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TwoKeyAVLTree: Add FindFirstClosest()

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This commit is contained in:
Ingo Weinhold 2011-07-07 11:27:33 +02:00
parent 46368f46f3
commit a058fbe8a1
1 changed files with 89 additions and 22 deletions
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111
headers/private/kernel/util/TwoKeyAVLTree.h
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@ -279,6 +279,8 @@ public:
Value* FindFirst(const PrimaryKey& key,
Iterator* iterator = NULL);
Value* FindFirstClosest(const PrimaryKey& key,
bool less, Iterator* iterator = NULL);
Value* FindLast(const PrimaryKey& key,
Iterator* iterator = NULL);
inline Value* Find(const PrimaryKey& primaryKey,
@ -296,6 +298,10 @@ public:
const SecondaryKey& secondaryKey);
inline status_t Remove(Node* node);
private:
Node* _FindFirst(const PrimaryKey& key,
Node** _parent) const;
private:
TreeMap fTreeMap;
PrimaryKeyCompare fPrimaryKeyCompare;
@ -432,35 +438,58 @@ TWO_KEY_AVL_TREE_CLASS_NAME::FindFirst(const PrimaryKey& key,
Iterator* iterator)
{
const NodeStrategy& strategy = fTreeMap.GetNodeStrategy();
Node* node = fTreeMap.RootNode();
while (node) {
int cmp = fPrimaryKeyCompare(key, fGetPrimaryKey(
strategy.GetValue(node)));
if (cmp == 0) {
// found a matching node, now get the left-most node with that key
while (node->left && fPrimaryKeyCompare(key,
fGetPrimaryKey(strategy.GetValue(
strategy.GetNode(node->left)))) == 0) {
node = strategy.GetNode(node->left);
}
if (iterator)
iterator->_SetTo(fTreeMap.GetIterator(node));
return &strategy.GetValue(node);
}
Node* node = _FindFirst(key, NULL);
if (node == NULL)
return NULL;
if (cmp < 0)
node = strategy.GetNode(node->left);
else
node = strategy.GetNode(node->right);
}
return NULL;
if (iterator != NULL)
iterator->_SetTo(fTreeMap.GetIterator(node));
return &strategy.GetValue(node);
}
TWO_KEY_AVL_TREE_TEMPLATE_LIST
Value*
TWO_KEY_AVL_TREE_CLASS_NAME::FindLast(const PrimaryKey& key, Iterator* iterator)
TWO_KEY_AVL_TREE_CLASS_NAME::FindFirstClosest(const PrimaryKey& key, bool less,
Iterator* iterator)
{
const NodeStrategy& strategy = fTreeMap.GetNodeStrategy();
Node* parent;
Node* node = _FindFirst(key, &parent);
if (node == NULL) {
// not found -- try to get the closest node
if (parent == NULL)
return NULL;
node = parent;
int expectedCmp = less ? 1 : -1;
int cmp = fPrimaryKeyCompare(key,
fGetPrimaryKey(strategy.GetValue(strategy.GetNode(node))));
if (cmp != expectedCmp) {
// The node's value is less although we were asked for a greater
// value, or the other way around. We need to iterate to the next
// node in the respective direction. If there is no node, we fail.
node = less ? Previous(node) : Next(node);
if (node == NULL)
return NULL;
}
}
if (iterator != NULL)
iterator->_SetTo(fTreeMap.GetIterator(node));
return &strategy.GetValue(node);
}
TWO_KEY_AVL_TREE_TEMPLATE_LIST
Value*
TWO_KEY_AVL_TREE_CLASS_NAME::FindLast(const PrimaryKey& key,
Iterator* iterator)
{
const NodeStrategy& strategy = fTreeMap.GetNodeStrategy();
Node* node = fTreeMap.RootNode();
@ -565,4 +594,42 @@ TWO_KEY_AVL_TREE_CLASS_NAME::Remove(Node* node)
}
TWO_KEY_AVL_TREE_TEMPLATE_LIST
TWO_KEY_AVL_TREE_CLASS_NAME::Node*
TWO_KEY_AVL_TREE_CLASS_NAME::_FindFirst(const PrimaryKey& key,
Node** _parent) const
{
const NodeStrategy& strategy = fTreeMap.GetNodeStrategy();
Node* node = fTreeMap.RootNode();
Node* parent = NULL;
while (node) {
int cmp = fPrimaryKeyCompare(key, fGetPrimaryKey(
strategy.GetValue(node)));
if (cmp == 0) {
// found a matching node, now get the left-most node with that key
while (node->left && fPrimaryKeyCompare(key,
fGetPrimaryKey(strategy.GetValue(
strategy.GetNode(node->left)))) == 0) {
node = strategy.GetNode(node->left);
}
return node;
}
parent = node;
if (cmp < 0)
node = strategy.GetNode(node->left);
else
node = strategy.GetNode(node->right);
}
if (_parent != NULL)
*_parent = parent;
return NULL;
}
#endif // _KERNEL_UTIL_TWO_KEY_AVL_TREE_H