } return(0); } int main(int argc,char **argv) { MY_INIT(argv[0]); if (get_options(argc,(char **) argv)) exit(1); printf("/* Copyright (C) 2001 MySQL AB\n\ This program is free software; you can redistribute it and/or modify\n\ it under the terms of the GNU General Public License as published by\n\ the Free Software Foundation; either version 2 of the License, or\n\ (at your option) any later version.\n\n\ This program is distributed in the hope that it will be useful,\n\ but WITHOUT ANY WARRANTY; without even the implied warranty of\n\ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the\n\ GNU General Public License for more details.\n\n\ You should have received a copy of the GNU General Public License\n\ along with this program; if not, write to the Free Software\n\ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307\ USA */\n\n"); printf("/* This code is generated by gen_lex_hash.cc that seeks for\ a perfect\nhash function */\n\n"); printf("#include \"lex.h\"\n\n"); generate_find_structs(); print_find_structs(); printf("\nunsigned int sql_functions_max_len=%d;\n",max_len); printf("\nunsigned int symbols_max_len=%d;\n\n",max_len2); printf ( "inline SYMBOL *get_hash_symbol(const char *s,\n\ unsigned int len,bool function)\n\ {\n\ register uchar *hash_map;\n\ register const char *cur_str= s;\n\ if (function){\n\ if (len>sql_functions_max_len) return 0;\n\ hash_map= sql_functions_map;\n\ register uint32 cur_struct= uint4korr(hash_map+((len-1)*4));\n\ \n\ for(;;){\n\ register uchar first_char= (uchar)cur_struct;\n\ \n\ if (first_char==0){\n\ register int16 ires= (int16)(cur_struct>>16);\n\ if (ires==array_elements(symbols)) return 0;\n\ register SYMBOL *res;\n\ if (ires>=0) \n\ res= symbols+ires;\n\ else\n\ res= sql_functions-ires-1;\n\ register uint count= cur_str-s;\n\ return lex_casecmp(cur_str,res->name+count,len-count) ? 0 : res;\n\ }\n\ \n\ register uchar cur_char= (uchar)to_upper_lex[(uchar)*cur_str];\n\ if (cur_char<first_char) return 0;\n\ cur_struct>>=8;\n\ if (cur_char>(uchar)cur_struct) return 0;\n\ \n\ cur_struct>>=8;\n\ cur_struct= uint4korr(hash_map+\n\ (((uint16)cur_struct + cur_char - first_char)*4));\n\ cur_str++;\n\ }\n\ }else{\n\ if (len>symbols_max_len) return 0;\n\ hash_map= symbols_map;\n\ register uint32 cur_struct= uint4korr(hash_map+((len-1)*4));\n\ \n\ for(;;){\n\ register uchar first_char= (uchar)cur_struct;\n\ \n\ if (first_char==0){\n\ register int16 ires= (int16)(cur_struct>>16);\n\ if (ires==array_elements(symbols)) return 0;\n\ register SYMBOL *res= symbols+ires;\n\ register uint count= cur_str-s;\n\ return lex_casecmp(cur_str,res->name+count,len-count)!=0 ? 0 : res;\n\ }\n\ \n\ register uchar cur_char= (uchar)to_upper_lex[(uchar)*cur_str];\n\ if (cur_char<first_char) return 0;\n\ cur_struct>>=8;\n\ if (cur_char>(uchar)cur_struct) return 0;\n\ \n\ cur_struct>>=8;\n\ cur_struct= uint4korr(hash_map+\n\ (((uint16)cur_struct + cur_char - first_char)*4));\n\ cur_str++;\n\ }\n\ }\n\ }\n" ); }