Mercurial > hgrepos > Python2 > PyMuPDF
diff mupdf-source/thirdparty/tesseract/src/ccutil/elst.h @ 2:b50eed0cc0ef upstream
ADD: MuPDF v1.26.7: the MuPDF source as downloaded by a default build of PyMuPDF 1.26.4.
The directory name has changed: no version number in the expanded directory now.
| author | Franz Glasner <fzglas.hg@dom66.de> |
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| date | Mon, 15 Sep 2025 11:43:07 +0200 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/mupdf-source/thirdparty/tesseract/src/ccutil/elst.h Mon Sep 15 11:43:07 2025 +0200 @@ -0,0 +1,813 @@ +/********************************************************************** + * File: elst.h (Formerly elist.h) + * Description: Embedded list module include file. + * Author: Phil Cheatle + * + * (C) Copyright 1991, Hewlett-Packard Ltd. + ** 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. + * + **********************************************************************/ + +#ifndef ELST_H +#define ELST_H + +#include "list.h" +#include "lsterr.h" +#include "serialis.h" + +#include <cstdio> + +namespace tesseract { + +class ELIST_ITERATOR; + +/********************************************************************** +This module implements list classes and iterators. +The following list types and iterators are provided: + + List type List Class Iterator Class Element Class + --------- ---------- -------------- ------------- + + Embedded list ELIST + ELIST_ITERATOR + ELIST_LINK + (Single linked) + + Embedded list ELIST2 + ELIST2_ITERATOR + ELIST2_LINK + (Double linked) + + Cons List CLIST + CLIST_ITERATOR + CLIST_LINK + (Single linked) + +An embedded list is where the list pointers are provided by a generic class. +Data types to be listed inherit from the generic class. Data is thus linked +in only ONE list at any one time. + +A cons list has a separate structure for a "cons cell". This contains the +list pointer(s) AND a pointer to the data structure held on the list. A +structure can be on many cons lists at the same time, and the structure does +not need to inherit from any generic class in order to be on the list. + +The implementation of lists is very careful about space and speed overheads. +This is why many embedded lists are provided. The same concerns mean that +in-line type coercion is done, rather than use virtual functions. This is +cumbersome in that each data type to be listed requires its own iterator and +list class - though macros can generate these. It also prevents heterogeneous +lists. +**********************************************************************/ + +/********************************************************************** + * CLASS - ELIST_LINK + * + * Generic link class for singly linked lists with + *embedded links + * + * Note: No destructor - elements are assumed to be destroyed EITHER after + * they have been extracted from a list OR by the ELIST destructor which + * walks the list. + **********************************************************************/ + +class ELIST_LINK { + friend class ELIST_ITERATOR; + friend class ELIST; + + ELIST_LINK *next; + +public: + ELIST_LINK() { + next = nullptr; + } + // constructor + + // The special copy constructor is used by lots of classes. + ELIST_LINK(const ELIST_LINK &) { + next = nullptr; + } + + // The special assignment operator is used by lots of classes. + void operator=(const ELIST_LINK &) { + next = nullptr; + } +}; + +/********************************************************************** + * CLASS - ELIST + * + * Generic list class for singly linked lists with embedded links + **********************************************************************/ + +class TESS_API ELIST { + friend class ELIST_ITERATOR; + + ELIST_LINK *last = nullptr; // End of list + //(Points to head) + ELIST_LINK *First() { // return first + return last ? last->next : nullptr; + } + +public: + // destroy all links + void internal_clear(void (*zapper)(void *)); + + bool empty() const { + return !last; + } + + bool singleton() const { + return last ? (last == last->next) : false; + } + + void shallow_copy( // dangerous!! + ELIST *from_list) { // beware destructors!! + last = from_list->last; + } + + // ptr to copier functn + void internal_deep_copy(ELIST_LINK *(*copier)(ELIST_LINK *), + const ELIST *list); // list being copied + + void assign_to_sublist( // to this list + ELIST_ITERATOR *start_it, // from list start + ELIST_ITERATOR *end_it); // from list end + + // # elements in list + int32_t length() const { + int32_t count = 0; + if (last != nullptr) { + count = 1; + for (auto it = last->next; it != last; it = it->next) { + count++; + } + } + return count; + } + + void sort( // sort elements + int comparator( // comparison routine + const void *, const void *)); + + // Assuming list has been sorted already, insert new_link to + // keep the list sorted according to the same comparison function. + // Comparison function is the same as used by sort, i.e. uses double + // indirection. Time is O(1) to add to beginning or end. + // Time is linear to add pre-sorted items to an empty list. + // If unique is set to true and comparator() returns 0 (an entry with the + // same information as the one contained in new_link is already in the + // list) - new_link is not added to the list and the function returns the + // pointer to the identical entry that already exists in the list + // (otherwise the function returns new_link). + ELIST_LINK *add_sorted_and_find(int comparator(const void *, const void *), bool unique, + ELIST_LINK *new_link); + + // Same as above, but returns true if the new entry was inserted, false + // if the identical entry already existed in the list. + bool add_sorted(int comparator(const void *, const void *), bool unique, ELIST_LINK *new_link) { + return (add_sorted_and_find(comparator, unique, new_link) == new_link); + } +}; + +/*********************************************************************** + * CLASS - ELIST_ITERATOR + * + * Generic iterator class for singly linked lists with + *embedded links + **********************************************************************/ + +class TESS_API ELIST_ITERATOR { + friend void ELIST::assign_to_sublist(ELIST_ITERATOR *, ELIST_ITERATOR *); + + ELIST *list; // List being iterated + ELIST_LINK *prev; // prev element + ELIST_LINK *current; // current element + ELIST_LINK *next; // next element + ELIST_LINK *cycle_pt; // point we are cycling the list to. + bool ex_current_was_last; // current extracted was end of list + bool ex_current_was_cycle_pt; // current extracted was cycle point + bool started_cycling; // Have we moved off the start? + + ELIST_LINK *extract_sublist( // from this current... + ELIST_ITERATOR *other_it); // to other current + +public: + ELIST_ITERATOR() { // constructor + list = nullptr; + } // unassigned list + + explicit ELIST_ITERATOR(ELIST *list_to_iterate); + + void set_to_list( // change list + ELIST *list_to_iterate); + + void add_after_then_move( // add after current & + ELIST_LINK *new_link); // move to new + + void add_after_stay_put( // add after current & + ELIST_LINK *new_link); // stay at current + + void add_before_then_move( // add before current & + ELIST_LINK *new_link); // move to new + + void add_before_stay_put( // add before current & + ELIST_LINK *new_link); // stay at current + + void add_list_after( // add a list & + ELIST *list_to_add); // stay at current + + void add_list_before( // add a list & + ELIST *list_to_add); // move to it 1st item + + ELIST_LINK *data() { // get current data +#ifndef NDEBUG + if (!list) { + NO_LIST.error("ELIST_ITERATOR::data", ABORT); + } + if (!current) { + NULL_DATA.error("ELIST_ITERATOR::data", ABORT); + } +#endif + return current; + } + + ELIST_LINK *data_relative( // get data + or - ... + int8_t offset); // offset from current + + ELIST_LINK *forward(); // move to next element + + ELIST_LINK *extract(); // remove from list + + ELIST_LINK *move_to_first(); // go to start of list + + ELIST_LINK *move_to_last(); // go to end of list + + void mark_cycle_pt(); // remember current + + bool empty() const { // is list empty? +#ifndef NDEBUG + if (!list) { + NO_LIST.error("ELIST_ITERATOR::empty", ABORT); + } +#endif + return list->empty(); + } + + bool current_extracted() const { // current extracted? + return !current; + } + + bool at_first() const; // Current is first? + + bool at_last() const; // Current is last? + + bool cycled_list() const; // Completed a cycle? + + void add_to_end( // add at end & + ELIST_LINK *new_link); // don't move + + void exchange( // positions of 2 links + ELIST_ITERATOR *other_it); // other iterator + + //# elements in list + int32_t length() const { + return list->length(); + } + + void sort( // sort elements + int comparator( // comparison routine + const void *, const void *)); +}; + +/*********************************************************************** + * ELIST_ITERATOR::set_to_list + * + * (Re-)initialise the iterator to point to the start of the list_to_iterate + * over. + **********************************************************************/ + +inline void ELIST_ITERATOR::set_to_list( // change list + ELIST *list_to_iterate) { +#ifndef NDEBUG + if (!list_to_iterate) { + BAD_PARAMETER.error("ELIST_ITERATOR::set_to_list", ABORT, "list_to_iterate is nullptr"); + } +#endif + + list = list_to_iterate; + prev = list->last; + current = list->First(); + next = current ? current->next : nullptr; + cycle_pt = nullptr; // await explicit set + started_cycling = false; + ex_current_was_last = false; + ex_current_was_cycle_pt = false; +} + +/*********************************************************************** + * ELIST_ITERATOR::ELIST_ITERATOR + * + * CONSTRUCTOR - set iterator to specified list; + **********************************************************************/ + +inline ELIST_ITERATOR::ELIST_ITERATOR(ELIST *list_to_iterate) { + set_to_list(list_to_iterate); +} + +/*********************************************************************** + * ELIST_ITERATOR::add_after_then_move + * + * Add a new element to the list after the current element and move the + * iterator to the new element. + **********************************************************************/ + +inline void ELIST_ITERATOR::add_after_then_move( // element to add + ELIST_LINK *new_element) { +#ifndef NDEBUG + if (!list) { + NO_LIST.error("ELIST_ITERATOR::add_after_then_move", ABORT); + } + if (!new_element) { + BAD_PARAMETER.error("ELIST_ITERATOR::add_after_then_move", ABORT, "new_element is nullptr"); + } + if (new_element->next) { + STILL_LINKED.error("ELIST_ITERATOR::add_after_then_move", ABORT); + } +#endif + + if (list->empty()) { + new_element->next = new_element; + list->last = new_element; + prev = next = new_element; + } else { + new_element->next = next; + + if (current) { // not extracted + current->next = new_element; + prev = current; + if (current == list->last) { + list->last = new_element; + } + } else { // current extracted + prev->next = new_element; + if (ex_current_was_last) { + list->last = new_element; + } + if (ex_current_was_cycle_pt) { + cycle_pt = new_element; + } + } + } + current = new_element; +} + +/*********************************************************************** + * ELIST_ITERATOR::add_after_stay_put + * + * Add a new element to the list after the current element but do not move + * the iterator to the new element. + **********************************************************************/ + +inline void ELIST_ITERATOR::add_after_stay_put( // element to add + ELIST_LINK *new_element) { +#ifndef NDEBUG + if (!list) { + NO_LIST.error("ELIST_ITERATOR::add_after_stay_put", ABORT); + } + if (!new_element) { + BAD_PARAMETER.error("ELIST_ITERATOR::add_after_stay_put", ABORT, "new_element is nullptr"); + } + if (new_element->next) { + STILL_LINKED.error("ELIST_ITERATOR::add_after_stay_put", ABORT); + } +#endif + + if (list->empty()) { + new_element->next = new_element; + list->last = new_element; + prev = next = new_element; + ex_current_was_last = false; + current = nullptr; + } else { + new_element->next = next; + + if (current) { // not extracted + current->next = new_element; + if (prev == current) { + prev = new_element; + } + if (current == list->last) { + list->last = new_element; + } + } else { // current extracted + prev->next = new_element; + if (ex_current_was_last) { + list->last = new_element; + ex_current_was_last = false; + } + } + next = new_element; + } +} + +/*********************************************************************** + * ELIST_ITERATOR::add_before_then_move + * + * Add a new element to the list before the current element and move the + * iterator to the new element. + **********************************************************************/ + +inline void ELIST_ITERATOR::add_before_then_move( // element to add + ELIST_LINK *new_element) { +#ifndef NDEBUG + if (!list) { + NO_LIST.error("ELIST_ITERATOR::add_before_then_move", ABORT); + } + if (!new_element) { + BAD_PARAMETER.error("ELIST_ITERATOR::add_before_then_move", ABORT, "new_element is nullptr"); + } + if (new_element->next) { + STILL_LINKED.error("ELIST_ITERATOR::add_before_then_move", ABORT); + } +#endif + + if (list->empty()) { + new_element->next = new_element; + list->last = new_element; + prev = next = new_element; + } else { + prev->next = new_element; + if (current) { // not extracted + new_element->next = current; + next = current; + } else { // current extracted + new_element->next = next; + if (ex_current_was_last) { + list->last = new_element; + } + if (ex_current_was_cycle_pt) { + cycle_pt = new_element; + } + } + } + current = new_element; +} + +/*********************************************************************** + * ELIST_ITERATOR::add_before_stay_put + * + * Add a new element to the list before the current element but don't move the + * iterator to the new element. + **********************************************************************/ + +inline void ELIST_ITERATOR::add_before_stay_put( // element to add + ELIST_LINK *new_element) { +#ifndef NDEBUG + if (!list) { + NO_LIST.error("ELIST_ITERATOR::add_before_stay_put", ABORT); + } + if (!new_element) { + BAD_PARAMETER.error("ELIST_ITERATOR::add_before_stay_put", ABORT, "new_element is nullptr"); + } + if (new_element->next) { + STILL_LINKED.error("ELIST_ITERATOR::add_before_stay_put", ABORT); + } +#endif + + if (list->empty()) { + new_element->next = new_element; + list->last = new_element; + prev = next = new_element; + ex_current_was_last = true; + current = nullptr; + } else { + prev->next = new_element; + if (current) { // not extracted + new_element->next = current; + if (next == current) { + next = new_element; + } + } else { // current extracted + new_element->next = next; + if (ex_current_was_last) { + list->last = new_element; + } + } + prev = new_element; + } +} + +/*********************************************************************** + * ELIST_ITERATOR::add_list_after + * + * Insert another list to this list after the current element but don't move + *the + * iterator. + **********************************************************************/ + +inline void ELIST_ITERATOR::add_list_after(ELIST *list_to_add) { +#ifndef NDEBUG + if (!list) { + NO_LIST.error("ELIST_ITERATOR::add_list_after", ABORT); + } + if (!list_to_add) { + BAD_PARAMETER.error("ELIST_ITERATOR::add_list_after", ABORT, "list_to_add is nullptr"); + } +#endif + + if (!list_to_add->empty()) { + if (list->empty()) { + list->last = list_to_add->last; + prev = list->last; + next = list->First(); + ex_current_was_last = true; + current = nullptr; + } else { + if (current) { // not extracted + current->next = list_to_add->First(); + if (current == list->last) { + list->last = list_to_add->last; + } + list_to_add->last->next = next; + next = current->next; + } else { // current extracted + prev->next = list_to_add->First(); + if (ex_current_was_last) { + list->last = list_to_add->last; + ex_current_was_last = false; + } + list_to_add->last->next = next; + next = prev->next; + } + } + list_to_add->last = nullptr; + } +} + +/*********************************************************************** + * ELIST_ITERATOR::add_list_before + * + * Insert another list to this list before the current element. Move the + * iterator to the start of the inserted elements + * iterator. + **********************************************************************/ + +inline void ELIST_ITERATOR::add_list_before(ELIST *list_to_add) { +#ifndef NDEBUG + if (!list) { + NO_LIST.error("ELIST_ITERATOR::add_list_before", ABORT); + } + if (!list_to_add) { + BAD_PARAMETER.error("ELIST_ITERATOR::add_list_before", ABORT, "list_to_add is nullptr"); + } +#endif + + if (!list_to_add->empty()) { + if (list->empty()) { + list->last = list_to_add->last; + prev = list->last; + current = list->First(); + next = current->next; + ex_current_was_last = false; + } else { + prev->next = list_to_add->First(); + if (current) { // not extracted + list_to_add->last->next = current; + } else { // current extracted + list_to_add->last->next = next; + if (ex_current_was_last) { + list->last = list_to_add->last; + } + if (ex_current_was_cycle_pt) { + cycle_pt = prev->next; + } + } + current = prev->next; + next = current->next; + } + list_to_add->last = nullptr; + } +} + +/*********************************************************************** + * ELIST_ITERATOR::extract + * + * Do extraction by removing current from the list, returning it to the + * caller, but NOT updating the iterator. (So that any calling loop can do + * this.) The iterator's current points to nullptr. If the extracted element + * is to be deleted, this is the callers responsibility. + **********************************************************************/ + +inline ELIST_LINK *ELIST_ITERATOR::extract() { + ELIST_LINK *extracted_link; + +#ifndef NDEBUG + if (!list) { + NO_LIST.error("ELIST_ITERATOR::extract", ABORT); + } + if (!current) { // list empty or + // element extracted + NULL_CURRENT.error("ELIST_ITERATOR::extract", ABORT); + } +#endif + + if (list->singleton()) { + // Special case where we do need to change the iterator. + prev = next = list->last = nullptr; + } else { + prev->next = next; // remove from list + + ex_current_was_last = (current == list->last); + if (ex_current_was_last) { + list->last = prev; + } + } + // Always set ex_current_was_cycle_pt so an add/forward will work in a loop. + ex_current_was_cycle_pt = (current == cycle_pt); + extracted_link = current; + extracted_link->next = nullptr; // for safety + current = nullptr; + return extracted_link; +} + +/*********************************************************************** + * ELIST_ITERATOR::move_to_first() + * + * Move current so that it is set to the start of the list. + * Return data just in case anyone wants it. + **********************************************************************/ + +inline ELIST_LINK *ELIST_ITERATOR::move_to_first() { +#ifndef NDEBUG + if (!list) { + NO_LIST.error("ELIST_ITERATOR::move_to_first", ABORT); + } +#endif + + current = list->First(); + prev = list->last; + next = current ? current->next : nullptr; + return current; +} + +/*********************************************************************** + * ELIST_ITERATOR::mark_cycle_pt() + * + * Remember the current location so that we can tell whether we've returned + * to this point later. + * + * If the current point is deleted either now, or in the future, the cycle + * point will be set to the next item which is set to current. This could be + * by a forward, add_after_then_move or add_after_then_move. + **********************************************************************/ + +inline void ELIST_ITERATOR::mark_cycle_pt() { +#ifndef NDEBUG + if (!list) { + NO_LIST.error("ELIST_ITERATOR::mark_cycle_pt", ABORT); + } +#endif + + if (current) { + cycle_pt = current; + } else { + ex_current_was_cycle_pt = true; + } + started_cycling = false; +} + +/*********************************************************************** + * ELIST_ITERATOR::at_first() + * + * Are we at the start of the list? + * + **********************************************************************/ + +inline bool ELIST_ITERATOR::at_first() const { +#ifndef NDEBUG + if (!list) { + NO_LIST.error("ELIST_ITERATOR::at_first", ABORT); + } +#endif + + // we're at a deleted + return ((list->empty()) || (current == list->First()) || + ((current == nullptr) && (prev == list->last) && // NON-last pt between + !ex_current_was_last)); // first and last +} + +/*********************************************************************** + * ELIST_ITERATOR::at_last() + * + * Are we at the end of the list? + * + **********************************************************************/ + +inline bool ELIST_ITERATOR::at_last() const { +#ifndef NDEBUG + if (!list) { + NO_LIST.error("ELIST_ITERATOR::at_last", ABORT); + } +#endif + + // we're at a deleted + return ((list->empty()) || (current == list->last) || + ((current == nullptr) && (prev == list->last) && // last point between + ex_current_was_last)); // first and last +} + +/*********************************************************************** + * ELIST_ITERATOR::cycled_list() + * + * Have we returned to the cycle_pt since it was set? + * + **********************************************************************/ + +inline bool ELIST_ITERATOR::cycled_list() const { +#ifndef NDEBUG + if (!list) { + NO_LIST.error("ELIST_ITERATOR::cycled_list", ABORT); + } +#endif + + return ((list->empty()) || ((current == cycle_pt) && started_cycling)); +} + +/*********************************************************************** + * ELIST_ITERATOR::sort() + * + * Sort the elements of the list, then reposition at the start. + * + **********************************************************************/ + +inline void ELIST_ITERATOR::sort( // sort elements + int comparator( // comparison routine + const void *, const void *)) { +#ifndef NDEBUG + if (!list) { + NO_LIST.error("ELIST_ITERATOR::sort", ABORT); + } +#endif + + list->sort(comparator); + move_to_first(); +} + +/*********************************************************************** + * ELIST_ITERATOR::add_to_end + * + * Add a new element to the end of the list without moving the iterator. + * This is provided because a single linked list cannot move to the last as + * the iterator couldn't set its prev pointer. Adding to the end is + * essential for implementing + queues. +**********************************************************************/ + +inline void ELIST_ITERATOR::add_to_end( // element to add + ELIST_LINK *new_element) { +#ifndef NDEBUG + if (!list) { + NO_LIST.error("ELIST_ITERATOR::add_to_end", ABORT); + } + if (!new_element) { + BAD_PARAMETER.error("ELIST_ITERATOR::add_to_end", ABORT, "new_element is nullptr"); + } + if (new_element->next) { + STILL_LINKED.error("ELIST_ITERATOR::add_to_end", ABORT); + } +#endif + + if (this->at_last()) { + this->add_after_stay_put(new_element); + } else { + if (this->at_first()) { + this->add_before_stay_put(new_element); + list->last = new_element; + } else { // Iteratr is elsewhere + new_element->next = list->last->next; + list->last->next = new_element; + list->last = new_element; + } + } +} + +#define ELISTIZEH(CLASSNAME) \ + class CLASSNAME##_LIST : public X_LIST<ELIST, ELIST_ITERATOR, CLASSNAME> { \ + using X_LIST<ELIST, ELIST_ITERATOR, CLASSNAME>::X_LIST; \ + }; \ + class CLASSNAME##_IT : public X_ITER<ELIST_ITERATOR, CLASSNAME> { \ + using X_ITER<ELIST_ITERATOR, CLASSNAME>::X_ITER; \ + }; + +} // namespace tesseract + +#endif
