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From 2b9bd55356616b24b6f01e11280de2c9b09237e9 Mon Sep 17 00:00:00 2001
From: Justus Winter <justus@gnupg.org>
Date: Thu, 28 Apr 2016 20:11:27 +0200
Subject: [PATCH hurd 1/2] libihash: keep track of free slots
* libihash/ihash.c (hurd_ihash_init): Init new field 'nr_free'.
(add_one): Decrement counter if a free slot is used.
(hurd_ihash_locp_add): Likewise.
(hurd_ihash_add): Reset counter on reallocation.
* libihash/ihash.h (struct hurd_ihash): New field 'nr_free'.
(hurd_ihash_get_effective_load): New function.
---
libihash/ihash.c | 5 +++++
libihash/ihash.h | 11 +++++++++++
2 files changed, 16 insertions(+)
diff --git a/libihash/ihash.c b/libihash/ihash.c
index 4bc54fd..66175ca 100644
--- a/libihash/ihash.c
+++ b/libihash/ihash.c
@@ -136,6 +136,7 @@ hurd_ihash_init (hurd_ihash_t ht, intptr_t locp_offs)
ht->cleanup = 0;
ht->fct_hash = NULL;
ht->fct_cmp = NULL;
+ ht->nr_free = 0;
}
@@ -251,6 +252,8 @@ add_one (hurd_ihash_t ht, hurd_ihash_key_t key, hurd_ihash_value_t value)
if (index_empty (ht, idx))
{
ht->nr_items++;
+ if (ht->items[idx].value == _HURD_IHASH_EMPTY)
+ ht->nr_free--;
ht->items[idx].value = value;
ht->items[idx].key = key;
@@ -295,6 +298,7 @@ hurd_ihash_locp_add (hurd_ihash_t ht, hurd_ihash_locp_t locp,
{
item->key = key;
ht->nr_items += 1;
+ ht->nr_free -= 1;
}
else
{
@@ -340,6 +344,7 @@ hurd_ihash_add (hurd_ihash_t ht, hurd_ihash_key_t key, hurd_ihash_value_t item)
ht->size = HURD_IHASH_MIN_SIZE;
else
ht->size <<= 1;
+ ht->nr_free = ht->size;
/* calloc() will initialize all values to _HURD_IHASH_EMPTY implicitly. */
ht->items = calloc (ht->size, sizeof (struct _hurd_ihash_item));
diff --git a/libihash/ihash.h b/libihash/ihash.h
index 356f647..80679f1 100644
--- a/libihash/ihash.h
+++ b/libihash/ihash.h
@@ -113,6 +113,9 @@ struct hurd_ihash
/* User-supplied functions for the generalized key interface. */
hurd_ihash_fct_hash_t fct_hash;
hurd_ihash_fct_cmp_t fct_cmp;
+
+ /* Number of free slots. */
+ size_t nr_free;
};
typedef struct hurd_ihash *hurd_ihash_t;
@@ -225,6 +228,14 @@ hurd_ihash_get_load (hurd_ihash_t ht)
return d >= 0 ? ht->nr_items >> d : ht->nr_items << -d;
}
+/* Similar, but counts tombstones as well. */
+static inline unsigned int
+hurd_ihash_get_effective_load (hurd_ihash_t ht)
+{
+ int d = __builtin_ctzl (ht->size) - 7;
+ return
+ d >= 0 ? (ht->size - ht->nr_free) >> d : (ht->size - ht->nr_free) << -d;
+}
/* Add ITEM to the hash table HT under the key KEY. If there already
is an item under this key, call the cleanup function (if any) for
--
2.1.4
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