LibLine: Use Core::EventLoop for outer read loop

This commit changes LibLine's internal structure to work in an event
loop, and as a result, also switches it to being a Core::Object.

Applications/Debugger/main.cpp

@@ -44,7 +44,7 @@
 #include <string.h>
 #include <unistd.h>
 
-static Line::Editor editor {};
+RefPtr<Line::Editor> editor;
 
 OwnPtr<DebugSession> g_debug_session;
 
@@ -173,6 +173,8 @@ void print_help()
 
 int main(int argc, char** argv)
 {
+    editor = Line::Editor::construct();
+
     if (pledge("stdio proc exec rpath tty sigaction", nullptr) < 0) {
         perror("pledge");
         return 1;
@@ -236,7 +238,7 @@ int main(int argc, char** argv)
         }
 
         for (;;) {
-            auto command_result = editor.get_line("(sdb) ");
+            auto command_result = editor->get_line("(sdb) ");
 
             if (command_result.is_error())
                 return DebugSession::DebugDecision::Detach;
@@ -246,8 +248,8 @@ int main(int argc, char** argv)
             bool success = false;
             Optional<DebugSession::DebugDecision> decision;
 
-            if (command.is_empty() && !editor.history().is_empty()) {
-                command = editor.history().last();
+            if (command.is_empty() && !editor->history().is_empty()) {
+                command = editor->history().last();
             }
             if (command == "cont") {
                 decision = DebugSession::DebugDecision::Continue;
@@ -276,8 +278,8 @@ int main(int argc, char** argv)
 
             if (success && !command.is_empty()) {
                 // Don't add repeated commands to history
-                if (editor.history().is_empty() || editor.history().last() != command)
-                    editor.add_to_history(command);
+                if (editor->history().is_empty() || editor->history().last() != command)
+                    editor->add_to_history(command);
             }
             if (!success) {
                 print_help();

Libraries/LibLine/Editor.cpp

@@ -25,9 +25,13 @@
  */
 
 #include "Editor.h"
+#include <AK/JsonObject.h>
 #include <AK/StringBuilder.h>
 #include <AK/Utf32View.h>
 #include <AK/Utf8View.h>
+#include <LibCore/Event.h>
+#include <LibCore/EventLoop.h>
+#include <LibCore/Notifier.h>
 #include <ctype.h>
 #include <stdio.h>
 #include <sys/ioctl.h>
@@ -252,7 +256,7 @@ void Editor::initialize()
     m_initialized = true;
 }
 
-Result<String, Editor::Error> Editor::get_line(const String& prompt)
+auto Editor::get_line(const String& prompt) -> Result<String, Editor::Error>
 {
     initialize();
     m_is_editing = true;
@@ -279,13 +283,22 @@ Result<String, Editor::Error> Editor::get_line(const String& prompt)
     strip_styles(true);
 
     m_history_cursor = m_history.size();
-    for (;;) {
+
+    refresh_display();
+
+    Core::EventLoop loop;
+
+    m_notifier = Core::Notifier::construct(STDIN_FILENO, Core::Notifier::Read);
+    add_child(*m_notifier);
+
+    m_notifier->on_ready_to_read = [&] {
+        handle_read_event();
+
         if (m_always_refresh)
             m_refresh_needed = true;
+
         refresh_display();
-        if (m_input_error.has_value()) {
-            return m_input_error.value();
-        }
+
         if (m_finish) {
             m_finish = false;
             printf("\n");
@@ -294,8 +307,25 @@ Result<String, Editor::Error> Editor::get_line(const String& prompt)
             m_buffer.clear();
             m_is_editing = false;
             restore();
-            return string;
+
+            m_returned_line = string;
+
+            m_notifier->set_event_mask(Core::Notifier::None);
+            deferred_invoke([this](auto&) {
+                remove_child(*m_notifier);
+                m_notifier = nullptr;
+                Core::EventLoop::current().quit(0);
+            });
         }
+    };
+
+    loop.exec();
+
+    return m_input_error.has_value() ? Result<String, Editor::Error> { m_input_error.value() } : Result<String, Editor::Error> { m_returned_line };
+}
+
+void Editor::handle_read_event()
+{
     char keybuf[16];
     ssize_t nread = 0;
 
@@ -306,10 +336,10 @@ Result<String, Editor::Error> Editor::get_line(const String& prompt)
         if (errno == EINTR) {
             if (!m_was_interrupted) {
                 if (m_was_resized)
-                        continue;
+                    return;
 
                 finish();
-                    continue;
+                return;
             }
 
             m_was_interrupted = false;
@@ -324,20 +354,25 @@ Result<String, Editor::Error> Editor::get_line(const String& prompt)
                 on_interrupt_handled();
 
             m_refresh_needed = true;
-                continue;
+            return;
         }
 
         ScopedValueRollback errno_restorer(errno);
         perror("read failed");
 
-            return Error::ReadFailure;
+        m_input_error = Error::ReadFailure;
+        finish();
+        return;
     }
 
     m_incomplete_data.append(keybuf, nread);
     nread = m_incomplete_data.size();
 
-        if (nread == 0)
-            return Error::Empty;
+    if (nread == 0) {
+        m_input_error = Error::Empty;
+        finish();
+        return;
+    }
 
     auto reverse_tab = false;
     auto ctrl_held = false;
@@ -700,7 +735,13 @@ Result<String, Editor::Error> Editor::get_line(const String& prompt)
                 for (auto codepoint : m_buffer)
                     m_pre_search_buffer.append(codepoint);
                 m_pre_search_cursor = m_cursor;
-                    m_search_editor = make<Editor>(Configuration { Configuration::Eager, m_configuration.split_mechanism }); // Has anyone seen 'Inception'?
+
+                // Disable our own notifier so as to avoid interfering with the search editor.
+                m_notifier->set_enabled(false);
+
+                m_search_editor = Editor::construct(Configuration { Configuration::Eager, m_configuration.split_mechanism }); // Has anyone seen 'Inception'?
+                add_child(*m_search_editor);
+
                 m_search_editor->on_display_refresh = [this](Editor& search_editor) {
                     StringBuilder builder;
                     builder.append(Utf32View { search_editor.buffer().data(), search_editor.buffer().size() });
@@ -760,13 +801,19 @@ Result<String, Editor::Error> Editor::get_line(const String& prompt)
                 auto search_prompt = "\x1b[32msearch:\x1b[0m ";
                 auto search_string_result = m_search_editor->get_line(search_prompt);
 
+                remove_child(*m_search_editor);
                 m_search_editor = nullptr;
                 m_is_searching = false;
                 m_search_offset = 0;
 
+                // Re-enable the notifier after discarding the search editor.
+                m_notifier->set_enabled(true);
+
                 if (search_string_result.is_error()) {
                     // Somethine broke, fail
-                        return search_string_result;
+                    m_input_error = search_string_result.error();
+                    finish();
+                    return;
                 }
 
                 auto& search_string = search_string_result.value();
@@ -796,14 +843,15 @@ Result<String, Editor::Error> Editor::get_line(const String& prompt)
             if (m_buffer.is_empty()) {
                 printf("<EOF>\n");
                 if (!m_always_refresh) {
-                        return Error::Eof;
+                    m_input_error = Error::Eof;
+                    finish();
+                    continue;
                 }
             }
             continue;
         }
         // ^E
         if (codepoint == 0x05) {
-
             m_cursor = m_buffer.size();
             continue;
         }
@@ -822,7 +870,6 @@ Result<String, Editor::Error> Editor::get_line(const String& prompt)
             m_incomplete_data.take_first();
     }
 }
-}
 
 bool Editor::search(const StringView& phrase, bool allow_empty, bool from_beginning)
 {
@@ -1304,6 +1351,7 @@ Vector<size_t, 2> Editor::vt_dsr()
             auto nread = read(0, buf, 16);
             if (nread < 0) {
                 m_input_error = Error::ReadFailure;
+                finish();
                 break;
             }
 
@@ -1330,10 +1378,12 @@ Vector<size_t, 2> Editor::vt_dsr()
             }
             dbg() << "Error while reading DSR: " << strerror(errno);
             m_input_error = Error::ReadFailure;
+            finish();
             return { 1, 1 };
         }
         if (nread == 0) {
             m_input_error = Error::Empty;
+            finish();
             dbg() << "Terminal DSR issue; received no response";
             return { 1, 1 };
         }

Libraries/LibLine/Editor.h

@@ -38,6 +38,8 @@
 #include <AK/Utf8View.h>
 #include <AK/Vector.h>
 #include <LibCore/DirIterator.h>
+#include <LibCore/Notifier.h>
+#include <LibCore/Object.h>
 #include <LibLine/Span.h>
 #include <LibLine/Style.h>
 #include <LibLine/SuggestionDisplay.h>
@@ -82,7 +84,9 @@ struct Configuration {
     OperationMode operation_mode { OperationMode::Full };
 };
 
-class Editor {
+class Editor : public Core::Object {
+    C_OBJECT(Editor);
+
 public:
     enum class Error {
         ReadFailure,
@@ -90,7 +94,6 @@ public:
         Eof,
     };
 
-    explicit Editor(Configuration configuration = {});
     ~Editor();
 
     Result<String, Error> get_line(const String& prompt);
@@ -160,6 +163,8 @@ public:
     bool is_editing() const { return m_is_editing; }
 
 private:
+    explicit Editor(Configuration configuration = {});
+
     struct KeyCallback {
         KeyCallback(Function<bool(Editor&)> cb)
             : callback(move(cb))
@@ -168,6 +173,8 @@ private:
         Function<bool(Editor&)> callback;
     };
 
+    void handle_read_event();
+
     Vector<size_t, 2> vt_dsr();
     void remove_at_index(size_t);
 
@@ -208,6 +215,7 @@ private:
         m_prompt_lines_at_suggestion_initiation = 0;
         m_refresh_needed = true;
         m_input_error.clear();
+        m_returned_line = String::empty();
     }
 
     void refresh_display();
@@ -266,7 +274,7 @@ private:
 
     bool m_finish { false };
 
-    OwnPtr<Editor> m_search_editor;
+    RefPtr<Editor> m_search_editor;
     bool m_is_searching { false };
     bool m_reset_buffer_on_search_end { true };
     size_t m_search_offset { 0 };
@@ -278,6 +286,7 @@ private:
     ByteBuffer m_pending_chars;
     Vector<char, 512> m_incomplete_data;
     Optional<Error> m_input_error;
+    String m_returned_line;
 
     size_t m_cursor { 0 };
     size_t m_drawn_cursor { 0 };
@@ -336,6 +345,8 @@ private:
     HashMap<u32, HashMap<u32, Style>> m_anchored_spans_starting;
     HashMap<u32, HashMap<u32, Style>> m_anchored_spans_ending;
 
+    RefPtr<Core::Notifier> m_notifier;
+
     bool m_initialized { false };
     bool m_refresh_needed { false };
 

Shell/Shell.cpp

@@ -55,7 +55,7 @@
 //        if we want to be more sh-like, we should do that some day
 static constexpr bool HighlightVariablesInsideStrings = false;
 static bool s_disable_hyperlinks = false;
-extern Line::Editor editor;
+extern RefPtr<Line::Editor> editor;
 
 //#define SH_DEBUG
 
@@ -126,7 +126,7 @@ String Shell::prompt() const
     };
 
     auto the_prompt = build_prompt();
-    auto prompt_length = editor.actual_rendered_string_length(the_prompt);
+    auto prompt_length = editor->actual_rendered_string_length(the_prompt);
 
     if (m_should_continue != ExitCodeOrContinuationRequest::Nothing) {
         const auto format_string = "\033[34m%.*-s\033[m";
@@ -511,8 +511,8 @@ int Shell::builtin_disown(int argc, const char** argv)
 
 int Shell::builtin_history(int, const char**)
 {
-    for (size_t i = 0; i < editor.history().size(); ++i) {
-        printf("%6zu  %s\n", i, editor.history()[i].characters());
+    for (size_t i = 0; i < editor->history().size(); ++i) {
+        printf("%6zu  %s\n", i, editor->history()[i].characters());
     }
     return 0;
 }
@@ -1385,7 +1385,7 @@ void Shell::load_history()
     while (history_file->can_read_line()) {
         auto b = history_file->read_line(1024);
         // skip the newline and terminating bytes
-        editor.add_to_history(String(reinterpret_cast<const char*>(b.data()), b.size() - 2));
+        editor->add_to_history(String(reinterpret_cast<const char*>(b.data()), b.size() - 2));
     }
 }
 
@@ -1395,7 +1395,7 @@ void Shell::save_history()
     if (file_or_error.is_error())
         return;
     auto& file = *file_or_error.value();
-    for (const auto& line : editor.history()) {
+    for (const auto& line : editor->history()) {
         file.write(line);
         file.write("\n");
     }
@@ -1484,7 +1484,7 @@ void Shell::cache_path()
     quick_sort(cached_path);
 }
 
-void Shell::highlight(Line::Editor&) const
+void Shell::highlight(Line::Editor& editor) const
 {
     StringBuilder builder;
     if (m_should_continue == ExitCodeOrContinuationRequest::DoubleQuotedString) {
@@ -1703,7 +1703,7 @@ Vector<Line::CompletionSuggestion> Shell::complete(const Line::Editor& editor)
 
 bool Shell::read_single_line()
 {
-    auto line_result = editor.get_line(prompt());
+    auto line_result = editor->get_line(prompt());
 
     if (line_result.is_error()) {
         m_complete_line_builder.clear();
@@ -1737,7 +1737,7 @@ bool Shell::read_single_line()
     if (!complete_or_exit_code.has_value())
         return true;
 
-    editor.add_to_history(m_complete_line_builder.build());
+    editor->add_to_history(m_complete_line_builder.build());
     m_complete_line_builder.clear();
     return true;
 }

Shell/main.cpp

@@ -35,7 +35,7 @@
 #include <string.h>
 #include <sys/wait.h>
 
-Line::Editor editor { Line::Configuration { Line::Configuration::UnescapedSpaces } };
+RefPtr<Line::Editor> editor;
 Shell* s_shell;
 
 void FileDescriptionCollector::collect()
@@ -60,11 +60,11 @@ int main(int argc, char** argv)
     Core::EventLoop loop;
     
     signal(SIGINT, [](int) {
-        editor.interrupted();
+        editor->interrupted();
     });
 
     signal(SIGWINCH, [](int) {
-        editor.resized();
+        editor->resized();
     });
 
     signal(SIGHUP, [](int) {
@@ -92,18 +92,20 @@ int main(int argc, char** argv)
         return 1;
     }
 
+    editor = Line::Editor::construct(Line::Configuration { Line::Configuration::UnescapedSpaces });
+
     auto shell = Shell::construct();
     s_shell = shell.ptr();
 
-    editor.initialize();
-    shell->termios = editor.termios();
-    shell->default_termios = editor.default_termios();
+    editor->initialize();
+    shell->termios = editor->termios();
+    shell->default_termios = editor->default_termios();
 
-    editor.on_display_refresh = [&](auto& editor) {
+    editor->on_display_refresh = [&](auto& editor) {
         editor.strip_styles();
         shell->highlight(editor);
     };
-    editor.on_tab_complete = [&](const Line::Editor& editor) {
+    editor->on_tab_complete = [&](const Line::Editor& editor) {
         return shell->complete(editor);
     };
 
@@ -128,13 +130,15 @@ int main(int argc, char** argv)
         return 0;
     }
 
-    editor.on_interrupt_handled = [&] {
+    editor->on_interrupt_handled = [&] {
         if (!shell->should_read_more()) {
             shell->finish_command();
-            editor.finish();
+            editor->finish();
         }
     };
 
+    shell->add_child(*editor);
+
     Core::EventLoop::current().post_event(*shell, make<Core::CustomEvent>(Shell::ShellEventType::ReadLine));
 
     return loop.exec();

Userland/js.cpp

@@ -65,7 +65,7 @@ private:
 
 static bool s_dump_ast = false;
 static bool s_print_last_result = false;
-static OwnPtr<Line::Editor> s_editor;
+static RefPtr<Line::Editor> s_editor;
 static int s_repl_line_level = 0;
 static bool s_fail_repl = false;
 
@@ -510,7 +510,7 @@ int main(int argc, char** argv)
         if (test_mode)
             enable_test_mode(*interpreter);
 
-        s_editor = make<Line::Editor>();
+        s_editor = Line::Editor::construct();
 
         signal(SIGINT, [](int) {
             if (!s_editor->is_editing())

Userland/test-crypto.cpp

@@ -110,10 +110,9 @@ Core::EventLoop loop;
 int run(Function<void(const char*, size_t)> fn)
 {
     if (interactive) {
-        Line::Editor editor;
-        editor.initialize();
+        auto editor = Line::Editor::construct();
         for (;;) {
-            auto line_result = editor.get_line("> ");
+            auto line_result = editor->get_line("> ");
 
             if (line_result.is_error())
                 break;