Move installation routines into proper library

python3/vimspector/installer.py

@@ -0,0 +1,218 @@
+#!/usr/bin/env python3
+
+# vimspector - A multi-language debugging system for Vim
+# Copyright 2019 Ben Jackson
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from urllib import request
+import io
+import contextlib
+import zipfile
+import gzip
+import shutil
+import tarfile
+import hashlib
+import time
+import ssl
+import subprocess
+import functools
+import os
+
+from vimspector import install
+
+
+@contextlib.contextmanager
+def CurrentWorkingDir( d ):
+  cur_d = os.getcwd()
+  try:
+    os.chdir( d )
+    yield
+  finally:
+    os.chdir( cur_d )
+
+
+def MakeExecutable( file_path ):
+  # TODO: import stat and use them by _just_ adding the X bit.
+  print( 'Making executable: {}'.format( file_path ) )
+  os.chmod( file_path, 0o755 )
+
+
+
+def WithRetry( f ):
+  retries = 5
+  timeout = 1 # seconds
+
+  @functools.wraps( f )
+  def wrapper( *args, **kwargs ):
+    thrown = None
+    for _ in range( retries ):
+      try:
+        return f( *args, **kwargs )
+      except Exception as e:
+        thrown = e
+        print( "Failed - {}, will retry in {} seconds".format( e, timeout ) )
+        time.sleep( timeout )
+    raise thrown
+
+  return wrapper
+
+
+@WithRetry
+def UrlOpen( *args, **kwargs ):
+  return request.urlopen( *args, **kwargs )
+
+
+def DownloadFileTo( url,
+                    destination,
+                    file_name = None,
+                    checksum = None,
+                    check_certificate = True ):
+  if not file_name:
+    file_name = url.split( '/' )[ -1 ]
+
+  file_path = os.path.abspath( os.path.join( destination, file_name ) )
+
+  if not os.path.isdir( destination ):
+    os.makedirs( destination )
+
+  if os.path.exists( file_path ):
+    if checksum:
+      if ValidateCheckSumSHA256( file_path, checksum ):
+        print( "Checksum matches for {}, using it".format( file_path ) )
+        return file_path
+      else:
+        print( "Checksum doesn't match for {}, removing it".format(
+          file_path ) )
+
+    print( "Removing existing {}".format( file_path ) )
+    os.remove( file_path )
+
+  r = request.Request( url, headers = { 'User-Agent': 'Vimspector' } )
+
+  print( "Downloading {} to {}/{}".format( url, destination, file_name ) )
+
+  if not check_certificate:
+    context = ssl.create_default_context()
+    context.check_hostname = False
+    context.verify_mode = ssl.CERT_NONE
+    kwargs = { "context":  context }
+  else:
+    kwargs = {}
+
+  with contextlib.closing( UrlOpen( r, **kwargs ) ) as u:
+    with open( file_path, 'wb' ) as f:
+      f.write( u.read() )
+
+  if checksum:
+    if not ValidateCheckSumSHA256( file_path, checksum ):
+      raise RuntimeError(
+        'Checksum for {} ({}) does not match expected {}'.format(
+          file_path,
+          GetChecksumSHA254( file_path ),
+          checksum ) )
+  else:
+    print( "Checksum for {}: {}".format( file_path,
+                                         GetChecksumSHA254( file_path ) ) )
+
+  return file_path
+
+
+def GetChecksumSHA254( file_path ):
+  with open( file_path, 'rb' ) as existing_file:
+    return hashlib.sha256( existing_file.read() ).hexdigest()
+
+
+def ValidateCheckSumSHA256( file_path, checksum ):
+  existing_sha256 = GetChecksumSHA254( file_path )
+  return existing_sha256 == checksum
+
+
+def RemoveIfExists( destination ):
+  if os.path.exists( destination ) or os.path.islink( destination ):
+    if os.path.islink( destination ):
+      print( "Removing file {}".format( destination ) )
+      os.remove( destination )
+    else:
+      print( "Removing dir {}".format( destination ) )
+      shutil.rmtree( destination )
+
+
+# Python's ZipFile module strips execute bits from files, for no good reason
+# other than crappy code. Let's do it's job for it.
+class ModePreservingZipFile( zipfile.ZipFile ):
+  def extract( self, member, path = None, pwd = None ):
+    if not isinstance( member, zipfile.ZipInfo ):
+      member = self.getinfo( member )
+
+    if path is None:
+      path = os.getcwd()
+
+    ret_val = self._extract_member( member, path, pwd )
+    attr = member.external_attr >> 16
+    os.chmod( ret_val, attr )
+    return ret_val
+
+
+def ExtractZipTo( file_path, destination, format ):
+  print( "Extracting {} to {}".format( file_path, destination ) )
+  RemoveIfExists( destination )
+
+  if format == 'zip':
+    with ModePreservingZipFile( file_path ) as f:
+      f.extractall( path = destination )
+  elif format == 'zip.gz':
+    with gzip.open( file_path, 'rb' ) as f:
+      file_contents = f.read()
+
+    with ModePreservingZipFile( io.BytesIO( file_contents ) ) as f:
+      f.extractall( path = destination )
+
+  elif format == 'tar':
+    try:
+      with tarfile.open( file_path ) as f:
+        f.extractall( path = destination )
+    except Exception:
+      # There seems to a bug in python's tarfile that means it can't read some
+      # windows-generated tar files
+      os.makedirs( destination )
+      with CurrentWorkingDir( destination ):
+        subprocess.check_call( [ 'tar', 'zxvf', file_path ] )
+
+
+def MakeExtensionSymlink( vimspector_base, name, root ):
+  MakeSymlink( install.GetGadgetDir( vimspector_base,
+                                     install.GetOS() ),
+               name,
+               os.path.join( root, 'extension' ) ),
+
+
+def MakeSymlink( in_folder, link, pointing_to ):
+  RemoveIfExists( os.path.join( in_folder, link ) )
+
+  in_folder = os.path.abspath( in_folder )
+  pointing_to = os.path.relpath( os.path.abspath( pointing_to ),
+                                 in_folder )
+  os.symlink( pointing_to, os.path.join( in_folder, link ) )
+
+
+def CloneRepoTo( url, ref, destination ):
+  RemoveIfExists( destination )
+  git_in_repo = [ 'git', '-C', destination ]
+  subprocess.check_call( [ 'git', 'clone', url, destination ] )
+  subprocess.check_call( git_in_repo + [ 'checkout', ref ] )
+  subprocess.check_call( git_in_repo + [ 'submodule', 'sync', '--recursive' ] )
+  subprocess.check_call( git_in_repo + [ 'submodule',
+                                         'update',
+                                         '--init',
+                                         '--recursive' ] )