Add zstd support.

Gemfile

@@ -18,4 +18,5 @@ group :development do
   gem 'rubocop'
   gem 'codeclimate-test-reporter', :require => nil
   gem 'simplecov'
+  gem 'zstd-ruby', '~> 1.5'
 end

cocoapods-downloader.gemspec

@@ -17,4 +17,6 @@ Gem::Specification.new do |s|
 
   s.required_ruby_version = '>= 2.6'
   s.specification_version = 3 if s.respond_to? :specification_version
+
+  s.add_runtime_dependency 'zstd-ruby', '~> 1.5'
 end

lib/cocoapods-downloader/remote_file.rb

@@ -1,6 +1,8 @@
 require 'fileutils'
 require 'uri'
 require 'zlib'
+require 'zstd-ruby'
+require 'pathname'
 
 module Pod
   module Downloader
@@ -49,7 +51,7 @@ def headers
       def should_flatten?
         if options.key?(:flatten)
           options[:flatten]
-        elsif [:tgz, :tar, :tbz, :txz].include?(type)
+        elsif [:tgz, :tar, :tbz, :txz, :zst].include?(type)
           true # those archives flatten by default
         else
           false # all others (actually only .zip) default not to flatten
@@ -68,14 +70,16 @@ def type_with_url(url)
           :tbz
         when /\.(txz|tar\.xz)$/
           :txz
+        when /\.(tzst|tar\.zst)$/
+          :zst
         when /\.dmg$/
           :dmg
         end
       end
 
       def filename_with_type(type = :zip)
         case type
-        when :zip, :tgz, :tar, :tbz, :txz, :dmg
+        when :zip, :tgz, :tar, :tbz, :txz, :zst, :dmg
           "file.#{type}"
         else
           raise UnsupportedFileTypeError, "Unsupported file type: #{type}"
@@ -95,6 +99,8 @@ def extract_with_type(full_filename, type = :zip)
           unzip! unpack_from, '-d', unpack_to
         when :tar, :tgz, :tbz, :txz
           tar! 'xf', unpack_from, '-C', unpack_to
+        when :zst
+          extract_tar_zstd(unpack_from, unpack_to)
         when :dmg
           extract_dmg(unpack_from, unpack_to)
         else
@@ -132,6 +138,29 @@ def extract_dmg(unpack_from, unpack_to)
         hdiutil! 'detach', mount_point
       end
 
+      def extract_tar_zstd(unpack_from, unpack_to)
+        tmp_tar_file = unpack_from.sub_ext(".tmp.tar")
+
+        begin
+          stream = Zstd::StreamingDecompress.new
+
+          File.open(unpack_from, 'rb') do |io|
+            buffer_size = 1024 * 1024
+            File.open(tmp_tar_file, 'wb') do |output|
+              until io.eof?
+                output.write(stream.decompress(io.read(buffer_size)))
+              end
+            end
+          end
+
+          tar! 'xf', tmp_tar_file, '-C', unpack_to
+        rescue StandardError => e
+          raise "Failed to decompress file: #{e}"
+        ensure
+          FileUtils.rm(tmp_tar_file) if File.exist?(tmp_tar_file)
+        end
+      end
+
       def compare_hash(filename, hasher, hash)
         incremental_hash = hasher.new
 

spec/remote_file_spec.rb

@@ -98,6 +98,14 @@ def download_file(full_filename)
         downloader.head_supported?.should.be.false
       end
 
+      it 'does not move unpacked contents to parent dir when archive contains multiple children' do
+        downloader = MockRemoteFile.new(tmp_folder, "#{@fixtures_url}/lib_multiple.tar.zst", {})
+        downloader.download
+        tmp_folder('lib_1/file.txt').should.exist
+        tmp_folder('lib_2/file.txt').should.exist
+        tmp_folder('lib_multiple.tar.zst').should.not.exist
+      end
+
       describe 'concerning archive validation' do
         it 'verifies that the downloaded file matches a sha1 hash' do
           options = { :sha1 => 'be62f423e2afde57ae7d79ba7bd3443df73e0021' }
@@ -166,6 +174,11 @@ def download_file(full_filename)
           downloader.send(:type).should == :txz
         end
 
+        it 'detects zst files' do
+          downloader = MockRemoteFile.new(tmp_folder, 'file:///path/to/file.tar.zst', {})
+          downloader.send(:type).should == :zst
+        end
+
         it 'detects dmg files' do
           downloader = MockRemoteFile.new(tmp_folder, 'file:///path/to/file.dmg', {})
           downloader.send(:type).should == :dmg