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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 09:00:29 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-28 09:00:29 +0000
commit52e25213825024b8bb446eb26b03bedc9d5c2103 (patch)
treeda70bf44b2423f6f8e9a070c063fed79d190b489 /Hashtable.c
parentInitial commit. (diff)
downloadhtop-52e25213825024b8bb446eb26b03bedc9d5c2103.tar.xz
htop-52e25213825024b8bb446eb26b03bedc9d5c2103.zip
Adding upstream version 3.2.2.upstream/3.2.2upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'Hashtable.c')
-rw-r--r--Hashtable.c330
1 files changed, 330 insertions, 0 deletions
diff --git a/Hashtable.c b/Hashtable.c
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index 0000000..2756b23
--- /dev/null
+++ b/Hashtable.c
@@ -0,0 +1,330 @@
+/*
+htop - Hashtable.c
+(C) 2004-2011 Hisham H. Muhammad
+Released under the GNU GPLv2+, see the COPYING file
+in the source distribution for its full text.
+*/
+
+#include "config.h" // IWYU pragma: keep
+
+#include "Hashtable.h"
+
+#include <assert.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "CRT.h"
+#include "Macros.h"
+#include "XUtils.h"
+
+#ifndef NDEBUG
+#include <stdio.h>
+#endif
+
+
+typedef struct HashtableItem_ {
+ ht_key_t key;
+ size_t probe;
+ void* value;
+} HashtableItem;
+
+struct Hashtable_ {
+ size_t size;
+ HashtableItem* buckets;
+ size_t items;
+ bool owner;
+};
+
+
+#ifndef NDEBUG
+
+static void Hashtable_dump(const Hashtable* this) {
+ fprintf(stderr, "Hashtable %p: size=%zu items=%zu owner=%s\n",
+ (const void*)this,
+ this->size,
+ this->items,
+ this->owner ? "yes" : "no");
+
+ size_t items = 0;
+ for (size_t i = 0; i < this->size; i++) {
+ fprintf(stderr, " item %5zu: key = %5u probe = %2zu value = %p\n",
+ i,
+ this->buckets[i].key,
+ this->buckets[i].probe,
+ this->buckets[i].value);
+
+ if (this->buckets[i].value)
+ items++;
+ }
+
+ fprintf(stderr, "Hashtable %p: items=%zu counted=%zu\n",
+ (const void*)this,
+ this->items,
+ items);
+}
+
+static bool Hashtable_isConsistent(const Hashtable* this) {
+ size_t items = 0;
+ for (size_t i = 0; i < this->size; i++) {
+ if (this->buckets[i].value)
+ items++;
+ }
+ bool res = items == this->items;
+ if (!res)
+ Hashtable_dump(this);
+ return res;
+}
+
+size_t Hashtable_count(const Hashtable* this) {
+ size_t items = 0;
+ for (size_t i = 0; i < this->size; i++) {
+ if (this->buckets[i].value)
+ items++;
+ }
+ assert(items == this->items);
+ return items;
+}
+
+#endif /* NDEBUG */
+
+/* https://oeis.org/A014234 */
+static const uint64_t OEISprimes[] = {
+ 7, 13, 31, 61, 127, 251, 509, 1021, 2039, 4093, 8191,
+ 16381, 32749, 65521, 131071, 262139, 524287, 1048573,
+ 2097143, 4194301, 8388593, 16777213, 33554393,
+ 67108859, 134217689, 268435399, 536870909, 1073741789,
+ 2147483647, 4294967291, 8589934583, 17179869143,
+ 34359738337, 68719476731, 137438953447
+};
+
+static size_t nextPrime(size_t n) {
+ /* on 32-bit make sure we do not return primes not fitting in size_t */
+ for (size_t i = 0; i < ARRAYSIZE(OEISprimes) && OEISprimes[i] < SIZE_MAX; i++) {
+ if (n <= OEISprimes[i])
+ return OEISprimes[i];
+ }
+
+ CRT_fatalError("Hashtable: no prime found");
+}
+
+Hashtable* Hashtable_new(size_t size, bool owner) {
+ Hashtable* this;
+
+ this = xMalloc(sizeof(Hashtable));
+ this->items = 0;
+ this->size = size ? nextPrime(size) : 13;
+ this->buckets = (HashtableItem*) xCalloc(this->size, sizeof(HashtableItem));
+ this->owner = owner;
+
+ assert(Hashtable_isConsistent(this));
+ return this;
+}
+
+void Hashtable_delete(Hashtable* this) {
+ Hashtable_clear(this);
+
+ free(this->buckets);
+ free(this);
+}
+
+void Hashtable_clear(Hashtable* this) {
+ assert(Hashtable_isConsistent(this));
+
+ if (this->owner)
+ for (size_t i = 0; i < this->size; i++)
+ free(this->buckets[i].value);
+
+ memset(this->buckets, 0, this->size * sizeof(HashtableItem));
+ this->items = 0;
+
+ assert(Hashtable_isConsistent(this));
+}
+
+static void insert(Hashtable* this, ht_key_t key, void* value) {
+ size_t index = key % this->size;
+ size_t probe = 0;
+#ifndef NDEBUG
+ size_t origIndex = index;
+#endif
+
+ for (;;) {
+ if (!this->buckets[index].value) {
+ this->items++;
+ this->buckets[index].key = key;
+ this->buckets[index].probe = probe;
+ this->buckets[index].value = value;
+ return;
+ }
+
+ if (this->buckets[index].key == key) {
+ if (this->owner && this->buckets[index].value != value)
+ free(this->buckets[index].value);
+ this->buckets[index].value = value;
+ return;
+ }
+
+ /* Robin Hood swap */
+ if (probe > this->buckets[index].probe) {
+ HashtableItem tmp = this->buckets[index];
+
+ this->buckets[index].key = key;
+ this->buckets[index].probe = probe;
+ this->buckets[index].value = value;
+
+ key = tmp.key;
+ probe = tmp.probe;
+ value = tmp.value;
+ }
+
+ index = (index + 1) % this->size;
+ probe++;
+
+ assert(index != origIndex);
+ }
+}
+
+void Hashtable_setSize(Hashtable* this, size_t size) {
+
+ assert(Hashtable_isConsistent(this));
+
+ if (size <= this->items)
+ return;
+
+ size_t newSize = nextPrime(size);
+ if (newSize == this->size)
+ return;
+
+ HashtableItem* oldBuckets = this->buckets;
+ size_t oldSize = this->size;
+
+ this->size = newSize;
+ this->buckets = (HashtableItem*) xCalloc(this->size, sizeof(HashtableItem));
+ this->items = 0;
+
+ /* rehash */
+ for (size_t i = 0; i < oldSize; i++) {
+ if (!oldBuckets[i].value)
+ continue;
+
+ insert(this, oldBuckets[i].key, oldBuckets[i].value);
+ }
+
+ free(oldBuckets);
+
+ assert(Hashtable_isConsistent(this));
+}
+
+void Hashtable_put(Hashtable* this, ht_key_t key, void* value) {
+
+ assert(Hashtable_isConsistent(this));
+ assert(this->size > 0);
+ assert(value);
+
+ /* grow on load-factor > 0.7 */
+ if (10 * this->items > 7 * this->size) {
+ if (SIZE_MAX / 2 < this->size)
+ CRT_fatalError("Hashtable: size overflow");
+
+ Hashtable_setSize(this, 2 * this->size);
+ }
+
+ insert(this, key, value);
+
+ assert(Hashtable_isConsistent(this));
+ assert(Hashtable_get(this, key) != NULL);
+ assert(this->size > this->items);
+}
+
+void* Hashtable_remove(Hashtable* this, ht_key_t key) {
+ size_t index = key % this->size;
+ size_t probe = 0;
+#ifndef NDEBUG
+ size_t origIndex = index;
+#endif
+
+ assert(Hashtable_isConsistent(this));
+
+ void* res = NULL;
+
+ while (this->buckets[index].value) {
+ if (this->buckets[index].key == key) {
+ if (this->owner) {
+ free(this->buckets[index].value);
+ } else {
+ res = this->buckets[index].value;
+ }
+
+ size_t next = (index + 1) % this->size;
+
+ while (this->buckets[next].value && this->buckets[next].probe > 0) {
+ this->buckets[index] = this->buckets[next];
+ this->buckets[index].probe -= 1;
+
+ index = next;
+ next = (index + 1) % this->size;
+ }
+
+ /* set empty after backward shifting */
+ this->buckets[index].value = NULL;
+ this->items--;
+
+ break;
+ }
+
+ if (this->buckets[index].probe < probe)
+ break;
+
+ index = (index + 1) % this->size;
+ probe++;
+
+ assert(index != origIndex);
+ }
+
+ assert(Hashtable_isConsistent(this));
+ assert(Hashtable_get(this, key) == NULL);
+
+ /* shrink on load-factor < 0.125 */
+ if (8 * this->items < this->size)
+ Hashtable_setSize(this, this->size / 3); /* account for nextPrime rounding up */
+
+ return res;
+}
+
+void* Hashtable_get(Hashtable* this, ht_key_t key) {
+ size_t index = key % this->size;
+ size_t probe = 0;
+ void* res = NULL;
+#ifndef NDEBUG
+ size_t origIndex = index;
+#endif
+
+ assert(Hashtable_isConsistent(this));
+
+ while (this->buckets[index].value) {
+ if (this->buckets[index].key == key) {
+ res = this->buckets[index].value;
+ break;
+ }
+
+ if (this->buckets[index].probe < probe)
+ break;
+
+ index = (index + 1) != this->size ? (index + 1) : 0;
+ probe++;
+
+ assert(index != origIndex);
+ }
+
+ return res;
+}
+
+void Hashtable_foreach(Hashtable* this, Hashtable_PairFunction f, void* userData) {
+ assert(Hashtable_isConsistent(this));
+ for (size_t i = 0; i < this->size; i++) {
+ HashtableItem* walk = &this->buckets[i];
+ if (walk->value)
+ f(walk->key, walk->value, userData);
+ }
+ assert(Hashtable_isConsistent(this));
+}