diff options
author | Stef Walter <stef@memberwebs.com> | 2008-12-09 20:59:55 +0000 |
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committer | Stef Walter <stef@memberwebs.com> | 2008-12-09 20:59:55 +0000 |
commit | ae56e5c788e3ed6c60d98d445574d3042aaae24f (patch) | |
tree | 9b3acb30fbdfd9e791c81dafb895fd92b396ebfd /p11-capi-util.c | |
parent | 398b05acabebf6d882c0aaa94a4dfd3f5d6431d4 (diff) |
Move into module folder
Diffstat (limited to 'p11-capi-util.c')
-rw-r--r-- | p11-capi-util.c | 547 |
1 files changed, 0 insertions, 547 deletions
diff --git a/p11-capi-util.c b/p11-capi-util.c deleted file mode 100644 index 5ebb72b..0000000 --- a/p11-capi-util.c +++ /dev/null @@ -1,547 +0,0 @@ -/* - * Copyright (C) 2007 Stef Walter - * - * 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 "p11-capi-util.h" - -#include <sys/types.h> -#include <stdlib.h> -#include <string.h> - - -void -p11c_reverse_memory (void* data, size_t length) -{ - size_t end = length - 1; - size_t middle = length / 2; - unsigned char* buf = data; - size_t i; - - for (i = 0; i < middle; i++) - { - unsigned char tmp = buf[i]; - buf[i] = buf[end - i]; - buf[end - i] = tmp; - } -} - -/* - * Array code originially from Glib. - * Modified extensively by Stef Walter <nielsen@memberwebs.com> - */ - -/* GLIB - Library of useful routines for C programming - * Copyright (C) 1995-1997 Peter Mattis, Spencer Kimball and Josh MacDonald - * - * 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. - */ - - -#define MIN_ARRAY_SIZE 16 - -typedef struct _RealArray -{ - P11cArray pub; - size_t alloc; - size_t elt_size; - int zero_terminated : 1; - int clear : 1; -} -RealArray; - -#define array_elt_len(array, i) ((array)->elt_size * (i)) -#define array_elt_pos(array, i) (((char*)(array)->pub.data) + array_elt_len((array),(i))) -#define array_elt_zero(array, pos, len) \ - (memset(array_elt_pos((array), pos), 0, array_elt_len((array), len))) -#define array_zero_terminate(array) \ - { if ((array)->zero_terminated) \ - array_elt_zero((array), (array)->pub.len, 1); } - -static unsigned int -nearest_pow(unsigned int num) -{ - unsigned int n = 1; - while(n < num) - n <<= 1; - return n; -} - -static int -maybe_expand(RealArray *array, size_t len) -{ - void* mem; - size_t want_alloc = array_elt_len(array, array->pub.len + len + - array->zero_terminated); - - if(want_alloc > array->alloc) - { - want_alloc = nearest_pow(want_alloc); - want_alloc = want_alloc > MIN_ARRAY_SIZE ? want_alloc : MIN_ARRAY_SIZE; - - mem = realloc(array->pub.data, want_alloc); - if(!mem) - return 0; - array->pub.data = mem; - - memset((char*)array->pub.data + array->alloc, 0, want_alloc - array->alloc); - array->alloc = want_alloc; - } - - return 1; -} - -P11cArray* -p11c_array_new(int zero_terminated, int clear, size_t elt_size) -{ - return p11c_array_sized_new(zero_terminated, clear, elt_size, 0); -} - -P11cArray* -p11c_array_sized_new(int zero_terminated, int clear, size_t elt_size, - size_t reserved_size) -{ - RealArray *array = malloc(sizeof(RealArray)); - if(!array) - return NULL; - - array->pub.data = NULL; - array->pub.len = 0; - array->alloc = 0; - array->zero_terminated = (zero_terminated ? 1 : 0); - array->clear = (clear ? 1 : 0); - array->elt_size = elt_size; - - if(array->zero_terminated || reserved_size != 0) - { - maybe_expand(array, reserved_size); - array_zero_terminate(array); - } - - return (P11cArray*)array; -} - -void* -p11c_array_free(P11cArray* array, int free_segment) -{ - void* segment; - - if(array == NULL) - return NULL; - - if(free_segment) - { - if(array->data) - free(array->data); - segment = NULL; - } - else - segment = array->data; - - free(array); - return segment; -} - -int -p11c_array_append_vals(P11cArray* parray, const void* data, size_t len) -{ - RealArray* array = (RealArray*)parray; - if(!maybe_expand(array, len)) - return 0; - - memcpy(array_elt_pos(array, array->pub.len), data, - array_elt_len(array, len)); - - array->pub.len += len; - array_zero_terminate(array); - - return 1; -} - -void -p11c_array_remove_index(P11cArray* parray, unsigned int index) -{ - RealArray* array = (RealArray*)parray; - - if(index >= array->pub.len) - return; - - if(index != array->pub.len - 1) - memmove(array_elt_pos (array, index), - array_elt_pos (array, index + 1), - array_elt_len (array, array->pub.len - index - 1)); - - array->pub.len -= 1; - - array_elt_zero (array, array->pub.len, 1); -} - -void -p11c_array_remove_range(P11cArray* parray, unsigned int index, size_t length) -{ - RealArray *array = (RealArray*)parray; - - if(index >= array->pub.len) - return; - if(index + length > array->pub.len) - length = array->pub.len - index; - if(length == 0) - return; - - if(index + length != array->pub.len) - memmove(array_elt_pos (array, index), - array_elt_pos (array, index + length), - (array->pub.len - (index + length)) * array->elt_size); - - array->pub.len -= length; - array_elt_zero(array, array->pub.len, length); -} - - -/* - * Originally from apache 2.0 - * Extensive modifications by <nielsen@memberwebs.com> - */ - -/* Copyright 2000-2004 The Apache Software Foundation - * - * Licensed under the Apache License, Version 2.0 (the "License"); - * you may not use this file except in compliance with the License. - * You may obtain a copy of the License at - * - * http://www.apache.org/licenses/LICENSE-2.0 - * - * Unless required by applicable law or agreed to in writing, software - * distributed under the License is distributed on an "AS IS" BASIS, - * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. - * See the License for the specific language governing permissions and - * limitations under the License. - */ - - -/* - * The internal form of a hash table. - * - * The table is an array indexed by the hash of the key; collisions - * are resolved by hanging a linked list of hash entries off each - * element of the array. Although this is a really simple design it - * isn't too bad given that pools have a low allocation overhead. - */ - -typedef struct _HashEntry -{ - struct _HashEntry* next; - unsigned int hash; - const void* key; - void* val; -} -HashEntry; - -/* - * The size of the array is always a power of two. We use the maximum - * index rather than the size so that we can use bitwise-AND for - * modular arithmetic. - * The count of hash entries may be greater depending on the chosen - * collision rate. - */ -struct _P11cHash -{ - HashEntry** array; - P11cHashFunc hash_func; - P11cHashEqual equal_func; - size_t count; - size_t max; -}; - - -#define INITIAL_MAX 15 /* tunable == 2^n - 1 */ - -static int -equal_default(const void* a, const void* b) -{ - return a == b; -} - -/* - * Hash creation functions. - */ - -static HashEntry** -alloc_array(P11cHash* ht, size_t max) -{ - return calloc(1, sizeof(*(ht->array)) * (max + 1)); -} - -P11cHash* -p11c_hash_new(P11cHashFunc hash_func, P11cHashEqual equal_func) -{ - P11cHash* ht = malloc(sizeof(P11cHash)); - if(ht) - { - ht->hash_func = hash_func ? hash_func : p11c_hash_pointer; - ht->equal_func = equal_func ? equal_func : equal_default; - ht->count = 0; - ht->max = INITIAL_MAX; - ht->array = alloc_array(ht, ht->max); - if(!ht->array) - { - free(ht); - ht = NULL; - } - } - return ht; -} - -void -p11c_hash_free(P11cHash* ht, P11cHashDestroy destroy_func) -{ - HashEntry* he; - HashEntry* next; - size_t i; - - for(i = 0; i <= ht->max; ++i) - { - for(he = ht->array[i]; he; ) - { - next = he->next; - if(destroy_func) - (destroy_func)((void*)he->val); - free(he); - he = next; - } - } - - if(ht->array) - free(ht->array); - free(ht); -} - -/* - * Expanding a hash table - */ -static int -expand_array(P11cHash* ht) -{ - HashEntry** new_array; - size_t new_max; - HashEntry* he; - HashEntry* next; - size_t i; - - new_max = ht->max * 2 + 1; - new_array = alloc_array(ht, new_max); - - if(!new_array) - return 0; - - for(i = 0; i <= ht->max; ++i) - { - for(he = ht->array[i], next = he ? he->next : NULL; - he != NULL; he = next, next = next ? next->next : NULL) - { - unsigned int j = he->hash & new_max; - he->next = new_array[j]; - new_array[j] = he; - } - } - - if(ht->array) - free(ht->array); - - ht->array = new_array; - ht->max = new_max; - return 1; -} - -/* - * This is where we keep the details of the hash function and control - * the maximum collision rate. - * - * If val is non-NULL it creates and initializes a new hash entry if - * there isn't already one there; it returns an updatable pointer so - * that hash entries can be removed. - */ - -static HashEntry** -find_entry(P11cHash* ht, const void* key, void* val) -{ - HashEntry** hep; - HashEntry* he; - unsigned int hash; - - hash = (ht->hash_func)(key); - - /* scan linked list */ - for(hep = &ht->array[hash & ht->max], he = *hep; - he; hep = &he->next, he = *hep) - { - if(he->hash == hash && (ht->equal_func)(he->key, key)) - break; - } - - if(he || !val) - return hep; - - /* add a new entry for non-NULL val */ - he = malloc(sizeof(*he)); - if(he) - { - /* Key points to external data */ - he->key = key; - he->next = NULL; - he->hash = hash; - he->val = val; - - *hep = he; - ht->count++; - } - - return hep; -} - -void* -p11c_hash_get(P11cHash* ht, const void *key) -{ - HashEntry** he = find_entry(ht, key, NULL); - if(he && *he) - return (void*)((*he)->val); - else - return NULL; -} - -int -p11c_hash_set(P11cHash* ht, const void* key, void* val) -{ - HashEntry** hep = find_entry(ht, key, val); - if(hep && *hep) - { - /* replace entry */ - (*hep)->key = key; - (*hep)->val = val; - - /* check that the collision rate isn't too high */ - if(ht->count > ht->max) - { - if(!expand_array(ht)) - return 0; - } - - return 1; - } - - return 0; -} - -void* -p11c_hash_rem(P11cHash* ht, const void* key) -{ - HashEntry** hep = find_entry(ht, key, NULL); - void* val = NULL; - - if(hep && *hep) - { - HashEntry* old = *hep; - *hep = (*hep)->next; - --ht->count; - val = (void*)old->val; - free(old); - } - - return val; -} - -size_t -p11c_hash_count(P11cHash* ht) -{ - return ht->count; -} - -unsigned int -p11c_hash_pointer(const void* ptr) -{ - return (unsigned int)ptr; -} - -unsigned int -p11c_hash_data(const void* data, size_t n_data) -{ - unsigned int hash = 0; - const unsigned char* end; - const unsigned char* p; - - /* - * This is the popular `times 33' hash algorithm which is used by - * perl and also appears in Berkeley DB. This is one of the best - * known hash functions for strings because it is both computed - * very fast and distributes very well. - * - * The originator may be Dan Bernstein but the code in Berkeley DB - * cites Chris Torek as the source. The best citation I have found - * is "Chris Torek, Hash function for text in C, Usenet message - * <27038@mimsy.umd.edu> in comp.lang.c , October, 1990." in Rich - * Salz's USENIX 1992 paper about INN which can be found at - * <http://citeseer.nj.nec.com/salz92internetnews.html>. - * - * The magic of number 33, i.e. why it works better than many other - * constants, prime or not, has never been adequately explained by - * anyone. So I try an explanation: if one experimentally tests all - * multipliers between 1 and 256 (as I did while writing a low-level - * data structure library some time ago) one detects that even - * numbers are not useable at all. The remaining 128 odd numbers - * (except for the number 1) work more or less all equally well. - * They all distribute in an acceptable way and this way fill a hash - * table with an average percent of approx. 86%. - * - * If one compares the chi^2 values of the variants (see - * Bob Jenkins ``Hashing Frequently Asked Questions'' at - * http://burtleburtle.net/bob/hash/hashfaq.html for a description - * of chi^2), the number 33 not even has the best value. But the - * number 33 and a few other equally good numbers like 17, 31, 63, - * 127 and 129 have nevertheless a great advantage to the remaining - * numbers in the large set of possible multipliers: their multiply - * operation can be replaced by a faster operation based on just one - * shift plus either a single addition or subtraction operation. And - * because a hash function has to both distribute good _and_ has to - * be very fast to compute, those few numbers should be preferred. - * - * -- Ralf S. Engelschall <rse@engelschall.com> - */ - - for(p = data, end = p + n_data; p != end; ++p) - hash = hash * 33 + *p; - - return hash; -} - -unsigned int -p11c_hash_integer(int integer) -{ - return integer; -} |