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Diffstat (limited to 'immer/detail/rbts/rbtree.hpp')
| -rw-r--r-- | immer/detail/rbts/rbtree.hpp | 509 |
1 files changed, 509 insertions, 0 deletions
diff --git a/immer/detail/rbts/rbtree.hpp b/immer/detail/rbts/rbtree.hpp new file mode 100644 index 000000000000..b31f5e9b0788 --- /dev/null +++ b/immer/detail/rbts/rbtree.hpp @@ -0,0 +1,509 @@ +// +// immer: immutable data structures for C++ +// Copyright (C) 2016, 2017, 2018 Juan Pedro Bolivar Puente +// +// This software is distributed under the Boost Software License, Version 1.0. +// See accompanying file LICENSE or copy at http://boost.org/LICENSE_1_0.txt +// + +#pragma once + +#include <immer/detail/rbts/node.hpp> +#include <immer/detail/rbts/operations.hpp> +#include <immer/detail/rbts/position.hpp> + +#include <immer/detail/type_traits.hpp> + +#include <cassert> +#include <memory> +#include <numeric> + +namespace immer { +namespace detail { +namespace rbts { + +template <typename T, typename MemoryPolicy, bits_t B, bits_t BL> +struct rbtree +{ + using node_t = node<T, MemoryPolicy, B, BL>; + using edit_t = typename node_t::edit_t; + using owner_t = typename MemoryPolicy::transience_t::owner; + + size_t size; + shift_t shift; + node_t* root; + node_t* tail; + + static const rbtree& empty() + { + static const rbtree empty_{ + 0, BL, node_t::make_inner_n(0u), node_t::make_leaf_n(0u)}; + return empty_; + } + + template <typename U> + static auto from_initializer_list(std::initializer_list<U> values) + { + auto e = owner_t{}; + auto result = rbtree{empty()}; + for (auto&& v : values) + result.push_back_mut(e, v); + return result; + } + + template <typename Iter, + typename Sent, + std::enable_if_t<compatible_sentinel_v<Iter, Sent>, bool> = true> + static auto from_range(Iter first, Sent last) + { + auto e = owner_t{}; + auto result = rbtree{empty()}; + for (; first != last; ++first) + result.push_back_mut(e, *first); + return result; + } + + static auto from_fill(size_t n, T v) + { + auto e = owner_t{}; + auto result = rbtree{empty()}; + while (n-- > 0) + result.push_back_mut(e, v); + return result; + } + + rbtree(size_t sz, shift_t sh, node_t* r, node_t* t) + : size{sz} + , shift{sh} + , root{r} + , tail{t} + { + assert(check_tree()); + } + + rbtree(const rbtree& other) + : rbtree{other.size, other.shift, other.root, other.tail} + { + inc(); + } + + rbtree(rbtree&& other) + : rbtree{empty()} + { + swap(*this, other); + } + + rbtree& operator=(const rbtree& other) + { + auto next = other; + swap(*this, next); + return *this; + } + + rbtree& operator=(rbtree&& other) + { + swap(*this, other); + return *this; + } + + friend void swap(rbtree& x, rbtree& y) + { + using std::swap; + swap(x.size, y.size); + swap(x.shift, y.shift); + swap(x.root, y.root); + swap(x.tail, y.tail); + } + + ~rbtree() { dec(); } + + void inc() const + { + root->inc(); + tail->inc(); + } + + void dec() const { traverse(dec_visitor()); } + + auto tail_size() const { return size ? ((size - 1) & mask<BL>) +1 : 0; } + + auto tail_offset() const { return size ? (size - 1) & ~mask<BL> : 0; } + + template <typename Visitor, typename... Args> + void traverse(Visitor v, Args&&... args) const + { + auto tail_off = tail_offset(); + auto tail_size = size - tail_off; + + if (tail_off) + make_regular_sub_pos(root, shift, tail_off).visit(v, args...); + else + make_empty_regular_pos(root).visit(v, args...); + + make_leaf_sub_pos(tail, tail_size).visit(v, args...); + } + + template <typename Visitor, typename... Args> + void traverse(Visitor v, size_t first, size_t last, Args&&... args) const + { + auto tail_off = tail_offset(); + auto tail_size = size - tail_off; + + if (first < tail_off) + make_regular_sub_pos(root, shift, tail_off) + .visit(v, first, last < tail_off ? last : tail_off, args...); + if (last > tail_off) + make_leaf_sub_pos(tail, tail_size) + .visit(v, + first > tail_off ? first - tail_off : 0, + last - tail_off, + args...); + } + + template <typename Visitor, typename... Args> + bool traverse_p(Visitor v, Args&&... args) const + { + auto tail_off = tail_offset(); + auto tail_size = size - tail_off; + return (tail_off ? make_regular_sub_pos(root, shift, tail_off) + .visit(v, args...) + : make_empty_regular_pos(root).visit(v, args...)) && + make_leaf_sub_pos(tail, tail_size).visit(v, args...); + } + + template <typename Visitor, typename... Args> + bool traverse_p(Visitor v, size_t first, size_t last, Args&&... args) const + { + auto tail_off = tail_offset(); + auto tail_size = size - tail_off; + + return (first < tail_off ? make_regular_sub_pos(root, shift, tail_off) + .visit(v, + first, + last < tail_off ? last : tail_off, + args...) + : true) && + (last > tail_off + ? make_leaf_sub_pos(tail, tail_size) + .visit(v, + first > tail_off ? first - tail_off : 0, + last - tail_off, + args...) + : true); + } + + template <typename Visitor> + decltype(auto) descend(Visitor v, size_t idx) const + { + auto tail_off = tail_offset(); + return idx >= tail_off ? make_leaf_descent_pos(tail).visit(v, idx) + : visit_regular_descent(root, shift, v, idx); + } + + template <typename Fn> + void for_each_chunk(Fn&& fn) const + { + traverse(for_each_chunk_visitor{}, std::forward<Fn>(fn)); + } + + template <typename Fn> + void for_each_chunk(size_t first, size_t last, Fn&& fn) const + { + traverse(for_each_chunk_i_visitor{}, first, last, std::forward<Fn>(fn)); + } + + template <typename Fn> + bool for_each_chunk_p(Fn&& fn) const + { + return traverse_p(for_each_chunk_p_visitor{}, std::forward<Fn>(fn)); + } + + template <typename Fn> + bool for_each_chunk_p(size_t first, size_t last, Fn&& fn) const + { + return traverse_p( + for_each_chunk_p_i_visitor{}, first, last, std::forward<Fn>(fn)); + } + + bool equals(const rbtree& other) const + { + if (size != other.size) + return false; + if (size == 0) + return true; + return (size <= branches<BL> || + make_regular_sub_pos(root, shift, tail_offset()) + .visit(equals_visitor{}, other.root)) && + make_leaf_sub_pos(tail, tail_size()) + .visit(equals_visitor{}, other.tail); + } + + void ensure_mutable_tail(edit_t e, count_t n) + { + if (!tail->can_mutate(e)) { + auto new_tail = node_t::copy_leaf_e(e, tail, n); + dec_leaf(tail, n); + tail = new_tail; + } + } + + void push_back_mut(edit_t e, T value) + { + auto tail_off = tail_offset(); + auto ts = size - tail_off; + if (ts < branches<BL>) { + ensure_mutable_tail(e, ts); + new (&tail->leaf()[ts]) T{std::move(value)}; + } else { + auto new_tail = node_t::make_leaf_e(e, std::move(value)); + try { + if (tail_off == size_t{branches<B>} << shift) { + auto new_root = node_t::make_inner_e(e); + try { + auto path = node_t::make_path_e(e, shift, tail); + new_root->inner()[0] = root; + new_root->inner()[1] = path; + root = new_root; + tail = new_tail; + shift += B; + } catch (...) { + node_t::delete_inner_e(new_root); + throw; + } + } else if (tail_off) { + auto new_root = + make_regular_sub_pos(root, shift, tail_off) + .visit(push_tail_mut_visitor<node_t>{}, e, tail); + root = new_root; + tail = new_tail; + } else { + auto new_root = node_t::make_path_e(e, shift, tail); + assert(tail_off == 0); + dec_empty_regular(root); + root = new_root; + tail = new_tail; + } + } catch (...) { + node_t::delete_leaf(new_tail, 1); + throw; + } + } + ++size; + } + + rbtree push_back(T value) const + { + auto tail_off = tail_offset(); + auto ts = size - tail_off; + if (ts < branches<BL>) { + auto new_tail = + node_t::copy_leaf_emplace(tail, ts, std::move(value)); + return {size + 1, shift, root->inc(), new_tail}; + } else { + auto new_tail = node_t::make_leaf_n(1, std::move(value)); + try { + if (tail_off == size_t{branches<B>} << shift) { + auto new_root = node_t::make_inner_n(2); + try { + auto path = node_t::make_path(shift, tail); + new_root->inner()[0] = root; + new_root->inner()[1] = path; + root->inc(); + tail->inc(); + return {size + 1, shift + B, new_root, new_tail}; + } catch (...) { + node_t::delete_inner(new_root, 2); + throw; + } + } else if (tail_off) { + auto new_root = + make_regular_sub_pos(root, shift, tail_off) + .visit(push_tail_visitor<node_t>{}, tail); + tail->inc(); + return {size + 1, shift, new_root, new_tail}; + } else { + auto new_root = node_t::make_path(shift, tail); + tail->inc(); + return {size + 1, shift, new_root, new_tail}; + } + } catch (...) { + node_t::delete_leaf(new_tail, 1); + throw; + } + } + } + + const T* array_for(size_t index) const + { + return descend(array_for_visitor<T>(), index); + } + + T& get_mut(edit_t e, size_t idx) + { + auto tail_off = tail_offset(); + if (idx >= tail_off) { + ensure_mutable_tail(e, size - tail_off); + return tail->leaf()[idx & mask<BL>]; + } else { + return make_regular_sub_pos(root, shift, tail_off) + .visit(get_mut_visitor<node_t>{}, idx, e, &root); + } + } + + const T& get(size_t index) const + { + return descend(get_visitor<T>(), index); + } + + const T& get_check(size_t index) const + { + if (index >= size) + throw std::out_of_range{"index out of range"}; + return descend(get_visitor<T>(), index); + } + + const T& front() const { return get(0); } + + const T& back() const { return tail->leaf()[(size - 1) & mask<BL>]; } + + template <typename FnT> + void update_mut(edit_t e, size_t idx, FnT&& fn) + { + auto& elem = get_mut(e, idx); + elem = std::forward<FnT>(fn)(std::move(elem)); + } + + template <typename FnT> + rbtree update(size_t idx, FnT&& fn) const + { + auto tail_off = tail_offset(); + if (idx >= tail_off) { + auto tail_size = size - tail_off; + auto new_tail = + make_leaf_sub_pos(tail, tail_size) + .visit(update_visitor<node_t>{}, idx - tail_off, fn); + return {size, shift, root->inc(), new_tail}; + } else { + auto new_root = make_regular_sub_pos(root, shift, tail_off) + .visit(update_visitor<node_t>{}, idx, fn); + return {size, shift, new_root, tail->inc()}; + } + } + + void assoc_mut(edit_t e, size_t idx, T value) + { + update_mut(e, idx, [&](auto&&) { return std::move(value); }); + } + + rbtree assoc(size_t idx, T value) const + { + return update(idx, [&](auto&&) { return std::move(value); }); + } + + rbtree take(size_t new_size) const + { + auto tail_off = tail_offset(); + if (new_size == 0) { + return empty(); + } else if (new_size >= size) { + return *this; + } else if (new_size > tail_off) { + auto new_tail = node_t::copy_leaf(tail, new_size - tail_off); + return {new_size, shift, root->inc(), new_tail}; + } else { + using std::get; + auto l = new_size - 1; + auto v = slice_right_visitor<node_t>(); + auto r = make_regular_sub_pos(root, shift, tail_off).visit(v, l); + auto new_shift = get<0>(r); + auto new_root = get<1>(r); + auto new_tail = get<3>(r); + if (new_root) { + IMMER_ASSERT_TAGGED(new_root->compute_shift() == get<0>(r)); + assert(new_root->check(new_shift, new_size - get<2>(r))); + return {new_size, new_shift, new_root, new_tail}; + } else { + return {new_size, BL, empty().root->inc(), new_tail}; + } + } + } + + void take_mut(edit_t e, size_t new_size) + { + auto tail_off = tail_offset(); + if (new_size == 0) { + // todo: more efficient? + *this = empty(); + } else if (new_size >= size) { + return; + } else if (new_size > tail_off) { + auto ts = size - tail_off; + auto newts = new_size - tail_off; + if (tail->can_mutate(e)) { + destroy_n(tail->leaf() + newts, ts - newts); + } else { + auto new_tail = node_t::copy_leaf_e(e, tail, newts); + dec_leaf(tail, ts); + tail = new_tail; + } + size = new_size; + return; + } else { + using std::get; + auto l = new_size - 1; + auto v = slice_right_mut_visitor<node_t>(); + auto r = make_regular_sub_pos(root, shift, tail_off).visit(v, l, e); + auto new_shift = get<0>(r); + auto new_root = get<1>(r); + auto new_tail = get<3>(r); + if (new_root) { + root = new_root; + shift = new_shift; + } else { + root = empty().root->inc(); + shift = BL; + } + dec_leaf(tail, size - tail_off); + size = new_size; + tail = new_tail; + return; + } + } + + bool check_tree() const + { +#if IMMER_DEBUG_DEEP_CHECK + assert(shift >= BL); + assert(tail_offset() <= size); + assert(check_root()); + assert(check_tail()); +#endif + return true; + } + + bool check_tail() const + { +#if IMMER_DEBUG_DEEP_CHECK + if (tail_size() > 0) + assert(tail->check(0, tail_size())); +#endif + return true; + } + + bool check_root() const + { +#if IMMER_DEBUG_DEEP_CHECK + if (tail_offset() > 0) + assert(root->check(shift, tail_offset())); + else { + IMMER_ASSERT_TAGGED(root->kind() == node_t::kind_t::inner); + assert(shift == BL); + } +#endif + return true; + } +}; + +} // namespace rbts +} // namespace detail +} // namespace immer |