Remote control: Fix kitty @ sometimes failing to read the response from kitty.

Fixes #614

docs/changelog.rst

@@ -80,6 +80,9 @@ Changelog
 
 - Linux: Include a man page and the HTML docs when building the linux-package
 
+- Remote control: Fix kitty @ sometimes failing to read the response from
+  kitty. (:iss:`614`)
+
 
 0.10.1 [2018-05-24]
 ------------------------------

kittens/tui/loop.py

@@ -22,7 +22,7 @@
     ALT, CTRL, PRESS, RELEASE, REPEAT, SHIFT, C, D, backspace_key,
     decode_key_event, enter_key
 )
-from kitty.utils import screen_size_function
+from kitty.utils import screen_size_function, write_all
 
 from .handler import Handler
 from .operations import init_state, reset_state
@@ -41,16 +41,6 @@ def debug(*a, **kw):
         fobj.flush()
 
 
-def write_all(fd, data):
-    if isinstance(data, str):
-        data = data.encode('utf-8')
-    while data:
-        n = os.write(fd, data)
-        if not n:
-            break
-        data = data[n:]
-
-
 class TermManager:
 
     def __init__(self, input_fd, output_fd):

kitty/data-types.c

@@ -11,12 +11,15 @@
 #include <unistd.h>
 #undef _DARWIN_C_SOURCE
 #endif
+#define _DEFAULT_SOURCE
+#include <termios.h>
 #include "data-types.h"
 #include "control-codes.h"
 #include "modes.h"
 #include <stddef.h>
 #include <termios.h>
 #include <signal.h>
+#include <fcntl.h>
 #ifdef WITH_PROFILER
 #include <gperftools/profiler.h>
 #endif
@@ -103,7 +106,34 @@ stop_profiler(PyObject UNUSED *self) {
 }
 #endif
 
+static PyObject*
+open_tty(PyObject *self UNUSED, PyObject *args UNUSED) {
+    int fd = open("/dev/tty", O_RDWR | O_NONBLOCK | O_CLOEXEC | O_NOCTTY);
+    struct termios *termios_p = calloc(1, sizeof(struct termios));
+    if (!termios_p) return PyErr_NoMemory();
+    if (tcgetattr(fd, termios_p) != 0) { free(termios_p); PyErr_SetFromErrno(PyExc_OSError); return NULL; }
+    struct termios raw_termios = *termios_p;
+    cfmakeraw(&raw_termios);
+    raw_termios.c_cc[VMIN] = 0; raw_termios.c_cc[VTIME] = 0;
+    if (tcsetattr(fd, TCSAFLUSH, &raw_termios) != 0) { free(termios_p); PyErr_SetFromErrno(PyExc_OSError); return NULL; }
+    return Py_BuildValue("iN", fd, PyLong_FromVoidPtr(termios_p));
+}
+
+static PyObject*
+close_tty(PyObject *self UNUSED, PyObject *args) {
+    PyObject *tp;
+    int fd;
+    if (!PyArg_ParseTuple(args, "iO!", &fd, &PyLong_Type, &tp)) return NULL;
+    struct termios *termios_p = PyLong_AsVoidPtr(tp);
+    tcsetattr(fd, TCSAFLUSH, termios_p);
+    free(termios_p);
+    close(fd);
+    Py_RETURN_NONE;
+}
+
 static PyMethodDef module_methods[] = {
+    {"open_tty", open_tty, METH_NOARGS, ""},
+    {"close_tty", close_tty, METH_VARARGS, ""},
     {"set_iutf8", (PyCFunction)pyset_iutf8, METH_VARARGS, ""},
     {"thread_write", (PyCFunction)cm_thread_write, METH_VARARGS, ""},
     {"parse_bytes", (PyCFunction)parse_bytes, METH_VARARGS, ""},

kitty/remote_control.py

@@ -3,15 +3,18 @@
 # License: GPL v3 Copyright: 2018, Kovid Goyal <kovid at kovidgoyal.net>
 
 import json
+import os
 import re
 import sys
 import types
 from functools import partial
+from io import DEFAULT_BUFFER_SIZE
 
 from .cli import emph, parse_args
-from .constants import appname, version
-from .utils import parse_address_spec, read_with_timeout
 from .cmds import cmap, parse_subcommand_cli
+from .constants import appname, version
+from .fast_data_types import close_tty, open_tty
+from .utils import parse_address_spec, write_all
 
 
 def handle_cmd(boss, window, cmd):
@@ -44,39 +47,85 @@ def encode_send(send):
     return b'\x1bP' + send + b'\x1b\\'
 
 
+class SocketIO:
+
+    def __init__(self, to):
+        self.family, self.address = parse_address_spec(to)[:2]
+
+    def __enter__(self):
+        import socket
+        self.socket = socket.socket(self.family)
+        self.socket.setblocking(True)
+        self.socket.connect(self.address)
+
+    def __exit__(self, *a):
+        import socket
+        self.socket.shutdown(socket.SHUT_RDWR)
+        self.socket.close()
+
+    def send(self, data):
+        import socket
+        with self.socket.makefile('wb') as out:
+            out.write(data)
+        self.socket.shutdown(socket.SHUT_WR)
+
+    def recv(self, more_needed, timeout):
+        # We dont bother with more_needed since the server will close the
+        # connection after transmission
+        self.socket.settimeout(timeout)
+        with self.socket.makefile('rb') as src:
+            data = src.read()
+        more_needed(data)
+
+
+class TTYIO:
+
+    def __enter__(self):
+        self.tty_fd, self.original_termios = open_tty()
+
+    def __exit__(self, *a):
+        close_tty(self.tty_fd, self.original_termios)
+
+    def send(self, data):
+        write_all(self.tty_fd, data)
+
+    def recv(self, more_needed, timeout):
+        import select
+        from time import monotonic
+        fd = self.tty_fd
+        start_time = monotonic()
+        while timeout > monotonic() - start_time:
+            rd = select.select([fd], [], [], max(0, timeout - (monotonic() - start_time)))[0]
+            if rd:
+                data = os.read(fd, DEFAULT_BUFFER_SIZE)
+                if not data:
+                    break  # eof
+                if not more_needed(data):
+                    break
+            else:
+                break
+
+
 def do_io(to, send, no_response):
-    import socket
     send = encode_send(send)
-    if to:
-        family, address = parse_address_spec(to)[:2]
-        s = socket.socket(family)
-        s.connect(address)
-        out = s.makefile('wb')
-    else:
-        out = open('/dev/tty', 'wb')
-    with out:
-        out.write(send)
-    if to:
-        s.shutdown(socket.SHUT_WR)
-    if no_response:
-        return {'ok': True}
+    io = SocketIO(to) if to else TTYIO()
+    with io:
+        io.send(send)
+        if no_response:
+            return {'ok': True}
+        dcs = re.compile(br'\x1bP@kitty-cmd([^\x1b]+)\x1b\\')
 
-    received = b''
-    dcs = re.compile(br'\x1bP@kitty-cmd([^\x1b]+)\x1b\\')
-    match = None
+        received = b''
+        match = None
 
-    def more_needed(data):
-        nonlocal received, match
-        received += data
-        match = dcs.search(received)
-        return match is None
+        def more_needed(data):
+            nonlocal received, match
+            received += data
+            match = dcs.search(received)
+            return match is None
+
+        io.recv(more_needed, timeout=10)
 
-    if to:
-        src = s.makefile('rb')
-    else:
-        src = open('/dev/tty', 'rb')
-    with src:
-        read_with_timeout(more_needed, src=src)
     if match is None:
         raise SystemExit('Failed to receive response from ' + appname)
     response = json.loads(match.group(1).decode('ascii'))

kitty/utils.py

@@ -352,6 +352,16 @@ def parse_address_spec(spec):
     return family, address, socket_path
 
 
+def write_all(fd, data):
+    if isinstance(data, str):
+        data = data.encode('utf-8')
+    while data:
+        n = os.write(fd, data)
+        if not n:
+            break
+        data = data[n:]
+
+
 def make_fd_non_blocking(fd):
     oldfl = fcntl.fcntl(fd, fcntl.F_GETFL)
     fcntl.fcntl(fd, fcntl.F_SETFL, oldfl | os.O_NONBLOCK)