xo-reader2/include/xo/ordinaltree/bplustree/InternalNode.hpp

768 lines
33 KiB
C++

/* @file InternalNode.hpp */
#pragma once
#include "GenericNode.hpp"
#include "xo/indentlog/scope.hpp"
#include "xo/indentlog/print/tostr.hpp"
#include <cassert>
namespace xo {
namespace tree {
// ----- InternalNodeItem ------
/* see also: NodeItem<NodeType::leaf, Key, Value, Properties> */
template <typename Key, typename Value, typename Properties>
struct NodeItem<NodeType::internal, Key, Value, Properties> {
using GenericNodeType = GenericNode<Key, Value, Properties>;
public:
NodeItem() = default;
explicit NodeItem(std::unique_ptr<GenericNodeType> child)
: child_{std::move(child)} {
if (child_)
this->key_ = child_->glb_key();
}
Key const & key() const { return key_; }
GenericNodeType * child() const { return child_.get(); }
std::unique_ptr<GenericNodeType> release_child() { return std::move(child_); }
void set_key(Key key) { key_ = std::move(key); }
void notify_remove() {
if (child_)
child_->notify_remove();
} /*notify_remove*/
private:
/* invariant: .key is leftmost key in subtree rooted at .child
* (i.e. greatest lower bound for keys in that subtree)
*/
Key key_;
/* subtree. subtree has minimum key value .key */
std::unique_ptr<GenericNodeType> child_;
}; /*NodeItem */
template <typename Key, typename Value, typename Properties>
using InternalNodeItem = NodeItem<NodeType::internal, Key, Value, Properties>;
/* struct with same size as InternalNodeItem<Key,Properties>, but POD + with no ctor/dtor */
template <typename Key, typename Value, typename Properties>
using InternalNodeItemPlaceholder = NodeItemPlaceholder<NodeType::internal, Key, Value, Properties>;
/* default implements tags::ordinal_disabled; see partial specialization below for ordinal_enabled */
template <typename Key, typename Value, typename Properties, tags::ordinal_tag OrdinalTag = Properties::ordinal_tag_value()>
struct InternalNodeShim : public GenericNode<Key, Value, Properties> {
public:
using GenericNodeType = GenericNode<Key, Value, Properties>;
public:
InternalNodeShim(NodeType ntype, std::size_t branching_factor) : GenericNode<Key, Value, Properties>{ntype, branching_factor} {}
protected:
/* not implemented with tags::ordinal_disabled */
void assign_size(std::size_t z) {}
};
template <typename Key, typename Value, typename Properties>
struct InternalNodeShim<Key, Value, Properties, tags::ordinal_enabled> : public GenericNode<Key, Value, Properties> {
public:
using GenericNodeType = GenericNode<Key, Value, Properties>;
public:
InternalNodeShim(NodeType ntype, std::size_t branching_factor) : GenericNode<Key, Value, Properties>{ntype, branching_factor} {}
void clear_size() { this->size_ = 0; }
void add_size(std::size_t z) { this->size_ += z; }
void sub_size(std::size_t z) { this->size_ -= z; }
virtual std::size_t size() const override { return size_; }
protected:
void assign_size(std::size_t z) { this->size_ = z; }
protected:
std::size_t size_ = 0;
}; /*InternalNodeShim*/
/* require:
* - Properties.branching_factor()
*/
template <typename Key, typename Value, typename Properties>
struct InternalNode : public InternalNodeShim<Key, Value, Properties> {
public:
using GenericNodeType = GenericNode<Key, Value, Properties>;
using InternalNodeType = InternalNode<Key, Value, Properties>;
using LeafNodeType = LeafNode<Key, Value, Properties>;
using InternalNodeItemPlaceholderType = InternalNodeItemPlaceholder<Key, Value, Properties>;
using InternalNodeItemType = InternalNodeItem<Key, Value, Properties>;
public:
virtual ~InternalNode();
/* node size in bytes (increases with branching factor) */
static std::size_t node_sizeof(std::size_t branching_factor);
/* use when splitting root node for the first time;
* new root node will be leaf->internal.
*
* require: child_1, child_2 are non-empty
*/
static std::unique_ptr<InternalNode> make_2(std::unique_ptr<GenericNodeType> child_1,
std::unique_ptr<GenericNodeType> child_2);
/* Before:
*
* m = mid_ix
* n = src.n_elt - 1
* xa @ [m-1]
* xb @ [m]
* xz @ [n-1]
*
* src.elt_v[]
*
* 0 m-1 m n-1
* +----+-...-+----+----+-...-+----+
* | x0 | ... | xa | xb | ... | xz |
* +----+-...-+----+----+-...-+----+
*
* <----------- n items ----------->
*
* After:
*
* src.elt_v[] new_node.elt_v[]
*
* n-m-1
* 0 m-1 0 v
* +----+-...-+----+ +----+-...-+----+
* | x0 | ... | xa | | xb | | xz |
* +----+-...-+----+ +----+-...-+----+
*
* <--- m items ---> <-- n-m items -->
*/
static std::unique_ptr<InternalNode> annex(std::size_t mid_ix,
InternalNode * src);
/* .elt_v[]
*
* 0 k n-1 with: n <= b = branching factor
* +---+---+- ... -+---+- ... -+---+---+ k = lub(key) in {e1..en}
* | e1| e2| | ek| | | en|
* +---+---+- ... -+---+- ... -+---+---+
*
* retval.first: true if key already present in tree. implies lub_ix_recd.second >= 1
* retval.second: upper bound (strict) index position in .elt_v[] of key
*
* Cost: O(log(bf)) key comparisons
*/
std::size_t find_lub_ix(Key const & key) const;
/* warning: requires key is present! */
std::size_t find_ix(Key const & key) const { return this->find_lub_ix(key) - 1; }
/* O(bf), but does not rely on key invariants. */
std::size_t locate_child_by_address(GenericNodeType const * target_child) const;
InternalNodeItemType & lookup_elt(std::size_t i) { return *(reinterpret_cast<InternalNodeItemType *>(&(elt_v_[i]))); }
InternalNodeItemType const & lookup_elt(std::size_t i) const { return *(reinterpret_cast<InternalNodeItemType const *>(&(elt_v_[i]))); }
FindNodeResult<GenericNodeType> find_child(Key const & key);
/* insert node at position ix; moving items starting in .elt_v[ix] one slot to the right */
void insert_node(std::size_t ix, std::unique_ptr<GenericNodeType> child, bool debug_flag);
/* remove node at position ix; moving items starting .elt_v[ix+1] one slot to the left;
* if target is a leaf node, also remove from prev_leafnode/next_leafnode list
*/
void remove_node(std::size_t ix, bool debug_flag);
/* redistribute last n items from left-hand sibling lh to this internal node */
void prepend_from_lh_sibling(InternalNode * lh, std::size_t n, bool debug_flag);
/* redistribute first n items from right-hand sibling rh to this internal node */
void append_from_rh_sibling(std::size_t n, InternalNode * rh);
void append_rh_sibling(InternalNode * rh) { this->append_from_rh_sibling(rh->n_elt(), rh); }
/* returns new node with upper half of original element vector (i.e. of this.elt_v[]);
* original updated to retain lower half
*/
std::unique_ptr<InternalNode> split_internal();
void set_glb_key(Key key) { this->lookup_elt(0).set_key(key); }
/* memory for InternalNode instances is always created using new[],
* so required to use delete[] to deallocate
*/
void operator delete (void * mem) noexcept { ::operator delete[](mem); }
// ----- inherited from GenericNode -----
virtual Key const & glb_key() const override { return this->lookup_elt(0).key(); }
virtual std::size_t verify_helper(InternalNode const * parent,
bool with_lub_flag,
Key const & lub_key,
LeafNodeType const * lh_leaf,
LeafNodeType const * rh_leaf) const override;
virtual void verify_glb_key(Key const & key) const override;
/* find in subtree_arg the leftmost leaf node (i.e. leaf node with smallest key) */
virtual FindNodeResult<LeafNodeType> find_min_leaf_node() override;
/* find in subtree_arg the rightmost leaf node (i.e. leaf node with largest key) */
virtual FindNodeResult<LeafNodeType> find_max_leaf_node() override;
private:
explicit InternalNode(std::size_t branching_factor);
private:
#ifdef OBSOLETE
/* total #of elements in this subtree */
std::size_t size_ = 0;
#endif
/* flexible array; actual size will be .branching_factor().
*
* .elt_v[i] is created/destroyed as an InternalNodeItemType with non-trivial ctor/dtor.
* we must declare member using POD placeholder to satisfy flexible array rules
*
* invariant:
* - with branching factor b, so range for .elt_v[] is 0 .. b-1:
* - .elt_v[j].child.ptr is null -> {.elt_v[j+1].child.ptr .. .elt_v[b-1].child.ptr} are also null
*/
InternalNodeItemPlaceholderType elt_v_[];
}; /*InternalNode*/
template <typename Key, typename Value, typename Properties>
InternalNode<Key, Value, Properties>::~InternalNode() {
/* since we're using flexible array for .elt_v[], need to manually run destructors */
for (std::size_t i=0, n=this->branching_factor_; i<n; ++i) {
this->lookup_elt(i).~InternalNodeItemType();
}
/* hygiene */
BplusTreeUtil<Key, Value, Properties>::node_clear_size(this);
this->n_elt_ = 0;
this->branching_factor_ = 0;
} /*dtor*/
template <typename Key, typename Value, typename Properties>
std::size_t
InternalNode<Key, Value, Properties>::node_sizeof(std::size_t branching_factor) {
return (sizeof(InternalNode)
+ (branching_factor
* sizeof(InternalNodeItemType)));
} /*node_sizeof*/
template <typename Key, typename Value, typename Properties>
std::unique_ptr<InternalNode<Key, Value, Properties>>
InternalNode<Key, Value, Properties>::make_2(std::unique_ptr<GenericNodeType> child_1,
std::unique_ptr<GenericNodeType> child_2) {
std::size_t branching_factor = child_1->branching_factor();
std::size_t mem_z = node_sizeof(branching_factor);
std::uint8_t * mem = new std::uint8_t[mem_z];
assert(child_1->n_elt() > 0);
assert(child_2->n_elt() > 0);
std::unique_ptr<InternalNode> retval(new (mem) InternalNode(branching_factor));
child_1->set_parent(retval.get());
child_2->set_parent(retval.get());
retval->assign_size(BplusTreeUtil<Key, Value, Properties>::get_node_size(child_1.get())
+ BplusTreeUtil<Key, Value, Properties>::get_node_size(child_2.get()));
retval->n_elt_ = 2;
retval->lookup_elt(0) = std::move(InternalNodeItemType(std::move(child_1)));
retval->lookup_elt(1) = std::move(InternalNodeItemType(std::move(child_2)));
return retval;
} /*make_2*/
template <typename Key, typename Value, typename Properties>
std::unique_ptr<InternalNode<Key, Value, Properties>>
InternalNode<Key, Value, Properties>::annex(std::size_t mid_ix,
InternalNode * src)
{
std::size_t branching_factor = src->branching_factor();
std::size_t mem_z = node_sizeof(branching_factor);
std::uint8_t * mem = new std::uint8_t[mem_z];
std::unique_ptr<InternalNode> new_node(new (mem) InternalNode(branching_factor));
std::size_t hi_ix = src->n_elt();
new_node->n_elt_ = hi_ix - mid_ix;
std::size_t annex_z = 0;
/* annexing upper-half of *src into new_node */
for (std::size_t i = 0, n = hi_ix - mid_ix; i < n; ++i) {
InternalNodeItemType & src_slot = src->lookup_elt(mid_ix + i);
InternalNodeItemType & new_slot = new_node->lookup_elt(i);
annex_z += BplusTreeUtil<Key, Value, Properties>::get_node_size(src_slot.child());
new_slot = std::move(src->lookup_elt(mid_ix + i));
new_slot.child()->set_parent(new_node.get());
}
new_node->assign_size(annex_z);
/* ordinal_disabled: noop
* ordinal_enabled: bookkeeping for src.size (+ new_node.size, see above)
*/
src->assign_size(BplusTreeUtil<Key, Value, Properties>::get_node_size(src) - annex_z);
src->n_elt_ = mid_ix;
return new_node;
} /*annex*/
template <typename Key, typename Value, typename Properties>
std::size_t
InternalNode<Key, Value, Properties>::find_lub_ix(Key const & key) const {
if (key < this->lookup_elt(0).key())
return 0;
std::size_t lo = 0;
std::size_t hi = this->n_elt_;
while (lo + 1 < hi) {
std::size_t mid = lo + (hi - lo) / 2;
if (key < this->lookup_elt(mid).key())
hi = mid;
else
lo = mid;
}
return hi;
} /*find_lub_ix*/
template <typename Key, typename Value, typename Properties>
std::size_t
InternalNode<Key, Value, Properties>::locate_child_by_address(GenericNodeType const * target_child) const {
for (std::size_t ix = 0; ix < this->n_elt_; ++ix) {
if (this->lookup_elt(ix).child() == target_child)
return ix;
}
return static_cast<std::size_t>(-1);
} /*locate_child_by_address*/
template <typename Key, typename Value, typename Properties>
FindNodeResult<LeafNode<Key, Value, Properties>>
InternalNode<Key, Value, Properties>::find_min_leaf_node() {
FindNodeResult<GenericNodeType> findresult(0, this);
while (findresult.node() && (findresult.node()->node_type() == NodeType::internal)) {
std::size_t min_ix = 0;
findresult = FindNodeResult<GenericNodeType>(min_ix,
(reinterpret_cast<InternalNodeType *>(findresult.node()))
->lookup_elt(min_ix /*leftmost child*/).child());
}
/* findresult.node()->node_type() == NodeType::leaf (if non-null) */
if (!findresult.node()) {
assert(false);
return FindNodeResult<LeafNodeType>();
}
assert(findresult.node()->node_type() == NodeType::leaf);
return FindNodeResult<LeafNodeType>(findresult.ix(),
reinterpret_cast<LeafNodeType *>(findresult.node()));
} /*find_min_leaf_node*/
template <typename Key, typename Value, typename Properties>
FindNodeResult<LeafNode<Key, Value, Properties>>
InternalNode<Key, Value, Properties>::find_max_leaf_node() {
FindNodeResult<GenericNodeType> findresult(0, this);
while (findresult.node() && (findresult.node()->node_type() == NodeType::internal)) {
std::size_t max_ix = findresult.node()->n_elt() - 1;
findresult = FindNodeResult<GenericNodeType>
(max_ix,
(reinterpret_cast<InternalNodeType *>(findresult.node()))
->lookup_elt(max_ix /*rightmost child*/).child());
}
/* findresult.node()->node_type() == NodeType::leaf (if non-null) */
if (!findresult.node()) {
assert(false);
return FindNodeResult<LeafNodeType>();
}
assert(findresult.node()->node_type() == NodeType::leaf);
return FindNodeResult<LeafNodeType>(findresult.ix(),
reinterpret_cast<LeafNodeType *>(findresult.node()));
} /*find_max_leaf_node*/
template <typename Key, typename Value, typename Properties>
FindNodeResult<GenericNode<Key, Value, Properties>>
InternalNode<Key, Value, Properties>::find_child(Key const & key) {
std::size_t lub_ix = this->find_lub_ix(key);
if (lub_ix > 0)
--lub_ix;
return FindNodeResult<GenericNodeType>(lub_ix, this->lookup_elt(lub_ix).child());
} /*find_child*/
template <typename Key, typename Value, typename Properties>
void
InternalNode<Key, Value, Properties>::insert_node(std::size_t ix, std::unique_ptr<GenericNodeType> child, bool debug_flag)
{
using xo::scope;
using xo::tostr;
using xo::xtag;
scope log(XO_DEBUG(debug_flag),
xtag("self", this),
xtag("n_elt", this->n_elt()),
xtag("bf", this->branching_factor()),
xtag("ix", ix),
xtag("child", child.get()));
if (this->n_elt_ >= this->branching_factor()) {
assert(false);
throw std::runtime_error(tostr("InternalNode::insert_node: node already full",
xtag("node.n_elt", this->n_elt()),
xtag("branching_factor", this->branching_factor())));
}
if (ix > this->n_elt_) {
assert(false);
throw std::runtime_error(tostr("InternalNode::insert_node: insert position out of range",
xtag("ix", ix),
xtag("node.n_elt", this->n_elt()),
xtag("bf", this->branching_factor())));
}
std::size_t pos_ix = this->n_elt_;
while (pos_ix > ix) {
this->lookup_elt(pos_ix) = std::move(this->lookup_elt(pos_ix - 1));
--pos_ix;
}
/* WARNING: don't update .size here
* in practice we use .insert_node() when introducing a single new key/value pair;
* when we use .insert_node() we split an existing node,
* and actually just want to increment .size.
*
* We leave this to caller (e.g. BplusTree.internal_insert_aux())
* because in that context can see the upstream split
*/
// this->size_ += child->n_elt();
++(this->n_elt_);
child->set_parent(this);
this->lookup_elt(ix) = InternalNodeItemType(std::move(child));
} /*insert_node*/
template <typename Key, typename Value, typename Properties>
void
InternalNode<Key, Value, Properties>::remove_node(std::size_t ix, bool debug_flag) {
using xo::scope;
using xo::tostr;
using xo::xtag;
scope log(XO_DEBUG(debug_flag),
xtag("self", this),
xtag("n_elt", this->n_elt()),
xtag("bf", this->branching_factor()),
xtag("ix", ix));
if (ix >= this->n_elt_) {
assert(false);
throw std::runtime_error(tostr("InternalNode::remove_node: target position out of range",
xtag("ix", ix),
xtag("node.n_elt", this->n_elt()),
xtag("bf", this->branching_factor())));
}
std::size_t pos_ix = ix;
std::size_t end_ix = this->n_elt_ - 1;
{
InternalNodeItemType & target_item = this->lookup_elt(pos_ix);
/* WARNING: don't update .size here
* in practice we use .remove_node() when deleting a single new key/value pair;
* when we use .remove_node() we merge existing nodes,
* and actually just want to decrement .size.
*
* We leave this to caller (e.g. BplusTree.internal_remove_aux())
* because in that context can see the upstream merge
*/
//this->size_ -= target_item.child()->size();
target_item.notify_remove();
}
while (pos_ix < end_ix) {
//scope x1("loop", debug_flag);
//x1(xtag("pos_ix", pos_ix));
this->lookup_elt(pos_ix) = std::move(this->lookup_elt(pos_ix + 1));
++pos_ix;
}
--(this->n_elt_);
} /*remove_node*/
template <typename Key, typename Value, typename Properties>
void
InternalNode<Key, Value, Properties>::prepend_from_lh_sibling(InternalNode * lh, std::size_t n, bool debug_flag) {
using xo::scope;
using xo::xtag;
scope log(XO_DEBUG(debug_flag),
xtag("@", this), xtag("n", n));
if (this->n_elt() + n > this->branching_factor()) {
assert(false);
throw std::runtime_error(tostr("InternalNode.prepend_from_lh_sibling: expected combined #elt <= bf",
xtag("self.n_elt", this->n_elt()),
xtag("n", n),
xtag("bf", this->branching_factor())));
}
std::size_t n_lh = lh->n_elt();
std::size_t n_rh = this->n_elt();
/* move elts in *this to the right n steps (starting from the end) */
for (std::size_t ixp1 = this->n_elt(); ixp1 > 0; --ixp1) {
std::size_t ix = ixp1 - 1;
//x.log("move", xtag("ix", ix), xtag("ix+n", ix+n));
this->lookup_elt(ix + n) = std::move(this->lookup_elt(ix));
}
std::size_t xfer_z = 0;
/* xfer n elts from upper end of lh, to lower end of *this */
for (std::size_t ix = 0; ix < n; ++ix) {
//x.log("fill", xtag("ix", ix), xtag("n_lh-n+ix", n_lh - n + ix));
InternalNodeItemType & lh_sibling_item = lh->lookup_elt(n_lh - n + ix);
xfer_z += BplusTreeUtil<Key, Value, Properties>::get_node_size(lh_sibling_item.child());
this->lookup_elt(ix) = std::move(lh_sibling_item);
/* + fixup parent pointer */
this->lookup_elt(ix).child()->set_parent(this);
}
BplusTreeUtil<Key, Value, Properties>::node_add_size(this, xfer_z);
BplusTreeUtil<Key, Value, Properties>::node_sub_size(lh, xfer_z);
this->n_elt_ += n;
lh->n_elt_ -= n;
log && log(xtag("this.glb_key", this->glb_key()),
xtag("this[0].key", this->lookup_elt(0).key()));
log.end_scope();
} /*prepend_from_lh_sibling*/
template <typename Key, typename Value, typename Properties>
void
InternalNode<Key, Value, Properties>::append_from_rh_sibling(std::size_t n, InternalNode * rh) {
using xo::xtag;
if (this->n_elt() + n > this->branching_factor()) {
assert(false);
throw std::runtime_error(tostr("InternalNode.append_from_rh_sibling: expected combined #elt <= bf",
xtag("self.n_elt", this->n_elt()),
xtag("n", n),
xtag("bf", this->branching_factor())));
}
std::size_t n_lh = this->n_elt();
std::size_t xfer_z = 0;
for (std::size_t ix = 0; ix < n; ++ix) {
InternalNodeItemType & rh_sibling_item = rh->lookup_elt(ix);
xfer_z += BplusTreeUtil<Key, Value, Properties>::get_node_size(rh_sibling_item.child());
this->lookup_elt(n_lh + ix) = std::move(rh_sibling_item);
/* + fixup parent pointer */
this->lookup_elt(n_lh + ix).child()->set_parent(this);
}
BplusTreeUtil<Key, Value, Properties>::node_add_size(this, xfer_z);
this->n_elt_ += n;
/* shuffle remaining members of rh sibling n items to the left */
for (std::size_t ix = 0; ix < rh->n_elt() - n; ++ix) {
rh->lookup_elt(ix) = std::move(rh->lookup_elt(ix + n));
}
BplusTreeUtil<Key, Value, Properties>::node_sub_size(rh, xfer_z);
rh->n_elt_ -= n;
} /*append_from_rh_sibling*/
template <typename Key, typename Value, typename Properties>
std::unique_ptr<InternalNode<Key, Value, Properties>>
InternalNode<Key, Value, Properties>::split_internal() {
std::size_t n_elt = this->n_elt_;
std::size_t mid_ix = n_elt / 2;
return InternalNode::annex(mid_ix, this);
} /*split_internal*/
template <typename Key, typename Value, typename Properties>
std::size_t
InternalNode<Key, Value, Properties>::verify_helper(InternalNode const * parent,
bool with_lub_flag,
Key const & lub_key,
LeafNodeType const * lh_leaf,
LeafNodeType const * rh_leaf) const
{
using xo::tostr;
using xo::xtag;
std::size_t retval = 0;
/* verify immediate parent pointer is correct */
if (this->parent() != parent) {
throw std::runtime_error(tostr("InternalNode::verify_helper"
": expected parent pointer to refer to actual parent",
xtag("stored_parent", this->parent()),
xtag("actual_parent", parent)));
}
std::size_t n = this->n_elt_;
/* verify all children have same NodeType (either all= internal or all= leaf) */
NodeType target_child_node_type = NodeType::leaf;
if (n > 0)
target_child_node_type = this->lookup_elt(0).child()->node_type();
LeafNodeType const * prev_lh_leaf = lh_leaf;
for (std::size_t i=0; i < n; ++i) {
/* check consistent node type */
NodeType i_nodetype = this->lookup_elt(i).child()->node_type();
if ((i > 0) && (i_nodetype != target_child_node_type)) {
throw std::runtime_error(tostr("InternalNode::verify_helper"
": expected all children to share the same node type",
xtag("i", i),
xtag("elt[0].node_type", target_child_node_type),
xtag("elt[i].node_type", i_nodetype)));
}
/* nested verify on child subtrees */
InternalNodeItemType const & i_elt = this->lookup_elt(i);
LeafNodeType const * next_lh_leaf = ((i+1 < n)
? this->lookup_elt(i+1).child()->find_min_leaf_node().node()
: rh_leaf);
retval += i_elt.child()->verify_helper(this,
(i+1 < n) ? true : with_lub_flag,
(i+1 < n) ? this->lookup_elt(i+1).key() : lub_key,
prev_lh_leaf,
next_lh_leaf);
prev_lh_leaf = i_elt.child()->find_max_leaf_node().node();
}
if (Properties::ordinal_tag_value() == tags::ordinal_enabled) {
/* verify stored subtree size is consistent with children's */
std::size_t sum_z = 0;
for (std::size_t i=0, n=this->n_elt_; i < n; ++i) {
InternalNodeItemType const & elt = this->lookup_elt(i);
sum_z += BplusTreeUtil<Key, Value, Properties>::get_node_size(elt.child());
}
std::size_t self_z = BplusTreeUtil<Key, Value, Properties>::get_node_size(this);
if (sum_z != self_z) {
throw std::runtime_error(tostr("InternalNode::verify_helper",
": inconsistent subtree size",
xtag("node", this),
xtag("treez[stored]", self_z),
xtag("treez[computed]", sum_z)));
}
}
/* verify stored glb_key is correct */
for (std::size_t i=0, n=this->n_elt_; i < n; ++i) {
InternalNodeItemType const & elt = this->lookup_elt(i);
elt.child()->verify_glb_key(elt.key());
}
/* verify locally stored keys appear in sorted order */
for (std::size_t i=1; i < n; ++i) {
InternalNodeItemType const & prev = this->lookup_elt(i-1);
InternalNodeItemType const & elt = this->lookup_elt(i);
if (prev.key() < elt.key()) {
;
} else {
throw std::runtime_error(tostr("InternalNode::verify_helper"
": expected local keys in strictly increasing order",
xtag("i", i),
xtag("key(i-1)", prev.key()),
xtag("key(i)", elt.key())));
}
}
/* verify highest stored key before parent-supplied upper bound */
if (with_lub_flag) {
if (this->lookup_elt(n-1).key() < lub_key) {
;
} else {
throw std::runtime_error(tostr("InternalNode::verify_helper"
": expected highest local key before parent-supplied lub key",
xtag("n", n),
xtag("key(n-1)", this->lookup_elt(n-1).key()),
xtag("lub_key", lub_key)));
}
}
return retval;
} /*verify_helper*/
template <typename Key, typename Value, typename Properties>
void
InternalNode<Key, Value, Properties>::verify_glb_key(Key const & key) const {
InternalNodeItemType const & elt = this->lookup_elt(0);
elt.child()->verify_glb_key(key);
} /*verify_glb_key*/
template <typename Key, typename Value, typename Properties>
InternalNode<Key, Value, Properties>::InternalNode(std::size_t branching_factor)
: InternalNodeShim<Key, Value, Properties>{NodeType::internal, branching_factor}
{
/* must invoke ctor explicitly for each .elt_v[i].
* compiler doesn't know extent of .elt_v[], since it's a flexible array
*/
for (std::size_t i = 0; i < branching_factor; ++i) {
/* using placement new to force ctor call inside flexible array */
new (&(this->lookup_elt(i))) InternalNodeItemType();
}
} /*ctor*/
} /*namespace tree*/
} /*namespace xo*/
/* end InternalNode.hpp */