debian-mirror-gitlab/app/services/projects/lfs_pointers/lfs_download_service.rb
2020-11-24 15:15:51 +05:30

159 lines
4.4 KiB
Ruby

# frozen_string_literal: true
# This service downloads and links lfs objects from a remote URL
module Projects
module LfsPointers
class LfsDownloadService < BaseService
SizeError = Class.new(StandardError)
OidError = Class.new(StandardError)
ResponseError = Class.new(StandardError)
LARGE_FILE_SIZE = 1.megabytes
attr_reader :lfs_download_object
delegate :oid, :size, :credentials, :sanitized_url, to: :lfs_download_object, prefix: :lfs
def initialize(project, lfs_download_object)
super(project)
@lfs_download_object = lfs_download_object
end
def execute
return unless project&.lfs_enabled? && lfs_download_object
return error("LFS file with oid #{lfs_oid} has invalid attributes") unless lfs_download_object.valid?
return link_existing_lfs_object! if Feature.enabled?(:lfs_link_existing_object, project, default_enabled: true) && lfs_size > LARGE_FILE_SIZE && lfs_object
wrap_download_errors do
download_lfs_file!
end
end
private
def wrap_download_errors(&block)
yield
rescue SizeError, OidError, ResponseError, StandardError => e
error("LFS file with oid #{lfs_oid} could't be downloaded from #{lfs_sanitized_url}: #{e.message}")
end
def download_lfs_file!
with_tmp_file do |tmp_file|
download_and_save_file!(tmp_file)
project.lfs_objects << find_or_create_lfs_object(tmp_file)
success
end
end
def find_or_create_lfs_object(tmp_file)
lfs_obj = LfsObject.safe_find_or_create_by!(
oid: lfs_oid,
size: lfs_size
)
lfs_obj.update!(file: tmp_file) unless lfs_obj.file.file
lfs_obj
end
def download_and_save_file!(file)
digester = Digest::SHA256.new
fetch_file do |fragment|
digester << fragment
file.write(fragment)
raise_size_error! if file.size > lfs_size
end
raise_size_error! if file.size != lfs_size
raise_oid_error! if digester.hexdigest != lfs_oid
end
def download_headers
{ stream_body: true }.tap do |headers|
if lfs_credentials[:user].present? || lfs_credentials[:password].present?
# Using authentication headers in the request
headers[:basic_auth] = { username: lfs_credentials[:user], password: lfs_credentials[:password] }
end
end
end
def fetch_file(&block)
response = Gitlab::HTTP.get(lfs_sanitized_url, download_headers, &block)
raise ResponseError, "Received error code #{response.code}" unless response.success?
end
def with_tmp_file
create_tmp_storage_dir
File.open(tmp_filename, 'wb') do |file|
yield file
rescue StandardError => e
# If the lfs file is successfully downloaded it will be removed
# when it is added to the project's lfs files.
# Nevertheless if any excetion raises the file would remain
# in the file system. Here we ensure to remove it
File.unlink(file) if File.exist?(file)
raise e
end
end
def tmp_filename
File.join(tmp_storage_dir, lfs_oid)
end
def create_tmp_storage_dir
FileUtils.makedirs(tmp_storage_dir) unless Dir.exist?(tmp_storage_dir)
end
def tmp_storage_dir
@tmp_storage_dir ||= File.join(storage_dir, 'tmp', 'download')
end
def storage_dir
@storage_dir ||= Gitlab.config.lfs.storage_path
end
def raise_size_error!
raise SizeError, 'Size mistmatch'
end
def raise_oid_error!
raise OidError, 'Oid mismatch'
end
def error(message, http_status = nil)
log_error(message)
super
end
def lfs_object
@lfs_object ||= LfsObject.find_by_oid(lfs_oid)
end
def link_existing_lfs_object!
existing_file = lfs_object.file.open
buffer_size = 0
result = fetch_file do |fragment|
unless fragment == existing_file.read(fragment.size)
break error("LFS file with oid #{lfs_oid} cannot be linked with an existing LFS object")
end
buffer_size += fragment.size
break success if buffer_size > LARGE_FILE_SIZE
end
project.lfs_objects << lfs_object
result
ensure
existing_file&.close
end
end
end
end