mirror of https://github.com/pissnet/pissircd.git
100 lines
2.2 KiB
C
100 lines
2.2 KiB
C
/* License: GPLv1 */
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/** @file
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* @brief String cache - only used for server names.
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*/
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#include "unrealircd.h"
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/*
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* ircd used to store full servernames in User as well as in the
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* whowas info. there can be some 40k such structures alive at any
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* given time, while the number of unique server names a server sees in
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* its lifetime is at most a few hundred. by tokenizing server names
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* internally, the server can easily save 2 or 3 megs of RAM.
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* -orabidoo
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*/
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/*
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* I could have tucked this code into hash.c I suppose but lets keep it
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* separate for now -Dianora
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*/
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#define SCACHE_HASH_SIZE 257
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typedef struct SCACHE SCACHE;
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struct SCACHE {
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char name[HOSTLEN + 1];
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SCACHE *next;
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};
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static SCACHE *scache_hash[SCACHE_HASH_SIZE];
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/*
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* renamed to keep it consistent with the other hash functions -Dianora
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*/
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/*
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* orabidoo had named it init_scache_hash();
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*/
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void clear_scache_hash_table(void)
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{
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memset((char *)scache_hash, '\0', sizeof(scache_hash));
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}
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static int hash(char *string)
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{
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int hash_value;
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hash_value = 0;
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while (*string)
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hash_value += (*string++ & 0xDF);
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return hash_value % SCACHE_HASH_SIZE;
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}
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/** Add a string to the string cache.
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* this takes a server name, and returns a pointer to the same string
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* (up to case) in the server name token list, adding it to the list if
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* it's not there. care must be taken not to call this with
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* user-supplied arguments that haven't been verified to be a valid,
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* existing, servername. use the hash in list.c for those. -orabidoo
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* @param name A valid server name
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* @returns Pointer to the server name
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*/
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char *find_or_add(char *name)
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{
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int hash_index;
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SCACHE *ptr, *newptr;
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ptr = scache_hash[hash_index = hash(name)];
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while (ptr)
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{
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if (!mycmp(ptr->name, name))
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{
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return (ptr->name);
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}
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else
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{
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ptr = ptr->next;
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}
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}
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/*
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* not found -- add it
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*/
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if ((ptr = scache_hash[hash_index]))
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{
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newptr = scache_hash[hash_index] = safe_alloc(sizeof(SCACHE));
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strlcpy(newptr->name, name, sizeof(newptr->name));
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newptr->next = ptr;
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return (newptr->name);
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}
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else
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{
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ptr = scache_hash[hash_index] = safe_alloc(sizeof(SCACHE));
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strlcpy(ptr->name, name, sizeof(newptr->name));
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ptr->next = (SCACHE *) NULL;
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return (ptr->name);
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}
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}
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