From 91a3c28862a5a96b08a81c38539dba0bc41bb1ee Mon Sep 17 00:00:00 2001
From: Arseny Kapoulkine <arseny.kapoulkine@gmail.com>
Date: Mon, 13 Nov 2017 08:37:34 -0800
Subject: [PATCH] Add count argument to compact_hash_table::rehash/reserve
This allows us to do a single reserve for a known amount of assignments
that is larger than the default minimum per reserve (16).
---
src/pugixml.cpp | 22 +++++++++++++---------
1 file changed, 13 insertions(+), 9 deletions(-)
diff --git a/src/pugixml.cpp b/src/pugixml.cpp
index 554d8df8..8f83619b 100644
--- a/src/pugixml.cpp
+++ b/src/pugixml.cpp
@@ -327,10 +327,10 @@ PUGI__NS_BEGIN
item->value = value;
}
- bool reserve()
+ bool reserve(size_t extra = 16)
{
- if (_count + 16 >= _capacity - _capacity / 4)
- return rehash();
+ if (_count + extra >= _capacity - _capacity / 4)
+ return rehash(_count + extra);
return true;
}
@@ -347,7 +347,7 @@ PUGI__NS_BEGIN
size_t _count;
- bool rehash();
+ bool rehash(size_t count);
item_t* get_item(const void* key)
{
@@ -387,16 +387,20 @@ PUGI__NS_BEGIN
}
};
- PUGI__FN_NO_INLINE bool compact_hash_table::rehash()
+ PUGI__FN_NO_INLINE bool compact_hash_table::rehash(size_t count)
{
+ size_t capacity = 32;
+ while (count >= capacity - capacity / 4)
+ capacity *= 2;
+
compact_hash_table rt;
- rt._capacity = (_capacity == 0) ? 32 : _capacity * 2;
- rt._items = static_cast<item_t*>(xml_memory::allocate(sizeof(item_t) * rt._capacity));
+ rt._capacity = capacity;
+ rt._items = static_cast<item_t*>(xml_memory::allocate(sizeof(item_t) * capacity));
if (!rt._items)
return false;
- memset(rt._items, 0, sizeof(item_t) * rt._capacity);
+ memset(rt._items, 0, sizeof(item_t) * capacity);
for (size_t i = 0; i < _capacity; ++i)
if (_items[i].key)
@@ -405,7 +409,7 @@ PUGI__NS_BEGIN
if (_items)
xml_memory::deallocate(_items);
- _capacity = rt._capacity;
+ _capacity = capacity;
_items = rt._items;
assert(_count == rt._count);
--
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