diff -r 666f914201fb -r 2fe1408b6811 epoc32/include/stdapis/boost/pending/relaxed_heap.hpp --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/epoc32/include/stdapis/boost/pending/relaxed_heap.hpp Tue Mar 16 16:12:26 2010 +0000 @@ -0,0 +1,642 @@ +// Copyright 2004 The Trustees of Indiana University. + +// Use, modification and distribution is subject to the Boost Software +// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at +// http://www.boost.org/LICENSE_1_0.txt) + +// Authors: Douglas Gregor +// Andrew Lumsdaine +#ifndef BOOST_RELAXED_HEAP_HEADER +#define BOOST_RELAXED_HEAP_HEADER + +#include +#include +#include +#include + +#ifdef BOOST_RELAXED_HEAP_DEBUG +# include +#endif // BOOST_RELAXED_HEAP_DEBUG + +#if defined(BOOST_MSVC) +# pragma warning(push) +# pragma warning(disable:4355) // complaint about using 'this' to +#endif // initialize a member + +namespace boost { + +template, + typename ID = identity_property_map> +class relaxed_heap +{ + struct group; + + typedef relaxed_heap self_type; + typedef std::size_t rank_type; + +public: + typedef IndexedType value_type; + typedef rank_type size_type; + +private: + /** + * The kind of key that a group has. The actual values are discussed + * in-depth in the documentation of the @c kind field of the @c group + * structure. Note that the order of the enumerators *IS* important + * and must not be changed. + */ + enum group_key_kind { smallest_key, stored_key, largest_key }; + + struct group { + explicit group(group_key_kind kind = largest_key) + : kind(kind), parent(this), rank(0) { } + + /** The value associated with this group. This value is only valid + * when @c kind!=largest_key (which indicates a deleted + * element). Note that the use of boost::optional increases the + * memory requirements slightly but does not result in extraneous + * memory allocations or deallocations. The optional could be + * eliminated when @c value_type is a model of + * DefaultConstructible. + */ + ::boost::optional value; + + /** + * The kind of key stored at this group. This may be @c + * smallest_key, which indicates that the key is infinitely small; + * @c largest_key, which indicates that the key is infinitely + * large; or @c stored_key, which means that the key is unknown, + * but its relationship to other keys can be determined via the + * comparison function object. + */ + group_key_kind kind; + + /// The parent of this group. Will only be NULL for the dummy root group + group* parent; + + /// The rank of this group. Equivalent to the number of children in + /// the group. + rank_type rank; + + /** The children of this group. For the dummy root group, these are + * the roots. This is an array of length log n containing pointers + * to the child groups. + */ + group** children; + }; + + size_type log_base_2(size_type n) // log2 is a macro on some platforms + { + size_type leading_zeroes = 0; + do { + size_type next = n << 1; + if (n == (next >> 1)) { + ++leading_zeroes; + n = next; + } else { + break; + } + } while (true); + return sizeof(size_type) * CHAR_BIT - leading_zeroes - 1; + } + +public: + relaxed_heap(size_type n, const Compare& compare = Compare(), + const ID& id = ID()) + : compare(compare), id(id), root(smallest_key), groups(n), + smallest_value(0) + { + if (n == 0) { + root.children = new group*[1]; + return; + } + + log_n = log_base_2(n); + if (log_n == 0) log_n = 1; + size_type g = n / log_n; + if (n % log_n > 0) ++g; + size_type log_g = log_base_2(g); + size_type r = log_g; + + // Reserve an appropriate amount of space for data structures, so + // that we do not need to expand them. + index_to_group.resize(g); + A.resize(r + 1, 0); + root.rank = r + 1; + root.children = new group*[(log_g + 1) * (g + 1)]; + for (rank_type i = 0; i < r+1; ++i) root.children[i] = 0; + + // Build initial heap + size_type idx = 0; + while (idx < g) { + root.children[r] = &index_to_group[idx]; + idx = build_tree(root, idx, r, log_g + 1); + if (idx != g) + r = static_cast(log_base_2(g-idx)); + } + } + + ~relaxed_heap() { delete [] root.children; } + + void push(const value_type& x) + { + groups[get(id, x)] = x; + update(x); + } + + void update(const value_type& x) + { + group* a = &index_to_group[get(id, x) / log_n]; + if (!a->value + || *a->value == x + || compare(x, *a->value)) { + if (a != smallest_value) smallest_value = 0; + a->kind = stored_key; + a->value = x; + promote(a); + } + } + + void remove(const value_type& x) + { + group* a = &index_to_group[get(id, x) / log_n]; + assert(groups[get(id, x)] != 0); + a->value = x; + a->kind = smallest_key; + promote(a); + smallest_value = a; + pop(); + } + + value_type& top() + { + find_smallest(); + assert(smallest_value->value != 0); + return *smallest_value->value; + } + + const value_type& top() const + { + find_smallest(); + assert(smallest_value->value != 0); + return *smallest_value->value; + } + + bool empty() const + { + find_smallest(); + return !smallest_value || (smallest_value->kind == largest_key); + } + + bool contains(const value_type& x) const { return groups[get(id, x)]; } + + void pop() + { + // Fill in smallest_value. This is the group x. + find_smallest(); + group* x = smallest_value; + smallest_value = 0; + + // Make x a leaf, giving it the smallest value within its group + rank_type r = x->rank; + group* p = x->parent; + { + assert(x->value != 0); + + // Find x's group + size_type start = get(id, *x->value) - get(id, *x->value) % log_n; + size_type end = start + log_n; + if (end > groups.size()) end = groups.size(); + + // Remove the smallest value from the group, and find the new + // smallest value. + groups[get(id, *x->value)].reset(); + x->value.reset(); + x->kind = largest_key; + for (size_type i = start; i < end; ++i) { + if (groups[i] && (!x->value || compare(*groups[i], *x->value))) { + x->kind = stored_key; + x->value = groups[i]; + } + } + } + x->rank = 0; + + // Combine prior children of x with x + group* y = x; + for (size_type c = 0; c < r; ++c) { + group* child = x->children[c]; + if (A[c] == child) A[c] = 0; + y = combine(y, child); + } + + // If we got back something other than x, let y take x's place + if (y != x) { + y->parent = p; + p->children[r] = y; + + assert(r == y->rank); + if (A[y->rank] == x) + A[y->rank] = do_compare(y, p)? y : 0; + } + } + +#ifdef BOOST_RELAXED_HEAP_DEBUG + /************************************************************************* + * Debugging support * + *************************************************************************/ + void dump_tree() { dump_tree(std::cout); } + void dump_tree(std::ostream& out) { dump_tree(out, &root); } + + void dump_tree(std::ostream& out, group* p, bool in_progress = false) + { + if (!in_progress) { + out << "digraph heap {\n" + << " edge[dir=\"back\"];\n"; + } + + size_type p_index = 0; + if (p != &root) while (&index_to_group[p_index] != p) ++p_index; + + for (size_type i = 0; i < p->rank; ++i) { + group* c = p->children[i]; + if (c) { + size_type c_index = 0; + if (c != &root) while (&index_to_group[c_index] != c) ++c_index; + + out << " "; + if (p == &root) out << 'p'; else out << p_index; + out << " -> "; + if (c == &root) out << 'p'; else out << c_index; + if (A[c->rank] == c) out << " [style=\"dotted\"]"; + out << ";\n"; + dump_tree(out, c, true); + + // Emit node information + out << " "; + if (c == &root) out << 'p'; else out << c_index; + out << " [label=\""; + if (c == &root) out << 'p'; else out << c_index; + out << ":"; + size_type start = c_index * log_n; + size_type end = start + log_n; + if (end > groups.size()) end = groups.size(); + while (start != end) { + if (groups[start]) { + out << " " << get(id, *groups[start]); + if (*groups[start] == *c->value) out << "(*)"; + } + ++start; + } + out << '"'; + + if (do_compare(c, p)) { + out << " "; + if (c == &root) out << 'p'; else out << c_index; + out << ", style=\"filled\", fillcolor=\"gray\""; + } + out << "];\n"; + } else { + assert(p->parent == p); + } + } + if (!in_progress) out << "}\n"; + } + + bool valid() + { + // Check that the ranks in the A array match the ranks of the + // groups stored there. Also, the active groups must be the last + // child of their parent. + for (size_type r = 0; r < A.size(); ++r) { + if (A[r] && A[r]->rank != r) return false; + + if (A[r] && A[r]->parent->children[A[r]->parent->rank-1] != A[r]) + return false; + } + + // The root must have no value and a key of -Infinity + if (root.kind != smallest_key) return false; + + return valid(&root); + } + + bool valid(group* p) + { + for (size_type i = 0; i < p->rank; ++i) { + group* c = p->children[i]; + if (c) { + // Check link structure + if (c->parent != p) return false; + if (c->rank != i) return false; + + // A bad group must be active + if (do_compare(c, p) && A[i] != c) return false; + + // Check recursively + if (!valid(c)) return false; + } else { + // Only the root may + if (p != &root) return false; + } + } + return true; + } + +#endif // BOOST_RELAXED_HEAP_DEBUG + +private: + size_type + build_tree(group& parent, size_type idx, size_type r, size_type max_rank) + { + group& this_group = index_to_group[idx]; + this_group.parent = &parent; + ++idx; + + this_group.children = root.children + (idx * max_rank); + this_group.rank = r; + for (size_type i = 0; i < r; ++i) { + this_group.children[i] = &index_to_group[idx]; + idx = build_tree(this_group, idx, i, max_rank); + } + return idx; + } + + void find_smallest() const + { + group** roots = root.children; + + if (!smallest_value) { + std::size_t i; + for (i = 0; i < root.rank; ++i) { + if (roots[i] && + (!smallest_value || do_compare(roots[i], smallest_value))) { + smallest_value = roots[i]; + } + } + for (i = 0; i < A.size(); ++i) { + if (A[i] && (!smallest_value || do_compare(A[i], smallest_value))) + smallest_value = A[i]; + } + } + } + + bool do_compare(group* x, group* y) const + { + return (x->kind < y->kind + || (x->kind == y->kind + && x->kind == stored_key + && compare(*x->value, *y->value))); + } + + void promote(group* a) + { + assert(a != 0); + rank_type r = a->rank; + group* p = a->parent; + assert(p != 0); + if (do_compare(a, p)) { + // s is the rank + 1 sibling + group* s = p->rank > r + 1? p->children[r + 1] : 0; + + // If a is the last child of p + if (r == p->rank - 1) { + if (!A[r]) A[r] = a; + else if (A[r] != a) pair_transform(a); + } else { + assert(s != 0); + if (A[r + 1] == s) active_sibling_transform(a, s); + else good_sibling_transform(a, s); + } + } + } + + group* combine(group* a1, group* a2) + { + assert(a1->rank == a2->rank); + if (do_compare(a2, a1)) do_swap(a1, a2); + a1->children[a1->rank++] = a2; + a2->parent = a1; + clean(a1); + return a1; + } + + void clean(group* q) + { + if (2 > q->rank) return; + group* qp = q->children[q->rank-1]; + rank_type s = q->rank - 2; + group* x = q->children[s]; + group* xp = qp->children[s]; + assert(s == x->rank); + + // If x is active, swap x and xp + if (A[s] == x) { + q->children[s] = xp; + xp->parent = q; + qp->children[s] = x; + x->parent = qp; + } + } + + void pair_transform(group* a) + { +#if defined(BOOST_RELAXED_HEAP_DEBUG) && BOOST_RELAXED_HEAP_DEBUG > 1 + std::cerr << "- pair transform\n"; +#endif + rank_type r = a->rank; + + // p is a's parent + group* p = a->parent; + assert(p != 0); + + // g is p's parent (a's grandparent) + group* g = p->parent; + assert(g != 0); + + // a' <- A(r) + assert(A[r] != 0); + group* ap = A[r]; + assert(ap != 0); + + // A(r) <- nil + A[r] = 0; + + // let a' have parent p' + group* pp = ap->parent; + assert(pp != 0); + + // let a' have grandparent g' + group* gp = pp->parent; + assert(gp != 0); + + // Remove a and a' from their parents + assert(ap == pp->children[pp->rank-1]); // Guaranteed because ap is active + --pp->rank; + + // Guaranteed by caller + assert(a == p->children[p->rank-1]); + --p->rank; + + // Note: a, ap, p, pp all have rank r + if (do_compare(pp, p)) { + do_swap(a, ap); + do_swap(p, pp); + do_swap(g, gp); + } + + // Assuming k(p) <= k(p') + // make p' the rank r child of p + assert(r == p->rank); + p->children[p->rank++] = pp; + pp->parent = p; + + // Combine a, ap into a rank r+1 group c + group* c = combine(a, ap); + + // make c the rank r+1 child of g' + assert(gp->rank > r+1); + gp->children[r+1] = c; + c->parent = gp; + +#if defined(BOOST_RELAXED_HEAP_DEBUG) && BOOST_RELAXED_HEAP_DEBUG > 1 + std::cerr << "After pair transform...\n"; + dump_tree(); +#endif + + if (A[r+1] == pp) A[r+1] = c; + else promote(c); + } + + void active_sibling_transform(group* a, group* s) + { +#if defined(BOOST_RELAXED_HEAP_DEBUG) && BOOST_RELAXED_HEAP_DEBUG > 1 + std::cerr << "- active sibling transform\n"; +#endif + group* p = a->parent; + group* g = p->parent; + + // remove a, s from their parents + assert(s->parent == p); + assert(p->children[p->rank-1] == s); + --p->rank; + assert(p->children[p->rank-1] == a); + --p->rank; + + rank_type r = a->rank; + A[r+1] = 0; + a = combine(p, a); + group* c = combine(a, s); + + // make c the rank r+2 child of g + assert(g->children[r+2] == p); + g->children[r+2] = c; + c->parent = g; + if (A[r+2] == p) A[r+2] = c; + else promote(c); + } + + void good_sibling_transform(group* a, group* s) + { +#if defined(BOOST_RELAXED_HEAP_DEBUG) && BOOST_RELAXED_HEAP_DEBUG > 1 + std::cerr << "- good sibling transform\n"; +#endif + rank_type r = a->rank; + group* c = s->children[s->rank-1]; + assert(c->rank == r); + if (A[r] == c) { +#if defined(BOOST_RELAXED_HEAP_DEBUG) && BOOST_RELAXED_HEAP_DEBUG > 1 + std::cerr << "- good sibling pair transform\n"; +#endif + A[r] = 0; + group* p = a->parent; + + // Remove c from its parent + --s->rank; + + // Make s the rank r child of p + s->parent = p; + p->children[r] = s; + + // combine a, c and let the result by the rank r+1 child of p + assert(p->rank > r+1); + group* x = combine(a, c); + x->parent = p; + p->children[r+1] = x; + + if (A[r+1] == s) A[r+1] = x; + else promote(x); + +#if defined(BOOST_RELAXED_HEAP_DEBUG) && BOOST_RELAXED_HEAP_DEBUG > 1 + dump_tree(std::cerr); +#endif + // pair_transform(a); + } else { + // Clean operation + group* p = a->parent; + s->children[r] = a; + a->parent = s; + p->children[r] = c; + c->parent = p; + + promote(a); + } + } + + static void do_swap(group*& x, group*& y) + { + group* tmp = x; + x = y; + y = tmp; + } + + /// Function object that compares two values in the heap + Compare compare; + + /// Mapping from values to indices in the range [0, n). + ID id; + + /** The root group of the queue. This group is special because it will + * never store a value, but it acts as a parent to all of the + * roots. Thus, its list of children is the list of roots. + */ + group root; + + /** Mapping from the group index of a value to the group associated + * with that value. If a value is not in the queue, then the "value" + * field will be empty. + */ + std::vector index_to_group; + + /** Flat data structure containing the values in each of the + * groups. It will be indexed via the id of the values. The groups + * are each log_n long, with the last group potentially being + * smaller. + */ + std::vector< ::boost::optional > groups; + + /** The list of active groups, indexed by rank. When A[r] is null, + * there is no active group of rank r. Otherwise, A[r] is the active + * group of rank r. + */ + std::vector A; + + /** The group containing the smallest value in the queue, which must + * be either a root or an active group. If this group is null, then we + * will need to search for this group when it is needed. + */ + mutable group* smallest_value; + + /// Cached value log_base_2(n) + size_type log_n; +}; + + +} // end namespace boost + +#if defined(BOOST_MSVC) +# pragma warning(pop) +#endif + +#endif // BOOST_RELAXED_HEAP_HEADER