From ff5a775b94465b30897964630af600fe5915fc51 Mon Sep 17 00:00:00 2001 From: Vadim Dashevskiy Date: Tue, 2 Apr 2013 13:54:21 +0000 Subject: VypressChat added (not adopted) git-svn-id: http://svn.miranda-ng.org/main/trunk@4285 1316c22d-e87f-b044-9b9b-93d7a3e3ba9c --- .../!NotAdopted/VypressChat/contrib/hashtable.c | 287 +++++++++++++++++++++ 1 file changed, 287 insertions(+) create mode 100644 plugins/!NotAdopted/VypressChat/contrib/hashtable.c (limited to 'plugins/!NotAdopted/VypressChat/contrib/hashtable.c') diff --git a/plugins/!NotAdopted/VypressChat/contrib/hashtable.c b/plugins/!NotAdopted/VypressChat/contrib/hashtable.c new file mode 100644 index 0000000000..5bc1b2f539 --- /dev/null +++ b/plugins/!NotAdopted/VypressChat/contrib/hashtable.c @@ -0,0 +1,287 @@ +/* Copyright (C) 2004 Christopher Clark */ + +#include "hashtable.h" +#include "hashtable_private.h" +#include +#include +#include +#include + +#ifdef MEMWATCH +# include "../contrib/memwatch.h" +#endif + +/* +Credit for primes table: Aaron Krowne + http://br.endernet.org/~akrowne/ + http://planetmath.org/encyclopedia/GoodHashTablePrimes.html +*/ +static const unsigned int primes[] = { +53, 97, 193, 389, +769, 1543, 3079, 6151, +12289, 24593, 49157, 98317, +196613, 393241, 786433, 1572869, +3145739, 6291469, 12582917, 25165843, +50331653, 100663319, 201326611, 402653189, +805306457, 1610612741 +}; +const unsigned int prime_table_length = sizeof(primes)/sizeof(primes[0]); +const float max_load_factor = 0.65; + +/*****************************************************************************/ +struct hashtable * +create_hashtable(unsigned int minsize, + unsigned int (*hashf) (void*), + int (*eqf) (void*,void*), + void (*value_free_fn)(void *)) +{ + struct hashtable *h; + unsigned int pindex, size = primes[0]; + /* Check requested hashtable isn't too large */ + if (minsize > (1u << 30)) return NULL; + /* Enforce size as prime */ + for (pindex=0; pindex < prime_table_length; pindex++) { + if (primes[pindex] > minsize) { size = primes[pindex]; break; } + } + h = (struct hashtable *)malloc(sizeof(struct hashtable)); + if (NULL == h) return NULL; /*oom*/ + h->table = (struct entry **)malloc(sizeof(struct entry*) * size); + if (NULL == h->table) { free(h); return NULL; } /*oom*/ + memset(h->table, 0, size * sizeof(struct entry *)); + h->tablelength = size; + h->primeindex = pindex; + h->entrycount = 0; + h->hashfn = hashf; + h->eqfn = eqf; + h->value_free_fn = value_free_fn; + h->loadlimit = (unsigned int) ceil(size * max_load_factor); + return h; +} + +/*****************************************************************************/ +unsigned int +hash(struct hashtable *h, void *k) +{ + /* Aim to protect against poor hash functions by adding logic here + * - logic taken from java 1.4 hashtable source */ + unsigned int i = h->hashfn(k); + i += ~(i << 9); + i ^= ((i >> 14) | (i << 18)); /* >>> */ + i += (i << 4); + i ^= ((i >> 10) | (i << 22)); /* >>> */ + return i; +} + +/*****************************************************************************/ +static int +hashtable_expand(struct hashtable *h) +{ + /* Double the size of the table to accomodate more entries */ + struct entry **newtable; + struct entry *e; + struct entry **pE; + unsigned int newsize, i, index; + /* Check we're not hitting max capacity */ + if (h->primeindex == (prime_table_length - 1)) return 0; + newsize = primes[++(h->primeindex)]; + + newtable = (struct entry **)malloc(sizeof(struct entry*) * newsize); + if (NULL != newtable) + { + memset(newtable, 0, newsize * sizeof(struct entry *)); + /* This algorithm is not 'stable'. ie. it reverses the list + * when it transfers entries between the tables */ + for (i = 0; i < h->tablelength; i++) { + while (NULL != (e = h->table[i])) { + h->table[i] = e->next; + index = indexFor(newsize,e->h); + e->next = newtable[index]; + newtable[index] = e; + } + } + free(h->table); + h->table = newtable; + } + /* Plan B: realloc instead */ + else + { + newtable = (struct entry **) + realloc(h->table, newsize * sizeof(struct entry *)); + if (NULL == newtable) { (h->primeindex)--; return 0; } + h->table = newtable; + memset(newtable[h->tablelength], 0, newsize - h->tablelength); + for (i = 0; i < h->tablelength; i++) { + for (pE = &(newtable[i]), e = *pE; e != NULL; e = *pE) { + index = indexFor(newsize,e->h); + if (index == i) + { + pE = &(e->next); + } + else + { + *pE = e->next; + e->next = newtable[index]; + newtable[index] = e; + } + } + } + } + h->tablelength = newsize; + h->loadlimit = (unsigned int) ceil(newsize * max_load_factor); + return -1; +} + +/*****************************************************************************/ +unsigned int +hashtable_count(struct hashtable *h) +{ + return h->entrycount; +} + +/*****************************************************************************/ +int +hashtable_insert(struct hashtable *h, void *k, void *v) +{ + /* This method allows duplicate keys - but they shouldn't be used */ + unsigned int index; + struct entry *e; + if (++(h->entrycount) > h->loadlimit) + { + /* Ignore the return value. If expand fails, we should + * still try cramming just this value into the existing table + * -- we may not have memory for a larger table, but one more + * element may be ok. Next time we insert, we'll try expanding again.*/ + hashtable_expand(h); + } + e = (struct entry *)malloc(sizeof(struct entry)); + if (NULL == e) { --(h->entrycount); return 0; } /*oom*/ + e->h = hash(h,k); + index = indexFor(h->tablelength,e->h); + e->k = k; + e->v = v; + e->next = h->table[index]; + h->table[index] = e; + return -1; +} + +/*****************************************************************************/ +void * /* returns value associated with key */ +hashtable_search(struct hashtable *h, void *k) +{ + struct entry *e; + unsigned int hashvalue, index; + hashvalue = hash(h,k); + index = indexFor(h->tablelength,hashvalue); + e = h->table[index]; + while (NULL != e) + { + /* Check hash value to short circuit heavier comparison */ + if ((hashvalue == e->h) && (h->eqfn(k, e->k))) return e->v; + e = e->next; + } + return NULL; +} + +/*****************************************************************************/ +void * /* returns value associated with key */ +hashtable_remove(struct hashtable *h, void *k, int free_value) +{ + /* TODO: consider compacting the table when the load factor drops enough, + * or provide a 'compact' method. */ + + struct entry *e; + struct entry **pE; + void *v; + unsigned int hashvalue, index; + + hashvalue = hash(h,k); + index = indexFor(h->tablelength,hash(h,k)); + pE = &(h->table[index]); + e = *pE; + while (NULL != e) + { + /* Check hash value to short circuit heavier comparison */ + if ((hashvalue == e->h) && (h->eqfn(k, e->k))) + { + *pE = e->next; + h->entrycount--; + v = e->v; + freekey(e->k); + free(e); + + if(h->value_free_fn && free_value) { + h->value_free_fn(v); + v = NULL; + } + + return v; + } + pE = &(e->next); + e = e->next; + } + return NULL; +} + +/*****************************************************************************/ +/* destroy */ +void +hashtable_destroy(struct hashtable *h, int free_values) +{ + unsigned int i; + struct entry *e, *f; + struct entry **table = h->table; + if (free_values) + { + for (i = 0; i < h->tablelength; i++) + { + e = table[i]; + while (NULL != e) + { f = e; e = e->next; freekey(f->k); + if(h->value_free_fn) h->value_free_fn(f->v); + free(f); } + } + } + else + { + for (i = 0; i < h->tablelength; i++) + { + e = table[i]; + while (NULL != e) + { f = e; e = e->next; freekey(f->k); free(f); } + } + } + free(h->table); + free(h); +} + +void hashtable_enumerate( + struct hashtable * h, + hashtable_enum_fn enum_fn, void * user_data) +{ + unsigned int i; + struct entry * e; + + for(i = 0; i < h->tablelength; i++) { + for(e = h->table[i]; e; e = e->next) + if(!enum_fn(e->k, e->v, user_data)) + return; + } +} + +/* + * Copyright (C) 2002 Christopher Clark + * + * 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, 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 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 AUTHORS 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. + * */ -- cgit v1.2.3