From c1563337ae366ca66f25ed71a2f462a486df1337 Mon Sep 17 00:00:00 2001
From: Benny Baumann <BenBE@geshi.org>
Date: Sun, 29 Nov 2020 14:54:10 +0100
Subject: [PATCH] Implement Hashtable_clear to empty an existing Hashtable

---
 Hashtable.c | 22 +++++++++++++++-------
 Hashtable.h |  2 ++
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/Hashtable.c b/Hashtable.c
index c03723a1..cd48fc46 100644
--- a/Hashtable.c
+++ b/Hashtable.c
@@ -98,23 +98,31 @@ Hashtable* Hashtable_new(unsigned int size, bool owner) {
    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) {
-
-   assert(Hashtable_isConsistent(this));
-
-   if (this->owner) {
-      for (unsigned int i = 0; i < this->size; i++)
-         free(this->buckets[i].value);
-   }
+   Hashtable_clear(this);
 
    free(this->buckets);
    free(this);
 }
 
+void Hashtable_clear(Hashtable* this) {
+   assert(Hashtable_isConsistent(this));
+
+   if (this->owner)
+      for (unsigned int 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, hkey_t key, void* value) {
    unsigned int index = key % this->size;
    unsigned int probe = 0;
diff --git a/Hashtable.h b/Hashtable.h
index f7d1aae2..6d934784 100644
--- a/Hashtable.h
+++ b/Hashtable.h
@@ -37,6 +37,8 @@ Hashtable* Hashtable_new(unsigned int size, bool owner);
 
 void Hashtable_delete(Hashtable* this);
 
+void Hashtable_clear(Hashtable* this);
+
 void Hashtable_setSize(Hashtable* this, unsigned int size);
 
 void Hashtable_put(Hashtable* this, hkey_t key, void* value);