Fix performance of word completion with many different selections

Fixes #1228

1 files changed, 11 insertions, 13 deletions

diff --git a/src/insert_completer.cc b/src/insert_completer.cc
index f61a9c1d..f11c0bf7 100644
--- a/src/insert_completer.cc
+++ b/src/insert_completer.cc
@@ -90,25 +90,24 @@ InsertCompletion complete_word(const SelectionList& sels, const OptionManager& o
         return {};
 
     BufferCoord word_begin;
-    String prefix;
-    IdMap<int> sel_word_counts;
+    StringView prefix;
+    UnorderedMap<StringView, int> sel_word_counts;
     for (int i = 0; i < sels.size(); ++i)
     {
         Utf8It end{buffer.iterator_at(sels[i].cursor()), buffer};
         Utf8It begin = end-1;
-        if (not skip_while_reverse(begin, buffer.begin(),
-                                   [&](Codepoint c) { return is_word_pred(c); }))
+        if (not skip_while_reverse(begin, buffer.begin(), is_word_pred))
             ++begin;
 
         if (i == sels.main_index())
         {
             word_begin = begin.base().coord();
-            prefix = buffer.string(word_begin, end.base().coord());
+            prefix = buffer.substr(word_begin, end.base().coord());
         }
 
-        skip_while(end, buffer.end(), [&](Codepoint c) { return is_word_pred(c); });
+        skip_while(end, buffer.end(), is_word_pred);
 
-        auto word = buffer.string(begin.base().coord(), end.base().coord());
+        StringView word = buffer.substr(begin.base().coord(), end.base().coord());
         ++sel_word_counts[word];
     }
 
@@ -137,8 +136,8 @@ InsertCompletion complete_word(const SelectionList& sels, const OptionManager& o
     // Remove words that are being edited
     for (auto& word_count : sel_word_counts)
     {
-        if (get_word_db(buffer).get_word_occurences(word_count.key) <= word_count.value)
-            unordered_erase(matches, StringView{word_count.key});
+        if (get_word_db(buffer).get_word_occurences(word_count.first) <= word_count.second)
+            unordered_erase(matches, word_count.first);
     }
 
     if (other_buffers)
@@ -156,7 +155,7 @@ InsertCompletion complete_word(const SelectionList& sels, const OptionManager& o
         if (RankedMatch match{word, prefix})
             matches.emplace_back(match, nullptr);
 
-    unordered_erase(matches, StringView{prefix});
+    unordered_erase(matches, prefix);
     std::sort(matches.begin(), matches.end());
     matches.erase(std::unique(matches.begin(), matches.end()), matches.end());
 
@@ -206,7 +205,7 @@ InsertCompletion complete_filename(const SelectionList& sels,
     if (begin == pos)
         return {};
 
-    auto prefix = buffer.string(begin.coord(), pos.coord());
+    StringView prefix = buffer.substr(begin.coord(), pos.coord());
     if (require_slash and not contains(prefix, '/'))
         return {};
 
@@ -273,8 +272,7 @@ InsertCompletion complete_option(const SelectionList& sels,
 
         if (cursor_pos.line == coord.line and cursor_pos.column >= coord.column)
         {
-            StringView query = buffer[coord.line].substr(
-                coord.column, cursor_pos.column - coord.column);
+            StringView query = buffer.substr(coord, cursor_pos);
 
             const ColumnCount tabstop = options["tabstop"].get<int>();
             const ColumnCount column = get_column(buffer, tabstop, cursor_pos);