From 6bf0a5cb5034a7e684dcc3500e841785237ce2dd Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 19:32:43 +0200 Subject: Adding upstream version 1:115.7.0. Signed-off-by: Daniel Baumann --- gfx/harfbuzz/src/graph/serialize.hh | 270 ++++++++++++++++++++++++++++++++++++ 1 file changed, 270 insertions(+) create mode 100644 gfx/harfbuzz/src/graph/serialize.hh (limited to 'gfx/harfbuzz/src/graph/serialize.hh') diff --git a/gfx/harfbuzz/src/graph/serialize.hh b/gfx/harfbuzz/src/graph/serialize.hh new file mode 100644 index 0000000000..2e0b845baa --- /dev/null +++ b/gfx/harfbuzz/src/graph/serialize.hh @@ -0,0 +1,270 @@ +/* + * 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 { + +struct overflow_record_t +{ + unsigned parent; + unsigned child; + + bool operator != (const overflow_record_t o) const + { return !(*this == o); } + + inline bool operator == (const overflow_record_t& o) const + { + return parent == o.parent && + child == o.child; + } + + inline uint32_t hash () const + { + uint32_t current = 0; + current = current * 31 + hb_hash (parent); + current = current * 31 + hb_hash (child); + return current; + } +}; + +inline +int64_t compute_offset ( + const graph_t& graph, + unsigned parent_idx, + const hb_serialize_context_t::object_t::link_t& link) +{ + const auto& parent = graph.vertices_[parent_idx]; + const auto& child = graph.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; +} + +inline +bool is_valid_offset (int64_t offset, + const hb_serialize_context_t::object_t::link_t& link) +{ + 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); + } +} + +/* + * Will any offsets overflow on graph when it's serialized? + */ +inline bool +will_overflow (graph_t& graph, + hb_vector_t* overflows = nullptr) +{ + if (overflows) overflows->resize (0); + graph.update_positions (); + + hb_hashmap_t record_set; + const auto& vertices = graph.vertices_; + 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.arrayZ[parent_idx].obj.real_links) + { + int64_t offset = compute_offset (graph, parent_idx, link); + if (likely (is_valid_offset (offset, link))) + continue; + + if (!overflows) return true; + + overflow_record_t r; + r.parent = parent_idx; + r.child = link.objidx; + if (record_set.has(&r)) continue; // don't keep duplicate overflows. + + overflows->push (r); + record_set.set(&r, true); + } + } + + if (!overflows) return false; + return overflows->length; +} + +inline +void print_overflows (graph_t& graph, + const hb_vector_t& overflows) +{ + if (!DEBUG_ENABLED(SUBSET_REPACK)) return; + + graph.update_parents (); + int limit = 10; + for (const auto& o : overflows) + { + if (!limit--) break; + const auto& parent = graph.vertices_[o.parent]; + const auto& child = graph.vertices_[o.child]; + DEBUG_MSG (SUBSET_REPACK, nullptr, + " overflow from " + "%4u (%4u in, %4u out, space %2u) => " + "%4u (%4u in, %4u out, space %2u)", + o.parent, + parent.incoming_edges (), + parent.obj.real_links.length + parent.obj.virtual_links.length, + graph.space_for (o.parent), + o.child, + child.incoming_edges (), + child.obj.real_links.length + child.obj.virtual_links.length, + graph.space_for (o.child)); + } + if (overflows.length > 10) { + DEBUG_MSG (SUBSET_REPACK, nullptr, " ... plus %u more overflows.", overflows.length - 10); + } +} + +template 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* offset = reinterpret_cast*> (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 (link, head, c); + } else { + serialize_link_of_type (link, head, c); + } + return; + case 2: + if (link.is_signed) + { + serialize_link_of_type (link, head, c); + } else { + serialize_link_of_type (link, head, c); + } + return; + case 3: + serialize_link_of_type (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 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 (); + 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 (size); + if (!start) { + DEBUG_MSG (SUBSET_REPACK, nullptr, "Buffer out of space."); + return nullptr; + } + + hb_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 -- cgit v1.2.3