[FIX] Infinite length console: #35

tests/parametric_printer.py

@@ -0,0 +1,32 @@
+'''
+This is is a very basic stdio handler script. This is used by python.py example.
+'''
+
+import time
+import sys
+
+# Read an integer from the user:
+
+while True:
+    print('Format:character,character_count,line_count,speed_ms> ', end='')
+    command = input()
+    (character,character_count,line_count,speed_ms) = command.split(',')
+    character_count = int(character_count)
+    speed_ms = int(speed_ms)
+    line_count = int(line_count)
+
+    if line_count<1:
+        sys.exit(0)
+    for _ in range(line_count):
+        if speed_ms<0:
+            print(character*character_count)
+            sys.stdout.flush()
+        else:
+            for i in range(character_count):
+                if i == character_count-1:
+                    print(character)
+                    sys.stdout.flush()
+                else:
+                    print(character, end='')
+                    sys.stdout.flush()
+                time.sleep(speed_ms/1000)

tests/test_parametric_printer.py

@@ -0,0 +1,86 @@
+import wexpect
+import unittest
+import sys
+import os
+import time
+from tests import PexpectTestCase
+
+class TestCaseParametricPrinter(PexpectTestCase.PexpectTestCase):
+    def test_all_line_length (self):
+
+        here = os.path.dirname(os.path.abspath(__file__))
+        sys.path.insert(0, here)
+
+        # With quotes (C:\Program Files\Python37\python.exe needs quotes)
+        python_executable = '"' + sys.executable + '" '
+        child_script = here + '\\parametric_printer.py'
+
+        self.prompt = '> '
+
+        # Start the child process
+        self.p = wexpect.spawn(python_executable + ' '  + child_script)
+        # Wait for prompt
+        self.p.expect(self.prompt)
+
+        self._test(['a'], range(1,200), [1], [0])
+
+
+    def test_random(self):
+
+        here = os.path.dirname(os.path.abspath(__file__))
+        sys.path.insert(0, here)
+
+        # With quotes (C:\Program Files\Python37\python.exe needs quotes)
+        python_executable = '"' + sys.executable + '" '
+        child_script = here + '\\parametric_printer.py'
+
+        self.prompt = '> '
+
+        # Start the child process
+        self.p = wexpect.spawn(python_executable + ' '  + child_script)
+        # Wait for prompt
+        self.p.expect(self.prompt)
+
+        self._test(['a', 'b', 'c'], [1, 2, 4, 8], [1, 2, 4, 8], [-1, 0, 1, 2])
+        self._test(['a', 'b', 'c'], [16], [16], [-1, 0, 1])
+        self._test(['a', 'b', 'c'], [16, 32, 64], [16, 32, 64], [-1, 0])
+
+    def test_long_console(self):
+
+        here = os.path.dirname(os.path.abspath(__file__))
+        sys.path.insert(0, here)
+
+        # With quotes (C:\Program Files\Python37\python.exe needs quotes)
+        python_executable = '"' + sys.executable + '" '
+        child_script = here + '\\parametric_printer.py'
+
+        self.prompt = '> '
+
+        # Start the child process
+        self.p = wexpect.spawn(python_executable + ' '  + child_script)
+        # Wait for prompt
+        self.p.expect(self.prompt)
+
+        self._test(['a', 'b', 'c', 'd', 'e', 'f'], [8, 16, 32, 64], [64, 128, 256], [-1, 0])
+
+    def _test(self, character_list, character_count_list, line_count_list, speed_ms_list):
+
+        # print(f'character_list: {character_list}  character_count_list: {character_count_list}  line_count_list: {line_count_list}  speed_ms_list: {speed_ms_list}')
+        for character in character_list:
+            for character_count in character_count_list:
+                for line_count in line_count_list:
+                    for speed_ms in speed_ms_list:
+                        command = f'{character},{character_count},{line_count},{speed_ms}'
+                        self.p.sendline(command)
+                        self.p.expect(self.prompt)
+                        expected = [character*character_count] * line_count
+                        try:
+                            self.assertEqual(self.p.before.splitlines()[1:-1], expected)
+                        except:
+                            time.sleep(5)
+                            raise
+
+if __name__ == '__main__':
+    unittest.main()
+
+suite = unittest.makeSuite(TestCaseParametricPrinter,'test')

wexpect/console_reader.py

@@ -96,7 +96,7 @@ class ConsoleReaderBase:
             try:
                 self.initConsole()
                 si = win32process.GetStartupInfo()
-                self.__childProcess, _, self.child_pid, self.__tid = win32process.CreateProcess(
+                self.__childProcess, _, self.child_pid, self.child_tid = win32process.CreateProcess(
                     None, path, None, None, False, 0, None, None, si)
                 self.child_process = psutil.Process(self.child_pid)
 
@@ -129,7 +129,6 @@ class ConsoleReaderBase:
                 logger.error(traceback.format_exc())
 
     def read_loop(self):
-        paused = False
 
         while True:
             if not self.isalive(self.host_process):
@@ -143,7 +142,20 @@ class ConsoleReaderBase:
 
             consinfo = self.consout.GetConsoleScreenBufferInfo()
             cursorPos = consinfo['CursorPosition']
-            self.send_to_host(self.readConsoleToCursor())
+
+            if cursorPos.Y > maxconsoleY:
+                '''If the console output becomes long, we suspend the child, read all output then
+                clear the console before we resume the child.
+                '''
+                logger.info('cursorPos %s' % cursorPos)
+                self.suspend_child()
+                time.sleep(.2)
+                self.send_to_host(self.readConsoleToCursor())
+                self.refresh_console()
+                self.resume_child()
+            else:
+                self.send_to_host(self.readConsoleToCursor())
+
             s = self.get_from_host()
             if s:
                 logger.debug(f'get_from_host: {s}')
@@ -156,18 +168,35 @@ class ConsoleReaderBase:
             s = s.decode()
             self.write(s)
 
-            if cursorPos.Y > maxconsoleY and not paused:
-                logger.info('cursorPos %s' % cursorPos)
-                self.suspendThread()
-                paused = True
-
-            if cursorPos.Y <= maxconsoleY and paused:
-                logger.info('cursorPos %s' % cursorPos)
-                self.resumeThread()
-                paused = False
 
             time.sleep(.02)
 
+    def suspend_child(self):
+        """Pauses the main thread of the child process."""
+        handle = windll.kernel32.OpenThread(win32con.THREAD_SUSPEND_RESUME, 0, self.child_tid)
+        win32process.SuspendThread(handle)
+
+    def resume_child(self):
+        """Un-pauses the main thread of the child process."""
+        handle = windll.kernel32.OpenThread(win32con.THREAD_SUSPEND_RESUME, 0, self.child_tid)
+        win32process.ResumeThread(handle)
+
+    def refresh_console(self):
+        """Clears the console after pausing the child and
+        reading all the data currently on the console."""
+
+        orig = win32console.PyCOORDType(0, 0)
+        self.consout.SetConsoleCursorPosition(orig)
+        self.__currentReadCo.X = 0
+        self.__currentReadCo.Y = 0
+        writelen = self.__consSize.X * self.__consSize.Y
+        # Use NUL as fill char because it displays as whitespace
+        # (if we interact() with the child)
+        self.consout.FillConsoleOutputCharacter(screenbufferfillchar, writelen, orig)
+
+        self.__bufferY = 0
+        self.__buffer.truncate(0)
+
     def terminate_child(self):
         try:
             if self.child_process: