Merge pull request #1496 from benoit-pierre/log_dbus_with_libdbus

oslayer/log_dbus: use `libdbus` directly

Author: benoit-pierre

linux/README.md

@@ -5,9 +5,8 @@
 To be able to setup a complete development environment, you'll need to manually
 install some system libraries (including the development version of your
 distribution corresponding packages):
-- [`hidapi` package](https://pypi.org/project/hidapi/) (Treal support) needs
-  `libusb` (1.0) and `libudev`.
-- [`dbus-python` package](https://pypi.org/project/dbus-python/) (log /
-  notifications support) needs `libdbus`.
+- Treal support: `libusb` (1.0) and `libudev` are needed by
+  the [`hidapi` package](https://pypi.org/project/hidapi/).
+- log / notifications support: `libdbus` is needed.
 
 For the rest of the steps, follow the [developer guide](../doc/developer_guide.md).

linux/appimage/Dockerfile

@@ -138,10 +138,11 @@ RUN ./install.sh \
       libp11-kit0 \
       ;
 
-# Install dbus-python build dependencies.
+# Install log_dbus dependencies.
+# Note: we install the `libdbus-1-dev` because the `libdbus-1.so`
+# symlink is not part of the base `libdbus-1-3` package…
 RUN ./install.sh \
       libdbus-1-dev \
-      libdbus-glib-1-dev \
       ;
 
 # Install PyQt5 (minimal) dependencies.

linux/appimage/build.sh

@@ -177,11 +177,8 @@ python='appdir_python'
 # Install boostrap requirements.
 get_base_devel
 
-# Install dbus-python before running linuxdeploy,
-# as there are no manylinux wheels available, so
-# we need to ensure its system dependencies are
-# included in the AppImage.
-install_wheels -c reqs/constraints.txt dbus-python
+# Copy log_dbus system dependencies.
+run cp -Lv /usr/lib/x86_64-linux-gnu/libdbus-1.so "$appdir/usr/lib"
 
 # Trim the fat, first pass.
 run cp linux/appimage/blacklist.txt "$builddir/blacklist.txt"

news.d/feature/1496.linux.md

@@ -0,0 +1 @@
+Improve D-Bus logger implementation.

plover/oslayer/log_dbus.py

@@ -1,46 +1,141 @@
-
+from contextlib import contextmanager
+import ctypes.util
 import os
 import logging
 
-import dbus
-
 from plover import log, __name__ as __software_name__
 from plover.oslayer.config import ASSETS_DIR
 
 
-APPNAME = __software_name__.capitalize()
-APPICON = os.path.join(ASSETS_DIR, 'plover.png')
-SERVICE = 'org.freedesktop.Notifications'
-INTERFACE = '/org/freedesktop/Notifications'
+APPNAME = ctypes.c_char_p(__software_name__.capitalize().encode())
+APPICON = ctypes.c_char_p(os.path.join(ASSETS_DIR, 'plover.png').encode())
+SERVICE = ctypes.c_char_p(b'org.freedesktop.Notifications')
+INTERFACE = ctypes.c_char_p(b'/org/freedesktop/Notifications')
+
+NOTIFY_URGENCY_LOW = ctypes.c_uint8(0)
+NOTIFY_URGENCY_NORMAL = ctypes.c_uint8(1)
+NOTIFY_URGENCY_CRITICAL = ctypes.c_uint8(2)
+
+DBUS_BUS_SESSION = ctypes.c_uint(0)
+
+DBUS_TYPE_ARRAY      = ctypes.c_int(ord('a'))
+DBUS_TYPE_BYTE       = ctypes.c_int(ord('y'))
+DBUS_TYPE_DICT_ENTRY = ctypes.c_int(ord('e'))
+DBUS_TYPE_INT32      = ctypes.c_int(ord('i'))
+DBUS_TYPE_STRING     = ctypes.c_int(ord('s'))
+DBUS_TYPE_UINT32     = ctypes.c_int(ord('u'))
+DBUS_TYPE_VARIANT    = ctypes.c_int(ord('v'))
+
+
+def ctypes_func(library, signature):
+    restype, func_name, *argtypes = signature.split()
+    func = getattr(library, func_name)
+    setattr(func, 'argtypes', [
+        ctypes.POINTER(getattr(ctypes, 'c_' + t[1:]))
+        if t.startswith('&') else getattr(ctypes, 'c_' + t)
+        for t in argtypes
+    ])
+    setattr(func, 'restype',
+            None if restype == 'void' else
+            getattr(ctypes, 'c_' + restype))
+    return func
 
 
 class DbusNotificationHandler(logging.Handler):
     """ Handler using DBus notifications to show messages. """
 
     def __init__(self):
         super().__init__()
-        self._bus = dbus.SessionBus()
-        self._proxy = self._bus.get_object(SERVICE, INTERFACE)
-        self._notify = dbus.Interface(self._proxy, SERVICE)
         self.setLevel(log.WARNING)
         self.setFormatter(log.NoExceptionTracebackFormatter('<b>%(levelname)s:</b> %(message)s'))
 
+        libname = ctypes.util.find_library('dbus-1')
+        if libname is None:
+            raise FileNotFoundError('dbus-1 library')
+        library = ctypes.cdll.LoadLibrary(libname)
+
+        bus_get = ctypes_func(library, 'void_p dbus_bus_get uint void_p')
+        message_new = ctypes_func(library, 'void_p dbus_message_new_method_call char_p char_p char_p char_p')
+        message_unref = ctypes_func(library, 'void dbus_message_unref void_p')
+        iter_init_append = ctypes_func(library, 'void dbus_message_iter_init_append void_p void_p')
+        iter_append_basic = ctypes_func(library, 'bool dbus_message_iter_append_basic void_p int void_p')
+        iter_open_container = ctypes_func(library, 'bool dbus_message_iter_open_container void_p int char_p void_p')
+        iter_close_container = ctypes_func(library, 'bool dbus_message_iter_close_container void_p void_p')
+        connection_send = ctypes_func(library, 'bool dbus_connection_send void_p void_p &uint32')
+
+        # Need message + container + dict_entry + variant = 4 iterators.
+        self._iter_stack = [ctypes.create_string_buffer(128) for __ in range(4)]
+        self._iter_stack_index = 0
+
+        @contextmanager
+        def open_container(kind, signature):
+            parent_iter = self._iter_stack[self._iter_stack_index]
+            sub_iter = self._iter_stack[self._iter_stack_index + 1]
+            if not iter_open_container(parent_iter, kind, signature, sub_iter):
+                raise MemoryError
+            self._iter_stack_index += 1
+            try:
+                yield
+            finally:
+                if not iter_close_container(parent_iter, sub_iter):
+                    raise MemoryError
+                self._iter_stack_index -= 1
+
+        def append_basic(kind, value):
+            if not iter_append_basic(self._iter_stack[self._iter_stack_index], kind, ctypes.byref(value)):
+                raise MemoryError
+
+        bus = bus_get(DBUS_BUS_SESSION, None)
+
+        actions_signature = ctypes.c_char_p(b's')
+        hints_signature = ctypes.c_char_p(b'{sv}')
+        notify_str = ctypes.c_char_p(b'Notify')
+        urgency_signature = ctypes.c_char_p(b'y')
+        urgency_str = ctypes.c_char_p(b'urgency')
+        zero = ctypes.c_uint(0)
+
+        def notify(body, urgency, timeout):
+            message = message_new(SERVICE, INTERFACE, SERVICE, notify_str)
+            try:
+                iter_init_append(message, self._iter_stack[self._iter_stack_index])
+                # app_name
+                append_basic(DBUS_TYPE_STRING, APPNAME)
+                # replaces_id
+                append_basic(DBUS_TYPE_UINT32, zero)
+                # app_icon
+                append_basic(DBUS_TYPE_STRING, APPICON)
+                # summary
+                append_basic(DBUS_TYPE_STRING, APPNAME)
+                # body
+                append_basic(DBUS_TYPE_STRING, body)
+                # actions
+                with open_container(DBUS_TYPE_ARRAY, actions_signature):
+                    pass
+                # hints
+                with open_container(DBUS_TYPE_ARRAY, hints_signature), open_container(DBUS_TYPE_DICT_ENTRY, None):
+                    append_basic(DBUS_TYPE_STRING, urgency_str)
+                    with open_container(DBUS_TYPE_VARIANT, urgency_signature):
+                        append_basic(DBUS_TYPE_BYTE, urgency)
+                # expire_timeout
+                append_basic(DBUS_TYPE_INT32, timeout)
+                connection_send(bus, message, None)
+            finally:
+                message_unref(message)
+
+        self._notify = notify
+
     def emit(self, record):
         level = record.levelno
         message = self.format(record)
         if message.endswith('\n'):
             message = message[:-1]
         if level <= log.INFO:
             timeout = 10
-            urgency = 0
+            urgency = NOTIFY_URGENCY_LOW
         elif level <= log.WARNING:
             timeout = 15
-            urgency = 1
+            urgency = NOTIFY_URGENCY_NORMAL
         else:
             timeout = 0
-            urgency = 2
-        self._notify.Notify(APPNAME, 0, APPICON,  # app_name, replaces_id, app_icon
-                            APPNAME, message, '', # actions
-                            { 'urgency': dbus.Byte(urgency) },
-                            timeout * 1000)
-
+            urgency = NOTIFY_URGENCY_CRITICAL
+        self._notify(ctypes.c_char_p(message.encode()), urgency, ctypes.c_int(timeout * 1000))

reqs/constraints.txt

@@ -15,7 +15,6 @@ click-default-group==1.2.2
 cmarkgfm==0.6.0
 colorama==0.4.4
 cryptography==35.0.0
-dbus-python==1.2.18
 dmgbuild==1.5.2
 docutils==0.18
 ds-store==1.3.0

reqs/dist_extra_log.txt

@@ -1,3 +1,2 @@
-dbus-python>=1.2.4; "linux" in sys_platform
 
 # vim: ft=cfg commentstring=#\ %s list