Add a snapshot of flutter/engine/src/build to our sdk

build/util/lib/common/util.py

Index: build/util/lib/common/util.py
diff --git a/build/util/lib/common/util.py b/build/util/lib/common/util.py
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+# Copyright 2013 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+"""Generic utilities for all python scripts."""
+
+import atexit
+import httplib
+import os
+import signal
+import stat
+import subprocess
+import sys
+import tempfile
+import urlparse
+
+
+def GetPlatformName():
+  """Return a string to be used in paths for the platform."""
+  if IsWindows():
+    return 'win'
+  if IsMac():
+    return 'mac'
+  if IsLinux():
+    return 'linux'
+  raise NotImplementedError('Unknown platform "%s".' % sys.platform)
+
+
+def IsWindows():
+  return sys.platform == 'cygwin' or sys.platform.startswith('win')
+
+
+def IsLinux():
+  return sys.platform.startswith('linux')
+
+
+def IsMac():
+  return sys.platform.startswith('darwin')
+
+
+def _DeleteDir(path):
+  """Deletes a directory recursively, which must exist."""
+  # Don't use shutil.rmtree because it can't delete read-only files on Win.
+  for root, dirs, files in os.walk(path, topdown=False):
+    for name in files:
+      filename = os.path.join(root, name)
+      os.chmod(filename, stat.S_IWRITE)
+      os.remove(filename)
+    for name in dirs:
+      os.rmdir(os.path.join(root, name))
+  os.rmdir(path)
+
+
+def Delete(path):
+  """Deletes the given file or directory (recursively), which must exist."""
+  if os.path.isdir(path):
+    _DeleteDir(path)
+  else:
+    os.remove(path)
+
+
+def MaybeDelete(path):
+  """Deletes the given file or directory (recurisvely), if it exists."""
+  if os.path.exists(path):
+    Delete(path)
+
+
+def MakeTempDir(parent_dir=None):
+  """Creates a temporary directory and returns an absolute path to it.
+
+  The temporary directory is automatically deleted when the python interpreter
+  exits normally.
+
+  Args:
+    parent_dir: the directory to create the temp dir in. If None, the system
+                temp dir is used.
+
+  Returns:
+    The absolute path to the temporary directory.
+  """
+  path = tempfile.mkdtemp(dir=parent_dir)
+  atexit.register(MaybeDelete, path)
+  return path
+
+
+def Unzip(zip_path, output_dir):
+  """Unzips the given zip file using a system installed unzip tool.
+
+  Args:
+    zip_path: zip file to unzip.
+    output_dir: directory to unzip the contents of the zip file. The directory
+                must exist.
+
+  Raises:
+    RuntimeError if the unzip operation fails.
+  """
+  if IsWindows():
+    unzip_cmd = ['C:\\Program Files\\7-Zip\\7z.exe', 'x', '-y']
+  else:
+    unzip_cmd = ['unzip', '-o']
+  unzip_cmd += [zip_path]
+  if RunCommand(unzip_cmd, output_dir) != 0:
+    raise RuntimeError('Unable to unzip %s to %s' % (zip_path, output_dir))
+
+
+def Kill(pid):
+  """Terminate the given pid."""
+  if IsWindows():
+    subprocess.call(['taskkill.exe', '/T', '/F', '/PID', str(pid)])
+  else:
+    os.kill(pid, signal.SIGTERM)
+
+
+def RunCommand(cmd, cwd=None):
+  """Runs the given command and returns the exit code.
+
+  Args:
+    cmd: list of command arguments.
+    cwd: working directory to execute the command, or None if the current
+         working directory should be used.
+
+  Returns:
+    The exit code of the command.
+  """
+  process = subprocess.Popen(cmd, cwd=cwd)
+  process.wait()
+  return process.returncode
+
+
+def DoesUrlExist(url):
+  """Determines whether a resource exists at the given URL.
+
+  Args:
+    url: URL to be verified.
+
+  Returns:
+    True if url exists, otherwise False.
+  """
+  parsed = urlparse.urlparse(url)
+  try:
+    conn = httplib.HTTPConnection(parsed.netloc)
+    conn.request('HEAD', parsed.path)
+    response = conn.getresponse()
+  except (socket.gaierror, socket.error):
+    return False
+  finally:
+    conn.close()
+  # Follow both permanent (301) and temporary (302) redirects.
+  if response.status == 302 or response.status == 301:
+    return DoesUrlExist(response.getheader('location'))
+  return response.status == 200