Add MiqLocalMountSession

This mount session is intended as being a pass through for when local
files are used.

The same API's for `#add` from MiqGenericMountSession are still usable
for this class, and it will just write to the local file system instead.

This also allows us to test the file splitting code without needing a
mount session in place to do so.

lib/gems/pending/util/mount/miq_local_mount_session.rb

@@ -0,0 +1,37 @@
+require 'util/mount/miq_generic_mount_session'
+
+# MiqLocalMountSession is meant to be a representation of the local file system
+# that conforms to the same interface as MiqLocalMountSession (and by proxy,
+# MiqFileSystem::Interface).
+#
+# See MiqGenericMountSession for info on methods available.
+class MiqLocalMountSession < MiqGenericMountSession
+  def self.uri_scheme
+    "file".freeze
+  end
+
+  # no-op these since they are not relavent to the local file system
+  #
+  # rubocop:disable Style/SingleLineMethods, Layout/EmptyLineBetweenDefs
+  def connect; end      # :nodoc:
+  def disconnect; end   # :nodoc:
+  def mount_share; end  # :nodoc:
+  # rubocop:enable Style/SingleLineMethods, Layout/EmptyLineBetweenDefs
+
+  def relative_to_mount(dest_uri) # :nodoc:
+    dest_uri
+  end
+
+  # :nodoc:
+  #
+  # This is an override to allow methods that make use of `@mnt_point` to
+  # behave as we would expect them to.
+  #
+  # Determine the mount point relative to the destination file, and just remove
+  # the portions of the expanded path that already exist in the
+  # `remote_file_path` (might be everything if `remote_file_path` is a absolute
+  # path)
+  def mnt_point
+    @mnt_point ||= File.expand_path(remote_file_path).sub(remote_file_path, "")
+  end
+end

spec/util/mount/miq_local_mount_session_spec.rb

@@ -0,0 +1,90 @@
+require 'util/mount/miq_local_mount_session'
+require 'tempfile'
+
+describe MiqLocalMountSession do
+  shared_context "generated tmp files" do
+    let!(:tmpfile_size) { 10.megabytes }
+    let!(:source_path)  { Pathname.new(source_file.path) }
+    let!(:source_file) do
+      Tempfile.new("source_file").tap do |file|
+        file.write("0" * tmpfile_size)
+        file.close
+      end
+    end
+    let!(:dest_path) do
+      Pathname.new(Dir::Tmpname.create("") {})
+    end
+
+    after do
+      source_file.unlink
+      Dir["#{source_path.expand_path}.*"].each do |file|
+        File.delete(file)
+      end
+    end
+  end
+
+  subject { described_class.new(:uri => "file://") }
+
+  describe "#add" do
+    include_context "generated tmp files"
+
+    it "copies single files" do
+      expect(subject.add(source_path.to_s, dest_path.to_s)).to eq(dest_path.to_s)
+      expect(File.exist?(dest_path)).to be true
+      expect(Pathname.new(dest_path).lstat.size).to eq(10.megabytes)
+    end
+
+    it "copies file to splits" do
+      expected_splitfiles = (1..5).map do |suffix|
+        source_path.dirname.join("#{dest_path.basename}.0000#{suffix}")
+      end
+
+      File.open(source_path) do |f| # with an IO object this time
+        subject.add(f, dest_path.to_s, "2M")
+      end
+
+      expected_splitfiles.each do |filename|
+        expect(File.exist?(filename)).to be true
+        expect(Pathname.new(filename).lstat.size).to eq(2.megabytes)
+      end
+    end
+
+    it "can take input from a command" do
+      expected_splitfiles = (1..5).map do |suffix|
+        source_path.dirname.join("#{dest_path.basename}.0000#{suffix}")
+      end
+
+      subject.add(dest_path.to_s, "2M") do |input_writer|
+        `#{Gem.ruby} -e "File.write('#{input_writer}', '0' * #{tmpfile_size})"`
+      end
+
+      expected_splitfiles.each do |filename|
+        expect(File.exist?(filename)).to be true
+        expect(Pathname.new(filename).lstat.size).to eq(2.megabytes)
+      end
+    end
+
+    context "with slightly a slightly smaller input file than 10MB" do
+      let(:tmpfile_size) { 10.megabytes - 1.kilobyte }
+
+      it "properly chunks the file" do
+        expected_splitfiles = (1..10).map do |suffix|
+          name = "#{dest_path.basename}.%<suffix>05d" % {:suffix => suffix}
+          source_path.dirname.join(name)
+        end
+
+        # using pathnames this time
+        subject.add(source_path, dest_path.to_s, 1.megabyte)
+
+        expected_splitfiles[0, 9].each do |filename|
+          expect(File.exist?(filename)).to be true
+          expect(Pathname.new(filename).lstat.size).to eq(1.megabyte)
+        end
+
+        last_split = expected_splitfiles.last
+        expect(File.exist?(last_split)).to be true
+        expect(Pathname.new(last_split).lstat.size).to eq(1.megabyte - 1.kilobyte)
+      end
+    end
+  end
+end