Extract out ProgressPrinter

This is a preparation before supporting 'clang-cl' for Windows (google#1179).

Our plan is to download LLVM for Windows in 'update_deps.py', and in
that process we would like to use 'ProgressPrinter' to show progress for
both downloading the archive and extracting it.

To avoid code duplicate between 'build_qt.py' and 'update_deps.py',
let's extract 'ProgressPrinter' into a new file first.

This is a mechanical refactoring commit. There must be no observable
behavior change.

src/build_tools/build_qt.py

@@ -58,8 +58,9 @@
 import subprocess
 import sys
 import tarfile
-import time
 from typing import Any, Union
+
+from progress_printer import ProgressPrinter
 from vs_util import get_vs_env_vars
 
 
@@ -156,66 +157,6 @@ def is_linux() -> bool:
   return os.name == 'posix' and os.uname()[0] == 'Linux'
 
 
-class ProgressPrinter:
-  """A utility to print progress message with carriage return and trancatoin."""
-
-  def __enter__(self):
-    if not sys.stdout.isatty():
-
-      class NoOpImpl:
-        """A no-op implementation in case stdout is not attached to concole."""
-
-        def print_line(self, msg: str) -> None:
-          """No-op implementation.
-
-          Args:
-            msg: Unused.
-          """
-          del msg  # Unused
-          return
-
-        def cleanup(self) -> None:
-          pass
-
-      self.impl = NoOpImpl()
-      return self
-
-    class Impl:
-      """A real implementation in case stdout is attached to concole."""
-
-      last_output_time_ns = time.time_ns()
-
-      def print_line(self, msg: str) -> None:
-        """Print the given message with carriage return and trancatoin.
-
-        Args:
-          msg: Message to be printed.
-        """
-        colmuns = os.get_terminal_size().columns
-        now = time.time_ns()
-        if (now - self.last_output_time_ns) < 25000000:
-          return
-        msg = msg + ' ' * max(colmuns - len(msg), 0)
-        msg = msg[0:(colmuns)] + '\r'
-        sys.stdout.write(msg)
-        sys.stdout.flush()
-        self.last_output_time_ns = now
-
-      def cleanup(self) -> None:
-        colmuns = os.get_terminal_size().columns
-        sys.stdout.write(' ' * colmuns + '\r')
-        sys.stdout.flush()
-
-    self.impl = Impl()
-    return self
-
-  def print_line(self, msg: str) -> None:
-    self.impl.print_line(msg)
-
-  def __exit__(self, *exc):
-    self.impl.cleanup()
-
-
 def qt_extract_filter(
     members: Iterator[tarfile.TarInfo],
 ) -> Iterator[tarfile.TarInfo]:

src/build_tools/progress_printer.py

@@ -0,0 +1,95 @@
+# -*- coding: utf-8 -*-
+# Copyright 2010-2021, Google Inc.
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""A console utility to show progress."""
+
+import os
+import sys
+import time
+
+
+class ProgressPrinter:
+  """A utility to print progress message with carriage return and trancatoin."""
+
+  def __enter__(self):
+    if not sys.stdout.isatty():
+
+      class NoOpImpl:
+        """A no-op implementation in case stdout is not attached to concole."""
+
+        def print_line(self, msg: str) -> None:
+          """No-op implementation.
+
+          Args:
+            msg: Unused.
+          """
+          del msg  # Unused
+          return
+
+        def cleanup(self) -> None:
+          pass
+
+      self.impl = NoOpImpl()
+      return self
+
+    class Impl:
+      """A real implementation in case stdout is attached to concole."""
+
+      last_output_time_ns = time.time_ns()
+
+      def print_line(self, msg: str) -> None:
+        """Print the given message with carriage return and trancatoin.
+
+        Args:
+          msg: Message to be printed.
+        """
+        colmuns = os.get_terminal_size().columns
+        now = time.time_ns()
+        if (now - self.last_output_time_ns) < 25000000:
+          return
+        msg = msg + ' ' * max(colmuns - len(msg), 0)
+        msg = msg[0:(colmuns)] + '\r'
+        sys.stdout.write(msg)
+        sys.stdout.flush()
+        self.last_output_time_ns = now
+
+      def cleanup(self) -> None:
+        colmuns = os.get_terminal_size().columns
+        sys.stdout.write(' ' * colmuns + '\r')
+        sys.stdout.flush()
+
+    self.impl = Impl()
+    return self
+
+  def print_line(self, msg: str) -> None:
+    self.impl.print_line(msg)
+
+  def __exit__(self, *exc):
+    self.impl.cleanup()

src/build_tools/update_deps.py

@@ -42,12 +42,12 @@
 import shutil
 import stat
 import subprocess
-import sys
-import time
 import zipfile
 
 import requests
 
+from progress_printer import ProgressPrinter
+
 
 ABS_SCRIPT_PATH = pathlib.Path(__file__).absolute()
 # src/build_tools/fetch_deps.py -> src/
@@ -182,61 +182,6 @@ def download(archive: ArchiveInfo, dryrun: bool = False) -> None:
     )
 
 
-class ProgressPrinter:
-  """A utility to print progress message with carriage return and trancatoin."""
-
-  def __enter__(self):
-    if not sys.stdout.isatty():
-
-      class NoOpImpl:
-        """A no-op implementation in case stdout is not attached to concole."""
-
-        def print_line(self, msg: str) -> None:
-          """No-op implementation.
-
-          Args:
-            msg: Unused.
-          """
-          del msg  # Unused
-          return
-
-      self.cleaner = None
-      return NoOpImpl()
-
-    class Impl:
-      """A real implementation in case stdout is attached to concole."""
-      last_output_time_ns = time.time_ns()
-
-      def print_line(self, msg: str) -> None:
-        """Print the given message with carriage return and trancatoin.
-
-        Args:
-          msg: Message to be printed.
-        """
-        colmuns = os.get_terminal_size().columns
-        now = time.time_ns()
-        if (now - self.last_output_time_ns) < 25000000:
-          return
-        msg = msg + ' ' * max(colmuns - len(msg), 0)
-        msg = msg[0 : (colmuns)] + '\r'
-        sys.stdout.write(msg)
-        sys.stdout.flush()
-        self.last_output_time_ns = now
-
-    class Cleaner:
-      def cleanup(self) -> None:
-        colmuns = os.get_terminal_size().columns
-        sys.stdout.write(' ' * colmuns + '\r')
-        sys.stdout.flush()
-
-    self.cleaner = Cleaner()
-    return Impl()
-
-  def __exit__(self, *exc):
-    if self.cleaner:
-      self.cleaner.cleanup()
-
-
 def extract_ninja(dryrun: bool = False) -> None:
   """Extract ninja-win archive.