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|
/*
* ***** BEGIN GPL LICENSE BLOCK *****
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
* All rights reserved.
*
* The Original Code is: all of this file.
*
* Contributor(s): none yet.
*
* ***** END GPL LICENSE BLOCK *****
*/
/** \file blender/blenlib/intern/BLI_ghash.c
* \ingroup bli
*
* A general (pointer -> pointer) chaining hash table
* for 'Abstract Data Types' (known as an ADT Hash Table).
*
* \note edgehash.c is based on this, make sure they stay in sync.
*/
#include <string.h>
#include <stdlib.h>
#include <stdarg.h>
#include <limits.h>
#include "MEM_guardedalloc.h"
#include "BLI_sys_types.h" /* for intptr_t support */
#include "BLI_utildefines.h"
#include "BLI_mempool.h"
#define GHASH_INTERNAL_API
#include "BLI_ghash.h" /* own include */
/* keep last */
#include "BLI_strict_flags.h"
/* -------------------------------------------------------------------- */
/** \name Structs & Constants
* \{ */
#define GHASH_USE_MODULO_BUCKETS
/**
* Next prime after `2^n` (skipping 2 & 3).
*
* \note Also used by: `BLI_edgehash` & `BLI_smallhash`.
*/
const uint hashsizes[] = {
5, 11, 17, 37, 67, 131, 257, 521, 1031, 2053, 4099, 8209,
16411, 32771, 65537, 131101, 262147, 524309, 1048583, 2097169,
4194319, 8388617, 16777259, 33554467, 67108879, 134217757,
268435459
};
#ifdef GHASH_USE_MODULO_BUCKETS
# define GHASH_MAX_SIZE 27
BLI_STATIC_ASSERT(ARRAY_SIZE(hashsizes) == GHASH_MAX_SIZE, "Invalid 'hashsizes' size");
#else
# define GHASH_BUCKET_BIT_MIN 2
# define GHASH_BUCKET_BIT_MAX 28 /* About 268M of buckets... */
#endif
/**
* \note Max load #GHASH_LIMIT_GROW used to be 3. (pre 2.74).
* Python uses 0.6666, tommyhashlib even goes down to 0.5.
* Reducing our from 3 to 0.75 gives huge speedup (about twice quicker pure GHash insertions/lookup,
* about 25% - 30% quicker 'dynamic-topology' stroke drawing e.g.).
* Min load #GHASH_LIMIT_SHRINK is a quarter of max load, to avoid resizing to quickly.
*/
#define GHASH_LIMIT_GROW(_nbkt) (((_nbkt) * 3) / 4)
#define GHASH_LIMIT_SHRINK(_nbkt) (((_nbkt) * 3) / 16)
/* WARNING! Keep in sync with ugly _gh_Entry in header!!! */
typedef struct Entry {
struct Entry *next;
void *key;
} Entry;
typedef struct GHashEntry {
Entry e;
void *val;
} GHashEntry;
typedef Entry GSetEntry;
#define GHASH_ENTRY_SIZE(_is_gset) \
((_is_gset) ? sizeof(GSetEntry) : sizeof(GHashEntry))
struct GHash {
GHashHashFP hashfp;
GHashCmpFP cmpfp;
Entry **buckets;
struct BLI_mempool *entrypool;
uint nbuckets;
uint limit_grow, limit_shrink;
#ifdef GHASH_USE_MODULO_BUCKETS
uint cursize, size_min;
#else
uint bucket_mask, bucket_bit, bucket_bit_min;
#endif
uint nentries;
uint flag;
};
/** \} */
/* -------------------------------------------------------------------- */
/** \name Internal Utility API
* \{ */
BLI_INLINE void ghash_entry_copy(
GHash *gh_dst, Entry *dst, GHash *gh_src, Entry *src,
GHashKeyCopyFP keycopyfp, GHashValCopyFP valcopyfp)
{
dst->key = (keycopyfp) ? keycopyfp(src->key) : src->key;
if ((gh_dst->flag & GHASH_FLAG_IS_GSET) == 0) {
if ((gh_src->flag & GHASH_FLAG_IS_GSET) == 0) {
((GHashEntry *)dst)->val = (valcopyfp) ? valcopyfp(((GHashEntry *)src)->val) : ((GHashEntry *)src)->val;
}
else {
((GHashEntry *)dst)->val = NULL;
}
}
}
/**
* Get the full hash for a key.
*/
BLI_INLINE uint ghash_keyhash(GHash *gh, const void *key)
{
return gh->hashfp(key);
}
/**
* Get the full hash for an entry.
*/
BLI_INLINE uint ghash_entryhash(GHash *gh, const Entry *e)
{
return gh->hashfp(e->key);
}
/**
* Get the bucket-index for an already-computed full hash.
*/
BLI_INLINE uint ghash_bucket_index(GHash *gh, const uint hash)
{
#ifdef GHASH_USE_MODULO_BUCKETS
return hash % gh->nbuckets;
#else
return hash & gh->bucket_mask;
#endif
}
/**
* Find the index of next used bucket, starting from \a curr_bucket (\a gh is assumed non-empty).
*/
BLI_INLINE uint ghash_find_next_bucket_index(GHash *gh, uint curr_bucket)
{
if (curr_bucket >= gh->nbuckets) {
curr_bucket = 0;
}
if (gh->buckets[curr_bucket]) {
return curr_bucket;
}
for (; curr_bucket < gh->nbuckets; curr_bucket++) {
if (gh->buckets[curr_bucket]) {
return curr_bucket;
}
}
for (curr_bucket = 0; curr_bucket < gh->nbuckets; curr_bucket++) {
if (gh->buckets[curr_bucket]) {
return curr_bucket;
}
}
BLI_assert(0);
return 0;
}
/**
* Expand buckets to the next size up or down.
*/
static void ghash_buckets_resize(GHash *gh, const uint nbuckets)
{
Entry **buckets_old = gh->buckets;
Entry **buckets_new;
const uint nbuckets_old = gh->nbuckets;
uint i;
BLI_assert((gh->nbuckets != nbuckets) || !gh->buckets);
// printf("%s: %d -> %d\n", __func__, nbuckets_old, nbuckets);
gh->nbuckets = nbuckets;
#ifdef GHASH_USE_MODULO_BUCKETS
#else
gh->bucket_mask = nbuckets - 1;
#endif
buckets_new = (Entry **)MEM_callocN(sizeof(*gh->buckets) * gh->nbuckets, __func__);
if (buckets_old) {
if (nbuckets > nbuckets_old) {
for (i = 0; i < nbuckets_old; i++) {
for (Entry *e = buckets_old[i], *e_next; e; e = e_next) {
const unsigned hash = ghash_entryhash(gh, e);
const unsigned bucket_index = ghash_bucket_index(gh, hash);
e_next = e->next;
e->next = buckets_new[bucket_index];
buckets_new[bucket_index] = e;
}
}
}
else {
for (i = 0; i < nbuckets_old; i++) {
#ifdef GHASH_USE_MODULO_BUCKETS
for (Entry *e = buckets_old[i], *e_next; e; e = e_next) {
const unsigned hash = ghash_entryhash(gh, e);
const unsigned bucket_index = ghash_bucket_index(gh, hash);
e_next = e->next;
e->next = buckets_new[bucket_index];
buckets_new[bucket_index] = e;
}
#else
/* No need to recompute hashes in this case, since our mask is just smaller,
* all items in old bucket 'i' will go in same new bucket (i & new_mask)! */
const unsigned bucket_index = ghash_bucket_index(gh, i);
BLI_assert(!buckets_old[i] || (bucket_index == ghash_bucket_index(gh, ghash_entryhash(gh, buckets_old[i]))));
Entry *e;
for (e = buckets_old[i]; e && e->next; e = e->next);
if (e) {
e->next = buckets_new[bucket_index];
buckets_new[bucket_index] = buckets_old[i];
}
#endif
}
}
}
gh->buckets = buckets_new;
if (buckets_old) {
MEM_freeN(buckets_old);
}
}
/**
* Check if the number of items in the GHash is large enough to require more buckets,
* or small enough to require less buckets, and resize \a gh accordingly.
*/
static void ghash_buckets_expand(
GHash *gh, const uint nentries, const bool user_defined)
{
uint new_nbuckets;
if (LIKELY(gh->buckets && (nentries < gh->limit_grow))) {
return;
}
new_nbuckets = gh->nbuckets;
#ifdef GHASH_USE_MODULO_BUCKETS
while ((nentries > gh->limit_grow) &&
(gh->cursize < GHASH_MAX_SIZE - 1))
{
new_nbuckets = hashsizes[++gh->cursize];
gh->limit_grow = GHASH_LIMIT_GROW(new_nbuckets);
}
#else
while ((nentries > gh->limit_grow) &&
(gh->bucket_bit < GHASH_BUCKET_BIT_MAX))
{
new_nbuckets = 1u << ++gh->bucket_bit;
gh->limit_grow = GHASH_LIMIT_GROW(new_nbuckets);
}
#endif
if (user_defined) {
#ifdef GHASH_USE_MODULO_BUCKETS
gh->size_min = gh->cursize;
#else
gh->bucket_bit_min = gh->bucket_bit;
#endif
}
if ((new_nbuckets == gh->nbuckets) && gh->buckets) {
return;
}
gh->limit_grow = GHASH_LIMIT_GROW(new_nbuckets);
gh->limit_shrink = GHASH_LIMIT_SHRINK(new_nbuckets);
ghash_buckets_resize(gh, new_nbuckets);
}
static void ghash_buckets_contract(
GHash *gh, const uint nentries, const bool user_defined, const bool force_shrink)
{
uint new_nbuckets;
if (!(force_shrink || (gh->flag & GHASH_FLAG_ALLOW_SHRINK))) {
return;
}
if (LIKELY(gh->buckets && (nentries > gh->limit_shrink))) {
return;
}
new_nbuckets = gh->nbuckets;
#ifdef GHASH_USE_MODULO_BUCKETS
while ((nentries < gh->limit_shrink) &&
(gh->cursize > gh->size_min))
{
new_nbuckets = hashsizes[--gh->cursize];
gh->limit_shrink = GHASH_LIMIT_SHRINK(new_nbuckets);
}
#else
while ((nentries < gh->limit_shrink) &&
(gh->bucket_bit > gh->bucket_bit_min))
{
new_nbuckets = 1u << --gh->bucket_bit;
gh->limit_shrink = GHASH_LIMIT_SHRINK(new_nbuckets);
}
#endif
if (user_defined) {
#ifdef GHASH_USE_MODULO_BUCKETS
gh->size_min = gh->cursize;
#else
gh->bucket_bit_min = gh->bucket_bit;
#endif
}
if ((new_nbuckets == gh->nbuckets) && gh->buckets) {
return;
}
gh->limit_grow = GHASH_LIMIT_GROW(new_nbuckets);
gh->limit_shrink = GHASH_LIMIT_SHRINK(new_nbuckets);
ghash_buckets_resize(gh, new_nbuckets);
}
/**
* Clear and reset \a gh buckets, reserve again buckets for given number of entries.
*/
BLI_INLINE void ghash_buckets_reset(GHash *gh, const uint nentries)
{
MEM_SAFE_FREE(gh->buckets);
#ifdef GHASH_USE_MODULO_BUCKETS
gh->cursize = 0;
gh->size_min = 0;
gh->nbuckets = hashsizes[gh->cursize];
#else
gh->bucket_bit = GHASH_BUCKET_BIT_MIN;
gh->bucket_bit_min = GHASH_BUCKET_BIT_MIN;
gh->nbuckets = 1u << gh->bucket_bit;
gh->bucket_mask = gh->nbuckets - 1;
#endif
gh->limit_grow = GHASH_LIMIT_GROW(gh->nbuckets);
gh->limit_shrink = GHASH_LIMIT_SHRINK(gh->nbuckets);
gh->nentries = 0;
ghash_buckets_expand(gh, nentries, (nentries != 0));
}
/**
* Internal lookup function.
* Takes hash and bucket_index arguments to avoid calling #ghash_keyhash and #ghash_bucket_index multiple times.
*/
BLI_INLINE Entry *ghash_lookup_entry_ex(
GHash *gh, const void *key, const uint bucket_index)
{
Entry *e;
/* If we do not store GHash, not worth computing it for each entry here!
* Typically, comparison function will be quicker, and since it's needed in the end anyway... */
for (e = gh->buckets[bucket_index]; e; e = e->next) {
if (UNLIKELY(gh->cmpfp(key, e->key) == false)) {
return e;
}
}
return NULL;
}
/**
* Internal lookup function, returns previous entry of target one too.
* Takes bucket_index argument to avoid calling #ghash_keyhash and #ghash_bucket_index multiple times.
* Useful when modifying buckets somehow (like removing an entry...).
*/
BLI_INLINE Entry *ghash_lookup_entry_prev_ex(
GHash *gh, const void *key,
Entry **r_e_prev, const uint bucket_index)
{
/* If we do not store GHash, not worth computing it for each entry here!
* Typically, comparison function will be quicker, and since it's needed in the end anyway... */
for (Entry *e_prev = NULL, *e = gh->buckets[bucket_index]; e; e_prev = e, e = e->next) {
if (UNLIKELY(gh->cmpfp(key, e->key) == false)) {
*r_e_prev = e_prev;
return e;
}
}
*r_e_prev = NULL;
return NULL;
}
/**
* Internal lookup function. Only wraps #ghash_lookup_entry_ex
*/
BLI_INLINE Entry *ghash_lookup_entry(GHash *gh, const void *key)
{
const uint hash = ghash_keyhash(gh, key);
const uint bucket_index = ghash_bucket_index(gh, hash);
return ghash_lookup_entry_ex(gh, key, bucket_index);
}
static GHash *ghash_new(
GHashHashFP hashfp, GHashCmpFP cmpfp, const char *info,
const uint nentries_reserve, const uint flag)
{
GHash *gh = MEM_mallocN(sizeof(*gh), info);
gh->hashfp = hashfp;
gh->cmpfp = cmpfp;
gh->buckets = NULL;
gh->flag = flag;
ghash_buckets_reset(gh, nentries_reserve);
gh->entrypool = BLI_mempool_create(GHASH_ENTRY_SIZE(flag & GHASH_FLAG_IS_GSET), 64, 64, BLI_MEMPOOL_NOP);
return gh;
}
/**
* Internal insert function.
* Takes hash and bucket_index arguments to avoid calling #ghash_keyhash and #ghash_bucket_index multiple times.
*/
BLI_INLINE void ghash_insert_ex(
GHash *gh, void *key, void *val, const uint bucket_index)
{
GHashEntry *e = BLI_mempool_alloc(gh->entrypool);
BLI_assert((gh->flag & GHASH_FLAG_ALLOW_DUPES) || (BLI_ghash_haskey(gh, key) == 0));
BLI_assert(!(gh->flag & GHASH_FLAG_IS_GSET));
e->e.next = gh->buckets[bucket_index];
e->e.key = key;
e->val = val;
gh->buckets[bucket_index] = (Entry *)e;
ghash_buckets_expand(gh, ++gh->nentries, false);
}
/**
* Insert function that takes a pre-allocated entry.
*/
BLI_INLINE void ghash_insert_ex_keyonly_entry(
GHash *gh, void *key, const uint bucket_index,
Entry *e)
{
BLI_assert((gh->flag & GHASH_FLAG_ALLOW_DUPES) || (BLI_ghash_haskey(gh, key) == 0));
e->next = gh->buckets[bucket_index];
e->key = key;
gh->buckets[bucket_index] = e;
ghash_buckets_expand(gh, ++gh->nentries, false);
}
/**
* Insert function that doesn't set the value (use for GSet)
*/
BLI_INLINE void ghash_insert_ex_keyonly(
GHash *gh, void *key, const uint bucket_index)
{
Entry *e = BLI_mempool_alloc(gh->entrypool);
BLI_assert((gh->flag & GHASH_FLAG_ALLOW_DUPES) || (BLI_ghash_haskey(gh, key) == 0));
BLI_assert((gh->flag & GHASH_FLAG_IS_GSET) != 0);
e->next = gh->buckets[bucket_index];
e->key = key;
gh->buckets[bucket_index] = e;
ghash_buckets_expand(gh, ++gh->nentries, false);
}
BLI_INLINE void ghash_insert(GHash *gh, void *key, void *val)
{
const uint hash = ghash_keyhash(gh, key);
const uint bucket_index = ghash_bucket_index(gh, hash);
ghash_insert_ex(gh, key, val, bucket_index);
}
BLI_INLINE bool ghash_insert_safe(
GHash *gh, void *key, void *val, const bool override,
GHashKeyFreeFP keyfreefp, GHashValFreeFP valfreefp)
{
const uint hash = ghash_keyhash(gh, key);
const uint bucket_index = ghash_bucket_index(gh, hash);
GHashEntry *e = (GHashEntry *)ghash_lookup_entry_ex(gh, key, bucket_index);
BLI_assert(!(gh->flag & GHASH_FLAG_IS_GSET));
if (e) {
if (override) {
if (keyfreefp) {
keyfreefp(e->e.key);
}
if (valfreefp) {
valfreefp(e->val);
}
e->e.key = key;
e->val = val;
}
return false;
}
else {
ghash_insert_ex(gh, key, val, bucket_index);
return true;
}
}
BLI_INLINE bool ghash_insert_safe_keyonly(
GHash *gh, void *key, const bool override,
GHashKeyFreeFP keyfreefp)
{
const uint hash = ghash_keyhash(gh, key);
const uint bucket_index = ghash_bucket_index(gh, hash);
Entry *e = ghash_lookup_entry_ex(gh, key, bucket_index);
BLI_assert((gh->flag & GHASH_FLAG_IS_GSET) != 0);
if (e) {
if (override) {
if (keyfreefp) {
keyfreefp(e->key);
}
e->key = key;
}
return false;
}
else {
ghash_insert_ex_keyonly(gh, key, bucket_index);
return true;
}
}
/**
* Remove the entry and return it, caller must free from gh->entrypool.
*/
static Entry *ghash_remove_ex(
GHash *gh, const void *key,
GHashKeyFreeFP keyfreefp, GHashValFreeFP valfreefp,
const uint bucket_index)
{
Entry *e_prev;
Entry *e = ghash_lookup_entry_prev_ex(gh, key, &e_prev, bucket_index);
BLI_assert(!valfreefp || !(gh->flag & GHASH_FLAG_IS_GSET));
if (e) {
if (keyfreefp) {
keyfreefp(e->key);
}
if (valfreefp) {
valfreefp(((GHashEntry *)e)->val);
}
if (e_prev) {
e_prev->next = e->next;
}
else {
gh->buckets[bucket_index] = e->next;
}
ghash_buckets_contract(gh, --gh->nentries, false, false);
}
return e;
}
/**
* Remove a random entry and return it (or NULL if empty), caller must free from gh->entrypool.
*/
static Entry *ghash_pop(GHash *gh, GHashIterState *state)
{
uint curr_bucket = state->curr_bucket;
if (gh->nentries == 0) {
return NULL;
}
/* Note: using first_bucket_index here allows us to avoid potential
* huge number of loops over buckets,
* in case we are popping from a large ghash with few items in it... */
curr_bucket = ghash_find_next_bucket_index(gh, curr_bucket);
Entry *e = gh->buckets[curr_bucket];
BLI_assert(e);
ghash_remove_ex(gh, e->key, NULL, NULL, curr_bucket);
state->curr_bucket = curr_bucket;
return e;
}
/**
* Run free callbacks for freeing entries.
*/
static void ghash_free_cb(
GHash *gh,
GHashKeyFreeFP keyfreefp, GHashValFreeFP valfreefp)
{
uint i;
BLI_assert(keyfreefp || valfreefp);
BLI_assert(!valfreefp || !(gh->flag & GHASH_FLAG_IS_GSET));
for (i = 0; i < gh->nbuckets; i++) {
Entry *e;
for (e = gh->buckets[i]; e; e = e->next) {
if (keyfreefp) {
keyfreefp(e->key);
}
if (valfreefp) {
valfreefp(((GHashEntry *)e)->val);
}
}
}
}
/**
* Copy the GHash.
*/
static GHash *ghash_copy(GHash *gh, GHashKeyCopyFP keycopyfp, GHashValCopyFP valcopyfp)
{
GHash *gh_new;
uint i;
/* This allows us to be sure to get the same number of buckets in gh_new as in ghash. */
const uint reserve_nentries_new = MAX2(GHASH_LIMIT_GROW(gh->nbuckets) - 1, gh->nentries);
BLI_assert(!valcopyfp || !(gh->flag & GHASH_FLAG_IS_GSET));
gh_new = ghash_new(gh->hashfp, gh->cmpfp, __func__, 0, gh->flag);
ghash_buckets_expand(gh_new, reserve_nentries_new, false);
BLI_assert(gh_new->nbuckets == gh->nbuckets);
for (i = 0; i < gh->nbuckets; i++) {
Entry *e;
for (e = gh->buckets[i]; e; e = e->next) {
Entry *e_new = BLI_mempool_alloc(gh_new->entrypool);
ghash_entry_copy(gh_new, e_new, gh, e, keycopyfp, valcopyfp);
/* Warning!
* This means entries in buckets in new copy will be in reversed order!
* This shall not be an issue though, since order should never be assumed in ghash. */
/* Note: We can use 'i' here, since we are sure that
* 'gh' and 'gh_new' have the same number of buckets! */
e_new->next = gh_new->buckets[i];
gh_new->buckets[i] = e_new;
}
}
gh_new->nentries = gh->nentries;
return gh_new;
}
/** \} */
/* -------------------------------------------------------------------- */
/** \name GHash Public API
* \{ */
/**
* Creates a new, empty GHash.
*
* \param hashfp: Hash callback.
* \param cmpfp: Comparison callback.
* \param info: Identifier string for the GHash.
* \param nentries_reserve: Optionally reserve the number of members that the hash will hold.
* Use this to avoid resizing buckets if the size is known or can be closely approximated.
* \return An empty GHash.
*/
GHash *BLI_ghash_new_ex(
GHashHashFP hashfp, GHashCmpFP cmpfp, const char *info,
const uint nentries_reserve)
{
return ghash_new(hashfp, cmpfp, info, nentries_reserve, 0);
}
/**
* Wraps #BLI_ghash_new_ex with zero entries reserved.
*/
GHash *BLI_ghash_new(GHashHashFP hashfp, GHashCmpFP cmpfp, const char *info)
{
return BLI_ghash_new_ex(hashfp, cmpfp, info, 0);
}
/**
* Copy given GHash. Keys and values are also copied if relevant callback is provided, else pointers remain the same.
*/
GHash *BLI_ghash_copy(GHash *gh, GHashKeyCopyFP keycopyfp, GHashValCopyFP valcopyfp)
{
return ghash_copy(gh, keycopyfp, valcopyfp);
}
/**
* Reserve given amount of entries (resize \a gh accordingly if needed).
*/
void BLI_ghash_reserve(GHash *gh, const uint nentries_reserve)
{
ghash_buckets_expand(gh, nentries_reserve, true);
ghash_buckets_contract(gh, nentries_reserve, true, false);
}
/**
* \return size of the GHash.
*/
uint BLI_ghash_len(GHash *gh)
{
return gh->nentries;
}
/**
* Insert a key/value pair into the \a gh.
*
* \note Duplicates are not checked,
* the caller is expected to ensure elements are unique unless
* GHASH_FLAG_ALLOW_DUPES flag is set.
*/
void BLI_ghash_insert(GHash *gh, void *key, void *val)
{
ghash_insert(gh, key, val);
}
/**
* Inserts a new value to a key that may already be in ghash.
*
* Avoids #BLI_ghash_remove, #BLI_ghash_insert calls (double lookups)
*
* \returns true if a new key has been added.
*/
bool BLI_ghash_reinsert(GHash *gh, void *key, void *val, GHashKeyFreeFP keyfreefp, GHashValFreeFP valfreefp)
{
return ghash_insert_safe(gh, key, val, true, keyfreefp, valfreefp);
}
/**
* Replaces the key of an item in the \a gh.
*
* Use when a key is re-allocated or it's memory location is changed.
*
* \returns The previous key or NULL if not found, the caller may free if it's needed.
*/
void *BLI_ghash_replace_key(GHash *gh, void *key)
{
const uint hash = ghash_keyhash(gh, key);
const uint bucket_index = ghash_bucket_index(gh, hash);
GHashEntry *e = (GHashEntry *)ghash_lookup_entry_ex(gh, key, bucket_index);
if (e != NULL) {
void *key_prev = e->e.key;
e->e.key = key;
return key_prev;
}
else {
return NULL;
}
}
/**
* Lookup the value of \a key in \a gh.
*
* \param key: The key to lookup.
* \returns the value for \a key or NULL.
*
* \note When NULL is a valid value, use #BLI_ghash_lookup_p to differentiate a missing key
* from a key with a NULL value. (Avoids calling #BLI_ghash_haskey before #BLI_ghash_lookup)
*/
void *BLI_ghash_lookup(GHash *gh, const void *key)
{
GHashEntry *e = (GHashEntry *)ghash_lookup_entry(gh, key);
BLI_assert(!(gh->flag & GHASH_FLAG_IS_GSET));
return e ? e->val : NULL;
}
/**
* A version of #BLI_ghash_lookup which accepts a fallback argument.
*/
void *BLI_ghash_lookup_default(GHash *gh, const void *key, void *val_default)
{
GHashEntry *e = (GHashEntry *)ghash_lookup_entry(gh, key);
BLI_assert(!(gh->flag & GHASH_FLAG_IS_GSET));
return e ? e->val : val_default;
}
/**
* Lookup a pointer to the value of \a key in \a gh.
*
* \param key: The key to lookup.
* \returns the pointer to value for \a key or NULL.
*
* \note This has 2 main benefits over #BLI_ghash_lookup.
* - A NULL return always means that \a key isn't in \a gh.
* - The value can be modified in-place without further function calls (faster).
*/
void **BLI_ghash_lookup_p(GHash *gh, const void *key)
{
GHashEntry *e = (GHashEntry *)ghash_lookup_entry(gh, key);
BLI_assert(!(gh->flag & GHASH_FLAG_IS_GSET));
return e ? &e->val : NULL;
}
/**
* Ensure \a key is exists in \a gh.
*
* This handles the common situation where the caller needs ensure a key is added to \a gh,
* constructing a new value in the case the key isn't found.
* Otherwise use the existing value.
*
* Such situations typically incur multiple lookups, however this function
* avoids them by ensuring the key is added,
* returning a pointer to the value so it can be used or initialized by the caller.
*
* \returns true when the value didn't need to be added.
* (when false, the caller _must_ initialize the value).
*/
bool BLI_ghash_ensure_p(GHash *gh, void *key, void ***r_val)
{
const uint hash = ghash_keyhash(gh, key);
const uint bucket_index = ghash_bucket_index(gh, hash);
GHashEntry *e = (GHashEntry *)ghash_lookup_entry_ex(gh, key, bucket_index);
const bool haskey = (e != NULL);
if (!haskey) {
e = BLI_mempool_alloc(gh->entrypool);
ghash_insert_ex_keyonly_entry(gh, key, bucket_index, (Entry *)e);
}
*r_val = &e->val;
return haskey;
}
/**
* A version of #BLI_ghash_ensure_p that allows caller to re-assign the key.
* Typically used when the key is to be duplicated.
*
* \warning Caller _must_ write to \a r_key when returning false.
*/
bool BLI_ghash_ensure_p_ex(
GHash *gh, const void *key, void ***r_key, void ***r_val)
{
const uint hash = ghash_keyhash(gh, key);
const uint bucket_index = ghash_bucket_index(gh, hash);
GHashEntry *e = (GHashEntry *)ghash_lookup_entry_ex(gh, key, bucket_index);
const bool haskey = (e != NULL);
if (!haskey) {
/* pass 'key' incase we resize */
e = BLI_mempool_alloc(gh->entrypool);
ghash_insert_ex_keyonly_entry(gh, (void *)key, bucket_index, (Entry *)e);
e->e.key = NULL; /* caller must re-assign */
}
*r_key = &e->e.key;
*r_val = &e->val;
return haskey;
}
/**
* Remove \a key from \a gh, or return false if the key wasn't found.
*
* \param key: The key to remove.
* \param keyfreefp: Optional callback to free the key.
* \param valfreefp: Optional callback to free the value.
* \return true if \a key was removed from \a gh.
*/
bool BLI_ghash_remove(GHash *gh, const void *key, GHashKeyFreeFP keyfreefp, GHashValFreeFP valfreefp)
{
const uint hash = ghash_keyhash(gh, key);
const uint bucket_index = ghash_bucket_index(gh, hash);
Entry *e = ghash_remove_ex(gh, key, keyfreefp, valfreefp, bucket_index);
if (e) {
BLI_mempool_free(gh->entrypool, e);
return true;
}
else {
return false;
}
}
/* same as above but return the value,
* no free value argument since it will be returned */
/**
* Remove \a key from \a gh, returning the value or NULL if the key wasn't found.
*
* \param key: The key to remove.
* \param keyfreefp: Optional callback to free the key.
* \return the value of \a key int \a gh or NULL.
*/
void *BLI_ghash_popkey(GHash *gh, const void *key, GHashKeyFreeFP keyfreefp)
{
const uint hash = ghash_keyhash(gh, key);
const uint bucket_index = ghash_bucket_index(gh, hash);
GHashEntry *e = (GHashEntry *)ghash_remove_ex(gh, key, keyfreefp, NULL, bucket_index);
BLI_assert(!(gh->flag & GHASH_FLAG_IS_GSET));
if (e) {
void *val = e->val;
BLI_mempool_free(gh->entrypool, e);
return val;
}
else {
return NULL;
}
}
/**
* \return true if the \a key is in \a gh.
*/
bool BLI_ghash_haskey(GHash *gh, const void *key)
{
return (ghash_lookup_entry(gh, key) != NULL);
}
/**
* Remove a random entry from \a gh, returning true if a key/value pair could be removed, false otherwise.
*
* \param r_key: The removed key.
* \param r_val: The removed value.
* \param state: Used for efficient removal.
* \return true if there was something to pop, false if ghash was already empty.
*/
bool BLI_ghash_pop(
GHash *gh, GHashIterState *state,
void **r_key, void **r_val)
{
GHashEntry *e = (GHashEntry *)ghash_pop(gh, state);
BLI_assert(!(gh->flag & GHASH_FLAG_IS_GSET));
if (e) {
*r_key = e->e.key;
*r_val = e->val;
BLI_mempool_free(gh->entrypool, e);
return true;
}
else {
*r_key = *r_val = NULL;
return false;
}
}
/**
* Reset \a gh clearing all entries.
*
* \param keyfreefp: Optional callback to free the key.
* \param valfreefp: Optional callback to free the value.
* \param nentries_reserve: Optionally reserve the number of members that the hash will hold.
*/
void BLI_ghash_clear_ex(
GHash *gh, GHashKeyFreeFP keyfreefp, GHashValFreeFP valfreefp,
const uint nentries_reserve)
{
if (keyfreefp || valfreefp)
ghash_free_cb(gh, keyfreefp, valfreefp);
ghash_buckets_reset(gh, nentries_reserve);
BLI_mempool_clear_ex(gh->entrypool, nentries_reserve ? (int)nentries_reserve : -1);
}
/**
* Wraps #BLI_ghash_clear_ex with zero entries reserved.
*/
void BLI_ghash_clear(GHash *gh, GHashKeyFreeFP keyfreefp, GHashValFreeFP valfreefp)
{
BLI_ghash_clear_ex(gh, keyfreefp, valfreefp, 0);
}
/**
* Frees the GHash and its members.
*
* \param gh: The GHash to free.
* \param keyfreefp: Optional callback to free the key.
* \param valfreefp: Optional callback to free the value.
*/
void BLI_ghash_free(GHash *gh, GHashKeyFreeFP keyfreefp, GHashValFreeFP valfreefp)
{
BLI_assert((int)gh->nentries == BLI_mempool_len(gh->entrypool));
if (keyfreefp || valfreefp)
ghash_free_cb(gh, keyfreefp, valfreefp);
MEM_freeN(gh->buckets);
BLI_mempool_destroy(gh->entrypool);
MEM_freeN(gh);
}
/**
* Sets a GHash flag.
*/
void BLI_ghash_flag_set(GHash *gh, uint flag)
{
gh->flag |= flag;
}
/**
* Clear a GHash flag.
*/
void BLI_ghash_flag_clear(GHash *gh, uint flag)
{
gh->flag &= ~flag;
}
/** \} */
/* -------------------------------------------------------------------- */
/** \name GHash Iterator API
* \{ */
/**
* Create a new GHashIterator. The hash table must not be mutated
* while the iterator is in use, and the iterator will step exactly
* BLI_ghash_len(gh) times before becoming done.
*
* \param gh: The GHash to iterate over.
* \return Pointer to a new DynStr.
*/
GHashIterator *BLI_ghashIterator_new(GHash *gh)
{
GHashIterator *ghi = MEM_mallocN(sizeof(*ghi), "ghash iterator");
BLI_ghashIterator_init(ghi, gh);
return ghi;
}
/**
* Init an already allocated GHashIterator. The hash table must not
* be mutated while the iterator is in use, and the iterator will
* step exactly BLI_ghash_len(gh) times before becoming done.
*
* \param ghi: The GHashIterator to initialize.
* \param gh: The GHash to iterate over.
*/
void BLI_ghashIterator_init(GHashIterator *ghi, GHash *gh)
{
ghi->gh = gh;
ghi->curEntry = NULL;
ghi->curBucket = UINT_MAX; /* wraps to zero */
if (gh->nentries) {
do {
ghi->curBucket++;
if (UNLIKELY(ghi->curBucket == ghi->gh->nbuckets))
break;
ghi->curEntry = ghi->gh->buckets[ghi->curBucket];
} while (!ghi->curEntry);
}
}
/**
* Steps the iterator to the next index.
*
* \param ghi: The iterator.
*/
void BLI_ghashIterator_step(GHashIterator *ghi)
{
if (ghi->curEntry) {
ghi->curEntry = ghi->curEntry->next;
while (!ghi->curEntry) {
ghi->curBucket++;
if (ghi->curBucket == ghi->gh->nbuckets)
break;
ghi->curEntry = ghi->gh->buckets[ghi->curBucket];
}
}
}
/**
* Free a GHashIterator.
*
* \param ghi: The iterator to free.
*/
void BLI_ghashIterator_free(GHashIterator *ghi)
{
MEM_freeN(ghi);
}
/* inline functions now */
#if 0
/**
* Retrieve the key from an iterator.
*
* \param ghi: The iterator.
* \return The key at the current index, or NULL if the
* iterator is done.
*/
void *BLI_ghashIterator_getKey(GHashIterator *ghi)
{
return ghi->curEntry->key;
}
/**
* Retrieve the value from an iterator.
*
* \param ghi: The iterator.
* \return The value at the current index, or NULL if the
* iterator is done.
*/
void *BLI_ghashIterator_getValue(GHashIterator *ghi)
{
return ghi->curEntry->val;
}
/**
* Retrieve the value from an iterator.
*
* \param ghi: The iterator.
* \return The value at the current index, or NULL if the
* iterator is done.
*/
void **BLI_ghashIterator_getValue_p(GHashIterator *ghi)
{
return &ghi->curEntry->val;
}
/**
* Determine if an iterator is done (has reached the end of
* the hash table).
*
* \param ghi: The iterator.
* \return True if done, False otherwise.
*/
bool BLI_ghashIterator_done(GHashIterator *ghi)
{
return ghi->curEntry == NULL;
}
#endif
/** \} */
/* -------------------------------------------------------------------- */
/** \name GSet Public API
*
* Use ghash API to give 'set' functionality
* \{ */
GSet *BLI_gset_new_ex(
GSetHashFP hashfp, GSetCmpFP cmpfp, const char *info,
const uint nentries_reserve)
{
return (GSet *)ghash_new(hashfp, cmpfp, info, nentries_reserve, GHASH_FLAG_IS_GSET);
}
GSet *BLI_gset_new(GSetHashFP hashfp, GSetCmpFP cmpfp, const char *info)
{
return BLI_gset_new_ex(hashfp, cmpfp, info, 0);
}
/**
* Copy given GSet. Keys are also copied if callback is provided, else pointers remain the same.
*/
GSet *BLI_gset_copy(GSet *gs, GHashKeyCopyFP keycopyfp)
{
return (GSet *)ghash_copy((GHash *)gs, keycopyfp, NULL);
}
uint BLI_gset_len(GSet *gs)
{
return ((GHash *)gs)->nentries;
}
/**
* Adds the key to the set (no checks for unique keys!).
* Matching #BLI_ghash_insert
*/
void BLI_gset_insert(GSet *gs, void *key)
{
const uint hash = ghash_keyhash((GHash *)gs, key);
const uint bucket_index = ghash_bucket_index((GHash *)gs, hash);
ghash_insert_ex_keyonly((GHash *)gs, key, bucket_index);
}
/**
* A version of BLI_gset_insert which checks first if the key is in the set.
* \returns true if a new key has been added.
*
* \note GHash has no equivalent to this because typically the value would be different.
*/
bool BLI_gset_add(GSet *gs, void *key)
{
return ghash_insert_safe_keyonly((GHash *)gs, key, false, NULL);
}
/**
* Set counterpart to #BLI_ghash_ensure_p_ex.
* similar to BLI_gset_add, except it returns the key pointer.
*
* \warning Caller _must_ write to \a r_key when returning false.
*/
bool BLI_gset_ensure_p_ex(GSet *gs, const void *key, void ***r_key)
{
const uint hash = ghash_keyhash((GHash *)gs, key);
const uint bucket_index = ghash_bucket_index((GHash *)gs, hash);
GSetEntry *e = (GSetEntry *)ghash_lookup_entry_ex((GHash *)gs, key, bucket_index);
const bool haskey = (e != NULL);
if (!haskey) {
/* pass 'key' incase we resize */
e = BLI_mempool_alloc(((GHash *)gs)->entrypool);
ghash_insert_ex_keyonly_entry((GHash *)gs, (void *)key, bucket_index, (Entry *)e);
e->key = NULL; /* caller must re-assign */
}
*r_key = &e->key;
return haskey;
}
/**
* Adds the key to the set (duplicates are managed).
* Matching #BLI_ghash_reinsert
*
* \returns true if a new key has been added.
*/
bool BLI_gset_reinsert(GSet *gs, void *key, GSetKeyFreeFP keyfreefp)
{
return ghash_insert_safe_keyonly((GHash *)gs, key, true, keyfreefp);
}
/**
* Replaces the key to the set if it's found.
* Matching #BLI_ghash_replace_key
*
* \returns The old key or NULL if not found.
*/
void *BLI_gset_replace_key(GSet *gs, void *key)
{
return BLI_ghash_replace_key((GHash *)gs, key);
}
bool BLI_gset_remove(GSet *gs, const void *key, GSetKeyFreeFP keyfreefp)
{
return BLI_ghash_remove((GHash *)gs, key, keyfreefp, NULL);
}
bool BLI_gset_haskey(GSet *gs, const void *key)
{
return (ghash_lookup_entry((GHash *)gs, key) != NULL);
}
/**
* Remove a random entry from \a gs, returning true if a key could be removed, false otherwise.
*
* \param r_key: The removed key.
* \param state: Used for efficient removal.
* \return true if there was something to pop, false if gset was already empty.
*/
bool BLI_gset_pop(
GSet *gs, GSetIterState *state,
void **r_key)
{
GSetEntry *e = (GSetEntry *)ghash_pop((GHash *)gs, (GHashIterState *)state);
if (e) {
*r_key = e->key;
BLI_mempool_free(((GHash *)gs)->entrypool, e);
return true;
}
else {
*r_key = NULL;
return false;
}
}
void BLI_gset_clear_ex(
GSet *gs, GSetKeyFreeFP keyfreefp,
const uint nentries_reserve)
{
BLI_ghash_clear_ex(
(GHash *)gs, keyfreefp, NULL,
nentries_reserve);
}
void BLI_gset_clear(GSet *gs, GSetKeyFreeFP keyfreefp)
{
BLI_ghash_clear((GHash *)gs, keyfreefp, NULL);
}
void BLI_gset_free(GSet *gs, GSetKeyFreeFP keyfreefp)
{
BLI_ghash_free((GHash *)gs, keyfreefp, NULL);
}
void BLI_gset_flag_set(GSet *gs, uint flag)
{
((GHash *)gs)->flag |= flag;
}
void BLI_gset_flag_clear(GSet *gs, uint flag)
{
((GHash *)gs)->flag &= ~flag;
}
/** \} */
/* -------------------------------------------------------------------- */
/** \name GSet Combined Key/Value Usage
*
* \note Not typical ``set`` use, only use when the pointer identity matters.
* This can be useful when the key references data stored outside the GSet.
* \{ */
/**
* Returns the pointer to the key if it's found.
*/
void *BLI_gset_lookup(GSet *gs, const void *key)
{
Entry *e = ghash_lookup_entry((GHash *)gs, key);
return e ? e->key : NULL;
}
/**
* Returns the pointer to the key if it's found, removing it from the GSet.
* \note Caller must handle freeing.
*/
void *BLI_gset_pop_key(GSet *gs, const void *key)
{
const uint hash = ghash_keyhash((GHash *)gs, key);
const uint bucket_index = ghash_bucket_index((GHash *)gs, hash);
Entry *e = ghash_remove_ex((GHash *)gs, key, NULL, NULL, bucket_index);
if (e) {
void *key_ret = e->key;
BLI_mempool_free(((GHash *)gs)->entrypool, e);
return key_ret;
}
else {
return NULL;
}
}
/** \} */
/* -------------------------------------------------------------------- */
/** \name Debugging & Introspection
* \{ */
#include "BLI_math.h"
/**
* \return number of buckets in the GHash.
*/
int BLI_ghash_buckets_len(GHash *gh)
{
return (int)gh->nbuckets;
}
int BLI_gset_buckets_len(GSet *gs)
{
return BLI_ghash_buckets_len((GHash *)gs);
}
/**
* Measure how well the hash function performs (1.0 is approx as good as random distribution),
* and return a few other stats like load, variance of the distribution of the entries in the buckets, etc.
*
* Smaller is better!
*/
double BLI_ghash_calc_quality_ex(
GHash *gh, double *r_load, double *r_variance,
double *r_prop_empty_buckets, double *r_prop_overloaded_buckets, int *r_biggest_bucket)
{
double mean;
uint i;
if (gh->nentries == 0) {
if (r_load) {
*r_load = 0.0;
}
if (r_variance) {
*r_variance = 0.0;
}
if (r_prop_empty_buckets) {
*r_prop_empty_buckets = 1.0;
}
if (r_prop_overloaded_buckets) {
*r_prop_overloaded_buckets = 0.0;
}
if (r_biggest_bucket) {
*r_biggest_bucket = 0;
}
return 0.0;
}
mean = (double)gh->nentries / (double)gh->nbuckets;
if (r_load) {
*r_load = mean;
}
if (r_biggest_bucket) {
*r_biggest_bucket = 0;
}
if (r_variance) {
/* We already know our mean (i.e. load factor), easy to compute variance.
* See https://en.wikipedia.org/wiki/Algorithms_for_calculating_variance#Two-pass_algorithm
*/
double sum = 0.0;
for (i = 0; i < gh->nbuckets; i++) {
int count = 0;
Entry *e;
for (e = gh->buckets[i]; e; e = e->next) {
count++;
}
sum += ((double)count - mean) * ((double)count - mean);
}
*r_variance = sum / (double)(gh->nbuckets - 1);
}
{
uint64_t sum = 0;
uint64_t overloaded_buckets_threshold = (uint64_t)max_ii(GHASH_LIMIT_GROW(1), 1);
uint64_t sum_overloaded = 0;
uint64_t sum_empty = 0;
for (i = 0; i < gh->nbuckets; i++) {
uint64_t count = 0;
Entry *e;
for (e = gh->buckets[i]; e; e = e->next) {
count++;
}
if (r_biggest_bucket) {
*r_biggest_bucket = max_ii(*r_biggest_bucket, (int)count);
}
if (r_prop_overloaded_buckets && (count > overloaded_buckets_threshold)) {
sum_overloaded++;
}
if (r_prop_empty_buckets && !count) {
sum_empty++;
}
sum += count * (count + 1);
}
if (r_prop_overloaded_buckets) {
*r_prop_overloaded_buckets = (double)sum_overloaded / (double)gh->nbuckets;
}
if (r_prop_empty_buckets) {
*r_prop_empty_buckets = (double)sum_empty / (double)gh->nbuckets;
}
return ((double)sum * (double)gh->nbuckets /
((double)gh->nentries * (gh->nentries + 2 * gh->nbuckets - 1)));
}
}
double BLI_gset_calc_quality_ex(
GSet *gs, double *r_load, double *r_variance,
double *r_prop_empty_buckets, double *r_prop_overloaded_buckets, int *r_biggest_bucket)
{
return BLI_ghash_calc_quality_ex(
(GHash *)gs, r_load, r_variance,
r_prop_empty_buckets, r_prop_overloaded_buckets, r_biggest_bucket);
}
double BLI_ghash_calc_quality(GHash *gh)
{
return BLI_ghash_calc_quality_ex(gh, NULL, NULL, NULL, NULL, NULL);
}
double BLI_gset_calc_quality(GSet *gs)
{
return BLI_ghash_calc_quality_ex((GHash *)gs, NULL, NULL, NULL, NULL, NULL);
}
/** \} */
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