Merge pull request #399 from NickLaMuro/support-byte-count-for-s3-obj…

…ect-store

[MiqS3Storage] Support @byte_count in #download_single

lib/gems/pending/util/object_storage/miq_s3_storage.rb

@@ -44,8 +44,15 @@ def download_single(source, destination)
     logger.debug("Downloading [#{source}] from bucket [#{bucket_name}] to local file [#{destination}]")
 
     with_standard_s3_error_handling("downloading", source) do
-      if destination.kind_of?(IO)
-        s3.client.get_object(:bucket => bucket_name, :key => object_key) do |chunk|
+      if destination.kind_of?(IO) || destination.kind_of?(StringIO)
+        get_object_opts = {
+          :bucket => bucket_name,
+          :key    => object_key
+        }
+        # :range is indexed starting at zero
+        get_object_opts[:range] = "bytes=0-#{byte_count - 1}" if byte_count
+
+        s3.client.get_object(get_object_opts) do |chunk|
           destination.write(chunk.force_encoding(destination.external_encoding))
         end
       else # assume file path