#include "Buffer.h"
#include "BufferParams.h"
+#include "Changes.h"
+#include "insets/InsetText.h"
+
+#include "support/lassert.h"
+
+#include <boost/next_prior.hpp>
using namespace std;
using namespace lyx::support;
namespace lyx {
+void step_forward(DocIterator & dit)
+{
+ dit.top().forwardPos();
+}
+
+
+void step_backward(DocIterator & dit)
+{
+ dit.top().backwardPos();
+}
+
+
+bool step_forward(DocIterator & dit, DocIterator const & end)
+{
+ if (dit == end)
+ return false;
+ step_forward(dit);
+ return true;
+}
+
+
+bool step_backward(DocIterator & dit, DocIterator const & beg)
+{
+ if (dit == beg)
+ return false;
+ step_backward(dit);
+ return true;
+}
+
+/**
+ * A pair of two DocIterators that form a range.
+ */
+class DocRange {
+public:
+ DocRange(DocIterator from_, DocIterator to_)
+ : from(from_), to(to_)
+ {}
+
+ DocRange(Buffer const * buf)
+ {
+ from = doc_iterator_begin(buf);
+ to = doc_iterator_end(buf);
+ to.backwardPos();
+ }
+
+ ///
+ Text * text() const { return from.text(); }
+ ///
+ bool empty() const { return to <= from; }
+ ///
+ size_t length() const;
+
+ /// The begin of the range
+ DocIterator from;
+ /// The end of the range
+ DocIterator to;
+};
+
+
+size_t DocRange::length() const
+{
+ pit_type startpit = from.pit();
+ pit_type endpit = to.pit();
+ ParagraphList const & ps_ = from.text()->paragraphs();
+
+ ParagraphList pars(boost::next(ps_.begin(), startpit),
+ boost::next(ps_.begin(), endpit + 1));
+
+ // Remove the end of the last paragraph; afterwards, remove the
+ // beginning of the first paragraph.
+ Paragraph & back = pars.back();
+ back.eraseChars(to.pos(), back.size(), false);
+ Paragraph & front = pars.front();
+ front.eraseChars(0, from.pos(), false);
+
+ ParagraphList::const_iterator pit = pars.begin();
+ ParagraphList::const_iterator end_it = pars.end();
+
+ size_t length = 0;
+ for (; pit != end_it; ++pit)
+ length += pit->size() + 1;
+
+ // The last paragraph has no paragraph-end
+ --length;
+ return length;
+}
+
+
+class DocPair {
+public:
+ DocPair() {}
+
+ DocPair(DocIterator o_, DocIterator n_)
+ : o(o_), n(n_)
+ {}
+
+ DocPair & operator++()
+ {
+ step_forward(o);
+ step_forward(n);
+ return *this;
+ }
+ ///
+ DocIterator o;
+ ///
+ DocIterator n;
+};
+
+/**
+ * A pair of two DocRanges.
+ */
+class DocRangePair {
+public:
+ DocRangePair(DocRange o_, DocRange n_)
+ : o(o_), n(n_)
+ {}
+
+ DocRangePair(DocPair from, DocPair to)
+ : o(from.o, to.o), n(from.n, to.n)
+ {}
+
+ DocRangePair(Buffer const * o_buf, Buffer const * n_buf)
+ : o(o_buf), n(n_buf)
+ {}
+
+ /// Returns the from pair
+ DocPair from() const { return DocPair(o.from, n.from); }
+
+ /// Returns the to pair
+ DocPair to() const { return DocPair(o.to, n.to); }
+
+ DocRange o;
+ DocRange n;
+};
+
+
+DocRangePair stepIntoInset(DocPair const & inset_location)
+{
+ DocRangePair rp(inset_location, inset_location);
+ rp.o.from.forwardPos();
+ rp.n.from.forwardPos();
+ step_forward(rp.o.to);
+ step_forward(rp.n.to);
+ rp.o.to.backwardPos();
+ rp.n.to.backwardPos();
+ return rp;
+}
+
+
/**
* The implementation of the algorithm that does the comparison
* between two documents.
///
~Impl() {}
- /// Set to true to abort the algorithm
+ // Algorithm to find the shortest edit string. This algorithm
+ // only needs a linear amount of memory (linear with the sum
+ // of the number of characters in the two paragraph-lists).
+ bool diff(Buffer const * new_buf, Buffer const * old_buf,
+ Buffer const * dest_buf);
+
+ /// Set to true to cancel the algorithm
bool abort_;
private:
+ // Finds the middle snake and returns the length of the
+ // shortest edit script.
+ int find_middle_snake(DocRangePair const & rp, DocPair & middle_snake);
+
+ // This function is called recursively by a divide and conquer
+ // algorithm. Each time, the string is divided into two split
+ // around the middle snake.
+ void diff_i(DocRangePair const & rp);
+
+ /// Processes the splitted chunks. It either adds them as deleted,
+ /// as added, or call diff_i for further processing.
+ void diff_part(DocRangePair const & rp);
+
+ /// Runs the algorithm for the inset located at /c it and /c it_n
+ /// and adds the result to /c pars.
+ void diff_inset(Inset * inset, DocPair const & p);
+
+ // Adds the snake to the destination buffer. The algorithm will
+ // recursively be applied to any InsetTexts that are within the snake.
+ void process_snake(DocRangePair const & rp);
+
+ /// Writes the range to the destination buffer
+ void writeToDestBuffer(DocRange const & range,
+ Change::Type type = Change::UNCHANGED);
+
+ /// Writes the paragraph list to the destination buffer
+ void writeToDestBuffer(ParagraphList const & copy_pars) const;
+
+ /// The length of the first chunk currently processed
+ int N;
+ /// The length of the second chunk currently processed
+ int M;
+
/// The thread object, used to emit signals to the GUI
Compare const & compare_;
+
+ /// The buffer containing text that will be marked as old
+ Buffer const * old_buf_;
+ /// The buffer containing text that will be marked as new
+ Buffer const * new_buf_;
+ /// The buffer containing text that will be marked as new
+ Buffer const * dest_buf_;
+
+ /// The paragraph list of the destination buffer
+ ParagraphList * dest_pars_;
+
+ /// The level of recursion
+ int recursion_level_;
+
+ /// The number of nested insets at this level
+ int nested_inset_level_;
};
+/////////////////////////////////////////////////////////////////////
+//
+// Compare
+//
+/////////////////////////////////////////////////////////////////////
Compare::Compare(Buffer const * new_buf, Buffer const * old_buf,
Buffer * const dest_buf, CompareOptions const & options)
void Compare::run()
{
- if (!dest_buffer || !new_buffer || !old_buffer) {
- error();
+ if (!dest_buffer || !new_buffer || !old_buffer)
return;
- }
// Copy the buffer params to the new buffer
dest_buffer->params() = options_.settings_from_new
// do the real work
if (!doCompare())
- error();
- else
- finished(pimpl_->abort_);
+ return;
+
+ finished(pimpl_->abort_);
return;
}
+int Compare::doCompare()
+{
+ return pimpl_->diff(new_buffer, old_buffer, dest_buffer);
+}
+
+
void Compare::abort()
{
pimpl_->abort_ = true;
}
-int Compare::doCompare()
+void get_paragraph_list(DocRange const & range,
+ ParagraphList & pars)
+{
+ // Clone the paragraphs within the selection.
+ pit_type startpit = range.from.pit();
+ pit_type endpit = range.to.pit();
+ ParagraphList const & ps_ = range.text()->paragraphs();
+ ParagraphList tmp_pars(boost::next(ps_.begin(), startpit),
+ boost::next(ps_.begin(), endpit + 1));
+
+ // Remove the end of the last paragraph; afterwards, remove the
+ // beginning of the first paragraph. Keep this order - there may only
+ // be one paragraph!
+ Paragraph & back = tmp_pars.back();
+ back.eraseChars(range.to.pos(), back.size(), false);
+ Paragraph & front = tmp_pars.front();
+ front.eraseChars(0, range.from.pos(), false);
+
+ pars.insert(pars.begin(), tmp_pars.begin(), tmp_pars.end());
+}
+
+
+bool equal(Inset const * i_o, Inset const * i_n)
+{
+ if (!i_o || !i_n)
+ return false;
+
+ // Different types of insets
+ if (i_o->lyxCode() != i_n->lyxCode())
+ return false;
+
+ // Editable insets are assumed to be the same as they are of the
+ // same type. If we later on decide that we insert them in the
+ // document as being unchanged, we will run the algorithm on the
+ // contents of the two insets.
+ // FIXME: This fails if the parameters of the insets differ.
+ // FIXME: We do not recurse into InsetTabulars.
+ // FIXME: We need methods inset->equivalent(inset).
+ if (i_o->editable() && !i_o->asInsetMath()
+ && i_o->asInsetText())
+ return true;
+
+ ostringstream o_os;
+ ostringstream n_os;
+ i_o->write(o_os);
+ i_n->write(n_os);
+ return o_os.str() == n_os.str();
+}
+
+
+bool equal(DocIterator & o, DocIterator & n) {
+ Paragraph const & old_par = o.text()->getPar(o.pit());
+ Paragraph const & new_par = n.text()->getPar(n.pit());
+
+ Inset const * i_o = old_par.getInset(o.pos());
+ Inset const * i_n = new_par.getInset(n.pos());
+
+ if (i_o && i_n)
+ return equal(i_o, i_n);
+
+ char_type c_o = old_par.getChar(o.pos());
+ char_type c_n = new_par.getChar(n.pos());
+ Font fo = old_par.getFontSettings(o.buffer()->params(), o.pos());
+ Font fn = new_par.getFontSettings(n.buffer()->params(), n.pos());
+ return c_o == c_n && fo == fn;
+}
+
+
+void traverse_snake_back(DocRangePair & rp)
+{
+ while (true) {
+ // Traverse snake
+ if (!step_backward(rp.o.to, rp.o.from))
+ break;
+
+ if (!step_backward(rp.n.to, rp.n.from)) {
+ step_forward(rp.o.to);
+ break;
+ }
+
+ if (!equal(rp.o.to, rp.n.to)) {
+ step_forward(rp.o.to);
+ step_forward(rp.n.to);
+ break;
+ }
+ }
+}
+
+
+void traverse_snake_forw(DocRangePair & rp)
+{
+ while (equal(rp.o.from, rp.n.from)) {
+ if (!step_forward(rp.o.from, rp.o.to))
+ break;
+
+ if (!step_forward(rp.n.from, rp.n.to)) {
+ step_backward(rp.o.from);
+ break;
+ }
+ }
+}
+
+/////////////////////////////////////////////////////////////////////
+//
+// Compare::Impl
+//
+/////////////////////////////////////////////////////////////////////
+
+int Compare::Impl::find_middle_snake(DocRangePair const & rp,
+ DocPair & middle_snake)
+{
+ N = rp.o.length();
+ M = rp.n.length();
+ return M+N;
+}
+
+
+bool Compare::Impl::diff(Buffer const * new_buf, Buffer const * old_buf,
+ Buffer const * dest_buf)
+{
+ if (!new_buf || !old_buf || !dest_buf)
+ return false;
+
+ old_buf_ = old_buf;
+ new_buf_ = new_buf;
+ dest_buf_ = dest_buf;
+ dest_pars_ = &dest_buf->inset().asInsetText()->paragraphs();
+ dest_pars_->clear();
+
+ recursion_level_ = 0;
+ nested_inset_level_ = 0;
+
+ DocRangePair rp(old_buf_, new_buf_);
+
+ DocPair from = rp.from();
+ traverse_snake_forw(rp);
+ DocRangePair const snake(from, rp.from());
+ process_snake(snake);
+
+ // Start the recursive algorithm
+ diff_i(rp);
+
+ for (pit_type p = 0; p < (pit_type)dest_pars_->size(); ++p) {
+ (*dest_pars_)[p].setBuffer(const_cast<Buffer &>(*dest_buf));
+ (*dest_pars_)[p].setInsetOwner(&dest_buf_->inset());
+ }
+
+ return true;
+}
+
+
+void Compare::Impl::diff_i(DocRangePair const & rp)
+{
+ // The middle snake
+ DocPair middle_snake;
+
+ // Divides the problem into two smaller problems, split around
+ // the snake in the middle.
+ int const L_ses = find_middle_snake(rp, middle_snake);
+
+ // Set maximum of progress bar
+ if (++recursion_level_ == 1)
+ compare_.progressMax(L_ses);
+
+ // There are now three possibilities: the strings were the same,
+ // the strings were completely different, or we found a middle
+ // snake and we can split the string into two parts to process.
+ if (L_ses == 0)
+ // Two the same strings (this must be a very rare case, because
+ // usually this will be part of a snake adjacent to these strings).
+ writeToDestBuffer(rp.o);
+
+ else if (middle_snake.o.empty()) {
+ // Two totally different strings
+ writeToDestBuffer(rp.o, Change::DELETED);
+ writeToDestBuffer(rp.n, Change::INSERTED);
+
+ } else {
+ // Retrieve the complete snake
+ DocRangePair first_part(rp.from(), middle_snake);
+ traverse_snake_back(first_part);
+
+ DocRangePair second_part(middle_snake, rp.to());
+ traverse_snake_forw(second_part);
+
+ // Split the string in three parts:
+ // 1. in front of the snake
+ diff_part(first_part);
+
+ // 2. the snake itself, and
+ DocRangePair const snake(first_part.to(), second_part.from());
+ process_snake(snake);
+
+ // 3. behind the snake.
+ diff_part(second_part);
+ }
+ --recursion_level_;
+}
+
+
+void Compare::Impl::diff_part(DocRangePair const & rp)
+{
+ // Is there a finite length string in both buffers, if not there
+ // is an empty string and we write the other one to the buffer.
+ if (!rp.o.empty() && !rp.n.empty())
+ diff_i(rp);
+
+ else if (!rp.o.empty())
+ writeToDestBuffer(rp.o, Change::DELETED);
+
+ else if (!rp.n.empty())
+ writeToDestBuffer(rp.n, Change::INSERTED);
+}
+
+
+void Compare::Impl::diff_inset(Inset * inset, DocPair const & p)
+{
+ // Find the dociterators for the beginning and the
+ // end of the inset, for the old and new document.
+ DocRangePair const rp = stepIntoInset(p);
+
+ // Recurse into the inset. Temporarily replace the dest_pars
+ // paragraph list by the paragraph list of the nested inset.
+ ParagraphList * backup_dest_pars = dest_pars_;
+ dest_pars_ = &inset->asInsetText()->text().paragraphs();
+ dest_pars_->clear();
+
+ ++nested_inset_level_;
+ diff_i(rp);
+ --nested_inset_level_;
+
+ dest_pars_ = backup_dest_pars;
+}
+
+
+void Compare::Impl::process_snake(DocRangePair const & rp)
+{
+ ParagraphList pars;
+ get_paragraph_list(rp.o, pars);
+
+ // Find insets in this paragaph list
+ DocPair it = rp.from();
+ for (; it.o < rp.o.to; ++it) {
+ Inset * inset = it.o.text()->getPar(it.o.pit()).getInset(it.o.pos());
+ if (inset && inset->editable() && inset->asInsetText()) {
+ // Find the inset in the paragraph list that will be pasted into
+ // the final document. The contents of the inset will be replaced
+ // by the output of the algorithm below.
+ pit_type const pit = it.o.pit() - rp.o.from.pit();
+ pos_type const pos = pit ? it.o.pos() : it.o.pos() - rp.o.from.pos();
+ inset = pars[pit].getInset(pos);
+ LASSERT(inset, /**/);
+ diff_inset(inset, it);
+ }
+ }
+ writeToDestBuffer(pars);
+}
+
+
+void Compare::Impl::writeToDestBuffer(DocRange const & range,
+ Change::Type type)
+{
+ ParagraphList pars;
+ get_paragraph_list(range, pars);
+
+ pos_type size = 0;
+
+ // Set the change
+ ParagraphList::iterator it = pars.begin();
+ for (; it != pars.end(); ++it) {
+ it->setChange(Change(type));
+ size += it->size();
+ }
+
+ writeToDestBuffer(pars);
+
+ if (nested_inset_level_ == 0)
+ compare_.progress(size);
+}
+
+
+void Compare::Impl::writeToDestBuffer(ParagraphList const & pars) const
{
- return 0;
+ pit_type const pit = dest_pars_->size() - 1;
+ dest_pars_->insert(dest_pars_->end(), pars.begin(), pars.end());
+ if (pit >= 0)
+ mergeParagraph(dest_buf_->params(), *dest_pars_, pit);
}
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