[repacker] Begin splitting up the repacker implementation into several files.
This commit is contained in:
Garret Rieger
parent
ad2ab1ddb4
commit
20b02a672d
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@ -0,0 +1,965 @@
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/*
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* Copyright © 2022 Google, Inc.
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*
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* This is part of HarfBuzz, a text shaping library.
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*
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* Permission is hereby granted, without written agreement and without
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* license or royalty fees, to use, copy, modify, and distribute this
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* software and its documentation for any purpose, provided that the
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* above copyright notice and the following two paragraphs appear in
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* all copies of this software.
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*
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* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
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* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
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* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
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* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
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* DAMAGE.
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*
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* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
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* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
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* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
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* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
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* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
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*
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* Google Author(s): Garret Rieger
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*/
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#ifndef GRAPH_GRAPH_HH
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#define GRAPH_GRAPH_HH
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namespace graph {
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struct graph_t
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{
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struct vertex_t
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{
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hb_serialize_context_t::object_t obj;
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int64_t distance = 0 ;
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int64_t space = 0 ;
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hb_vector_t<unsigned> parents;
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unsigned start = 0;
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unsigned end = 0;
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unsigned priority = 0;
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friend void swap (vertex_t& a, vertex_t& b)
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{
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hb_swap (a.obj, b.obj);
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hb_swap (a.distance, b.distance);
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hb_swap (a.space, b.space);
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hb_swap (a.parents, b.parents);
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hb_swap (a.start, b.start);
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hb_swap (a.end, b.end);
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hb_swap (a.priority, b.priority);
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}
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bool is_shared () const
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{
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return parents.length > 1;
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}
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unsigned incoming_edges () const
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{
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return parents.length;
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}
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void remove_parent (unsigned parent_index)
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{
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for (unsigned i = 0; i < parents.length; i++)
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{
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if (parents[i] != parent_index) continue;
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parents.remove (i);
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break;
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}
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}
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void remap_parents (const hb_vector_t<unsigned>& id_map)
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{
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for (unsigned i = 0; i < parents.length; i++)
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parents[i] = id_map[parents[i]];
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}
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void remap_parent (unsigned old_index, unsigned new_index)
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{
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for (unsigned i = 0; i < parents.length; i++)
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{
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if (parents[i] == old_index)
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parents[i] = new_index;
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}
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}
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bool is_leaf () const
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{
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return !obj.real_links.length && !obj.virtual_links.length;
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}
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bool raise_priority ()
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{
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if (has_max_priority ()) return false;
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priority++;
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return true;
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}
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bool has_max_priority () const {
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return priority >= 3;
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}
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int64_t modified_distance (unsigned order) const
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{
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// TODO(garretrieger): once priority is high enough, should try
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// setting distance = 0 which will force to sort immediately after
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// it's parent where possible.
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int64_t modified_distance =
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hb_min (hb_max(distance + distance_modifier (), 0), 0x7FFFFFFFFFF);
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if (has_max_priority ()) {
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modified_distance = 0;
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}
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return (modified_distance << 18) | (0x003FFFF & order);
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}
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int64_t distance_modifier () const
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{
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if (!priority) return 0;
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int64_t table_size = obj.tail - obj.head;
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if (priority == 1)
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return -table_size / 2;
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return -table_size;
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}
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};
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struct overflow_record_t
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{
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unsigned parent;
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unsigned child;
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};
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/*
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* A topological sorting of an object graph. Ordered
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* in reverse serialization order (first object in the
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* serialization is at the end of the list). This matches
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* the 'packed' object stack used internally in the
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* serializer
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*/
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template<typename T>
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graph_t (const T& objects)
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: parents_invalid (true),
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distance_invalid (true),
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positions_invalid (true),
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successful (true)
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{
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num_roots_for_space_.push (1);
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bool removed_nil = false;
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vertices_.alloc (objects.length);
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vertices_scratch_.alloc (objects.length);
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for (unsigned i = 0; i < objects.length; i++)
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{
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// TODO(grieger): check all links point to valid objects.
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// If this graph came from a serialization buffer object 0 is the
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// nil object. We don't need it for our purposes here so drop it.
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if (i == 0 && !objects[i])
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{
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removed_nil = true;
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continue;
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}
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vertex_t* v = vertices_.push ();
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if (check_success (!vertices_.in_error ()))
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v->obj = *objects[i];
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if (!removed_nil) continue;
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// Fix indices to account for removed nil object.
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for (auto& l : v->obj.all_links_writer ()) {
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l.objidx--;
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}
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}
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}
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~graph_t ()
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{
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vertices_.fini ();
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}
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bool in_error () const
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{
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return !successful ||
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vertices_.in_error () ||
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num_roots_for_space_.in_error ();
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}
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const vertex_t& root () const
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{
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return vertices_[root_idx ()];
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}
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unsigned root_idx () const
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{
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// Object graphs are in reverse order, the first object is at the end
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// of the vector. Since the graph is topologically sorted it's safe to
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// assume the first object has no incoming edges.
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return vertices_.length - 1;
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}
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const hb_serialize_context_t::object_t& object(unsigned i) const
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{
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return vertices_[i].obj;
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}
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/*
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* Generates a new topological sorting of graph ordered by the shortest
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* distance to each node.
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*/
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void sort_shortest_distance ()
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{
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positions_invalid = true;
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if (vertices_.length <= 1) {
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// Graph of 1 or less doesn't need sorting.
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return;
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}
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update_distances ();
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hb_priority_queue_t queue;
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hb_vector_t<vertex_t> &sorted_graph = vertices_scratch_;
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if (unlikely (!check_success (sorted_graph.resize (vertices_.length)))) return;
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hb_vector_t<unsigned> id_map;
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if (unlikely (!check_success (id_map.resize (vertices_.length)))) return;
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hb_vector_t<unsigned> removed_edges;
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if (unlikely (!check_success (removed_edges.resize (vertices_.length)))) return;
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update_parents ();
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queue.insert (root ().modified_distance (0), root_idx ());
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int new_id = root_idx ();
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unsigned order = 1;
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while (!queue.in_error () && !queue.is_empty ())
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{
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unsigned next_id = queue.pop_minimum().second;
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hb_swap (sorted_graph[new_id], vertices_[next_id]);
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const vertex_t& next = sorted_graph[new_id];
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id_map[next_id] = new_id--;
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for (const auto& link : next.obj.all_links ()) {
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removed_edges[link.objidx]++;
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if (!(vertices_[link.objidx].incoming_edges () - removed_edges[link.objidx]))
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// Add the order that the links were encountered to the priority.
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// This ensures that ties between priorities objects are broken in a consistent
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// way. More specifically this is set up so that if a set of objects have the same
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// distance they'll be added to the topological order in the order that they are
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// referenced from the parent object.
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queue.insert (vertices_[link.objidx].modified_distance (order++),
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link.objidx);
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}
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}
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check_success (!queue.in_error ());
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check_success (!sorted_graph.in_error ());
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if (!check_success (new_id == -1))
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print_orphaned_nodes ();
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remap_all_obj_indices (id_map, &sorted_graph);
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hb_swap (vertices_, sorted_graph);
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}
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/*
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* Assign unique space numbers to each connected subgraph of 32 bit offset(s).
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*/
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bool assign_32bit_spaces ()
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{
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unsigned root_index = root_idx ();
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hb_set_t visited;
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hb_set_t roots;
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for (unsigned i = 0; i <= root_index; i++)
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{
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// Only real links can form 32 bit spaces
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for (auto& l : vertices_[i].obj.real_links)
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{
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if (l.width == 4 && !l.is_signed)
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{
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roots.add (l.objidx);
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find_subgraph (l.objidx, visited);
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}
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}
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}
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// Mark everything not in the subgraphs of 32 bit roots as visited.
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// This prevents 32 bit subgraphs from being connected via nodes not in the 32 bit subgraphs.
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visited.invert ();
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if (!roots) return false;
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while (roots)
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{
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unsigned next = HB_SET_VALUE_INVALID;
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if (unlikely (!check_success (!roots.in_error ()))) break;
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if (!roots.next (&next)) break;
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hb_set_t connected_roots;
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find_connected_nodes (next, roots, visited, connected_roots);
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if (unlikely (!check_success (!connected_roots.in_error ()))) break;
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isolate_subgraph (connected_roots);
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if (unlikely (!check_success (!connected_roots.in_error ()))) break;
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unsigned next_space = this->next_space ();
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num_roots_for_space_.push (0);
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for (unsigned root : connected_roots)
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{
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DEBUG_MSG (SUBSET_REPACK, nullptr, "Subgraph %u gets space %u", root, next_space);
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vertices_[root].space = next_space;
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num_roots_for_space_[next_space] = num_roots_for_space_[next_space] + 1;
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distance_invalid = true;
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positions_invalid = true;
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}
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// TODO(grieger): special case for GSUB/GPOS use extension promotions to move 16 bit space
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// into the 32 bit space as needed, instead of using isolation.
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}
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return true;
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}
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/*
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* Isolates the subgraph of nodes reachable from root. Any links to nodes in the subgraph
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* that originate from outside of the subgraph will be removed by duplicating the linked to
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* object.
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*
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* Indices stored in roots will be updated if any of the roots are duplicated to new indices.
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*/
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bool isolate_subgraph (hb_set_t& roots)
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{
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update_parents ();
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hb_map_t subgraph;
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// incoming edges to root_idx should be all 32 bit in length so we don't need to de-dup these
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// set the subgraph incoming edge count to match all of root_idx's incoming edges
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hb_set_t parents;
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for (unsigned root_idx : roots)
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{
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subgraph.set (root_idx, wide_parents (root_idx, parents));
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find_subgraph (root_idx, subgraph);
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}
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unsigned original_root_idx = root_idx ();
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hb_map_t index_map;
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bool made_changes = false;
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for (auto entry : subgraph.iter ())
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{
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const auto& node = vertices_[entry.first];
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unsigned subgraph_incoming_edges = entry.second;
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if (subgraph_incoming_edges < node.incoming_edges ())
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{
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// Only de-dup objects with incoming links from outside the subgraph.
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made_changes = true;
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duplicate_subgraph (entry.first, index_map);
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}
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}
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if (!made_changes)
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return false;
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if (original_root_idx != root_idx ()
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&& parents.has (original_root_idx))
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{
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// If the root idx has changed since parents was determined, update root idx in parents
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parents.add (root_idx ());
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parents.del (original_root_idx);
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}
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auto new_subgraph =
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+ subgraph.keys ()
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| hb_map([&] (unsigned node_idx) {
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const unsigned *v;
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if (index_map.has (node_idx, &v)) return *v;
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return node_idx;
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})
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;
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remap_obj_indices (index_map, new_subgraph);
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remap_obj_indices (index_map, parents.iter (), true);
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// Update roots set with new indices as needed.
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unsigned next = HB_SET_VALUE_INVALID;
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while (roots.next (&next))
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{
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const unsigned *v;
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if (index_map.has (next, &v))
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{
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roots.del (next);
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roots.add (*v);
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}
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}
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return true;
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}
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void find_subgraph (unsigned node_idx, hb_map_t& subgraph)
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{
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for (const auto& link : vertices_[node_idx].obj.all_links ())
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{
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const unsigned *v;
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if (subgraph.has (link.objidx, &v))
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{
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subgraph.set (link.objidx, *v + 1);
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continue;
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}
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subgraph.set (link.objidx, 1);
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find_subgraph (link.objidx, subgraph);
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}
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}
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void find_subgraph (unsigned node_idx, hb_set_t& subgraph)
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{
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if (subgraph.has (node_idx)) return;
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subgraph.add (node_idx);
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for (const auto& link : vertices_[node_idx].obj.all_links ())
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find_subgraph (link.objidx, subgraph);
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}
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/*
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* duplicates all nodes in the subgraph reachable from node_idx. Does not re-assign
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* links. index_map is updated with mappings from old id to new id. If a duplication has already
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* been performed for a given index, then it will be skipped.
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*/
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void duplicate_subgraph (unsigned node_idx, hb_map_t& index_map)
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{
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if (index_map.has (node_idx))
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return;
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index_map.set (node_idx, duplicate (node_idx));
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for (const auto& l : object (node_idx).all_links ()) {
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duplicate_subgraph (l.objidx, index_map);
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}
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}
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/*
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* Creates a copy of node_idx and returns it's new index.
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*/
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unsigned duplicate (unsigned node_idx)
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{
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positions_invalid = true;
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distance_invalid = true;
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auto* clone = vertices_.push ();
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auto& child = vertices_[node_idx];
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if (vertices_.in_error ()) {
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return -1;
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}
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clone->obj.head = child.obj.head;
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clone->obj.tail = child.obj.tail;
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clone->distance = child.distance;
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clone->space = child.space;
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clone->parents.reset ();
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unsigned clone_idx = vertices_.length - 2;
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for (const auto& l : child.obj.real_links)
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{
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clone->obj.real_links.push (l);
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vertices_[l.objidx].parents.push (clone_idx);
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}
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for (const auto& l : child.obj.virtual_links)
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{
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clone->obj.virtual_links.push (l);
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vertices_[l.objidx].parents.push (clone_idx);
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}
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check_success (!clone->obj.real_links.in_error ());
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check_success (!clone->obj.virtual_links.in_error ());
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// The last object is the root of the graph, so swap back the root to the end.
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// The root's obj idx does change, however since it's root nothing else refers to it.
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// all other obj idx's will be unaffected.
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hb_swap (vertices_[vertices_.length - 2], *clone);
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// Since the root moved, update the parents arrays of all children on the root.
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for (const auto& l : root ().obj.all_links ())
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vertices_[l.objidx].remap_parent (root_idx () - 1, root_idx ());
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return clone_idx;
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}
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/*
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* Creates a copy of child and re-assigns the link from
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* parent to the clone. The copy is a shallow copy, objects
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* linked from child are not duplicated.
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*/
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bool duplicate (unsigned parent_idx, unsigned child_idx)
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{
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update_parents ();
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unsigned links_to_child = 0;
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for (const auto& l : vertices_[parent_idx].obj.all_links ())
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{
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if (l.objidx == child_idx) links_to_child++;
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}
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if (vertices_[child_idx].incoming_edges () <= links_to_child)
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{
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// Can't duplicate this node, doing so would orphan the original one as all remaining links
|
||||
// to child are from parent.
|
||||
DEBUG_MSG (SUBSET_REPACK, nullptr, " Not duplicating %d => %d",
|
||||
parent_idx, child_idx);
|
||||
return false;
|
||||
}
|
||||
|
||||
DEBUG_MSG (SUBSET_REPACK, nullptr, " Duplicating %d => %d",
|
||||
parent_idx, child_idx);
|
||||
|
||||
unsigned clone_idx = duplicate (child_idx);
|
||||
if (clone_idx == (unsigned) -1) return false;
|
||||
// duplicate shifts the root node idx, so if parent_idx was root update it.
|
||||
if (parent_idx == clone_idx) parent_idx++;
|
||||
|
||||
auto& parent = vertices_[parent_idx];
|
||||
for (auto& l : parent.obj.all_links_writer ())
|
||||
{
|
||||
if (l.objidx != child_idx)
|
||||
continue;
|
||||
|
||||
reassign_link (l, parent_idx, clone_idx);
|
||||
}
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
/*
|
||||
* Raises the sorting priority of all children.
|
||||
*/
|
||||
bool raise_childrens_priority (unsigned parent_idx)
|
||||
{
|
||||
DEBUG_MSG (SUBSET_REPACK, nullptr, " Raising priority of all children of %d",
|
||||
parent_idx);
|
||||
// This operation doesn't change ordering until a sort is run, so no need
|
||||
// to invalidate positions. It does not change graph structure so no need
|
||||
// to update distances or edge counts.
|
||||
auto& parent = vertices_[parent_idx].obj;
|
||||
bool made_change = false;
|
||||
for (auto& l : parent.all_links_writer ())
|
||||
made_change |= vertices_[l.objidx].raise_priority ();
|
||||
return made_change;
|
||||
}
|
||||
|
||||
/*
|
||||
* Will any offsets overflow on graph when it's serialized?
|
||||
*/
|
||||
bool will_overflow (hb_vector_t<overflow_record_t>* overflows = nullptr)
|
||||
{
|
||||
if (overflows) overflows->resize (0);
|
||||
update_positions ();
|
||||
|
||||
for (int parent_idx = vertices_.length - 1; parent_idx >= 0; parent_idx--)
|
||||
{
|
||||
// Don't need to check virtual links for overflow
|
||||
for (const auto& link : vertices_[parent_idx].obj.real_links)
|
||||
{
|
||||
int64_t offset = compute_offset (parent_idx, link);
|
||||
if (is_valid_offset (offset, link))
|
||||
continue;
|
||||
|
||||
if (!overflows) return true;
|
||||
|
||||
overflow_record_t r;
|
||||
r.parent = parent_idx;
|
||||
r.child = link.objidx;
|
||||
overflows->push (r);
|
||||
}
|
||||
}
|
||||
|
||||
if (!overflows) return false;
|
||||
return overflows->length;
|
||||
}
|
||||
|
||||
void print_orphaned_nodes ()
|
||||
{
|
||||
if (!DEBUG_ENABLED(SUBSET_REPACK)) return;
|
||||
|
||||
DEBUG_MSG (SUBSET_REPACK, nullptr, "Graph is not fully connected.");
|
||||
parents_invalid = true;
|
||||
update_parents();
|
||||
|
||||
for (unsigned i = 0; i < root_idx (); i++)
|
||||
{
|
||||
const auto& v = vertices_[i];
|
||||
if (!v.parents)
|
||||
DEBUG_MSG (SUBSET_REPACK, nullptr, "Node %u is orphaned.", i);
|
||||
}
|
||||
}
|
||||
|
||||
void print_overflows (const hb_vector_t<overflow_record_t>& overflows)
|
||||
{
|
||||
if (!DEBUG_ENABLED(SUBSET_REPACK)) return;
|
||||
|
||||
update_parents ();
|
||||
int limit = 10;
|
||||
for (const auto& o : overflows)
|
||||
{
|
||||
if (!limit--) break;
|
||||
const auto& parent = vertices_[o.parent];
|
||||
const auto& child = vertices_[o.child];
|
||||
DEBUG_MSG (SUBSET_REPACK, nullptr,
|
||||
" overflow from "
|
||||
"%4d (%4d in, %4d out, space %2d) => "
|
||||
"%4d (%4d in, %4d out, space %2d)",
|
||||
o.parent,
|
||||
parent.incoming_edges (),
|
||||
parent.obj.real_links.length + parent.obj.virtual_links.length,
|
||||
space_for (o.parent),
|
||||
o.child,
|
||||
child.incoming_edges (),
|
||||
child.obj.real_links.length + child.obj.virtual_links.length,
|
||||
space_for (o.child));
|
||||
}
|
||||
if (overflows.length > 10) {
|
||||
DEBUG_MSG (SUBSET_REPACK, nullptr, " ... plus %d more overflows.", overflows.length - 10);
|
||||
}
|
||||
}
|
||||
|
||||
unsigned num_roots_for_space (unsigned space) const
|
||||
{
|
||||
return num_roots_for_space_[space];
|
||||
}
|
||||
|
||||
unsigned next_space () const
|
||||
{
|
||||
return num_roots_for_space_.length;
|
||||
}
|
||||
|
||||
void move_to_new_space (const hb_set_t& indices)
|
||||
{
|
||||
num_roots_for_space_.push (0);
|
||||
unsigned new_space = num_roots_for_space_.length - 1;
|
||||
|
||||
for (unsigned index : indices) {
|
||||
auto& node = vertices_[index];
|
||||
num_roots_for_space_[node.space] = num_roots_for_space_[node.space] - 1;
|
||||
num_roots_for_space_[new_space] = num_roots_for_space_[new_space] + 1;
|
||||
node.space = new_space;
|
||||
distance_invalid = true;
|
||||
positions_invalid = true;
|
||||
}
|
||||
}
|
||||
|
||||
unsigned space_for (unsigned index, unsigned* root = nullptr) const
|
||||
{
|
||||
const auto& node = vertices_[index];
|
||||
if (node.space)
|
||||
{
|
||||
if (root != nullptr)
|
||||
*root = index;
|
||||
return node.space;
|
||||
}
|
||||
|
||||
if (!node.parents)
|
||||
{
|
||||
if (root)
|
||||
*root = index;
|
||||
return 0;
|
||||
}
|
||||
|
||||
return space_for (node.parents[0], root);
|
||||
}
|
||||
|
||||
void err_other_error () { this->successful = false; }
|
||||
|
||||
size_t total_size_in_bytes () const {
|
||||
size_t total_size = 0;
|
||||
for (unsigned i = 0; i < vertices_.length; i++) {
|
||||
size_t size = vertices_[i].obj.tail - vertices_[i].obj.head;
|
||||
total_size += size;
|
||||
}
|
||||
return total_size;
|
||||
}
|
||||
|
||||
|
||||
private:
|
||||
|
||||
/*
|
||||
* Returns the numbers of incoming edges that are 32bits wide.
|
||||
*/
|
||||
unsigned wide_parents (unsigned node_idx, hb_set_t& parents) const
|
||||
{
|
||||
unsigned count = 0;
|
||||
hb_set_t visited;
|
||||
for (unsigned p : vertices_[node_idx].parents)
|
||||
{
|
||||
if (visited.has (p)) continue;
|
||||
visited.add (p);
|
||||
|
||||
// Only real links can be wide
|
||||
for (const auto& l : vertices_[p].obj.real_links)
|
||||
{
|
||||
if (l.objidx == node_idx && l.width == 4 && !l.is_signed)
|
||||
{
|
||||
count++;
|
||||
parents.add (p);
|
||||
}
|
||||
}
|
||||
}
|
||||
return count;
|
||||
}
|
||||
|
||||
bool check_success (bool success)
|
||||
{ return this->successful && (success || ((void) err_other_error (), false)); }
|
||||
|
||||
/*
|
||||
* Creates a map from objid to # of incoming edges.
|
||||
*/
|
||||
void update_parents ()
|
||||
{
|
||||
if (!parents_invalid) return;
|
||||
|
||||
for (unsigned i = 0; i < vertices_.length; i++)
|
||||
vertices_[i].parents.reset ();
|
||||
|
||||
for (unsigned p = 0; p < vertices_.length; p++)
|
||||
{
|
||||
for (auto& l : vertices_[p].obj.all_links ())
|
||||
{
|
||||
vertices_[l.objidx].parents.push (p);
|
||||
}
|
||||
}
|
||||
|
||||
parents_invalid = false;
|
||||
}
|
||||
|
||||
/*
|
||||
* compute the serialized start and end positions for each vertex.
|
||||
*/
|
||||
void update_positions ()
|
||||
{
|
||||
if (!positions_invalid) return;
|
||||
|
||||
unsigned current_pos = 0;
|
||||
for (int i = root_idx (); i >= 0; i--)
|
||||
{
|
||||
auto& v = vertices_[i];
|
||||
v.start = current_pos;
|
||||
current_pos += v.obj.tail - v.obj.head;
|
||||
v.end = current_pos;
|
||||
}
|
||||
|
||||
positions_invalid = false;
|
||||
}
|
||||
|
||||
/*
|
||||
* Finds the distance to each object in the graph
|
||||
* from the initial node.
|
||||
*/
|
||||
void update_distances ()
|
||||
{
|
||||
if (!distance_invalid) return;
|
||||
|
||||
// Uses Dijkstra's algorithm to find all of the shortest distances.
|
||||
// https://en.wikipedia.org/wiki/Dijkstra%27s_algorithm
|
||||
//
|
||||
// Implementation Note:
|
||||
// Since our priority queue doesn't support fast priority decreases
|
||||
// we instead just add new entries into the queue when a priority changes.
|
||||
// Redundant ones are filtered out later on by the visited set.
|
||||
// According to https://www3.cs.stonybrook.edu/~rezaul/papers/TR-07-54.pdf
|
||||
// for practical performance this is faster then using a more advanced queue
|
||||
// (such as a fibonacci queue) with a fast decrease priority.
|
||||
for (unsigned i = 0; i < vertices_.length; i++)
|
||||
{
|
||||
if (i == vertices_.length - 1)
|
||||
vertices_[i].distance = 0;
|
||||
else
|
||||
vertices_[i].distance = hb_int_max (int64_t);
|
||||
}
|
||||
|
||||
hb_priority_queue_t queue;
|
||||
queue.insert (0, vertices_.length - 1);
|
||||
|
||||
hb_vector_t<bool> visited;
|
||||
visited.resize (vertices_.length);
|
||||
|
||||
while (!queue.in_error () && !queue.is_empty ())
|
||||
{
|
||||
unsigned next_idx = queue.pop_minimum ().second;
|
||||
if (visited[next_idx]) continue;
|
||||
const auto& next = vertices_[next_idx];
|
||||
int64_t next_distance = vertices_[next_idx].distance;
|
||||
visited[next_idx] = true;
|
||||
|
||||
for (const auto& link : next.obj.all_links ())
|
||||
{
|
||||
if (visited[link.objidx]) continue;
|
||||
|
||||
const auto& child = vertices_[link.objidx].obj;
|
||||
unsigned link_width = link.width ? link.width : 4; // treat virtual offsets as 32 bits wide
|
||||
int64_t child_weight = (child.tail - child.head) +
|
||||
((int64_t) 1 << (link_width * 8)) * (vertices_[link.objidx].space + 1);
|
||||
int64_t child_distance = next_distance + child_weight;
|
||||
|
||||
if (child_distance < vertices_[link.objidx].distance)
|
||||
{
|
||||
vertices_[link.objidx].distance = child_distance;
|
||||
queue.insert (child_distance, link.objidx);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
check_success (!queue.in_error ());
|
||||
if (!check_success (queue.is_empty ()))
|
||||
{
|
||||
print_orphaned_nodes ();
|
||||
return;
|
||||
}
|
||||
|
||||
distance_invalid = false;
|
||||
}
|
||||
|
||||
int64_t compute_offset (
|
||||
unsigned parent_idx,
|
||||
const hb_serialize_context_t::object_t::link_t& link) const
|
||||
{
|
||||
const auto& parent = vertices_[parent_idx];
|
||||
const auto& child = vertices_[link.objidx];
|
||||
int64_t offset = 0;
|
||||
switch ((hb_serialize_context_t::whence_t) link.whence) {
|
||||
case hb_serialize_context_t::whence_t::Head:
|
||||
offset = child.start - parent.start; break;
|
||||
case hb_serialize_context_t::whence_t::Tail:
|
||||
offset = child.start - parent.end; break;
|
||||
case hb_serialize_context_t::whence_t::Absolute:
|
||||
offset = child.start; break;
|
||||
}
|
||||
|
||||
assert (offset >= link.bias);
|
||||
offset -= link.bias;
|
||||
return offset;
|
||||
}
|
||||
|
||||
bool is_valid_offset (int64_t offset,
|
||||
const hb_serialize_context_t::object_t::link_t& link) const
|
||||
{
|
||||
if (unlikely (!link.width))
|
||||
// Virtual links can't overflow.
|
||||
return link.is_signed || offset >= 0;
|
||||
|
||||
if (link.is_signed)
|
||||
{
|
||||
if (link.width == 4)
|
||||
return offset >= -((int64_t) 1 << 31) && offset < ((int64_t) 1 << 31);
|
||||
else
|
||||
return offset >= -(1 << 15) && offset < (1 << 15);
|
||||
}
|
||||
else
|
||||
{
|
||||
if (link.width == 4)
|
||||
return offset >= 0 && offset < ((int64_t) 1 << 32);
|
||||
else if (link.width == 3)
|
||||
return offset >= 0 && offset < ((int32_t) 1 << 24);
|
||||
else
|
||||
return offset >= 0 && offset < (1 << 16);
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* Updates a link in the graph to point to a different object. Corrects the
|
||||
* parents vector on the previous and new child nodes.
|
||||
*/
|
||||
void reassign_link (hb_serialize_context_t::object_t::link_t& link,
|
||||
unsigned parent_idx,
|
||||
unsigned new_idx)
|
||||
{
|
||||
unsigned old_idx = link.objidx;
|
||||
link.objidx = new_idx;
|
||||
vertices_[old_idx].remove_parent (parent_idx);
|
||||
vertices_[new_idx].parents.push (parent_idx);
|
||||
}
|
||||
|
||||
/*
|
||||
* Updates all objidx's in all links using the provided mapping. Corrects incoming edge counts.
|
||||
*/
|
||||
template<typename Iterator, hb_requires (hb_is_iterator (Iterator))>
|
||||
void remap_obj_indices (const hb_map_t& id_map,
|
||||
Iterator subgraph,
|
||||
bool only_wide = false)
|
||||
{
|
||||
if (!id_map) return;
|
||||
for (unsigned i : subgraph)
|
||||
{
|
||||
for (auto& link : vertices_[i].obj.all_links_writer ())
|
||||
{
|
||||
const unsigned *v;
|
||||
if (!id_map.has (link.objidx, &v)) continue;
|
||||
if (only_wide && !(link.width == 4 && !link.is_signed)) continue;
|
||||
|
||||
reassign_link (link, i, *v);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* Updates all objidx's in all links using the provided mapping.
|
||||
*/
|
||||
void remap_all_obj_indices (const hb_vector_t<unsigned>& id_map,
|
||||
hb_vector_t<vertex_t>* sorted_graph) const
|
||||
{
|
||||
for (unsigned i = 0; i < sorted_graph->length; i++)
|
||||
{
|
||||
(*sorted_graph)[i].remap_parents (id_map);
|
||||
for (auto& link : (*sorted_graph)[i].obj.all_links_writer ())
|
||||
{
|
||||
link.objidx = id_map[link.objidx];
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* Finds all nodes in targets that are reachable from start_idx, nodes in visited will be skipped.
|
||||
* For this search the graph is treated as being undirected.
|
||||
*
|
||||
* Connected targets will be added to connected and removed from targets. All visited nodes
|
||||
* will be added to visited.
|
||||
*/
|
||||
void find_connected_nodes (unsigned start_idx,
|
||||
hb_set_t& targets,
|
||||
hb_set_t& visited,
|
||||
hb_set_t& connected)
|
||||
{
|
||||
if (unlikely (!check_success (!visited.in_error ()))) return;
|
||||
if (visited.has (start_idx)) return;
|
||||
visited.add (start_idx);
|
||||
|
||||
if (targets.has (start_idx))
|
||||
{
|
||||
targets.del (start_idx);
|
||||
connected.add (start_idx);
|
||||
}
|
||||
|
||||
const auto& v = vertices_[start_idx];
|
||||
|
||||
// Graph is treated as undirected so search children and parents of start_idx
|
||||
for (const auto& l : v.obj.all_links ())
|
||||
find_connected_nodes (l.objidx, targets, visited, connected);
|
||||
|
||||
for (unsigned p : v.parents)
|
||||
find_connected_nodes (p, targets, visited, connected);
|
||||
}
|
||||
|
||||
public:
|
||||
// TODO(garretrieger): make private, will need to move most of offset overflow code into graph.
|
||||
hb_vector_t<vertex_t> vertices_;
|
||||
hb_vector_t<vertex_t> vertices_scratch_;
|
||||
private:
|
||||
bool parents_invalid;
|
||||
bool distance_invalid;
|
||||
bool positions_invalid;
|
||||
bool successful;
|
||||
hb_vector_t<unsigned> num_roots_for_space_;
|
||||
};
|
||||
|
||||
}
|
||||
|
||||
#endif // GRAPH_GRAPH_HH
|
||||
|
|
@ -0,0 +1,130 @@
|
|||
/*
|
||||
* Copyright © 2022 Google, Inc.
|
||||
*
|
||||
* This is part of HarfBuzz, a text shaping library.
|
||||
*
|
||||
* Permission is hereby granted, without written agreement and without
|
||||
* license or royalty fees, to use, copy, modify, and distribute this
|
||||
* software and its documentation for any purpose, provided that the
|
||||
* above copyright notice and the following two paragraphs appear in
|
||||
* all copies of this software.
|
||||
*
|
||||
* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
|
||||
* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
|
||||
* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
|
||||
* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
|
||||
* DAMAGE.
|
||||
*
|
||||
* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
|
||||
* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
|
||||
* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS
|
||||
* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
|
||||
* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
|
||||
*
|
||||
* Google Author(s): Garret Rieger
|
||||
*/
|
||||
|
||||
#ifndef GRAPH_SERIALIZE_HH
|
||||
#define GRAPH_SERIALIZE_HH
|
||||
|
||||
namespace graph {
|
||||
|
||||
template <typename O> inline void
|
||||
serialize_link_of_type (const hb_serialize_context_t::object_t::link_t& link,
|
||||
char* head,
|
||||
hb_serialize_context_t* c)
|
||||
{
|
||||
OT::Offset<O>* offset = reinterpret_cast<OT::Offset<O>*> (head + link.position);
|
||||
*offset = 0;
|
||||
c->add_link (*offset,
|
||||
// serializer has an extra nil object at the start of the
|
||||
// object array. So all id's are +1 of what our id's are.
|
||||
link.objidx + 1,
|
||||
(hb_serialize_context_t::whence_t) link.whence,
|
||||
link.bias);
|
||||
}
|
||||
|
||||
inline
|
||||
void serialize_link (const hb_serialize_context_t::object_t::link_t& link,
|
||||
char* head,
|
||||
hb_serialize_context_t* c)
|
||||
{
|
||||
switch (link.width)
|
||||
{
|
||||
case 0:
|
||||
// Virtual links aren't serialized.
|
||||
return;
|
||||
case 4:
|
||||
if (link.is_signed)
|
||||
{
|
||||
serialize_link_of_type<OT::HBINT32> (link, head, c);
|
||||
} else {
|
||||
serialize_link_of_type<OT::HBUINT32> (link, head, c);
|
||||
}
|
||||
return;
|
||||
case 2:
|
||||
if (link.is_signed)
|
||||
{
|
||||
serialize_link_of_type<OT::HBINT16> (link, head, c);
|
||||
} else {
|
||||
serialize_link_of_type<OT::HBUINT16> (link, head, c);
|
||||
}
|
||||
return;
|
||||
case 3:
|
||||
serialize_link_of_type<OT::HBUINT24> (link, head, c);
|
||||
return;
|
||||
default:
|
||||
// Unexpected link width.
|
||||
assert (0);
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* serialize graph into the provided serialization buffer.
|
||||
*/
|
||||
inline hb_blob_t* serialize (const graph_t& graph)
|
||||
{
|
||||
hb_vector_t<char> buffer;
|
||||
size_t size = graph.total_size_in_bytes ();
|
||||
if (!buffer.alloc (size)) {
|
||||
DEBUG_MSG (SUBSET_REPACK, nullptr, "Unable to allocate output buffer.");
|
||||
return nullptr;
|
||||
}
|
||||
hb_serialize_context_t c((void *) buffer, size);
|
||||
|
||||
c.start_serialize<void> ();
|
||||
const auto& vertices = graph.vertices_;
|
||||
for (unsigned i = 0; i < vertices.length; i++) {
|
||||
c.push ();
|
||||
|
||||
size_t size = vertices[i].obj.tail - vertices[i].obj.head;
|
||||
char* start = c.allocate_size <char> (size);
|
||||
if (!start) {
|
||||
DEBUG_MSG (SUBSET_REPACK, nullptr, "Buffer out of space.");
|
||||
return nullptr;
|
||||
}
|
||||
|
||||
memcpy (start, vertices[i].obj.head, size);
|
||||
|
||||
// Only real links needs to be serialized.
|
||||
for (const auto& link : vertices[i].obj.real_links)
|
||||
serialize_link (link, start, &c);
|
||||
|
||||
// All duplications are already encoded in the graph, so don't
|
||||
// enable sharing during packing.
|
||||
c.pop_pack (false);
|
||||
}
|
||||
c.end_serialize ();
|
||||
|
||||
if (c.in_error ()) {
|
||||
DEBUG_MSG (SUBSET_REPACK, nullptr, "Error during serialization. Err flag: %d",
|
||||
c.errors);
|
||||
return nullptr;
|
||||
}
|
||||
|
||||
return c.copy_blob ();
|
||||
}
|
||||
|
||||
} // namespace graph
|
||||
|
||||
#endif // GRAPH_SERIALIZE_HH
|
||||
1031
src/hb-repacker.hh
1031
src/hb-repacker.hh
File diff suppressed because it is too large
Load Diff
|
|
@ -28,6 +28,7 @@
|
|||
|
||||
#include "hb-repacker.hh"
|
||||
#include "hb-open-type.hh"
|
||||
#include "graph/serialize.hh"
|
||||
|
||||
static void start_object(const char* tag,
|
||||
unsigned len,
|
||||
|
|
@ -931,7 +932,7 @@ test_serialize ()
|
|||
hb_bytes_t expected = c1.copy_bytes ();
|
||||
|
||||
graph_t graph (c1.object_graph ());
|
||||
hb_blob_t* out = graph.serialize ();
|
||||
hb_blob_t* out = graph::serialize (graph);
|
||||
free (buffer_1);
|
||||
|
||||
hb_bytes_t actual = out->as_bytes ();
|
||||
|
|
|
|||
Loading…
Reference in New Issue