DynamicSelectionList: optimize updating on buffer modification

Now that we know selections are sorted, we can get the set of selections
needing updating in log(n) time using a binary search, for modification
not changing the line count, this makes updating selections run in log(n)
instead of n.
This commit is contained in:
Maxime Coste 2013-03-18 19:06:04 +01:00
parent 354ae7ad89
commit e6c635be34

View File

@ -72,62 +72,94 @@ void DynamicSelectionList::check_invariant() const
#endif
}
static void update_insert(BufferIterator& it,
const BufferCoord& begin, const BufferCoord& end)
namespace
{
BufferCoord coord = it.coord();
if (coord < begin)
return;
if (begin.line == coord.line)
coord.column = end.column + coord.column - begin.column;
coord.line += end.line - begin.line;
template<template <bool, bool> class UpdateFunc>
void on_buffer_change(SelectionList& sels, const BufferCoord& begin, const BufferCoord& end, LineCount end_line)
{
auto update_beg = std::lower_bound(sels.begin(), sels.end(), begin,
[](const Selection& s, const BufferCoord& c) { return std::max(s.first(), s.last()).coord() < c; });
auto update_only_line_beg = std::upper_bound(sels.begin(), sels.end(), end_line,
[](LineCount l, const Selection& s) { return l < std::min(s.first(), s.last()).line(); });
it = coord;
if (update_beg != update_only_line_beg)
{
// for the first one, we are not sure if min < begin
UpdateFunc<false, false>{}(update_beg->first(), begin, end);
UpdateFunc<false, false>{}(update_beg->last(), begin, end);
}
for (auto it = update_beg+1; it < update_only_line_beg; ++it)
{
UpdateFunc<false, true>{}(it->first(), begin, end);
UpdateFunc<false, true>{}(it->last(), begin, end);
}
if (end.line > begin.line)
{
for (auto it = update_only_line_beg; it != sels.end(); ++it)
{
UpdateFunc<true, true>{}(it->first(), begin, end);
UpdateFunc<true, true>{}(it->last(), begin, end);
}
}
}
static void update_erase(BufferIterator& it,
const BufferCoord& begin, const BufferCoord& end)
template<bool assume_different_line, bool assume_greater_than_begin>
struct UpdateInsert
{
BufferCoord coord = it.coord();
if (coord < begin)
return;
if (coord <= end)
coord = it.buffer().clamp(begin);
else
void operator()(BufferIterator& it,
const BufferCoord& begin, const BufferCoord& end) const
{
if (end.line == coord.line)
{
coord.line = begin.line;
coord.column = begin.column + coord.column - end.column;
}
else
coord.line -= end.line - begin.line;
BufferCoord coord = it.coord();
if (assume_different_line)
assert(begin.line < coord.line);
if (not assume_greater_than_begin and coord < begin)
return;
if (not assume_different_line and begin.line == coord.line)
coord.column = end.column + coord.column - begin.column;
coord.line += end.line - begin.line;
it = coord;
}
it = coord;
};
template<bool assume_different_line, bool assume_greater_than_begin>
struct UpdateErase
{
void operator()(BufferIterator& it,
const BufferCoord& begin, const BufferCoord& end) const
{
BufferCoord coord = it.coord();
if (not assume_greater_than_begin and coord < begin)
return;
if (assume_different_line)
assert(end.line < coord.line);
if (not assume_different_line and coord <= end)
coord = it.buffer().clamp(begin);
else
{
if (not assume_different_line and end.line == coord.line)
{
coord.line = begin.line;
coord.column = begin.column + coord.column - end.column;
}
else
coord.line -= end.line - begin.line;
}
it = coord;
}
};
}
void DynamicSelectionList::on_insert(const BufferIterator& begin, const BufferIterator& end)
{
const BufferCoord begin_coord{begin.coord()};
const BufferCoord end_coord{end.coord()};
for (auto& sel : *this)
{
update_insert(sel.first(), begin_coord, end_coord);
update_insert(sel.last(), begin_coord, end_coord);
}
on_buffer_change<UpdateInsert>(*this, begin.coord(), end.coord(), begin.line());
}
void DynamicSelectionList::on_erase(const BufferIterator& begin, const BufferIterator& end)
{
const BufferCoord begin_coord{begin.coord()};
const BufferCoord end_coord{end.coord()};
for (auto& sel : *this)
{
update_erase(sel.first(), begin_coord, end_coord);
update_erase(sel.last(), begin_coord, end_coord);
}
on_buffer_change<UpdateErase>(*this, begin.coord(), end.coord(), end.line());
}
}