/* $OpenBSD: comp_hash.c,v 1.6 2003/03/18 16:55:54 millert Exp $ */ /**************************************************************************** * Copyright (c) 1998 Free Software Foundation, Inc. * * * * Permission is hereby granted, free of charge, to any person obtaining a * * copy of this software and associated documentation files (the * * "Software"), to deal in the Software without restriction, including * * without limitation the rights to use, copy, modify, merge, publish, * * distribute, distribute with modifications, sublicense, and/or sell * * copies of the Software, and to permit persons to whom the Software is * * furnished to do so, subject to the following conditions: * * * * The above copyright notice and this permission notice shall be included * * in all copies or substantial portions of the Software. * * * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * * IN NO EVENT SHALL THE ABOVE COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, * * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR * * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR * * THE USE OR OTHER DEALINGS IN THE SOFTWARE. * * * * Except as contained in this notice, the name(s) of the above copyright * * holders shall not be used in advertising or otherwise to promote the * * sale, use or other dealings in this Software without prior written * * authorization. * ****************************************************************************/ /**************************************************************************** * Author: Zeyd M. Ben-Halim 1992,1995 * * and: Eric S. Raymond * ****************************************************************************/ /* * comp_hash.c --- Routines to deal with the hashtable of capability * names. * */ #include #include #include #ifdef MAIN_PROGRAM #include #undef DEBUG #define DEBUG(level, params) /*nothing*/ #endif MODULE_ID("$From: comp_hash.c,v 1.21 1999/06/26 21:25:11 tom Exp $") static int hash_function(const char *); /* * _nc_make_hash_table() * * Takes the entries in table[] and hashes them into hash_table[] * by name. There are CAPTABSIZE entries in table[] and HASHTABSIZE * slots in hash_table[]. * */ #ifdef MAIN_PROGRAM #undef MODULE_ID #define MODULE_ID(id) /*nothing*/ #include static void _nc_make_hash_table(struct name_table_entry *table, struct name_table_entry **hash_table) { int i; int hashvalue; int collisions = 0; for (i = 0; i < CAPTABSIZE; i++) { hashvalue = hash_function(table[i].nte_name); if (hash_table[hashvalue] != (struct name_table_entry *) 0) collisions++; if (hash_table[hashvalue] != 0) table[i].nte_link = (short)(hash_table[hashvalue] - table); hash_table[hashvalue] = &table[i]; } DEBUG(4, ("Hash table complete: %d collisions out of %d entries", collisions, CAPTABSIZE)); } #endif /* * int hash_function(string) * * Computes the hashing function on the given string. * * The current hash function is the sum of each consectutive pair * of characters, taken as two-byte integers, mod Hashtabsize. * */ static int hash_function(const char *string) { long sum = 0; DEBUG(9, ("hashing %s", string)); while (*string) { sum += (long)(*string + (*(string + 1) << 8)); string++; } DEBUG(9, ("sum is %ld", sum)); return (int)(sum % HASHTABSIZE); } /* * struct name_table_entry * * find_entry(string) * * Finds the entry for the given string in the hash table if present. * Returns a pointer to the entry in the table or 0 if not found. * */ #ifndef MAIN_PROGRAM struct name_table_entry const * _nc_find_entry(const char *string, const struct name_table_entry *const *hash_table) { int hashvalue; struct name_table_entry const *ptr; hashvalue = hash_function(string); if ((ptr = hash_table[hashvalue]) != 0) { while (strcmp(ptr->nte_name, string) != 0) { if (ptr->nte_link < 0) return 0; ptr = ptr->nte_link + hash_table[HASHTABSIZE]; } } return (ptr); } /* * struct name_table_entry * * find_type_entry(string, type, table) * * Finds the first entry for the given name with the given type in the * given table if present (as distinct from find_entry, which finds the * the last entry regardless of type). You can use this if you detect * a name clash. It's slower, though. Returns a pointer to the entry * in the table or 0 if not found. */ struct name_table_entry const * _nc_find_type_entry(const char *string, int type, const struct name_table_entry *table) { struct name_table_entry const *ptr; for (ptr = table; ptr < table + CAPTABSIZE; ptr++) { if (ptr->nte_type == type && strcmp(string, ptr->nte_name) == 0) return(ptr); } return ((struct name_table_entry *)NULL); } #endif #ifdef MAIN_PROGRAM /* * This filter reads from standard input a list of tab-delimited columns, * (e.g., from Caps.filtered) computes the hash-value of a specified column and * writes the hashed tables to standard output. * * By compiling the hash table at build time, we're able to make the entire * set of terminfo and termcap tables readonly (and also provide some runtime * performance enhancement). */ #define MAX_COLUMNS BUFSIZ /* this _has_ to be worst-case */ static char **parse_columns(char *buffer) { static char **list; int col = 0; if (list == 0 && (list = typeCalloc(char *, MAX_COLUMNS)) == 0) return(0); if (*buffer != '#') { while (*buffer != '\0') { char *s; for (s = buffer; (*s != '\0') && !isspace(*s); s++) /*EMPTY*/; if (s != buffer) { char mark = *s; *s = '\0'; if ((s - buffer) > 1 && (*buffer == '"') && (s[-1] == '"')) { /* strip the quotes */ buffer++; s[-1] = '\0'; } list[col] = buffer; col++; if (mark == '\0') break; while (*++s && isspace(*s)) /*EMPTY*/; buffer = s; } else break; } } return col ? list : 0; } int main(int argc, char **argv) { struct name_table_entry *name_table = typeCalloc(struct name_table_entry, CAPTABSIZE); struct name_table_entry **hash_table = typeCalloc(struct name_table_entry *, HASHTABSIZE); const char *root_name = ""; int column = 0; int n; char buffer[BUFSIZ]; static const char * typenames[] = { "BOOLEAN", "NUMBER", "STRING" }; short BoolCount = 0; short NumCount = 0; short StrCount = 0; /* The first argument is the column-number (starting with 0). * The second is the root name of the tables to generate. */ if (argc <= 2 || (column = atoi(argv[1])) <= 0 || (column >= MAX_COLUMNS) || *(root_name = argv[2]) == 0) { fprintf(stderr, "usage: make_hash column root_name\n"); exit(EXIT_FAILURE); } /* * Read the table into our arrays. */ for (n = 0; (n < CAPTABSIZE) && fgets(buffer, BUFSIZ, stdin); ) { char **list, *nlp = strchr(buffer, '\n'); if (nlp) *nlp = '\0'; list = parse_columns(buffer); if (list == 0) /* blank or comment */ continue; name_table[n].nte_link = -1; /* end-of-hash */ name_table[n].nte_name = strdup(list[column]); if (!strcmp(list[2], "bool")) { name_table[n].nte_type = BOOLEAN; name_table[n].nte_index = BoolCount++; } else if (!strcmp(list[2], "num")) { name_table[n].nte_type = NUMBER; name_table[n].nte_index = NumCount++; } else if (!strcmp(list[2], "str")) { name_table[n].nte_type = STRING; name_table[n].nte_index = StrCount++; } else { fprintf(stderr, "Unknown type: %s\n", list[2]); exit(EXIT_FAILURE); } n++; } _nc_make_hash_table(name_table, hash_table); /* * Write the compiled tables to standard output */ printf("static struct name_table_entry const _nc_%s_table[] =\n", root_name); printf("{\n"); for (n = 0; n < CAPTABSIZE; n++) { snprintf(buffer, sizeof(buffer), "\"%s\"", name_table[n].nte_name); printf("\t{ %15s,\t%10s,\t%3d, %3d }%c\n", buffer, typenames[name_table[n].nte_type], name_table[n].nte_index, name_table[n].nte_link, n < CAPTABSIZE - 1 ? ',' : ' '); } printf("};\n\n"); printf("const struct name_table_entry * const _nc_%s_hash_table[%d] =\n", root_name, HASHTABSIZE+1); printf("{\n"); for (n = 0; n < HASHTABSIZE; n++) { if (hash_table[n] != 0) { snprintf(buffer, sizeof(buffer), "_nc_%s_table + %3ld", root_name, (long) (hash_table[n] - name_table)); } else { buffer[0] = '0'; buffer[1] = '\0'; } printf("\t%s,\n", buffer); } printf("\t_nc_%s_table\t/* base-of-table */\n", root_name); printf("};\n\n"); printf("#if (BOOLCOUNT!=%d)||(NUMCOUNT!=%d)||(STRCOUNT!=%d)\n", BoolCount, NumCount, StrCount); printf("#error\t--> term.h and comp_captab.c disagree about the <--\n"); printf("#error\t--> numbers of booleans, numbers and/or strings <--\n"); printf("#endif\n\n"); return EXIT_SUCCESS; } #endif