read in chunks

Author: chris-eibl

Lib/_pyrepl/windows_console.py

@@ -64,6 +64,8 @@ def __init__(self, err: int | None, descr: str | None = None) -> None:
 if TYPE_CHECKING:
     from typing import IO
 
+INPUT_BUFFER_LEN = 10 * 1024
+
 # Virtual-Key Codes: https://learn.microsoft.com/en-us/windows/win32/inputdev/virtual-key-codes
 VK_MAP: dict[int, str] = {
     0x23: "end",  # VK_END
@@ -165,6 +167,10 @@ def __init__(
             # Console I/O is redirected, fallback...
             self.out = None
 
+        self.input_buffer = (INPUT_RECORD * INPUT_BUFFER_LEN)()
+        self.input_buffer_pos = 0
+        self.input_buffer_count = 0
+
     def refresh(self, screen: list[str], c_xy: tuple[int, int]) -> None:
         """
         Refresh the console screen.
@@ -415,16 +421,27 @@ def _getscrollbacksize(self) -> int:
 
         return info.srWindow.Bottom  # type: ignore[no-any-return]
 
+    def more_in_buffer(self) -> bool:
+        return self.input_buffer_pos < self.input_buffer_count - 1
+
     def _read_input(self, block: bool = True) -> INPUT_RECORD | None:
         if not block and not self.wait(timeout=0):
             return None
 
-        rec = INPUT_RECORD()
+        if self.more_in_buffer():
+            self.input_buffer_pos += 1
+            return self.input_buffer[self.input_buffer_pos]
+
+        # read next chunk
+        self.input_buffer_pos = 0
+        self.input_buffer_count = 0
         read = DWORD()
-        if not ReadConsoleInput(InHandle, rec, 1, read):
+
+        if not ReadConsoleInput(InHandle, self.input_buffer, INPUT_BUFFER_LEN, read):
             raise WinError(GetLastError())
 
-        return rec
+        self.input_buffer_count = read.value
+        return self.input_buffer[0]
 
     def get_event(self, block: bool = True) -> Event | None:
         """Return an Event instance.  Returns None if |block| is false
@@ -521,9 +538,14 @@ def forgetinput(self) -> None:
     def getpending(self) -> Event:
         """Return the characters that have been typed but not yet
         processed."""
-        return Event("key", "", b"")
+        e = Event("key", "", b"")
+
+        while not self.event_queue.empty():
+            e2 = self.event_queue.get()
+            e.data += e2.data
+            e.raw += e.raw
 
-    def wait(self, timeout: float | None) -> bool:
+    def wait_for_event(self, timeout: float | None) -> bool:
         """Wait for an event."""
         if timeout is None:
             timeout = INFINITE
@@ -536,6 +558,16 @@ def wait(self, timeout: float | None) -> bool:
             return False
         return True
 
+    def wait(self, timeout: float | None = None) -> bool:
+        """
+        Wait for events on the console.
+        """
+        return (
+            not self.event_queue.empty()
+            or self.more_in_buffer()
+            or self.wait_for_event(timeout)
+        )
+
     def repaint(self) -> None:
         raise NotImplementedError("No repaint support")