/* GLIB - Library of useful routines for C programming * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald * Copyright (C) 1999 The Free Software Foundation * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library 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 * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with this library; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 02111-1307, USA. */ #include #include #include #include #include "std_hash.h" int array[10000]; static int my_hash_callback_remove (void* key, void* value, void* user_data) { int *d = value; if ((*d) % 2) return 1; return 0; } static void my_hash_callback_remove_test (void* key, void* value, void* user_data) { int *d = value; if ((*d) % 2) fprintf ( stderr, "%s:%d should not be reached\n", __FILE__, __LINE__ ); } static void my_hash_callback (void* key, void* value, void* user_data) { int *d = value; *d = 1; } static unsigned int my_hash (const void* key) { return (unsigned int) *((const int*) key); } static int my_hash_equal (const void* a, const void* b) { return *((const int*) a) == *((const int*) b); } /* * This is a simplified version of the pathalias hashing function. * Thanks to Steve Belovin and Peter Honeyman * * hash a string into a long int. 31 bit crc (from andrew appel). * the crc table is computed at run time by crcinit() -- we could * precompute, but it takes 1 clock tick on a 750. * * This fast table calculation works only if POLY is a prime polynomial * in the field of integers modulo 2. Since the coefficients of a * 32-bit polynomial won't fit in a 32-bit word, the high-order bit is * implicit. IT MUST ALSO BE THE CASE that the coefficients of orders * 31 down to 25 are zero. Happily, we have candidates, from * E. J. Watson, "Primitive Polynomials (Mod 2)", Math. Comp. 16 (1962): * x^32 + x^7 + x^5 + x^3 + x^2 + x^1 + x^0 * x^31 + x^3 + x^0 * * We reverse the bits to get: * 111101010000000000000000000000001 but drop the last 1 * f 5 0 0 0 0 0 0 * 010010000000000000000000000000001 ditto, for 31-bit crc * 4 8 0 0 0 0 0 0 */ #define POLY 0x48000000L /* 31-bit polynomial (avoids sign problems) */ static unsigned int CrcTable[128]; /* - crcinit - initialize tables for hash function */ static void crcinit(void) { int i, j; unsigned int sum; for (i = 0; i < 128; ++i) { sum = 0L; for (j = 7 - 1; j >= 0; --j) if (i & (1 << j)) sum ^= POLY >> j; CrcTable[i] = sum; } } /* - hash - Honeyman's nice hashing function */ static unsigned int honeyman_hash(const void* key) { const char *name = (const char *) key; int size; unsigned int sum = 0; assert (name != NULL); assert (*name != 0); size = strlen(name); while (size--) { sum = (sum >> 7) ^ CrcTable[(sum ^ (*name++)) & 0x7f]; } return(sum); } static int second_hash_cmp (const void* a, const void* b) { return (strcmp (a, b) == 0); } static unsigned int one_hash(const void* key) { return 1; } static void not_even_foreach (void* key, void* value, void* user_data) { const char *_key = (const char *) key; const char *_value = (const char *) value; int i; char val [20]; assert (_key != NULL); assert (*_key != 0); assert (_value != NULL); assert (*_value != 0); i = atoi (_key); sprintf (val, "%d value", i); assert (strcmp (_value, val) == 0); assert ((i % 2) != 0); assert (i != 3); } static int remove_even_foreach (void* key, void* value, void* user_data) { const char *_key = (const char *) key; const char *_value = (const char *) value; int i; char val [20]; assert (_key != NULL); assert (*_key != 0); assert (_value != NULL); assert (*_value != 0); i = atoi (_key); sprintf (val, "%d value", i); assert (strcmp (_value, val) == 0); return ((i % 2) == 0) ? 1 : 0; } static void second_hash_test (int simple_hash) { int i; char key[20] = "", val[20]="", *v, *orig_key, *orig_val; struct std_hashtable *h; int found; crcinit (); h = std_hash_table_new (simple_hash ? one_hash : honeyman_hash, second_hash_cmp); assert (h != NULL); for (i=0; i<20; i++) { sprintf (key, "%d", i); assert (atoi (key) == i); sprintf (val, "%d value", i); assert (atoi (val) == i); std_hash_table_insert (h, strdup (key), strdup (val)); } assert (std_hash_table_size (h) == 20); for (i=0; i<20; i++) { sprintf (key, "%d", i); assert (atoi(key) == i); v = (char *) std_hash_table_lookup (h, key); assert (v != NULL); assert (*v != 0); assert (atoi (v) == i); } sprintf (key, "%d", 3); std_hash_table_remove (h, key); std_hash_table_foreach_remove (h, remove_even_foreach, NULL); std_hash_table_foreach (h, not_even_foreach, NULL); for (i=0; i<20; i++) { if ((i % 2) == 0 || i == 3) continue; sprintf (key, "%d", i); assert (atoi(key) == i); sprintf (val, "%d value", i); assert (atoi (val) == i); orig_key = orig_val = NULL; found = std_hash_table_lookup_extended (h, key, (void*)&orig_key, (void*)&orig_val); assert (found); std_hash_table_remove (h, key); assert (orig_key != NULL); assert (strcmp (key, orig_key) == 0); free (orig_key); assert (orig_val != NULL); assert (strcmp (val, orig_val) == 0); free (orig_val); } std_hash_table_destroy (h); } static int find_first (void* key, void* value, void* user_data) { int *v = value; int *test = user_data; return (*v == *test); } static void direct_hash_test (void) { int i, rc; struct std_hashtable *h; h = std_hash_table_new (NULL, NULL); assert (h != NULL); for (i=1; i<=20; i++) { std_hash_table_insert (h, ((void*) (i)), (void*) (i + 42)); } assert (std_hash_table_size (h) == 20); for (i=1; i<=20; i++) { rc = ((int) ( std_hash_table_lookup (h, ((void*) (i))))); assert (rc != 0); assert ((rc - 42) == i); } std_hash_table_destroy (h); } int main (int argc, char *argv[]) { struct std_hashtable *hash_table; int i; int value = 120; int *pvalue; hash_table = std_hash_table_new (my_hash, my_hash_equal); for (i = 0; i < 10000; i++) { array[i] = i; std_hash_table_insert (hash_table, &array[i], &array[i]); } pvalue = std_hash_table_find (hash_table, find_first, &value); if (!pvalue || *pvalue != value) fprintf ( stderr, "%s:%d should not be reached\n", __FILE__, __LINE__ ); std_hash_table_foreach (hash_table, my_hash_callback, NULL); for (i = 0; i < 10000; i++) if (array[i] == 0) fprintf ( stderr, "%s:%d should not be reached\n", __FILE__, __LINE__ ); for (i = 0; i < 10000; i++) std_hash_table_remove (hash_table, &array[i]); for (i = 0; i < 10000; i++) { array[i] = i; std_hash_table_insert (hash_table, &array[i], &array[i]); } if (std_hash_table_foreach_remove (hash_table, my_hash_callback_remove, NULL) != 5000 || std_hash_table_size (hash_table) != 5000) fprintf ( stderr, "%s:%d should not be reached\n", __FILE__, __LINE__ ); std_hash_table_foreach (hash_table, my_hash_callback_remove_test, NULL); std_hash_table_destroy (hash_table); second_hash_test (1); second_hash_test (0); direct_hash_test (); printf ( "PASSED\n" ); return 0; }