use libarchive by preference

Signed-off-by: Thom May <[email protected]>

Gemfile

@@ -3,6 +3,8 @@ source "https://rubygems.org"
 # Specify your gem's dependencies in mixlib-archive.gemspec
 gemspec
 
+gem "ffi-libarchive"
+
 group(:changelog) do
   gem "github_changelog_generator", git: "https://github.com/chef/github-changelog-generator"
 end

lib/mixlib/archive.rb

@@ -11,8 +11,14 @@ def initialize(archive, empty: false)
       @empty = empty
 
       archive = File.expand_path(archive)
-      # for now we only support Tar format archives.
-      @archiver = Mixlib::Archive::Tar.new(archive)
+      begin
+        # we prefer to use libarchive, which supports a great big pile o' stuff
+        require "mixlib/archive/lib_archive"
+        @archiver = Mixlib::Archive::LibArchive.new(archive)
+      rescue LoadError
+        # but if we can't use that, we'll fall back to ruby's native tar implementation
+        @archiver = Mixlib::Archive::Tar.new(archive)
+      end
     end
 
     class Log

lib/mixlib/archive/lib_archive.rb

@@ -0,0 +1,63 @@
+require "ffi-libarchive"
+
+module Mixlib
+  class Archive
+    class LibArchive
+      attr_reader :options
+      attr_reader :archive
+
+      def initialize(archive, options = {})
+        @archive = archive
+        @options = options
+      end
+
+      # Extracts the archive to the given +destination+
+      #
+      # === Parameters
+      # perms<Boolean>:: should the extracter use permissions from the archive.
+      # ignore[Array]:: an array of matches of file paths to ignore
+      def extract(destination, perms: true, ignore: [])
+        ignore_re = Regexp.union(ignore)
+        flags = perms ? ::Archive::EXTRACT_PERM : nil
+        Dir.chdir(destination) do
+          reader = ::Archive::Reader.open_filename(@archive)
+
+          reader.each_entry do |entry|
+            if entry.pathname =~ ignore_re
+              Mixlib::Archive::Log.warn "ignoring entry #{entry.pathname}"
+              next
+            end
+
+            reader.extract(entry, flags.to_i)
+          end
+          reader.close
+        end
+      end
+
+      # Creates an archive with the given set of +files+
+      #
+      # === Parameters
+      # gzip<Boolean>:: should the archive be gzipped?
+      def create(files, gzip: false)
+        compression = gzip ? ::Archive::COMPRESSION_GZIP : ::Archive::COMPRESSION_NONE
+        # "PAX restricted" will use PAX extensions when it has to, but will otherwise
+        # use ustar for maximum compatibility
+        format = ::Archive::FORMAT_TAR_PAX_RESTRICTED
+
+        ::Archive.write_open_filename(archive, compression, format) do |tar|
+          files.each do |fn|
+            tar.new_entry do |entry|
+              entry.pathname = fn
+              entry.copy_stat(fn)
+              tar.write_header(entry)
+              if File.file?(fn)
+                content = File.read(fn)
+                tar.write_data(content)
+              end
+            end
+          end
+        end
+      end
+    end
+  end
+end