add opt-in asyncio task integration

(cherry picked from commit 73ccded3ac)

docs/plugin-api-additions/async.md

@@ -0,0 +1,30 @@
+# Optional Python asyncio integration
+
+`run_async(coroutine, context=None, interval=10)` returns an AsyncTask with
+`done()`, `cancel()` and `result()`. Each invocation owns a separate event loop
+pumped by an existing main-loop timer. A ready stop callback ensures selector
+polling never blocks the UI. The captured context is restored after every pump;
+a closed context cancels the work. No process-wide event-loop policy is changed.
+
+Existing synchronous scripts are unaffected. Use `asyncio.get_running_loop()`
+inside the coroutine. Child tasks use the same loop/context and are cancelled
+when the main coroutine finishes or the script unloads. Cancellation cleanup is
+bounded; tasks must not suppress cancellation indefinitely. Cleanup uses the
+captured context while it remains open; after it closes, cancellation cleanup uses
+the current valid context. Use explicit Context methods for context-specific
+output in finally blocks, and do not issue context-dependent commands there. This provides normal
+asyncio sockets/timers, not Windows subprocess support or a new HTTP library.
+Asyncio hostname resolution can use its executor; use a resolver appropriate to
+your library if you require no worker threads. Blocking work inside a coroutine
+still blocks the client and must be avoided.
+
+```python
+import asyncio
+import zoitechat
+
+async def later():
+    await asyncio.sleep(1)
+    zoitechat.prnt('Still in the context where this task was started')
+
+task = zoitechat.run_async(later())
+```

docs/plugin-api-additions/compatibility.md

@@ -0,0 +1,24 @@
+# Optional plugin API additions (discussion #144)
+
+Existing hooks, callbacks, return values, context lookup, strings and menu behaviour
+remain unchanged. The C plugin function table gains four fixed append-only slots;
+unused slots are NULL. Older binaries use the unchanged prefix. A plugin must check
+the documented get_info() feature key before accessing a new slot on an older host.
+New Python modules are installed by Meson and the existing Windows copy/installer
+pipeline. Only modules present in the installation are exported; imports of
+zoitechat, hexchat and xchat retain their compatibility aliases.
+
+All APIs run on the client main thread unless explicitly documented otherwise.
+New reserved flags must be zero. These changes do not make old API calls thread-safe.
+
+Nested hook dispatch defers deleted-hook reclamation until its outermost return,
+so new observers can safely emit events and unhook themselves or other hooks.
+
+The optional asyncio module requires Python 3.7 or newer; older supported
+interpreters skip that module and retain the existing scripting API.
+
+Python reload drops the script/API modules while retaining the embedding module
+so callback and lib.ph pointer types keep the same CFFI identity.
+
+Server-hook insertion matches both raw and attrs hooks so documented priorities
+are honoured for mixed registrations, including new filtered attrs callbacks.

plugins/python/_zoitechat.py

@@ -383,3 +383,24 @@ def find_context(server=None, channel=None):
         return None
 
     return Context(ctx)
+
+
+# Optional additive APIs live in separate modules so builds can select features.
+def __load_additive_features():
+    import importlib
+    import os
+
+    for suffix in ('fd', 'events', 'async', 'names', 'contexts',
+                   'post', 'filters', 'caps'):
+        if suffix == 'async' and sys.version_info < (3, 7):
+            continue
+        name = '_zoitechat_' + suffix
+        if not os.path.isfile(os.path.join(os.path.dirname(__file__), name + '.py')):
+            continue
+        module = importlib.import_module(name)
+        for symbol in module.__all__:
+            globals()[symbol] = getattr(module, symbol)
+            __all__.append(symbol)
+
+
+__load_additive_features()

plugins/python/_zoitechat_async.py

@@ -0,0 +1,100 @@
+"""Opt-in asyncio tasks pumped without blocking the client main loop."""
+import asyncio
+import operator
+import traceback
+import _zoitechat as api
+
+__all__ = ['AsyncTask', 'run_async']
+
+
+class AsyncTask:
+    """A script-owned task and isolated event loop; cancel() is cooperative."""
+    def __init__(self, coroutine, plugin, context, interval):
+        self._plugin = plugin
+        self._context = context
+        self._loop = asyncio.new_event_loop()
+        self._task = self._loop.create_task(coroutine)
+        self._closed = False
+        self._unload_hook = api.hook_unload(lambda data: self._close())
+        self._timer_hook = api.hook_timer(interval, self._tick)
+
+    def done(self):
+        return self._task.done()
+
+    def cancel(self):
+        if not self._closed:
+            return self._task.cancel()
+        return False
+
+    def result(self):
+        return self._task.result()
+
+    def _pump(self):
+        # A ready stop callback forces the selector's timeout to zero.
+        self._loop.call_soon(self._loop.stop)
+        self._loop.run_forever()
+
+    def _close(self):
+        if self._closed:
+            return
+        self._closed = True
+        previous = api.get_context()
+        self._context.set()
+        try:
+            pending = asyncio.all_tasks(self._loop)
+            for task in pending:
+                task.cancel()
+            # Bound cleanup work; tasks must cooperate with cancellation.
+            for unused in range(3):
+                if not any(not task.done() for task in pending):
+                    break
+                self._pump()
+            for task in pending:
+                if not task.done():
+                    self._loop.call_exception_handler({
+                        'message': 'Script task ignored cancellation during unload',
+                        'task': task,
+                    })
+        finally:
+            self._loop.close()
+            previous.set()
+
+    def _tick(self, userdata):
+        if self._closed:
+            return False
+        previous = api.get_context()
+        if not self._context.set():
+            self._close()
+            self._plugin.remove_hook(self._unload_hook)
+            return False
+        try:
+            self._pump()
+            if not self._task.done():
+                return True
+            try:
+                self._task.result()
+            except asyncio.CancelledError:
+                pass
+            except Exception:
+                traceback.print_exc()
+            self._close()
+            self._plugin.remove_hook(self._unload_hook)
+            return False
+        except Exception:
+            traceback.print_exc()
+            self._close()
+            self._plugin.remove_hook(self._unload_hook)
+            return False
+        finally:
+            previous.set()
+
+
+def run_async(coroutine, context=None, interval=10):
+    """Schedule a coroutine in a captured context; return an AsyncTask handle."""
+    interval = operator.index(interval)
+    if interval < 1 or interval > 2147483647:
+        raise ValueError('interval must be a positive C int in milliseconds')
+    if not asyncio.iscoroutine(coroutine):
+        raise TypeError('run_async expects a coroutine object')
+    plugin = api.__get_current_plugin()
+    return AsyncTask(coroutine, plugin, context or api.get_context(), interval)

plugins/python/meson.build

@@ -27,7 +27,11 @@ python3_source = custom_target('python-bindings',
   command: [find_program('generate_plugin.py'), '@INPUT@', '@OUTPUT@']
 )
 
-install_data(['_zoitechat.py', 'zoitechat.py', 'xchat.py', 'hexchat.py'],
+# Include any selected additive API modules alongside the compatibility modules.
+python_api_files = run_command(python3, '-c',
+  'import glob,sys; print("\\n".join(sorted(glob.glob(sys.argv[1] + "/_zoitechat*.py"))))',
+  meson.current_source_dir(), check: true).stdout().strip().split('\n')
+install_data(python_api_files + ['zoitechat.py', 'xchat.py', 'hexchat.py'],
   install_dir: join_paths(get_option('libdir'), 'zoitechat/python')
 )
 

plugins/python/python.py

@@ -590,7 +590,12 @@ def _on_plugin_deinit():
     sys.stderr = sys.__stderr__
     pydoc.help = pydoc.Helper()
 
-    for mod in ('_zoitechat', 'zoitechat', 'xchat', '_zoitechat_embedded'):
+    # CFFI callbacks keep the embedding module's ffi/lib identity for the
+    # process lifetime; deleting it creates incompatible types on reload.
+    for mod in ('_zoitechat', 'zoitechat', 'hexchat', 'xchat',
+                '_zoitechat_fd', '_zoitechat_events', '_zoitechat_async',
+                '_zoitechat_names', '_zoitechat_contexts', '_zoitechat_post',
+                '_zoitechat_filters', '_zoitechat_caps'):
         try:
             del sys.modules[mod]
 

plugins/python/python3.vcxproj

@@ -52,6 +52,7 @@
     <None Include="xchat.py" />
     <None Include="hexchat.py" />
     <None Include="_zoitechat.py" />
+    <None Include="_zoitechat_*.py" />
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="$(IntDir)python.c" />

plugins/python/python38.vcxproj

@@ -52,6 +52,7 @@
     <None Include="xchat.py" />
     <None Include="hexchat.py" />
     <None Include="_zoitechat.py" />
+    <None Include="_zoitechat_*.py" />
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="$(IntDir)python.c" />

src/common/plugin.c

@@ -176,6 +176,7 @@ enum
 
 GSList *plugin_list = NULL;	/* export for plugingui.c */
 static GSList *hook_list = NULL;
+static unsigned int plugin_dispatch_depth;
 
 extern const struct prefs vars[];	/* cfgfiles.c */
 
@@ -243,7 +244,7 @@ plugin_list_add (zoitechat_context *ctx, char *filename, const char *name,
 {
 	zoitechat_plugin *pl;
 
-	pl = g_new (zoitechat_plugin, 1);
+	pl = g_new0 (zoitechat_plugin, 1);
 	pl->handle = handle;
 	pl->filename = filename;
 	pl->context = ctx;
@@ -610,6 +611,7 @@ plugin_hook_run (session *sess, char *name, char *word[], char *word_eol[],
 	zoitechat_hook *hook;
 	int ret, eat = 0;
 
+	plugin_dispatch_depth++;
 	list = hook_list;
 	while (1)
 	{
@@ -655,6 +657,10 @@ plugin_hook_run (session *sess, char *name, char *word[], char *word_eol[],
 	}
 
 xit:
+	/* Nested callbacks can unhook entries still used by an outer dispatch.
+	 * Keep both hook objects and list links alive until the outermost return. */
+	if (--plugin_dispatch_depth != 0)
+		return eat;
 	/* really remove deleted hooks now */
 	list = hook_list;
 	while (list)
@@ -806,7 +812,7 @@ plugin_insert_hook (zoitechat_hook *new_hook)
 			break;
 		case HOOK_SERVER:
 		case HOOK_SERVER_ATTRS:
-			new_hook_type = HOOK_SERVER | HOOK_PRINT_ATTRS;
+			new_hook_type = HOOK_SERVER | HOOK_SERVER_ATTRS;
 			break;
 		default:
 			new_hook_type = new_hook->type;

src/common/plugin.h

@@ -150,6 +150,15 @@ struct _zoitechat_plugin
 	void (*zoitechat_event_attrs_free) (zoitechat_plugin *ph,
 									  zoitechat_event_attrs *attrs);
 
+	/* Additive API slots: append only; old binary offsets are unchanged. */
+	zoitechat_hook *(*zoitechat_hook_print_after) (zoitechat_plugin *, const char *, int,
+		int, int (*)(char *[], zoitechat_event_attrs *, void *), void *);
+	zoitechat_hook *(*zoitechat_hook_server_filtered) (zoitechat_plugin *, const char *, int,
+		int, int, const char *, int (*)(char *[], char *[], zoitechat_event_attrs *, void *), void *);
+	zoitechat_hook *(*zoitechat_hook_print_filtered) (zoitechat_plugin *, const char *, int,
+		int, int, const char *, int (*)(char *[], zoitechat_event_attrs *, void *), void *);
+	zoitechat_hook *(*zoitechat_register_capability) (zoitechat_plugin *, const char *, int, int, void *);
+
 	/* PRIVATE FIELDS! */
 	void *handle;		/* from dlopen */
 	char *filename;	/* loaded from */

src/common/zoitechat-plugin.h

@@ -193,6 +193,15 @@ struct _zoitechat_plugin
 	zoitechat_event_attrs *(*zoitechat_event_attrs_create) (zoitechat_plugin *ph);
 	void (*zoitechat_event_attrs_free) (zoitechat_plugin *ph,
 									  zoitechat_event_attrs *attrs);
+	/* Additive API slots: append only; old binary offsets are unchanged. */
+	zoitechat_hook *(*zoitechat_hook_print_after) (zoitechat_plugin *, const char *, int,
+		int, int (*)(char *[], zoitechat_event_attrs *, void *), void *);
+	zoitechat_hook *(*zoitechat_hook_server_filtered) (zoitechat_plugin *, const char *, int,
+		int, int, const char *, int (*)(char *[], char *[], zoitechat_event_attrs *, void *), void *);
+	zoitechat_hook *(*zoitechat_hook_print_filtered) (zoitechat_plugin *, const char *, int,
+		int, int, const char *, int (*)(char *[], zoitechat_event_attrs *, void *), void *);
+	zoitechat_hook *(*zoitechat_register_capability) (zoitechat_plugin *, const char *, int, int, void *);
+
 };
 #endif
 

win32/copy/copy.vcxproj

@@ -90,6 +90,7 @@
       <MSWindowsTheme Include="$(DepsRoot)\share\themes\MS-Windows\**\*" />
       <HicolorIcons Include="$(DepsRoot)\share\icons\hicolor\index.theme" />
       <HicolorIcons Include="$(DepsRoot)\share\icons\hicolor\**\*.*" />
+      <PythonAdditiveApis Include="..\..\plugins\python\_zoitechat_*.py" />
     </ItemGroup>
 
     <Copy SourceFiles="@(None)" DestinationFolder="$(ZoiteChatRel)" />
@@ -115,6 +116,7 @@
     <Copy SourceFiles="..\..\plugins\python\hexchat.py" DestinationFolder="$(ZoiteChatRel)\python" Condition="'$(Python3Enabled)'=='true' or '$(Python38Enabled)'=='true'" />
     <Copy SourceFiles="..\..\plugins\python\zoitechat.py" DestinationFolder="$(ZoiteChatRel)\python" Condition="'$(Python3Enabled)'=='true' or '$(Python38Enabled)'=='true'" />
     <Copy SourceFiles="..\..\plugins\python\_zoitechat.py" DestinationFolder="$(ZoiteChatRel)\python" Condition="'$(Python3Enabled)'=='true' or '$(Python38Enabled)'=='true'" />
+    <Copy SourceFiles="@(PythonAdditiveApis)" DestinationFolder="$(ZoiteChatRel)\python" Condition="('$(Python3Enabled)'=='true' or '$(Python38Enabled)'=='true') and '@(PythonAdditiveApis)' != ''" />
 
     <WriteLinesToFile File="$(ZoiteChatRel)portable-mode" Lines="2" Overwrite="true" />