History is now a singleton.

This simplifies different components accessing the history database.

clink/app/src/host/host.cpp

@@ -349,7 +349,6 @@ host::~host()
     delete m_prompt_filter;
     delete m_suggester;
     delete m_lua;
-    delete m_history;
     delete m_printer;
     terminal_destroy(m_terminal);
 }
@@ -464,18 +463,6 @@ void host::pop_queued_line()
     m_char_cursor = 0;
 }
 
-//------------------------------------------------------------------------------
-int host::add_history(const char* line)
-{
-    return !!m_history->add(line);
-}
-
-//------------------------------------------------------------------------------
-int host::remove_history(int rl_history_index, const char* line)
-{
-    return !!m_history->remove(rl_history_index, line);
-}
-
 //------------------------------------------------------------------------------
 void host::filter_prompt()
 {
@@ -861,28 +848,29 @@ bool host::edit_line(const char* prompt, const char* rprompt, str_base& out, boo
 
     // Initialize history before filtering the prompt, so that the Lua history
     // APIs can work.
+    history_db* history = history_database::get();
     if (init_history)
     {
-        if (m_history &&
-            ((g_save_history.get() != m_history->has_bank(bank_master)) ||
-             m_history->is_stale_name()))
+        if (history &&
+            ((g_save_history.get() != history->has_bank(bank_master)) ||
+             history->is_stale_name()))
         {
-            delete m_history;
-            m_history = 0;
+            delete history;
+            history = nullptr;
         }
 
-        if (!m_history)
+        if (!history)
         {
             dbg_ignore_scope(snapshot, "History");
             str<> history_path;
             app->get_history_path(history_path);
-            m_history = new history_db(history_path.c_str(), app->get_id(), g_save_history.get());
+            history = new history_database(history_path.c_str(), app->get_id(), g_save_history.get());
         }
 
-        if (m_history)
+        if (history)
         {
-            m_history->initialise();
-            m_history->load_rl_history();
+            history->initialise();
+            history->load_rl_history();
         }
     }
 
@@ -994,7 +982,7 @@ bool host::edit_line(const char* prompt, const char* rprompt, str_base& out, boo
 
         // Handle history event expansion.  expand() is a static method,
         // so can call it even when m_history is nullptr.
-        if (m_history->expand(out.c_str(), out) == history_db::expand_print)
+        if (history->expand(out.c_str(), out) == history_db::expand_print)
         {
             puts(out.c_str());
             out.clear();
@@ -1030,8 +1018,9 @@ bool host::edit_line(const char* prompt, const char* rprompt, str_base& out, boo
         }
 
         // Add the line to the history.
-        if (add_history)
-            m_history->add(out.c_str());
+        assert(history);
+        if (add_history && history)
+            history->add(out.c_str());
         break;
     }
 

clink/app/src/host/host.h

@@ -60,8 +60,6 @@ class host : public host_callbacks
     void            cleanup_after_signal();
 
     // host_callbacks:
-    int             add_history(const char* line) override;
-    int             remove_history(int rl_history_index, const char* line) override;
     void            filter_prompt() override;
     void            filter_transient_prompt(bool final) override;
     bool            can_suggest(const line_state& line) override;
@@ -90,7 +88,6 @@ class host : public host_callbacks
     doskey          m_doskey;
     terminal        m_terminal;
     printer*        m_printer;
-    history_db*     m_history = nullptr;
     host_lua*       m_lua = nullptr;
     prompt_filter*  m_prompt_filter = nullptr;
     suggester*      m_suggester = nullptr;

clink/lib/include/lib/history_db.h

@@ -4,6 +4,7 @@
 #pragma once
 
 #include <core/str_iter.h>
+#include <core/singleton.h>
 
 #include <vector>
 
@@ -167,4 +168,11 @@ template <int S> history_db::iter history_db::read_lines(char (&buffer)[S])
     return read_lines(buffer, S);
 }
 
+//------------------------------------------------------------------------------
+class history_database : public history_db, public singleton<history_database>
+{
+public:
+    history_database(const char* path, int id, bool use_master_bank);
+};
+
 #define DIAG(fmt, ...)          do { if (m_diagnostic) fprintf(stderr, fmt, ##__VA_ARGS__); } while (false)

clink/lib/include/lib/host_callbacks.h

@@ -13,8 +13,6 @@ enum class recognition : char;
 class host_callbacks
 {
 public:
-    virtual int add_history(const char* line) = 0;
-    virtual int remove_history(int rl_history_index, const char* line) = 0;
     virtual void filter_prompt() = 0;
     virtual void filter_transient_prompt(bool final) = 0;
     virtual bool can_suggest(const line_state& line) = 0;

clink/lib/src/history_db.cpp

@@ -1828,6 +1828,14 @@ bool history_db::is_stale_name() const
 
 
 
+//------------------------------------------------------------------------------
+history_database::history_database(const char* path, int id, bool use_master_bank)
+: history_db(path, id, use_master_bank)
+{
+}
+
+
+
 //------------------------------------------------------------------------------
 bool expand_history(const char* in, str_base& out)
 {

clink/lib/src/line_editor_impl.cpp

@@ -151,24 +151,6 @@ void set_prompt(const char* prompt, const char* rprompt, bool redisplay)
 
 
 
-//------------------------------------------------------------------------------
-int host_add_history(int, const char* line)
-{
-    if (!s_callbacks)
-        return 0;
-
-    return s_callbacks->add_history(line);
-}
-
-//------------------------------------------------------------------------------
-int host_remove_history(int rl_history_index, const char* line)
-{
-    if (!s_callbacks)
-        return 0;
-
-    return s_callbacks->remove_history(rl_history_index, line);
-}
-
 //------------------------------------------------------------------------------
 void host_filter_prompt()
 {

clink/lib/src/rl/rl_commands.cpp

@@ -10,6 +10,7 @@
 #include "rl_commands.h"
 #include "doskey.h"
 #include "textlist_impl.h"
+#include "history_db.h"
 
 #include "rl_suggestions.h"
 
@@ -89,7 +90,6 @@ extern line_buffer* g_rl_buffer;
 extern word_collector* g_word_collector;
 extern editor_module::result* g_result;
 extern void host_cmd_enqueue_lines(std::list<str_moveable>& lines, bool hide_prompt, bool show_line);
-extern int host_add_history(int, const char* line);
 extern void host_get_app_context(int& id, str_base& binaries, str_base& profile, str_base& scripts);
 extern "C" int show_cursor(int visible);
 extern int ellipsify(const char* in, int limit, str_base& out, bool expand_ctrl);
@@ -231,6 +231,22 @@ static void get_word_bounds(const line_buffer& buffer, int* left, int* right)
 
 
 
+//------------------------------------------------------------------------------
+int host_add_history(int, const char* line)
+{
+    history_database* h = history_database::get();
+    return h && h->add(line);
+}
+
+//------------------------------------------------------------------------------
+int host_remove_history(int rl_history_index, const char* line)
+{
+    history_database* h = history_database::get();
+    return h && h->remove(rl_history_index, line);
+}
+
+
+
 //------------------------------------------------------------------------------
 static int s_cua_anchor = -1;
 

clink/lib/src/rl/rl_commands.h

@@ -34,6 +34,10 @@ bool    is_force_reload_scripts();
 void    clear_force_reload_scripts();
 int     force_reload_scripts();
 
+//------------------------------------------------------------------------------
+int     host_add_history(int, const char* line);
+int     host_remove_history(int rl_history_index, const char* line);
+
 //------------------------------------------------------------------------------
 int     show_rl_help(int, int);
 int     show_rl_help_raw(int, int);

clink/lib/src/rl/rl_module.cpp

@@ -86,8 +86,6 @@ extern int          _rl_last_v_pos;
 
 extern int clink_diagnostics(int, int);
 
-extern int host_add_history(int rl_history_index, const char* line);
-extern int host_remove_history(int rl_history_index, const char* line);
 extern void host_send_event(const char* event_name);
 extern void host_cleanup_after_signal();
 extern int macro_hook_func(const char* macro);