From fed8b06afff540c1af3a83fb5f5115e3336ee9ff Mon Sep 17 00:00:00 2001
From: Přemysl Janouch
Date: Thu, 27 Oct 2016 17:03:53 +0200
Subject: degesch: begin work on direct introspection
---
degesch.c | 206 +++++++++++++++++++++++++++++++++++++++++++++++++++++---------
1 file changed, 176 insertions(+), 30 deletions(-)
diff --git a/degesch.c b/degesch.c
index bbc9b0f..255bcff 100644
--- a/degesch.c
+++ b/degesch.c
@@ -1241,6 +1241,49 @@ weak_unref (struct weak_ref_link **list, struct weak_ref_link **link)
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+// Simple introspection framework to simplify exporting stuff to Lua, since
+// there is a lot of it. While not fully automated, at least we have control
+// over which fields are exported.
+
+enum ispect_type
+{
+ ISPECT_BOOL,
+ ISPECT_INT,
+ ISPECT_UINT,
+ ISPECT_SIZE,
+ ISPECT_STRING,
+#if 0
+ // TODO: also str_map, str_vector
+ ISPECT_REF, ///< Weakly referenced
+ ISPECT_LIST, ///< Typically copied, depending on type
+#endif
+};
+
+// TODO: once this finalizes, turn instatiations into macros
+struct ispect
+{
+ // TODO:
+ // - "list" flag?
+ // - weak_ref/weak_unref methods?
+ struct ispect_field *fields; ///< Fields
+};
+
+struct ispect_field
+{
+ const char *name; ///< Name of the field
+ size_t offset; ///< Offset in the structure
+ enum ispect_type type; ///< Type of the field
+ struct ispect *subtype; ///< Subtype information
+};
+
+#define ISPECT(object, field, type) \
+ { #field, offsetof (struct object, field), ISPECT_ ## type, NULL },
+#define ISPECT_(object, field, type, subtype) \
+ { #field, offsetof (struct object, field), ISPECT_ ## type, \
+ &g_ ## subtype ## _type },
+
+// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+
struct user_channel
{
LIST_HEADER (struct user_channel)
@@ -1279,6 +1322,18 @@ struct user
struct user_channel *channels; ///< Channels the user is on
};
+static struct ispect_field g_user_ispect_fields[] =
+{
+ ISPECT( user, nickname, STRING )
+ ISPECT( user, away, BOOL )
+ {}
+};
+
+static struct ispect g_user_ispect =
+{
+ .fields = g_user_ispect_fields,
+};
+
static struct user *
user_new (void)
{
@@ -1347,6 +1402,20 @@ struct channel
bool left_manually; ///< Don't rejoin on reconnect
};
+static struct ispect_field g_channel_ispect_fields[] =
+{
+ ISPECT( channel, name, STRING )
+ ISPECT( channel, topic, STRING )
+ ISPECT( channel, users_len, SIZE )
+ ISPECT( channel, left_manually, BOOL )
+ {}
+};
+
+static struct ispect g_channel_ispect =
+{
+ .fields = g_channel_ispect_fields,
+};
+
static struct channel *
channel_new (void)
{
@@ -1519,6 +1588,21 @@ struct buffer
struct user *user; ///< Reference to user
};
+static struct ispect_field g_buffer_ispect_fields[] =
+{
+ ISPECT( buffer, name, STRING )
+ ISPECT( buffer, new_messages_count, UINT )
+ ISPECT( buffer, new_unimportant_count, UINT )
+ ISPECT( buffer, highlighted, BOOL )
+ ISPECT( buffer, hide_unimportant, BOOL )
+ {}
+};
+
+static struct ispect g_buffer_ispect =
+{
+ .fields = g_buffer_ispect_fields,
+};
+
static struct buffer *
buffer_new (struct input *input)
{
@@ -1667,6 +1751,23 @@ struct server
unsigned irc_max_modes; ///< Max parametrized modes per command
};
+static struct ispect_field g_server_ispect_fields[] =
+{
+ ISPECT( server, name, STRING )
+ ISPECT( server, state, INT )
+ ISPECT( server, reconnect_attempt, UINT )
+ ISPECT( server, manual_disconnect, BOOL )
+ ISPECT( server, irc_user_host, STRING )
+ ISPECT( server, autoaway_active, BOOL )
+ ISPECT( server, cap_echo_message, BOOL )
+ {}
+};
+
+static struct ispect g_server_ispect =
+{
+ .fields = g_server_ispect_fields,
+};
+
static void on_irc_timeout (void *user_data);
static void on_irc_ping_timeout (void *user_data);
static void on_irc_autojoin_timeout (void *user_data);
@@ -8418,6 +8519,10 @@ typedef void (*lua_weak_unref_fn) (void *object, struct weak_ref_link **link);
struct lua_weak_info
{
const char *name; ///< Metatable name
+ struct ispect *ispect; ///< Introspection data
+
+ // XXX: not sure if these should be _here_ and not in "struct ispect"
+
lua_weak_ref_fn ref; ///< Weak link invalidator
lua_weak_unref_fn unref; ///< Weak link generator
};
@@ -8425,6 +8530,7 @@ struct lua_weak_info
struct lua_weak
{
struct lua_plugin *plugin; ///< The plugin we belong to
+ struct lua_weak_info *info; ///< Introspection data
void *object; ///< The object
struct weak_ref_link *weak_ref; ///< A weak reference link
};
@@ -8455,6 +8561,7 @@ lua_weak_push (struct lua_plugin *plugin, void *object,
struct lua_weak *wrapper = lua_newuserdata (L, sizeof *wrapper);
luaL_setmetatable (L, info->name);
wrapper->plugin = plugin;
+ wrapper->info = info;
wrapper->object = object;
wrapper->weak_ref = info->ref (object, lua_weak_invalidate, wrapper);
lua_cache_store (L, object, -1);
@@ -8486,9 +8593,10 @@ lua_weak_deref (lua_State *L, const struct lua_weak_info *info)
#define LUA_WEAK_DECLARE(id, metatable_id) \
static struct lua_weak_info lua_ ## id ## _info = \
{ \
- .name = metatable_id, \
- .ref = (lua_weak_ref_fn) id ## _weak_ref, \
- .unref = (lua_weak_unref_fn) id ## _weak_unref, \
+ .name = metatable_id, \
+ .ispect = &g_ ## id ## _ispect, \
+ .ref = (lua_weak_ref_fn) id ## _weak_ref, \
+ .unref = (lua_weak_unref_fn) id ## _weak_unref, \
};
#define XLUA_USER_METATABLE "user" ///< Identifier for Lua metatable
@@ -8509,15 +8617,6 @@ lua_user_gc (lua_State *L)
return lua_weak_gc (L, &lua_user_info);
}
-static int
-lua_user_get_nickname (lua_State *L)
-{
- struct lua_weak *wrapper = lua_weak_deref (L, &lua_user_info);
- struct user *user = wrapper->object;
- lua_pushstring (L, user->nickname);
- return 1;
-}
-
static int
lua_user_get_channels (lua_State *L)
{
@@ -8537,7 +8636,6 @@ lua_user_get_channels (lua_State *L)
static luaL_Reg lua_user_table[] =
{
{ "__gc", lua_user_gc },
- { "get_nickname", lua_user_get_nickname },
{ "get_channels", lua_user_get_channels },
{ NULL, NULL }
};
@@ -8550,15 +8648,6 @@ lua_channel_gc (lua_State *L)
return lua_weak_gc (L, &lua_channel_info);
}
-static int
-lua_channel_get_name (lua_State *L)
-{
- struct lua_weak *wrapper = lua_weak_deref (L, &lua_channel_info);
- struct channel *channel = wrapper->object;
- lua_pushstring (L, channel->name);
- return 1;
-}
-
static int
lua_channel_get_users (lua_State *L)
{
@@ -8582,7 +8671,6 @@ lua_channel_get_users (lua_State *L)
static luaL_Reg lua_channel_table[] =
{
{ "__gc", lua_channel_gc },
- { "get_name", lua_channel_get_name },
{ "get_users", lua_channel_get_users },
{ NULL, NULL }
};
@@ -8645,7 +8733,6 @@ lua_buffer_execute (lua_State *L)
static luaL_Reg lua_buffer_table[] =
{
- // TODO: some useful methods or values
{ "__gc", lua_buffer_gc },
{ "get_user", lua_buffer_get_user },
{ "get_channel", lua_buffer_get_channel },
@@ -8692,7 +8779,6 @@ lua_server_send (lua_State *L)
static luaL_Reg lua_server_table[] =
{
- // TODO: some useful methods or values
{ "__gc", lua_server_gc },
{ "get_user", lua_server_get_user },
{ "get_buffer", lua_server_get_buffer },
@@ -9701,6 +9787,16 @@ static luaL_Reg lua_plugin_library[] =
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
+static struct lua_ispect_mapping
+{
+ struct ispect *ispect; ///< Type info
+ struct lua_weak_info *info; ///< Lua-specific additions
+}
+lua_types[] =
+{
+ { &g_buffer_ispect, &lua_buffer_info },
+};
+
static void *
lua_plugin_alloc (void *ud, void *ptr, size_t o_size, size_t n_size)
{
@@ -9724,6 +9820,35 @@ lua_plugin_panic (lua_State *L)
return 0;
}
+static bool
+lua_plugin_property_get_ispect (lua_State *L, const char *property_name)
+{
+ struct lua_weak_info *info = lua_touserdata (L, lua_upvalueindex (1));
+ if (!info || !info->ispect)
+ return false;
+
+ struct lua_weak *weak = luaL_checkudata (L, 1, info->name);
+ // TODO: I think we can do better than this, maybe binary search at least?
+ struct ispect_field *iter;
+ for (iter = info->ispect->fields; iter->name; iter++)
+ if (!strcmp (property_name, iter->name))
+ break;
+
+ if (iter->name)
+ {
+ void *p = (uint8_t *) weak->object + iter->offset;
+ switch (iter->type)
+ {
+ case ISPECT_BOOL: lua_pushboolean (L, *(bool *) p); return true;
+ case ISPECT_INT: lua_pushinteger (L, *(int *) p); return true;
+ case ISPECT_UINT: lua_pushinteger (L, *(unsigned *) p); return true;
+ case ISPECT_SIZE: lua_pushinteger (L, *(size_t *) p); return true;
+ case ISPECT_STRING: lua_pushstring (L, *(char **) p); return true;
+ }
+ }
+ return false;
+}
+
static int
lua_plugin_property_get (lua_State *L)
{
@@ -9746,6 +9871,10 @@ lua_plugin_property_get (lua_State *L)
return 1;
}
+ // Maybe we can find it via introspection
+ if (lua_plugin_property_get_ispect (L, property_name))
+ return 1;
+
// Or we look for a property set by the user (__gc cannot be overriden)
if (lua_getuservalue (L, 1) != LUA_TTABLE)
lua_pushnil (L);
@@ -9787,7 +9916,24 @@ lua_plugin_create_meta (lua_State *L, const char *name, luaL_Reg *fns)
luaL_setfuncs (L, fns, 0);
// Emulate properties for convenience
- lua_pushcfunction (L, lua_plugin_property_get);
+ lua_pushlightuserdata (L, NULL);
+ lua_pushcclosure (L, lua_plugin_property_get, 1);
+ lua_setfield (L, -2, "__index");
+ lua_pushcfunction (L, lua_plugin_property_set);
+ lua_setfield (L, -2, "__newindex");
+
+ lua_pop (L, 1);
+}
+
+static void
+lua_plugin_create_weak (lua_State *L, struct lua_weak_info *info, luaL_Reg *fns)
+{
+ luaL_newmetatable (L, info->name);
+ luaL_setfuncs (L, fns, 0);
+
+ // Emulate properties for convenience
+ lua_pushlightuserdata (L, info);
+ lua_pushcclosure (L, lua_plugin_property_get, 1);
lua_setfield (L, -2, "__index");
lua_pushcfunction (L, lua_plugin_property_set);
lua_setfield (L, -2, "__newindex");
@@ -9824,10 +9970,10 @@ lua_plugin_load (struct app_context *ctx, const char *filename,
// Create metatables for our objects
lua_plugin_create_meta (L, XLUA_HOOK_METATABLE, lua_hook_table);
- lua_plugin_create_meta (L, XLUA_USER_METATABLE, lua_user_table);
- lua_plugin_create_meta (L, XLUA_CHANNEL_METATABLE, lua_channel_table);
- lua_plugin_create_meta (L, XLUA_BUFFER_METATABLE, lua_buffer_table);
- lua_plugin_create_meta (L, XLUA_SERVER_METATABLE, lua_server_table);
+ lua_plugin_create_weak (L, &lua_user_info, lua_user_table);
+ lua_plugin_create_weak (L, &lua_channel_info, lua_channel_table);
+ lua_plugin_create_weak (L, &lua_buffer_info, lua_buffer_table);
+ lua_plugin_create_weak (L, &lua_server_info, lua_server_table);
lua_plugin_create_meta (L, XLUA_SCHEMA_METATABLE, lua_schema_table);
lua_plugin_create_meta (L, XLUA_CONNECTION_METATABLE, lua_connection_table);
lua_plugin_create_meta (L, XLUA_CONNECTOR_METATABLE, lua_connector_table);
--
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