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[btree] Implement btree::remove()

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This commit is contained in:
Ming-Hung Tsai
2020-06-04 16:31:24 +08:00
parent ef8e94b22c
commit e724a72045
3 changed files with 572 additions and 7 deletions
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98
persistent-data/data-structures/btree.h
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@ -110,12 +110,34 @@ namespace persistent_data {
uint64_t key,
typename ValueTraits::value_type const &v);
// Decrements the nr_entries field
void delete_at(unsigned i);
// Copies entries from another node, appends them
// to the back of this node. Adjusts nr_entries.
void copy_entries(node_ref const &rhs,
unsigned begin,
unsigned end);
// Moves entries between the sibling node,
// and maintains the key ordering.
// The nr_entreis of both nodes are adjusted.
void move_entries(node_ref &rhs,
int count);
// Copies entries from the beginning of rhs to the end of lhs,
// or copies entries from the end of lhs to the beginning of rhs.
// The nr_entries is not adjusted.
void copy_entries_to_left(node_ref const &rhs, unsigned count);
void copy_entries_to_right(node_ref &rhs, unsigned count) const;
// Shifts entries to left or right.
// The nr_entries is not adjusted.
void shift_entries_left(unsigned shift);
void shift_entries_right(unsigned shift);
unsigned merge_threshold() const;
// Various searches
int bsearch(uint64_t key, int want_hi) const;
boost::optional<unsigned> exact_search(uint64_t key) const;
@ -259,6 +281,26 @@ namespace persistent_data {
maybe_block root_;
};
class shadow_child {
public:
shadow_child(block_manager::write_ref &wr, node_type type)
: wr_(wr), type_(type) {
}
node_type get_type() const {
return type_;
}
template <typename ValueTraits>
node_ref<ValueTraits> get_node() {
return to_node<ValueTraits>(wr_);
}
private:
block_manager::write_ref wr_;
node_type type_;
};
// Used to keep a record of a nested btree's position.
typedef std::vector<uint64_t> btree_path;
@ -399,6 +441,14 @@ namespace persistent_data {
int *index,
RC &leaf_rc);
template <typename ValueTraits2, typename RC>
bool
remove_location(btree_detail::shadow_spine &spine,
block_address block,
uint64_t key,
unsigned *index,
RC &leaf_rc);
void walk_tree(visitor &visitor,
btree_detail::node_location const &loc,
block_address b) const;
@ -411,6 +461,53 @@ namespace persistent_data {
void inc_children(btree_detail::shadow_spine &spine,
RefCounter &leaf_rc);
btree_detail::shadow_child
create_shadow_child(internal_node &parent,
unsigned index);
template <typename ValueTraits2>
bool rebalance_children(btree_detail::shadow_spine &spine,
uint64_t key);
template <typename ValueTraits2>
void rebalance2(btree_detail::shadow_spine &spine,
unsigned left_index);
template <typename ValueTraits2>
void rebalance3(btree_detail::shadow_spine &spine,
unsigned left_index);
template <typename ValueTraits2>
void
__rebalance2(internal_node &parent,
btree_detail::node_ref<ValueTraits2> &left,
btree_detail::node_ref<ValueTraits2> &right,
unsigned left_index);
template <typename ValueTraits2>
void
__rebalance3(internal_node &parent,
btree_detail::node_ref<ValueTraits2> &left,
btree_detail::node_ref<ValueTraits2> &center,
btree_detail::node_ref<ValueTraits2> &right,
unsigned left_index);
template <typename ValueTraits2>
void
delete_center_node(internal_node &parent,
btree_detail::node_ref<ValueTraits2> &left,
btree_detail::node_ref<ValueTraits2> &center,
btree_detail::node_ref<ValueTraits2> &right,
unsigned left_index);
template <typename ValueTraits2>
void
redistribute3(internal_node &parent,
btree_detail::node_ref<ValueTraits2> &left,
btree_detail::node_ref<ValueTraits2> &center,
btree_detail::node_ref<ValueTraits2> &right,
unsigned left_index);
transaction_manager &tm_;
bool destroy_;
block_address root_;
@ -421,6 +518,7 @@ namespace persistent_data {
};
#include "btree.tcc"
#include "btree-remove.tcc"
//----------------------------------------------------------------