/* * Hash Table Data Type * Copyright (C) 1997 Kaz Kylheku * * Free Software License: * * All rights are reserved by the author, with the following exceptions: * Permission is granted to freely reproduce and distribute this software, * possibly in exchange for a fee, provided that this copyright notice appears * intact. Permission is also granted to adapt this software to produce * derivative works, as long as the modified versions carry this copyright * notice and additional notices stating that the work has been modified. * This source code may be translated into executable form and incorporated * into proprietary software; there is no requirement for such software to * contain a copyright notice related to this source. * * $Id: hash.c,v 1.1 2002/09/17 02:49:36 jick Exp $ * $Name: EKHTML_RELEASE_0_3_2 $ */ #include #include #include #include #define HASH_IMPLEMENTATION #include "hash.h" #ifdef KAZLIB_RCSID static const char rcsid[] = "$Id: hash.c,v 1.1 2002/09/17 02:49:36 jick Exp $"; #endif #define INIT_BITS 6 #define INIT_SIZE (1UL << (INIT_BITS)) /* must be power of two */ #define INIT_MASK ((INIT_SIZE) - 1) #define next hash_next #define key hash_key #define data hash_data #define hkey hash_hkey #define table hash_table #define nchains hash_nchains #define nodecount hash_nodecount #define maxcount hash_maxcount #define highmark hash_highmark #define lowmark hash_lowmark #define compare hash_compare #define function hash_function #define allocnode hash_allocnode #define freenode hash_freenode #define context hash_context #define mask hash_mask #define dynamic hash_dynamic #define table hash_table #define chain hash_chain #define hash_val_t_bit (compute_bits()) static hnode_t *hnode_alloc(void *context); static void hnode_free(hnode_t *node, void *context); static hash_val_t hash_fun_default(const void *key); static int hash_comp_default(const void *key1, const void *key2); int hash_val_t_bit; /* * Compute the number of bits in the hash_val_t type. We know that hash_val_t * is an unsigned integral type. Thus the highest value it can hold is a * Mersenne number (power of two, less one). We initialize a hash_val_t * object with this value and then shift bits out one by one while counting. * Notes: * 1. HASH_VAL_T_MAX is a Mersenne number---one that is one less than a power * of two. This means that its binary representation consists of all one * bits, and hence ``val'' is initialized to all one bits. * 2. While bits remain in val, we increment the bit count and shift it to the * right, replacing the topmost bit by zero. */ /* * Verify whether the given argument is a power of two. */ static int is_power_of_two(hash_val_t arg) { if (arg == 0) return 0; while ((arg & 1) == 0) arg >>= 1; return (arg == 1); } /* * Compute a shift amount from a given table size */ static hash_val_t compute_mask(hashcount_t size) { assert (is_power_of_two(size)); assert (size >= 2); return size - 1; } /* * Initialize the table of pointers to null. */ static void clear_table(hash_t *hash) { hash_val_t i; for (i = 0; i < hash->nchains; i++) hash->table[i] = NULL; } /* * Double the size of a dynamic table. This works as follows. Each chain splits * into two adjacent chains. The shift amount increases by one, exposing an * additional bit of each hashed key. For each node in the original chain, the * value of this newly exposed bit will decide which of the two new chains will * receive the node: if the bit is 1, the chain with the higher index will have * the node, otherwise the lower chain will receive the node. In this manner, * the hash table will continue to function exactly as before without having to * rehash any of the keys. * Notes: * 1. Overflow check. * 2. The new number of chains is twice the old number of chains. * 3. The new mask is one bit wider than the previous, revealing a * new bit in all hashed keys. * 4. Allocate a new table of chain pointers that is twice as large as the * previous one. * 5. If the reallocation was successful, we perform the rest of the growth * algorithm, otherwise we do nothing. * 6. The exposed_bit variable holds a mask with which each hashed key can be * AND-ed to test the value of its newly exposed bit. * 7. Now loop over each chain in the table and sort its nodes into two * chains based on the value of each node's newly exposed hash bit. * 8. The low chain replaces the current chain. The high chain goes * into the corresponding sister chain in the upper half of the table. * 9. We have finished dealing with the chains and nodes. We now update * the various bookeeping fields of the hash structure. */ static void grow_table(hash_t *hash) { hnode_t **newtable; assert (2 * hash->nchains > hash->nchains); /* 1 */ newtable = realloc(hash->table, sizeof *newtable * hash->nchains * 2); /* 4 */ if (newtable) { /* 5 */ hash_val_t mask = (hash->mask << 1) | 1; /* 3 */ hash_val_t exposed_bit = mask ^ hash->mask; /* 6 */ hash_val_t chain; assert (mask != hash->mask); for (chain = 0; chain < hash->nchains; chain++) { /* 7 */ hnode_t *low_chain = 0, *high_chain = 0, *hptr, *next; for (hptr = newtable[chain]; hptr != 0; hptr = next) { next = hptr->next; if (hptr->hkey & exposed_bit) { hptr->next = high_chain; high_chain = hptr; } else { hptr->next = low_chain; low_chain = hptr; } } newtable[chain] = low_chain; /* 8 */ newtable[chain + hash->nchains] = high_chain; } hash->table = newtable; /* 9 */ hash->mask = mask; hash->nchains *= 2; hash->lowmark *= 2; hash->highmark *= 2; } assert (hash_verify(hash)); } /* * Cut a table size in half. This is done by folding together adjacent chains * and populating the lower half of the table with these chains. The chains are * simply spliced together. Once this is done, the whole table is reallocated * to a smaller object. * Notes: * 1. It is illegal to have a hash table with one slot. This would mean that * hash->shift is equal to hash_val_t_bit, an illegal shift value. * Also, other things could go wrong, such as hash->lowmark becoming zero. * 2. Looping over each pair of sister chains, the low_chain is set to * point to the head node of the chain in the lower half of the table, * and high_chain points to the head node of the sister in the upper half. * 3. The intent here is to compute a pointer to the last node of the * lower chain into the low_tail variable. If this chain is empty, * low_tail ends up with a null value. * 4. If the lower chain is not empty, we simply tack the upper chain onto it. * If the upper chain is a null pointer, nothing happens. * 5. Otherwise if the lower chain is empty but the upper one is not, * If the low chain is empty, but the high chain is not, then the * high chain is simply transferred to the lower half of the table. * 6. Otherwise if both chains are empty, there is nothing to do. * 7. All the chain pointers are in the lower half of the table now, so * we reallocate it to a smaller object. This, of course, invalidates * all pointer-to-pointers which reference into the table from the * first node of each chain. * 8. Though it's unlikely, the reallocation may fail. In this case we * pretend that the table _was_ reallocated to a smaller object. * 9. Finally, update the various table parameters to reflect the new size. */ static void shrink_table(hash_t *hash) { hash_val_t chain, nchains; hnode_t **newtable, *low_tail, *low_chain, *high_chain; assert (hash->nchains >= 2); /* 1 */ nchains = hash->nchains / 2; for (chain = 0; chain < nchains; chain++) { low_chain = hash->table[chain]; /* 2 */ high_chain = hash->table[chain + nchains]; for (low_tail = low_chain; low_tail && low_tail->next; low_tail = low_tail->next) ; /* 3 */ if (low_chain != 0) /* 4 */ low_tail->next = high_chain; else if (high_chain != 0) /* 5 */ hash->table[chain] = high_chain; else assert (hash->table[chain] == NULL); /* 6 */ } newtable = realloc(hash->table, sizeof *newtable * nchains); /* 7 */ if (newtable) /* 8 */ hash->table = newtable; hash->mask >>= 1; /* 9 */ hash->nchains = nchains; hash->lowmark /= 2; hash->highmark /= 2; assert (hash_verify(hash)); } /* * Create a dynamic hash table. Both the hash table structure and the table * itself are dynamically allocated. Furthermore, the table is extendible in * that it will automatically grow as its load factor increases beyond a * certain threshold. * Notes: * 1. If the number of bits in the hash_val_t type has not been computed yet, * we do so here, because this is likely to be the first function that the * user calls. * 2. Allocate a hash table control structure. * 3. If a hash table control structure is successfully allocated, we * proceed to initialize it. Otherwise we return a null pointer. * 4. We try to allocate the table of hash chains. * 5. If we were able to allocate the hash chain table, we can finish * initializing the hash structure and the table. Otherwise, we must * backtrack by freeing the hash structure. * 6. INIT_SIZE should be a power of two. The high and low marks are always set * to be twice the table size and half the table size respectively. When the * number of nodes in the table grows beyond the high size (beyond load * factor 2), it will double in size to cut the load factor down to about * about 1. If the table shrinks down to or beneath load factor 0.5, * it will shrink, bringing the load up to about 1. However, the table * will never shrink beneath INIT_SIZE even if it's emptied. * 7. This indicates that the table is dynamically allocated and dynamically * resized on the fly. A table that has this value set to zero is * assumed to be statically allocated and will not be resized. * 8. The table of chains must be properly reset to all null pointers. */ hash_t *hash_create(hashcount_t maxcount, hash_comp_t compfun, hash_fun_t hashfun) { hash_t *hash; if (hash_val_t_bit == 0) /* 1 */ compute_bits(); hash = malloc(sizeof *hash); /* 2 */ if (hash) { /* 3 */ hash->table = malloc(sizeof *hash->table * INIT_SIZE); /* 4 */ if (hash->table) { /* 5 */ hash->nchains = INIT_SIZE; /* 6 */ hash->highmark = INIT_SIZE * 2; hash->lowmark = INIT_SIZE / 2; hash->nodecount = 0; hash->maxcount = maxcount; hash->compare = compfun ? compfun : hash_comp_default; hash->function = hashfun ? hashfun : hash_fun_default; hash->allocnode = hnode_alloc; hash->freenode = hnode_free; hash->context = NULL; hash->mask = INIT_MASK; hash->dynamic = 1; /* 7 */ clear_table(hash); /* 8 */ assert (hash_verify(hash)); return hash; } free(hash); } return NULL; } /* * Select a different set of node allocator routines. */ void hash_set_allocator(hash_t *hash, hnode_alloc_t al, hnode_free_t fr, void *context) { assert (hash_count(hash) == 0); assert ((al == 0 && fr == 0) || (al != 0 && fr != 0)); hash->allocnode = al ? al : hnode_alloc; hash->freenode = fr ? fr : hnode_free; hash->context = context; } /* * Free every node in the hash using the hash->freenode() function pointer, and * cause the hash to become empty. */ void hash_free_nodes(hash_t *hash) { hscan_t hs; hnode_t *node; hash_scan_begin(&hs, hash); while ((node = hash_scan_next(&hs))) { hash_scan_delete(hash, node); hash->freenode(node, hash->context); } hash->nodecount = 0; clear_table(hash); } /* * Obsolescent function for removing all nodes from a table, * freeing them and then freeing the table all in one step. */ void hash_free(hash_t *hash) { #ifdef KAZLIB_OBSOLESCENT_DEBUG assert ("call to obsolescent function hash_free()" && 0); #endif hash_free_nodes(hash); hash_destroy(hash); } /* * Free a dynamic hash table structure. */ void hash_destroy(hash_t *hash) { assert (hash_val_t_bit != 0); assert (hash_isempty(hash)); free(hash->table); free(hash); } /* * Initialize a user supplied hash structure. The user also supplies a table of * chains which is assigned to the hash structure. The table is static---it * will not grow or shrink. * 1. See note 1. in hash_create(). * 2. The user supplied array of pointers hopefully contains nchains nodes. * 3. See note 7. in hash_create(). * 4. We must dynamically compute the mask from the given power of two table * size. * 5. The user supplied table can't be assumed to contain null pointers, * so we reset it here. */ hash_t *hash_init(hash_t *hash, hashcount_t maxcount, hash_comp_t compfun, hash_fun_t hashfun, hnode_t **table, hashcount_t nchains) { if (hash_val_t_bit == 0) /* 1 */ compute_bits(); assert (is_power_of_two(nchains)); hash->table = table; /* 2 */ hash->nchains = nchains; hash->nodecount = 0; hash->maxcount = maxcount; hash->compare = compfun ? compfun : hash_comp_default; hash->function = hashfun ? hashfun : hash_fun_default; hash->dynamic = 0; /* 3 */ hash->mask = compute_mask(nchains); /* 4 */ clear_table(hash); /* 5 */ assert (hash_verify(hash)); return hash; } /* * Reset the hash scanner so that the next element retrieved by * hash_scan_next() shall be the first element on the first non-empty chain. * Notes: * 1. Locate the first non empty chain. * 2. If an empty chain is found, remember which one it is and set the next * pointer to refer to its first element. * 3. Otherwise if a chain is not found, set the next pointer to NULL * so that hash_scan_next() shall indicate failure. */ void hash_scan_begin(hscan_t *scan, hash_t *hash) { hash_val_t nchains = hash->nchains; hash_val_t chain; scan->table = hash; /* 1 */ for (chain = 0; chain < nchains && hash->table[chain] == 0; chain++) ; if (chain < nchains) { /* 2 */ scan->chain = chain; scan->next = hash->table[chain]; } else { /* 3 */ scan->next = NULL; } } /* * Retrieve the next node from the hash table, and update the pointer * for the next invocation of hash_scan_next(). * Notes: * 1. Remember the next pointer in a temporary value so that it can be * returned. * 2. This assertion essentially checks whether the module has been properly * initialized. The first point of interaction with the module should be * either hash_create() or hash_init(), both of which set hash_val_t_bit to * a non zero value. * 3. If the next pointer we are returning is not NULL, then the user is * allowed to call hash_scan_next() again. We prepare the new next pointer * for that call right now. That way the user is allowed to delete the node * we are about to return, since we will no longer be needing it to locate * the next node. * 4. If there is a next node in the chain (next->next), then that becomes the * new next node, otherwise ... * 5. We have exhausted the current chain, and must locate the next subsequent * non-empty chain in the table. * 6. If a non-empty chain is found, the first element of that chain becomes * the new next node. Otherwise there is no new next node and we set the * pointer to NULL so that the next time hash_scan_next() is called, a null * pointer shall be immediately returned. */ hnode_t *hash_scan_next(hscan_t *scan) { hnode_t *next = scan->next; /* 1 */ hash_t *hash = scan->table; hash_val_t chain = scan->chain + 1; hash_val_t nchains = hash->nchains; assert (hash_val_t_bit != 0); /* 2 */ if (next) { /* 3 */ if (next->next) { /* 4 */ scan->next = next->next; } else { while (chain < nchains && hash->table[chain] == 0) /* 5 */ chain++; if (chain < nchains) { /* 6 */ scan->chain = chain; scan->next = hash->table[chain]; } else { scan->next = NULL; } } } return next; } /* * Insert a node into the hash table. * Notes: * 1. It's illegal to insert more than the maximum number of nodes. The client * should verify that the hash table is not full before attempting an * insertion. * 2. The same key may not be inserted into a table twice. * 3. If the table is dynamic and the load factor is already at >= 2, * grow the table. * 4. We take the bottom N bits of the hash value to derive the chain index, * where N is the base 2 logarithm of the size of the hash table. */ void hash_insert(hash_t *hash, hnode_t *node, const void *key) { hash_val_t hkey, chain; assert (hash_val_t_bit != 0); assert (node->next == NULL); assert (hash->nodecount < hash->maxcount); /* 1 */ assert (hash_lookup(hash, key) == NULL); /* 2 */ if (hash->dynamic && hash->nodecount >= hash->highmark) /* 3 */ grow_table(hash); hkey = hash->function(key); chain = hkey & hash->mask; /* 4 */ node->key = key; node->hkey = hkey; node->next = hash->table[chain]; hash->table[chain] = node; hash->nodecount++; assert (hash_verify(hash)); } /* * Find a node in the hash table and return a pointer to it. * Notes: * 1. We hash the key and keep the entire hash value. As an optimization, when * we descend down the chain, we can compare hash values first and only if * hash values match do we perform a full key comparison. * 2. To locate the chain from among 2^N chains, we look at the lower N bits of * the hash value by anding them with the current mask. * 3. Looping through the chain, we compare the stored hash value inside each * node against our computed hash. If they match, then we do a full * comparison between the unhashed keys. If these match, we have located the * entry. */ hnode_t *hash_lookup(hash_t *hash, const void *key) { hash_val_t hkey, chain; hnode_t *nptr; hkey = hash->function(key); /* 1 */ chain = hkey & hash->mask; /* 2 */ for (nptr = hash->table[chain]; nptr; nptr = nptr->next) { /* 3 */ if (nptr->hkey == hkey && hash->compare(nptr->key, key) == 0) return nptr; } return NULL; } /* * Delete the given node from the hash table. Since the chains * are singly linked, we must locate the start of the node's chain * and traverse. * Notes: * 1. The node must belong to this hash table, and its key must not have * been tampered with. * 2. If this deletion will take the node count below the low mark, we * shrink the table now. * 3. Determine which chain the node belongs to, and fetch the pointer * to the first node in this chain. * 4. If the node being deleted is the first node in the chain, then * simply update the chain head pointer. * 5. Otherwise advance to the node's predecessor, and splice out * by updating the predecessor's next pointer. * 6. Indicate that the node is no longer in a hash table. */ hnode_t *hash_delete(hash_t *hash, hnode_t *node) { hash_val_t chain; hnode_t *hptr; assert (hash_lookup(hash, node->key) == node); /* 1 */ assert (hash_val_t_bit != 0); if (hash->dynamic && hash->nodecount <= hash->lowmark && hash->nodecount > INIT_SIZE) shrink_table(hash); /* 2 */ chain = node->hkey & hash->mask; /* 3 */ hptr = hash->table[chain]; if (hptr == node) { /* 4 */ hash->table[chain] = node->next; } else { while (hptr->next != node) { /* 5 */ assert (hptr != 0); hptr = hptr->next; } assert (hptr->next == node); hptr->next = node->next; } hash->nodecount--; assert (hash_verify(hash)); node->next = NULL; /* 6 */ return node; } int hash_alloc_insert(hash_t *hash, const void *key, void *data) { hnode_t *node = hash->allocnode(hash->context); if (node) { hnode_init(node, data); hash_insert(hash, node, key); return 1; } return 0; } void hash_delete_free(hash_t *hash, hnode_t *node) { hash_delete(hash, node); hash->freenode(node, hash->context); } /* * Exactly like hash_delete, except does not trigger table shrinkage. This is to be * used from within a hash table scan operation. See notes for hash_delete. */ hnode_t *hash_scan_delete(hash_t *hash, hnode_t *node) { hash_val_t chain; hnode_t *hptr; assert (hash_lookup(hash, node->key) == node); assert (hash_val_t_bit != 0); chain = node->hkey & hash->mask; hptr = hash->table[chain]; if (hptr == node) { hash->table[chain] = node->next; } else { while (hptr->next != node) hptr = hptr->next; hptr->next = node->next; } hash->nodecount--; assert (hash_verify(hash)); node->next = NULL; return node; } /* * Like hash_delete_free but based on hash_scan_delete. */ void hash_scan_delfree(hash_t *hash, hnode_t *node) { hash_scan_delete(hash, node); hash->freenode(node, hash->context); } /* * Verify whether the given object is a valid hash table. This means * Notes: * 1. If the hash table is dynamic, verify whether the high and * low expansion/shrinkage thresholds are powers of two. * 2. Count all nodes in the table, and test each hash value * to see whether it is correct for the node's chain. */ int hash_verify(hash_t *hash) { hashcount_t count = 0; hash_val_t chain; hnode_t *hptr; if (hash->dynamic) { /* 1 */ if (hash->lowmark >= hash->highmark) return 0; if (!is_power_of_two(hash->highmark)) return 0; if (!is_power_of_two(hash->lowmark)) return 0; } for (chain = 0; chain < hash->nchains; chain++) { /* 2 */ for (hptr = hash->table[chain]; hptr != 0; hptr = hptr->next) { if ((hptr->hkey & hash->mask) != chain) return 0; count++; } } if (count != hash->nodecount) return 0; return 1; } /* * Test whether the hash table is full and return 1 if this is true, * 0 if it is false. */ #undef hash_isfull int hash_isfull(hash_t *hash) { return hash->nodecount == hash->maxcount; } /* * Test whether the hash table is empty and return 1 if this is true, * 0 if it is false. */ #undef hash_isempty int hash_isempty(hash_t *hash) { return hash->nodecount == 0; } static hnode_t *hnode_alloc(void *context) { return malloc(sizeof *hnode_alloc(NULL)); } static void hnode_free(hnode_t *node, void *context) { free(node); } /* * Create a hash table node dynamically and assign it the given data. */ hnode_t *hnode_create(void *data) { hnode_t *node = malloc(sizeof *node); if (node) { node->data = data; node->next = NULL; } return node; } /* * Initialize a client-supplied node */ hnode_t *hnode_init(hnode_t *hnode, void *data) { hnode->data = data; hnode->next = NULL; return hnode; } /* * Destroy a dynamically allocated node. */ void hnode_destroy(hnode_t *hnode) { free(hnode); } #undef hnode_put void hnode_put(hnode_t *node, void *data) { node->data = data; } #undef hnode_get void *hnode_get(hnode_t *node) { return node->data; } #undef hnode_getkey const void *hnode_getkey(hnode_t *node) { return node->key; } #undef hash_count hashcount_t hash_count(hash_t *hash) { return hash->nodecount; } #undef hash_size hashcount_t hash_size(hash_t *hash) { return hash->nchains; } static hash_val_t hash_fun_default(const void *key) { static unsigned long randbox[] = { 0x49848f1bU, 0xe6255dbaU, 0x36da5bdcU, 0x47bf94e9U, 0x8cbcce22U, 0x559fc06aU, 0xd268f536U, 0xe10af79aU, 0xc1af4d69U, 0x1d2917b5U, 0xec4c304dU, 0x9ee5016cU, 0x69232f74U, 0xfead7bb3U, 0xe9089ab6U, 0xf012f6aeU, }; const unsigned char *str = key; hash_val_t acc = 0; while (*str) { acc ^= randbox[(*str + acc) & 0xf]; acc = (acc << 1) | (acc >> 31); acc &= 0xffffffffU; acc ^= randbox[((*str++ >> 4) + acc) & 0xf]; acc = (acc << 2) | (acc >> 30); acc &= 0xffffffffU; } return acc; } static int hash_comp_default(const void *key1, const void *key2) { return strcmp(key1, key2); } #ifdef KAZLIB_TEST_MAIN #include #include #include typedef char input_t[256]; static int tokenize(char *string, ...) { char **tokptr; va_list arglist; int tokcount = 0; va_start(arglist, string); tokptr = va_arg(arglist, char **); while (tokptr) { while (*string && isspace((unsigned char) *string)) string++; if (!*string) break; *tokptr = string; while (*string && !isspace((unsigned char) *string)) string++; tokptr = va_arg(arglist, char **); tokcount++; if (!*string) break; *string++ = 0; } va_end(arglist); return tokcount; } static char *dupstring(char *str) { int sz = strlen(str) + 1; char *new = malloc(sz); if (new) memcpy(new, str, sz); return new; } static hnode_t *new_node(void *c) { static hnode_t few[5]; static int count; if (count < 5) return few + count++; return NULL; } static void del_node(hnode_t *n, void *c) { } int main(void) { input_t in; hash_t *h = hash_create(HASHCOUNT_T_MAX, 0, 0); hnode_t *hn; hscan_t hs; char *tok1, *tok2, *val; const char *key; int prompt = 0; char *help = "a add value to hash table\n" "d delete value from hash table\n" "l lookup value in hash table\n" "n show size of hash table\n" "c show number of entries\n" "t dump whole hash table\n" "+ increase hash table (private func)\n" "- decrease hash table (private func)\n" "b print hash_t_bit value\n" "p turn prompt on\n" "s switch to non-functioning allocator\n" "q quit"; if (!h) puts("hash_create failed"); for (;;) { if (prompt) putchar('>'); fflush(stdout); if (!fgets(in, sizeof(input_t), stdin)) break; switch(in[0]) { case '?': puts(help); break; case 'b': printf("%d\n", hash_val_t_bit); break; case 'a': if (tokenize(in+1, &tok1, &tok2, (char **) 0) != 2) { puts("what?"); break; } key = dupstring(tok1); val = dupstring(tok2); if (!key || !val) { puts("out of memory"); free((void *) key); free(val); } if (!hash_alloc_insert(h, key, val)) { puts("hash_alloc_insert failed"); free((void *) key); free(val); break; } break; case 'd': if (tokenize(in+1, &tok1, (char **) 0) != 1) { puts("what?"); break; } hn = hash_lookup(h, tok1); if (!hn) { puts("hash_lookup failed"); break; } val = hnode_get(hn); key = hnode_getkey(hn); hash_scan_delfree(h, hn); free((void *) key); free(val); break; case 'l': if (tokenize(in+1, &tok1, (char **) 0) != 1) { puts("what?"); break; } hn = hash_lookup(h, tok1); if (!hn) { puts("hash_lookup failed"); break; } val = hnode_get(hn); puts(val); break; case 'n': printf("%lu\n", (unsigned long) hash_size(h)); break; case 'c': printf("%lu\n", (unsigned long) hash_count(h)); break; case 't': hash_scan_begin(&hs, h); while ((hn = hash_scan_next(&hs))) printf("%s\t%s\n", (char*) hnode_getkey(hn), (char*) hnode_get(hn)); break; case '+': grow_table(h); /* private function */ break; case '-': shrink_table(h); /* private function */ break; case 'q': exit(0); break; case '\0': break; case 'p': prompt = 1; break; case 's': hash_set_allocator(h, new_node, del_node, NULL); break; default: putchar('?'); putchar('\n'); break; } } return 0; } #endif