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author | Erlang/OTP <[email protected]> | 2009-11-20 14:54:40 +0000 |
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committer | Erlang/OTP <[email protected]> | 2009-11-20 14:54:40 +0000 |
commit | 84adefa331c4159d432d22840663c38f155cd4c1 (patch) | |
tree | bff9a9c66adda4df2106dfd0e5c053ab182a12bd /erts/emulator/beam/hash.c | |
download | otp-84adefa331c4159d432d22840663c38f155cd4c1.tar.gz otp-84adefa331c4159d432d22840663c38f155cd4c1.tar.bz2 otp-84adefa331c4159d432d22840663c38f155cd4c1.zip |
The R13B03 release.OTP_R13B03
Diffstat (limited to 'erts/emulator/beam/hash.c')
-rw-r--r-- | erts/emulator/beam/hash.c | 407 |
1 files changed, 407 insertions, 0 deletions
diff --git a/erts/emulator/beam/hash.c b/erts/emulator/beam/hash.c new file mode 100644 index 0000000000..afaf32f8ce --- /dev/null +++ b/erts/emulator/beam/hash.c @@ -0,0 +1,407 @@ +/* + * %CopyrightBegin% + * + * Copyright Ericsson AB 1996-2009. All Rights Reserved. + * + * The contents of this file are subject to the Erlang Public License, + * Version 1.1, (the "License"); you may not use this file except in + * compliance with the License. You should have received a copy of the + * Erlang Public License along with this software. If not, it can be + * retrieved online at http://www.erlang.org/. + * + * Software distributed under the License is distributed on an "AS IS" + * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See + * the License for the specific language governing rights and limitations + * under the License. + * + * %CopyrightEnd% + */ + +/* +** General hash functions +** +*/ +#ifdef HAVE_CONFIG_H +# include "config.h" +#endif + +#include "sys.h" +#include "erl_vm.h" +#include "global.h" +#include "hash.h" + +/* +** List of sizes (all are primes) +*/ +static const int h_size_table[] = { + 2, 5, 11, 23, 47, 97, 197, 397, 797, /* double upto here */ + 1201, 1597, + 2411, 3203, + 4813, 6421, + 9643, 12853, + 19289, 25717, + 51437, + 102877, + 205759, + 411527, + 823117, + 1646237, + 3292489, + 6584983, + 13169977, + 26339969, + 52679969, + -1 +}; + +/* +** Get info about hash +** +*/ + +void hash_get_info(HashInfo *hi, Hash *h) +{ + int size = h->size; + int i; + int max_depth = 0; + int objects = 0; + + for (i = 0; i < size; i++) { + int depth = 0; + HashBucket* b = h->bucket[i]; + + while (b != (HashBucket*) 0) { + objects++; + depth++; + b = b->next; + } + if (depth > max_depth) + max_depth = depth; + } + + hi->name = h->name; + hi->size = h->size; + hi->used = h->used; + hi->objs = objects; + hi->depth = max_depth; +} + +/* +** Display info about hash +** +*/ + +void hash_info(int to, void *arg, Hash* h) +{ + HashInfo hi; + + hash_get_info(&hi, h); + + erts_print(to, arg, "=hash_table:%s\n", hi.name); + erts_print(to, arg, "size: %d\n", hi.size); + erts_print(to, arg, "used: %d\n", hi.used); + erts_print(to, arg, "objs: %d\n", hi.objs); + erts_print(to, arg, "depth: %d\n", hi.depth); +} + + +/* + * Returns size of table in bytes. Stored objects not included. + */ +int +hash_table_sz(Hash *h) +{ + int i; + for(i=0;h->name[i];i++); + i++; + return sizeof(Hash) + h->size*sizeof(HashBucket*) + i; +} + + +/* +** init a pre allocated or static hash structure +** and allocate buckets. +*/ +Hash* hash_init(ErtsAlcType_t type, Hash* h, char* name, int size, HashFunctions fun) +{ + int sz; + int ix = 0; + + h->type = type; + + while (h_size_table[ix] != -1 && h_size_table[ix] < size) + ix++; + if (h_size_table[ix] == -1) + erl_exit(1, "panic: too large hash table size (%d)\n", size); + + size = h_size_table[ix]; + sz = size*sizeof(HashBucket*); + + h->bucket = (HashBucket**) erts_alloc(h->type, sz); + + sys_memzero(h->bucket, sz); + h->is_allocated = 0; + h->name = name; + h->fun = fun; + h->size = size; + h->size20percent = h->size/5; + h->size80percent = (4*h->size)/5; + h->ix = ix; + h->used = 0; + return h; +} + +/* +** Create a new hash table +*/ +Hash* hash_new(ErtsAlcType_t type, char* name, int size, HashFunctions fun) +{ + Hash* h; + + h = erts_alloc(type, sizeof(Hash)); + + h = hash_init(type, h, name, size, fun); + h->is_allocated = 1; + return h; +} + +/* +** Delete hash table and all objects +*/ +void hash_delete(Hash* h) +{ + int old_size = h->size; + int i; + + for (i = 0; i < old_size; i++) { + HashBucket* b = h->bucket[i]; + while (b != (HashBucket*) 0) { + HashBucket* b_next = b->next; + + h->fun.free((void*) b); + b = b_next; + } + } + erts_free(h->type, h->bucket); + if (h->is_allocated) + erts_free(h->type, (void*) h); +} + +/* +** Rehash all objects +*/ +static void rehash(Hash* h, int grow) +{ + int sz; + int old_size = h->size; + HashBucket** new_bucket; + int i; + + if (grow) { + if ((h_size_table[h->ix+1]) == -1) + return; + h->ix++; + } + else { + if (h->ix == 0) + return; + h->ix--; + } + h->size = h_size_table[h->ix]; + h->size20percent = h->size/5; + h->size80percent = (4*h->size)/5; + sz = h->size*sizeof(HashBucket*); + + new_bucket = (HashBucket **) erts_alloc(h->type, sz); + sys_memzero(new_bucket, sz); + + h->used = 0; + + for (i = 0; i < old_size; i++) { + HashBucket* b = h->bucket[i]; + while (b != (HashBucket*) 0) { + HashBucket* b_next = b->next; + int ix = b->hvalue % h->size; + if (new_bucket[ix] == NULL) + h->used++; + b->next = new_bucket[ix]; + new_bucket[ix] = b; + b = b_next; + } + } + erts_free(h->type, (void *) h->bucket); + h->bucket = new_bucket; +} + +/* +** Find an object in the hash table +** +*/ +void* hash_get(Hash* h, void* tmpl) +{ + HashValue hval = h->fun.hash(tmpl); + int ix = hval % h->size; + HashBucket* b = h->bucket[ix]; + + while(b != (HashBucket*) 0) { + if ((b->hvalue == hval) && (h->fun.cmp(tmpl, (void*)b) == 0)) + return (void*) b; + b = b->next; + } + return (void*) 0; +} + +/* +** Find or insert an object in the hash table +*/ +void* hash_put(Hash* h, void* tmpl) +{ + HashValue hval = h->fun.hash(tmpl); + int ix = hval % h->size; + HashBucket* b = h->bucket[ix]; + + while(b != (HashBucket*) 0) { + if ((b->hvalue == hval) && (h->fun.cmp(tmpl, (void*)b) == 0)) + return (void*) b; + b = b->next; + } + b = (HashBucket*) h->fun.alloc(tmpl); + + if (h->bucket[ix] == NULL) + h->used++; + + b->hvalue = hval; + b->next = h->bucket[ix]; + h->bucket[ix] = b; + + if (h->used > h->size80percent) /* rehash at 80% */ + rehash(h, 1); + return (void*) b; +} + +static void +hash_insert_entry(Hash* h, HashBucket* entry) +{ + HashValue hval = entry->hvalue; + int ix = hval % h->size; + HashBucket* b = h->bucket[ix]; + + while (b != (HashBucket*) 0) { + if ((b->hvalue == hval) && (h->fun.cmp((void*)entry, (void*)b) == 0)) { + abort(); /* Should not happen */ + } + b = b->next; + } + + if (h->bucket[ix] == NULL) + h->used++; + + entry->next = h->bucket[ix]; + h->bucket[ix] = entry; + + if (h->used > h->size80percent) /* rehash at 80% */ + rehash(h, 1); +} + + +/* + * Move all entries in src into dst; empty src. + * Entries in src must not exist in dst. + */ +void +erts_hash_merge(Hash* src, Hash* dst) +{ + int limit = src->size; + HashBucket** bucket = src->bucket; + int i; + + src->used = 0; + for (i = 0; i < limit; i++) { + HashBucket* b = bucket[i]; + HashBucket* next; + + bucket[i] = NULL; + while (b) { + next = b->next; + hash_insert_entry(dst, b); + b = next; + } + } +} + +/* +** Erase hash entry return template if erased +** return 0 if not erased +*/ +void* hash_erase(Hash* h, void* tmpl) +{ + HashValue hval = h->fun.hash(tmpl); + int ix = hval % h->size; + HashBucket* b = h->bucket[ix]; + HashBucket* prev = 0; + + while(b != 0) { + if ((b->hvalue == hval) && (h->fun.cmp(tmpl, (void*)b) == 0)) { + if (prev != 0) + prev->next = b->next; + else + h->bucket[ix] = b->next; + h->fun.free((void*)b); + if (h->bucket[ix] == NULL) + h->used--; + if (h->used < h->size20percent) /* rehash at 20% */ + rehash(h, 0); + return tmpl; + } + prev = b; + b = b->next; + } + return (void*)0; +} + +/* +** Remove hash entry from table return entry if removed +** return NULL if not removed +** NOTE: hash_remove() differs from hash_erase() in that +** it returns entry (not the template) and does +** *not* call the free() callback. +*/ +void * +hash_remove(Hash *h, void *tmpl) +{ + HashValue hval = h->fun.hash(tmpl); + int ix = hval % h->size; + HashBucket *b = h->bucket[ix]; + HashBucket *prev = NULL; + + while (b) { + if ((b->hvalue == hval) && (h->fun.cmp(tmpl, (void*)b) == 0)) { + if (prev) + prev->next = b->next; + else + h->bucket[ix] = b->next; + if (h->bucket[ix] == NULL) + h->used--; + if (h->used < h->size20percent) /* rehash at 20% */ + rehash(h, 0); + return (void *) b; + } + prev = b; + b = b->next; + } + return NULL; +} + +void hash_foreach(Hash* h, void (*func)(void *, void *), void *func_arg2) +{ + int i; + + for (i = 0; i < h->size; i++) { + HashBucket* b = h->bucket[i]; + while(b != (HashBucket*) 0) { + (*func)((void *) b, func_arg2); + b = b->next; + } + } +} + |