GH-130328: further speedup of pasting in new REPL on Windows by reading in chunks

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 +538,15 @@ 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
 
- def wait(self, timeout: float | None) -> bool:
+ return e
+
+ def wait_for_event(self, timeout: float | None) -> bool:
  """Wait for an event."""
  if timeout is None:
  timeout = INFINITE
@@ -536,6 +559,16 @@ 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")