Python2/PyMuPDF: mupdf-source/thirdparty/tesseract/src/dict/trie.cpp comparison

comparison mupdf-source/thirdparty/tesseract/src/dict/trie.cpp @ 3:2c135c81b16c

MERGE: upstream PyMuPDF 1.26.4 with MuPDF 1.26.7

author	Franz Glasner <fzglas.hg@dom66.de>
date	Mon, 15 Sep 2025 11:44:09 +0200
parents	b50eed0cc0ef
children

comparison

equal deleted inserted replaced

-:6015a75abc2d
+:2c135c81b16c
+/******************************************************************************
+*
+* File:         trie.cpp  (Formerly trie.c)
+* Description:  Functions to build a trie data structure.
+* Author:       Mark Seaman, OCR Technology
+*
+* (c) Copyright 1987, Hewlett-Packard Company.
+** Licensed under the Apache License, Version 2.0 (the "License");
+** you may not use this file except in compliance with the License.
+** You may obtain a copy of the License at
+** http://www.apache.org/licenses/LICENSE-2.0
+** Unless required by applicable law or agreed to in writing, software
+** distributed under the License is distributed on an "AS IS" BASIS,
+** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+** See the License for the specific language governing permissions and
+** limitations under the License.
+*
+*****************************************************************************/
+/*----------------------------------------------------------------------
+I n c l u d e s
+----------------------------------------------------------------------*/
+#include "trie.h"
+#include "dawg.h"
+#include "dict.h"
+#include "helpers.h"
+#include "kdpair.h"
+namespace tesseract {
+const char kDoNotReverse[] = "RRP_DO_NO_REVERSE";
+const char kReverseIfHasRTL[] = "RRP_REVERSE_IF_HAS_RTL";
+const char kForceReverse[] = "RRP_FORCE_REVERSE";
+const char *const RTLReversePolicyNames[] = {kDoNotReverse, kReverseIfHasRTL, kForceReverse};
+const char Trie::kAlphaPatternUnicode[] = "\u2000";
+const char Trie::kDigitPatternUnicode[] = "\u2001";
+const char Trie::kAlphanumPatternUnicode[] = "\u2002";
+const char Trie::kPuncPatternUnicode[] = "\u2003";
+const char Trie::kLowerPatternUnicode[] = "\u2004";
+const char Trie::kUpperPatternUnicode[] = "\u2005";
+const char *Trie::get_reverse_policy_name(RTLReversePolicy reverse_policy) {
+return RTLReversePolicyNames[reverse_policy];
+}
+// Reset the Trie to empty.
+void Trie::clear() {
+for (auto node : nodes_) {
+delete node;
+}
+nodes_.clear();
+root_back_freelist_.clear();
+num_edges_ = 0;
+new_dawg_node(); // Need to allocate node 0.
+}
+bool Trie::edge_char_of(NODE_REF node_ref, NODE_REF next_node, int direction, bool word_end,
+UNICHAR_ID unichar_id, EDGE_RECORD **edge_ptr,
+EDGE_INDEX *edge_index) const {
+if (debug_level_ == 3) {
+tprintf("edge_char_of() given node_ref " REFFORMAT " next_node " REFFORMAT
+" direction %d word_end %d unichar_id %d, exploring node:\n",
+node_ref, next_node, direction, word_end, unichar_id);
+if (node_ref != NO_EDGE) {
+print_node(node_ref, nodes_[node_ref]->forward_edges.size());
+}
+}
+if (node_ref == NO_EDGE) {
+return false;
+}
+assert(static_cast<size_t>(node_ref) < nodes_.size());
+EDGE_VECTOR &vec = (direction == FORWARD_EDGE) ? nodes_[node_ref]->forward_edges
+: nodes_[node_ref]->backward_edges;
+int vec_size = vec.size();
+if (node_ref == 0 && direction == FORWARD_EDGE) { // binary search
+EDGE_INDEX start = 0;
+EDGE_INDEX end = vec_size - 1;
+EDGE_INDEX k;
+int compare;
+while (start <= end) {
+k = (start + end) >> 1; // (start + end) / 2
+compare = given_greater_than_edge_rec(next_node, word_end, unichar_id, vec[k]);
+if (compare == 0) { // given == vec[k]
+*edge_ptr = &(vec[k]);
+*edge_index = k;
+return true;
+} else if (compare == 1) { // given > vec[k]
+start = k + 1;
+} else { // given < vec[k]
+end = k - 1;
+}
+}
+} else { // linear search
+for (int i = 0; i < vec_size; ++i) {
+EDGE_RECORD &edge_rec = vec[i];
+if (edge_rec_match(next_node, word_end, unichar_id, next_node_from_edge_rec(edge_rec),
+end_of_word_from_edge_rec(edge_rec), unichar_id_from_edge_rec(edge_rec))) {
+*edge_ptr = &(edge_rec);
+*edge_index = i;
+return true;
+}
+}
+}
+return false; // not found
+}
+bool Trie::add_edge_linkage(NODE_REF node1, NODE_REF node2, bool marker_flag, int direction,
+bool word_end, UNICHAR_ID unichar_id) {
+EDGE_VECTOR *vec = (direction == FORWARD_EDGE) ? &(nodes_[node1]->forward_edges)
+: &(nodes_[node1]->backward_edges);
+unsigned search_index;
+if (node1 == 0 && direction == FORWARD_EDGE) {
+search_index = 0; // find the index to make the add sorted
+while (search_index < vec->size() &&
+given_greater_than_edge_rec(node2, word_end, unichar_id, (*vec)[search_index]) == 1) {
+search_index++;
+}
+} else {
+search_index = vec->size(); // add is unsorted, so index does not matter
+}
+EDGE_RECORD edge_rec;
+link_edge(&edge_rec, node2, marker_flag, direction, word_end, unichar_id);
+if (node1 == 0 && direction == BACKWARD_EDGE && !root_back_freelist_.empty()) {
+EDGE_INDEX edge_index = root_back_freelist_.back();
+root_back_freelist_.pop_back();
+(*vec)[edge_index] = edge_rec;
+} else if (search_index < vec->size()) {
+vec->insert(vec->begin() + search_index, edge_rec);
+} else {
+vec->push_back(edge_rec);
+}
+if (debug_level_ > 1) {
+tprintf("new edge in nodes_[" REFFORMAT "]: ", node1);
+print_edge_rec(edge_rec);
+tprintf("\n");
+}
+num_edges_++;
+return true;
+}
+void Trie::add_word_ending(EDGE_RECORD *edge_ptr, NODE_REF the_next_node, bool marker_flag,
+UNICHAR_ID unichar_id) {
+EDGE_RECORD *back_edge_ptr;
+EDGE_INDEX back_edge_index;
+ASSERT_HOST(edge_char_of(the_next_node, NO_EDGE, BACKWARD_EDGE, false, unichar_id, &back_edge_ptr,
+&back_edge_index));
+if (marker_flag) {
+*back_edge_ptr |= (MARKER_FLAG << flag_start_bit_);
+*edge_ptr |= (MARKER_FLAG << flag_start_bit_);
+}
+// Mark both directions as end of word.
+*back_edge_ptr |= (WERD_END_FLAG << flag_start_bit_);
+*edge_ptr |= (WERD_END_FLAG << flag_start_bit_);
+}
+bool Trie::add_word_to_dawg(const WERD_CHOICE &word, const std::vector<bool> *repetitions) {
+if (word.length() <= 0) {
+return false; // can't add empty words
+}
+if (repetitions != nullptr) {
+ASSERT_HOST(repetitions->size() == word.length());
+}
+// Make sure the word does not contain invalid unchar ids.
+for (unsigned i = 0; i < word.length(); ++i) {
+if (word.unichar_id(i) < 0 || word.unichar_id(i) >= unicharset_size_) {
+return false;
+}
+}
+EDGE_RECORD *edge_ptr;
+NODE_REF last_node = 0;
+NODE_REF the_next_node;
+bool marker_flag = false;
+EDGE_INDEX edge_index;
+int32_t still_finding_chars = true;
+int32_t word_end = false;
+bool add_failed = false;
+bool found;
+if (debug_level_ > 1) {
+word.print("\nAdding word: ");
+}
+UNICHAR_ID unichar_id;
+unsigned i;
+for (i = 0; i < word.length() - 1; ++i) {
+unichar_id = word.unichar_id(i);
+marker_flag = (repetitions != nullptr) ? (*repetitions)[i] : false;
+if (debug_level_ > 1) {
+tprintf("Adding letter %d\n", unichar_id);
+}
+if (still_finding_chars) {
+found = edge_char_of(last_node, NO_EDGE, FORWARD_EDGE, word_end, unichar_id, &edge_ptr,
+&edge_index);
+if (found && debug_level_ > 1) {
+tprintf("exploring edge " REFFORMAT " in node " REFFORMAT "\n", edge_index, last_node);
+}
+if (!found) {
+still_finding_chars = false;
+} else if (next_node_from_edge_rec(*edge_ptr) == 0) {
+// We hit the end of an existing word, but the new word is longer.
+// In this case we have to disconnect the existing word from the
+// backwards root node, mark the current position as end-of-word
+// and add new nodes for the increased length. Disconnecting the
+// existing word from the backwards root node requires a linear
+// search, so it is much faster to add the longest words first,
+// to avoid having to come here.
+word_end = true;
+still_finding_chars = false;
+remove_edge(last_node, 0, word_end, unichar_id);
+} else {
+// We have to add a new branch here for the new word.
+if (marker_flag) {
+set_marker_flag_in_edge_rec(edge_ptr);
+}
+last_node = next_node_from_edge_rec(*edge_ptr);
+}
+}
+if (!still_finding_chars) {
+the_next_node = new_dawg_node();
+if (debug_level_ > 1) {
+tprintf("adding node " REFFORMAT "\n", the_next_node);
+}
+if (the_next_node == 0) {
+add_failed = true;
+break;
+}
+if (!add_new_edge(last_node, the_next_node, marker_flag, word_end, unichar_id)) {
+add_failed = true;
+break;
+}
+word_end = false;
+last_node = the_next_node;
+}
+}
+the_next_node = 0;
+unichar_id = word.unichar_id(i);
+marker_flag = (repetitions != nullptr) ? (*repetitions)[i] : false;
+if (debug_level_ > 1) {
+tprintf("Adding letter %d\n", unichar_id);
+}
+if (still_finding_chars &&
+edge_char_of(last_node, NO_EDGE, FORWARD_EDGE, false, unichar_id, &edge_ptr, &edge_index)) {
+// An extension of this word already exists in the trie, so we
+// only have to add the ending flags in both directions.
+add_word_ending(edge_ptr, next_node_from_edge_rec(*edge_ptr), marker_flag, unichar_id);
+} else {
+// Add a link to node 0. All leaves connect to node 0 so the back links can
+// be used in reduction to a dawg. This root backward node has one edge
+// entry for every word, (except prefixes of longer words) so it is huge.
+if (!add_failed && !add_new_edge(last_node, the_next_node, marker_flag, true, unichar_id)) {
+add_failed = true;
+}
+}
+if (add_failed) {
+tprintf("Re-initializing document dictionary...\n");
+clear();
+return false;
+} else {
+return true;
+}
+}
+NODE_REF Trie::new_dawg_node() {
+auto *node = new TRIE_NODE_RECORD();
+nodes_.push_back(node);
+return nodes_.size() - 1;
+}
+bool Trie::read_and_add_word_list(const char *filename, const UNICHARSET &unicharset,
+Trie::RTLReversePolicy reverse_policy) {
+std::vector<std::string> word_list;
+if (!read_word_list(filename, &word_list)) {
+return false;
+}
+std::sort(word_list.begin(), word_list.end(),
+[](auto &s1, auto &s2) { return s1.size() > s2.size(); });
+return add_word_list(word_list, unicharset, reverse_policy);
+}
+bool Trie::read_word_list(const char *filename, std::vector<std::string> *words) {
+FILE *word_file;
+char line_str[CHARS_PER_LINE];
+int word_count = 0;
+word_file = fopen(filename, "rb");
+if (word_file == nullptr) {
+return false;
+}
+while (fgets(line_str, sizeof(line_str), word_file) != nullptr) {
+chomp_string(line_str); // remove newline
+std::string word_str(line_str);
+++word_count;
+if (debug_level_ && word_count % 10000 == 0) {
+tprintf("Read %d words so far\n", word_count);
+}
+words->push_back(word_str);
+}
+if (debug_level_) {
+tprintf("Read %d words total.\n", word_count);
+}
+fclose(word_file);
+return true;
+}
+bool Trie::add_word_list(const std::vector<std::string> &words, const UNICHARSET &unicharset,
+Trie::RTLReversePolicy reverse_policy) {
+for (const auto &i : words) {
+WERD_CHOICE word(i.c_str(), unicharset);
+if (word.empty() || word.contains_unichar_id(INVALID_UNICHAR_ID)) {
+continue;
+}
+if ((reverse_policy == RRP_REVERSE_IF_HAS_RTL && word.has_rtl_unichar_id()) ||
+reverse_policy == RRP_FORCE_REVERSE) {
+word.reverse_and_mirror_unichar_ids();
+}
+if (!word_in_dawg(word)) {
+add_word_to_dawg(word);
+if (!word_in_dawg(word)) {
+tprintf("Error: word '%s' not in DAWG after adding it\n", i.c_str());
+return false;
+}
+}
+}
+return true;
+}
+void Trie::initialize_patterns(UNICHARSET *unicharset) {
+unicharset->unichar_insert(kAlphaPatternUnicode);
+alpha_pattern_ = unicharset->unichar_to_id(kAlphaPatternUnicode);
+unicharset->unichar_insert(kDigitPatternUnicode);
+digit_pattern_ = unicharset->unichar_to_id(kDigitPatternUnicode);
+unicharset->unichar_insert(kAlphanumPatternUnicode);
+alphanum_pattern_ = unicharset->unichar_to_id(kAlphanumPatternUnicode);
+unicharset->unichar_insert(kPuncPatternUnicode);
+punc_pattern_ = unicharset->unichar_to_id(kPuncPatternUnicode);
+unicharset->unichar_insert(kLowerPatternUnicode);
+lower_pattern_ = unicharset->unichar_to_id(kLowerPatternUnicode);
+unicharset->unichar_insert(kUpperPatternUnicode);
+upper_pattern_ = unicharset->unichar_to_id(kUpperPatternUnicode);
+initialized_patterns_ = true;
+unicharset_size_ = unicharset->size();
+}
+void Trie::unichar_id_to_patterns(UNICHAR_ID unichar_id, const UNICHARSET &unicharset,
+std::vector<UNICHAR_ID> *vec) const {
+bool is_alpha = unicharset.get_isalpha(unichar_id);
+if (is_alpha) {
+vec->push_back(alpha_pattern_);
+vec->push_back(alphanum_pattern_);
+if (unicharset.get_islower(unichar_id)) {
+vec->push_back(lower_pattern_);
+} else if (unicharset.get_isupper(unichar_id)) {
+vec->push_back(upper_pattern_);
+}
+}
+if (unicharset.get_isdigit(unichar_id)) {
+vec->push_back(digit_pattern_);
+if (!is_alpha) {
+vec->push_back(alphanum_pattern_);
+}
+}
+if (unicharset.get_ispunctuation(unichar_id)) {
+vec->push_back(punc_pattern_);
+}
+}
+UNICHAR_ID Trie::character_class_to_pattern(char ch) {
+if (ch == 'c') {
+return alpha_pattern_;
+} else if (ch == 'd') {
+return digit_pattern_;
+} else if (ch == 'n') {
+return alphanum_pattern_;
+} else if (ch == 'p') {
+return punc_pattern_;
+} else if (ch == 'a') {
+return lower_pattern_;
+} else if (ch == 'A') {
+return upper_pattern_;
+} else {
+return INVALID_UNICHAR_ID;
+}
+}
+bool Trie::read_pattern_list(const char *filename, const UNICHARSET &unicharset) {
+if (!initialized_patterns_) {
+tprintf("please call initialize_patterns() before read_pattern_list()\n");
+return false;
+}
+FILE *pattern_file = fopen(filename, "rb");
+if (pattern_file == nullptr) {
+tprintf("Error opening pattern file %s\n", filename);
+return false;
+}
+int pattern_count = 0;
+char string[CHARS_PER_LINE];
+while (fgets(string, CHARS_PER_LINE, pattern_file) != nullptr) {
+chomp_string(string); // remove newline
+// Parse the pattern and construct a unichar id vector.
+// Record the number of repetitions of each unichar in the parallel vector.
+WERD_CHOICE word(&unicharset);
+std::vector<bool> repetitions_vec;
+const char *str_ptr = string;
+int step = unicharset.step(str_ptr);
+bool failed = false;
+while (step > 0) {
+UNICHAR_ID curr_unichar_id = INVALID_UNICHAR_ID;
+if (step == 1 && *str_ptr == '\\') {
+++str_ptr;
+if (*str_ptr == '\\') { // regular '\' unichar that was escaped
+curr_unichar_id = unicharset.unichar_to_id(str_ptr, step);
+} else {
+#if 0 // TODO: This code should be enabled if kSaneNumConcreteChars != 0.
+if (word.length() < kSaneNumConcreteChars) {
+tprintf(
+"Please provide at least %d concrete characters at the"
+" beginning of the pattern\n",
+kSaneNumConcreteChars);
+failed = true;
+break;
+}
+#endif
+// Parse character class from expression.
+curr_unichar_id = character_class_to_pattern(*str_ptr);
+}
+} else {
+curr_unichar_id = unicharset.unichar_to_id(str_ptr, step);
+}
+if (curr_unichar_id == INVALID_UNICHAR_ID) {
+failed = true;
+break; // failed to parse this pattern
+}
+word.append_unichar_id(curr_unichar_id, 1, 0.0, 0.0);
+repetitions_vec.push_back(false);
+str_ptr += step;
+step = unicharset.step(str_ptr);
+// Check if there is a repetition pattern specified after this unichar.
+if (step == 1 && *str_ptr == '\\' && *(str_ptr + 1) == '*') {
+repetitions_vec[repetitions_vec.size() - 1] = true;
+str_ptr += 2;
+step = unicharset.step(str_ptr);
+}
+}
+if (failed) {
+tprintf("Invalid user pattern %s\n", string);
+continue;
+}
+// Insert the pattern into the trie.
+if (debug_level_ > 2) {
+tprintf("Inserting expanded user pattern %s\n", word.debug_string().c_str());
+}
+if (!this->word_in_dawg(word)) {
+this->add_word_to_dawg(word, &repetitions_vec);
+if (!this->word_in_dawg(word)) {
+tprintf("Error: failed to insert pattern '%s'\n", string);
+}
+}
+++pattern_count;
+}
+if (debug_level_) {
+tprintf("Read %d valid patterns from %s\n", pattern_count, filename);
+}
+fclose(pattern_file);
+return true;
+}
+void Trie::remove_edge_linkage(NODE_REF node1, NODE_REF node2, int direction, bool word_end,
+UNICHAR_ID unichar_id) {
+EDGE_RECORD *edge_ptr = nullptr;
+EDGE_INDEX edge_index = 0;
+ASSERT_HOST(edge_char_of(node1, node2, direction, word_end, unichar_id, &edge_ptr, &edge_index));
+if (debug_level_ > 1) {
+tprintf("removed edge in nodes_[" REFFORMAT "]: ", node1);
+print_edge_rec(*edge_ptr);
+tprintf("\n");
+}
+if (direction == FORWARD_EDGE) {
+nodes_[node1]->forward_edges.erase(nodes_[node1]->forward_edges.begin() + edge_index);
+} else if (node1 == 0) {
+KillEdge(&nodes_[node1]->backward_edges[edge_index]);
+root_back_freelist_.push_back(edge_index);
+} else {
+nodes_[node1]->backward_edges.erase(nodes_[node1]->backward_edges.begin() + edge_index);
+}
+--num_edges_;
+}
+// Some optimizations employed in add_word_to_dawg and trie_to_dawg:
+// 1 Avoid insertion sorting or bubble sorting the tail root node
+//   (back links on node 0, a list of all the leaves.). The node is
+//   huge, and sorting it with n^2 time is terrible.
+// 2 Avoid using vector::erase on the tail root node.
+//   (a) During add of words to the trie, zero-out the unichars and
+//       keep a freelist of spaces to re-use.
+//   (b) During reduction, just zero-out the unichars of deleted back
+//       links, skipping zero entries while searching.
+// 3 Avoid linear search of the tail root node. This has to be done when
+//   a suffix is added to an existing word. Adding words by decreasing
+//   length avoids this problem entirely. Words can still be added in
+//   any order, but it is faster to add the longest first.
+SquishedDawg *Trie::trie_to_dawg() {
+root_back_freelist_.clear(); // Will be invalided by trie_to_dawg.
+if (debug_level_ > 2) {
+print_all("Before reduction:", MAX_NODE_EDGES_DISPLAY);
+}
+std::vector<bool> reduced_nodes(nodes_.size());
+this->reduce_node_input(0, reduced_nodes);
+if (debug_level_ > 2) {
+print_all("After reduction:", MAX_NODE_EDGES_DISPLAY);
+}
+// Build a translation map from node indices in nodes_ vector to
+// their target indices in EDGE_ARRAY.
+std::vector<NODE_REF> node_ref_map(nodes_.size() + 1);
+unsigned i;
+for (i = 0; i < nodes_.size(); ++i) {
+node_ref_map[i + 1] = node_ref_map[i] + nodes_[i]->forward_edges.size();
+}
+int num_forward_edges = node_ref_map[i];
+// Convert nodes_ vector into EDGE_ARRAY translating the next node references
+// in edges using node_ref_map. Empty nodes and backward edges are dropped.
+auto edge_array = new EDGE_RECORD[num_forward_edges];
+EDGE_ARRAY edge_array_ptr = edge_array;
+for (i = 0; i < nodes_.size(); ++i) {
+TRIE_NODE_RECORD *node_ptr = nodes_[i];
+int end = node_ptr->forward_edges.size();
+for (int j = 0; j < end; ++j) {
+EDGE_RECORD &edge_rec = node_ptr->forward_edges[j];
+NODE_REF node_ref = next_node_from_edge_rec(edge_rec);
+ASSERT_HOST(static_cast<size_t>(node_ref) < nodes_.size());
+UNICHAR_ID unichar_id = unichar_id_from_edge_rec(edge_rec);
+link_edge(edge_array_ptr, node_ref_map[node_ref], false, FORWARD_EDGE,
+end_of_word_from_edge_rec(edge_rec), unichar_id);
+if (j == end - 1) {
+set_marker_flag_in_edge_rec(edge_array_ptr);
+}
+++edge_array_ptr;
+}
+}
+return new SquishedDawg(edge_array, num_forward_edges, type_, lang_, perm_, unicharset_size_,
+debug_level_);
+}
+bool Trie::eliminate_redundant_edges(NODE_REF node, const EDGE_RECORD &edge1,
+const EDGE_RECORD &edge2) {
+if (debug_level_ > 1) {
+tprintf("\nCollapsing node %" PRIi64 ":\n", node);
+print_node(node, MAX_NODE_EDGES_DISPLAY);
+tprintf("Candidate edges: ");
+print_edge_rec(edge1);
+tprintf(", ");
+print_edge_rec(edge2);
+tprintf("\n\n");
+}
+NODE_REF next_node1 = next_node_from_edge_rec(edge1);
+NODE_REF next_node2 = next_node_from_edge_rec(edge2);
+TRIE_NODE_RECORD *next_node2_ptr = nodes_[next_node2];
+// Translate all edges going to/from next_node2 to go to/from next_node1.
+EDGE_RECORD *edge_ptr = nullptr;
+EDGE_INDEX edge_index;
+// The backward link in node to next_node2 will be zeroed out by the caller.
+// Copy all the backward links in next_node2 to node next_node1
+for (unsigned i = 0; i < next_node2_ptr->backward_edges.size(); ++i) {
+const EDGE_RECORD &bkw_edge = next_node2_ptr->backward_edges[i];
+NODE_REF curr_next_node = next_node_from_edge_rec(bkw_edge);
+UNICHAR_ID curr_unichar_id = unichar_id_from_edge_rec(bkw_edge);
+int curr_word_end = end_of_word_from_edge_rec(bkw_edge);
+bool marker_flag = marker_flag_from_edge_rec(bkw_edge);
+add_edge_linkage(next_node1, curr_next_node, marker_flag, BACKWARD_EDGE, curr_word_end,
+curr_unichar_id);
+// Relocate the corresponding forward edge in curr_next_node
+ASSERT_HOST(edge_char_of(curr_next_node, next_node2, FORWARD_EDGE, curr_word_end,
+curr_unichar_id, &edge_ptr, &edge_index));
+set_next_node_in_edge_rec(edge_ptr, next_node1);
+}
+int next_node2_num_edges =
+(next_node2_ptr->forward_edges.size() + next_node2_ptr->backward_edges.size());
+if (debug_level_ > 1) {
+tprintf("removed %d edges from node " REFFORMAT "\n", next_node2_num_edges, next_node2);
+}
+next_node2_ptr->forward_edges.clear();
+next_node2_ptr->backward_edges.clear();
+num_edges_ -= next_node2_num_edges;
+return true;
+}
+bool Trie::reduce_lettered_edges(EDGE_INDEX edge_index, UNICHAR_ID unichar_id, NODE_REF node,
+EDGE_VECTOR *backward_edges, std::vector<bool> &reduced_nodes) {
+if (debug_level_ > 1) {
+tprintf("reduce_lettered_edges(edge=" REFFORMAT ")\n", edge_index);
+}
+// Compare each of the edge pairs with the given unichar_id.
+bool did_something = false;
+for (unsigned i = edge_index; i < backward_edges->size() - 1; ++i) {
+// Find the first edge that can be eliminated.
+UNICHAR_ID curr_unichar_id = INVALID_UNICHAR_ID;
+while (i < backward_edges->size()) {
+if (!DeadEdge((*backward_edges)[i])) {
+curr_unichar_id = unichar_id_from_edge_rec((*backward_edges)[i]);
+if (curr_unichar_id != unichar_id) {
+return did_something;
+}
+if (can_be_eliminated((*backward_edges)[i])) {
+break;
+}
+}
+++i;
+}
+if (i == backward_edges->size()) {
+break;
+}
+const EDGE_RECORD &edge_rec = (*backward_edges)[i];
+// Compare it to the rest of the edges with the given unichar_id.
+for (auto j = i + 1; j < backward_edges->size(); ++j) {
+const EDGE_RECORD &next_edge_rec = (*backward_edges)[j];
+if (DeadEdge(next_edge_rec)) {
+continue;
+}
+UNICHAR_ID next_id = unichar_id_from_edge_rec(next_edge_rec);
+if (next_id != unichar_id) {
+break;
+}
+if (end_of_word_from_edge_rec(next_edge_rec) == end_of_word_from_edge_rec(edge_rec) &&
+can_be_eliminated(next_edge_rec) &&
+eliminate_redundant_edges(node, edge_rec, next_edge_rec)) {
+reduced_nodes[next_node_from_edge_rec(edge_rec)] = false;
+did_something = true;
+KillEdge(&(*backward_edges)[j]);
+}
+}
+}
+return did_something;
+}
+void Trie::sort_edges(EDGE_VECTOR *edges) {
+int num_edges = edges->size();
+if (num_edges <= 1) {
+return;
+}
+std::vector<KDPairInc<UNICHAR_ID, EDGE_RECORD>> sort_vec;
+sort_vec.reserve(num_edges);
+for (int i = 0; i < num_edges; ++i) {
+sort_vec.emplace_back(unichar_id_from_edge_rec((*edges)[i]), (*edges)[i]);
+}
+std::sort(sort_vec.begin(), sort_vec.end());
+for (int i = 0; i < num_edges; ++i) {
+(*edges)[i] = sort_vec[i].data();
+}
+}
+void Trie::reduce_node_input(NODE_REF node, std::vector<bool> &reduced_nodes) {
+EDGE_VECTOR &backward_edges = nodes_[node]->backward_edges;
+sort_edges(&backward_edges);
+if (debug_level_ > 1) {
+tprintf("reduce_node_input(node=" REFFORMAT ")\n", node);
+print_node(node, MAX_NODE_EDGES_DISPLAY);
+}
+EDGE_INDEX edge_index = 0;
+while (static_cast<size_t>(edge_index) < backward_edges.size()) {
+if (DeadEdge(backward_edges[edge_index])) {
+continue;
+}
+UNICHAR_ID unichar_id = unichar_id_from_edge_rec(backward_edges[edge_index]);
+while (reduce_lettered_edges(edge_index, unichar_id, node, &backward_edges, reduced_nodes)) {
+;
+}
+while (static_cast<size_t>(++edge_index) < backward_edges.size()) {
+UNICHAR_ID id = unichar_id_from_edge_rec(backward_edges[edge_index]);
+if (!DeadEdge(backward_edges[edge_index]) && id != unichar_id) {
+break;
+}
+}
+}
+reduced_nodes[node] = true; // mark as reduced
+if (debug_level_ > 1) {
+tprintf("Node " REFFORMAT " after reduction:\n", node);
+print_node(node, MAX_NODE_EDGES_DISPLAY);
+}
+for (auto &backward_edge : backward_edges) {
+if (DeadEdge(backward_edge)) {
+continue;
+}
+NODE_REF next_node = next_node_from_edge_rec(backward_edge);
+if (next_node != 0 && !reduced_nodes[next_node]) {
+reduce_node_input(next_node, reduced_nodes);
+}
+}
+}
+void Trie::print_node(NODE_REF node, int max_num_edges) const {
+if (node == NO_EDGE) {
+return; // nothing to print
+}
+TRIE_NODE_RECORD *node_ptr = nodes_[node];
+int num_fwd = node_ptr->forward_edges.size();
+int num_bkw = node_ptr->backward_edges.size();
+EDGE_VECTOR *vec;
+for (int dir = 0; dir < 2; ++dir) {
+if (dir == 0) {
+vec = &(node_ptr->forward_edges);
+tprintf(REFFORMAT " (%d %d): ", node, num_fwd, num_bkw);
+} else {
+vec = &(node_ptr->backward_edges);
+tprintf("\t");
+}
+int i;
+for (i = 0; (dir == 0 ? i < num_fwd : i < num_bkw) && i < max_num_edges; ++i) {
+if (DeadEdge((*vec)[i])) {
+continue;
+}
+print_edge_rec((*vec)[i]);
+tprintf(" ");
+}
+if (dir == 0 ? i < num_fwd : i < num_bkw) {
+tprintf("...");
+}
+tprintf("\n");
+}
+}
+} // namespace tesseract

Mercurial > hgrepos > Python2 > PyMuPDF

comparison mupdf-source/thirdparty/tesseract/src/dict/trie.cpp @ 3:2c135c81b16c