rename SharedString::Storage to StringStorage and use directly in Buffer

src/buffer.cc

@@ -34,7 +34,7 @@ Buffer::Buffer(String name, Flags flags, Vector<String> lines,
     for (auto& line : lines)
     {
         kak_assert(not line.empty() and line.back() == '\n');
-        m_lines.emplace_back(std::move(line));
+        m_lines.emplace_back(StringStorage::create(line));
     }
 
     m_changes.push_back({ Change::Insert, {0,0}, line_count(), true });
@@ -107,7 +107,7 @@ ByteCoord Buffer::clamp(ByteCoord coord) const
 
 ByteCoord Buffer::offset_coord(ByteCoord coord, CharCount offset)
 {
-    auto& line = m_lines[coord.line];
+    StringView line = m_lines[coord.line];
     auto character = std::max(0_char, std::min(line.char_count_to(coord.column) + offset,
                                                line.char_length() - 1));
     return {coord.line, line.byte_count_to(character)};
@@ -117,7 +117,7 @@ ByteCoordAndTarget Buffer::offset_coord(ByteCoordAndTarget coord, LineCount offs
 {
     auto character = coord.target == -1 ? m_lines[coord.line].char_count_to(coord.column) : coord.target;
     auto line = Kakoune::clamp(coord.line + offset, 0_line, line_count()-1);
-    auto& content = m_lines[line];
+    StringView content = m_lines[line];
 
     character = std::max(0_char, std::min(character, content.char_length() - 2));
     return {line, content.byte_count_to(character), character};
@@ -178,7 +178,7 @@ void Buffer::reload(Vector<String> lines, time_t fs_timestamp)
     for (auto& line : lines)
     {
         kak_assert(not line.empty() and line.back() == '\n');
-        m_lines.emplace_back(std::move(line));
+        m_lines.emplace_back(StringStorage::create(line));
         if (not (m_flags & Flags::NoUndo))
             m_current_undo_group.emplace_back(
                 Modification::Insert, line_count()-1, m_lines.back());
@@ -243,8 +243,8 @@ void Buffer::check_invariant() const
     kak_assert(not m_lines.empty());
     for (auto& line : m_lines)
     {
-        kak_assert(line.length() > 0);
+        kak_assert(line->strview().length() > 0);
-        kak_assert(line.back() == '\n');
+        kak_assert(line->strview().back() == '\n');
     }
 #endif
 }
@@ -268,12 +268,12 @@ ByteCoord Buffer::do_insert(ByteCoord pos, StringView content)
         {
             if (content[i] == '\n')
             {
-                m_lines.push_back(content.substr(start, i + 1 - start));
+                m_lines.push_back(StringStorage::create(content.substr(start, i + 1 - start)));
                 start = i + 1;
             }
         }
         if (start != content.length())
-            m_lines.push_back(content.substr(start));
+            m_lines.push_back(StringStorage::create(content.substr(start)));
 
         begin = pos.column == 0 ? pos : ByteCoord{ pos.line + 1, 0 };
         end = ByteCoord{ line_count(), 0 };
@@ -284,7 +284,7 @@ ByteCoord Buffer::do_insert(ByteCoord pos, StringView content)
         StringView prefix = m_lines[pos.line].substr(0, pos.column);
         StringView suffix = m_lines[pos.line].substr(pos.column);
 
-        Vector<SharedString> new_lines;
+        LineList new_lines;
 
         ByteCount start = 0;
         for (ByteCount i = 0; i < content.length(); ++i)
@@ -293,16 +293,16 @@ ByteCoord Buffer::do_insert(ByteCoord pos, StringView content)
             {
                 StringView line_content = content.substr(start, i + 1 - start);
                 if (start == 0)
-                    new_lines.emplace_back(prefix + line_content);
+                    new_lines.emplace_back(StringStorage::create(prefix + line_content));
                 else
-                    new_lines.push_back(line_content);
+                    new_lines.push_back(StringStorage::create(line_content));
                 start = i + 1;
             }
         }
         if (start == 0)
-            new_lines.emplace_back(prefix + content + suffix);
+            new_lines.emplace_back(StringStorage::create(prefix + content + suffix));
         else if (start != content.length() or not suffix.empty())
-            new_lines.emplace_back(content.substr(start) + suffix);
+            new_lines.emplace_back(StringStorage::create(content.substr(start) + suffix));
 
         LineCount last_line = pos.line + new_lines.size() - 1;
 
@@ -332,7 +332,7 @@ ByteCoord Buffer::do_erase(ByteCoord begin, ByteCoord end)
     if (new_line.length() != 0)
     {
         m_lines.erase(m_lines.begin() + (int)begin.line, m_lines.begin() + (int)end.line);
-        m_lines[begin.line] = SharedString(new_line);
+        m_lines.get_storage(begin.line) = StringStorage::create(new_line);
         next = begin;
     }
     else
@@ -547,7 +547,7 @@ String Buffer::debug_description() const
 
     size_t content_size = 0;
     for (auto& line : m_lines)
-        content_size += (int)line.length();
+        content_size += (int)line->strview().length();
 
     size_t additional_size = 0;
     for (auto& undo_group : m_history)

src/buffer.hh

@@ -121,9 +121,12 @@ public:
     BufferIterator end() const;
     LineCount      line_count() const;
 
-    const SharedString& operator[](LineCount line) const
+    StringView operator[](LineCount line) const
     { return m_lines[line]; }
 
+    SharedString shared_line(LineCount line) const
+    { return m_lines.get_shared(line); }
+
     // returns an iterator at given coordinates. clamp line_and_column
     BufferIterator iterator_at(ByteCoord coord) const;
 
@@ -166,16 +169,27 @@ private:
 
     void on_option_changed(const Option& option) override;
 
-    using LineListBase = Vector<SharedString, MemoryDomain::BufferContent>;
+    using LineListBase = Vector<ref_ptr<StringStorage>, MemoryDomain::BufferContent>;
     struct LineList : LineListBase
     {
         [[gnu::always_inline]]
-        SharedString& operator[](LineCount line)
+        ref_ptr<StringStorage>& get_storage(LineCount line)
         { return LineListBase::operator[]((int)line); }
 
         [[gnu::always_inline]]
-        const SharedString& operator[](LineCount line) const
+        const ref_ptr<StringStorage>& get_storage(LineCount line) const
         { return LineListBase::operator[]((int)line); }
+
+        [[gnu::always_inline]]
+        SharedString get_shared(LineCount line) const
+        { return SharedString{get_storage(line)}; }
+
+        [[gnu::always_inline]]
+        StringView operator[](LineCount line) const
+        { return get_storage(line)->strview(); }
+
+        StringView front() const { return LineListBase::front()->strview(); }
+        StringView back() const { return LineListBase::back()->strview(); }
     };
     LineList m_lines;
 

src/shared_string.cc

@@ -12,7 +12,7 @@ SharedString StringRegistry::intern(StringView str)
         SharedString shared_str = str;
         it = m_strings.emplace(shared_str, shared_str.m_storage).first;
     }
-    return {it->second->strview(), it->second};
+    return SharedString{it->second};
 }
 
 void StringRegistry::purge_unused()

src/shared_string.hh

@@ -9,44 +9,44 @@
 namespace Kakoune
 {
 
+struct StringStorage : UseMemoryDomain<MemoryDomain::SharedString>
+{
+    int refcount;
+    int length;
+    char data[1];
+
+    StringView strview() const { return {data, length}; }
+
+    static StringStorage* create(StringView str)
+    {
+        const int len = (int)str.length();
+        void* ptr = StringStorage::operator new(sizeof(StringStorage) + len);
+        StringStorage* res = reinterpret_cast<StringStorage*>(ptr);
+        memcpy(res->data, str.data(), len);
+        res->refcount = 0;
+        res->length = len;
+        res->data[len] = 0;
+        return res;
+    }
+
+    static void destroy(StringStorage* s)
+    {
+        StringStorage::operator delete(s, sizeof(StringStorage) + s->length);
+    }
+
+    friend void inc_ref_count(StringStorage* s) { ++s->refcount; }
+    friend void dec_ref_count(StringStorage* s) { if (--s->refcount == 0) StringStorage::destroy(s); }
+};
+
 class SharedString : public StringView
 {
 public:
-    struct Storage : UseMemoryDomain<MemoryDomain::SharedString>
-    {
-        int refcount;
-        int length;
-        char data[1];
-
-        StringView strview() const { return {data, length}; }
-
-        static Storage* create(StringView str)
-        {
-            const int len = (int)str.length();
-            void* ptr = Storage::operator new(sizeof(Storage) + len);
-            Storage* res = reinterpret_cast<Storage*>(ptr);
-            memcpy(res->data, str.data(), len);
-            res->refcount = 0;
-            res->length = len;
-            res->data[len] = 0;
-            return res;
-        }
-
-        static void destroy(Storage* s)
-        {
-            Storage::operator delete(s, sizeof(Storage) + s->length);
-        }
-
-        friend void inc_ref_count(Storage* s) { ++s->refcount; }
-        friend void dec_ref_count(Storage* s) { if (--s->refcount == 0) Storage::destroy(s); }
-    };
-
     SharedString() = default;
     SharedString(StringView str)
     {
         if (not str.empty())
         {
-            m_storage = Storage::create(str);
+            m_storage = StringStorage::create(str);
             StringView::operator=(m_storage->strview());
         }
     }
@@ -64,12 +64,15 @@ public:
         return SharedString{StringView::substr(from, length), m_storage};
     }
 
+    explicit SharedString(ref_ptr<StringStorage> storage)
+        : StringView{storage->strview()}, m_storage(std::move(storage)) {}
+
 private:
-    SharedString(StringView str, ref_ptr<Storage> storage)
+    SharedString(StringView str, ref_ptr<StringStorage> storage)
         : StringView{str}, m_storage(std::move(storage)) {}
 
     friend class StringRegistry;
-    ref_ptr<Storage> m_storage;
+    ref_ptr<StringStorage> m_storage;
 };
 
 inline size_t hash_value(const SharedString& str)
@@ -85,7 +88,7 @@ public:
     void purge_unused();
 
 private:
-    UnorderedMap<StringView, ref_ptr<SharedString::Storage>, MemoryDomain::SharedString> m_strings;
+    UnorderedMap<StringView, ref_ptr<StringStorage>, MemoryDomain::SharedString> m_strings;
 };
 
 inline SharedString intern(StringView str)

src/word_db.cc

@@ -119,7 +119,7 @@ void WordDB::update_db()
             if (modif.new_line + l >= buffer.line_count())
                 break;
 
-            new_lines.push_back(buffer[modif.new_line + l]);
+            new_lines.push_back(buffer.shared_line(modif.new_line + l));
             add_words(get_words(new_lines.back()));
         }
     }