1 files changed, 187 insertions, 0 deletions
diff --git a/lib/gitlab/ci/trace/http_io.rb b/lib/gitlab/ci/trace/http_io.rb
new file mode 100644
index 00000000000..ac4308f4e2c
--- /dev/null
+++ b/lib/gitlab/ci/trace/http_io.rb
@@ -0,0 +1,187 @@
+##
+# This class is compatible with IO class (https://ruby-doc.org/core-2.3.1/IO.html)
+# source: https://gitlab.com/snippets/1685610
+module Gitlab
+  module Ci
+    class Trace
+      class HttpIO
+        BUFFER_SIZE = 128.kilobytes
+
+        InvalidURLError = Class.new(StandardError)
+        FailedToGetChunkError = Class.new(StandardError)
+
+        attr_reader :uri, :size
+        attr_reader :tell
+        attr_reader :chunk, :chunk_range
+
+        alias_method :pos, :tell
+
+        def initialize(url, size)
+          raise InvalidURLError unless ::Gitlab::UrlSanitizer.valid?(url)
+
+          @uri = URI(url)
+          @size = size
+          @tell = 0
+        end
+
+        def close
+          # no-op
+        end
+
+        def binmode
+          # no-op
+        end
+
+        def binmode?
+          true
+        end
+
+        def path
+          nil
+        end
+
+        def url
+          @uri.to_s
+        end
+
+        def seek(pos, where = IO::SEEK_SET)
+          new_pos =
+            case where
+            when IO::SEEK_END
+              size + pos
+            when IO::SEEK_SET
+              pos
+            when IO::SEEK_CUR
+              tell + pos
+            else
+              -1
+            end
+
+          raise 'new position is outside of file' if new_pos < 0 || new_pos > size
+
+          @tell = new_pos
+        end
+
+        def eof?
+          tell == size
+        end
+
+        def each_line
+          until eof?
+            line = readline
+            break if line.nil?
+
+            yield(line)
+          end
+        end
+
+        def read(length = nil)
+          out = ""
+
+          until eof? || (length && out.length >= length)
+            data = get_chunk
+            break if data.empty?
+
+            out << data
+            @tell += data.bytesize
+          end
+
+          out = out[0, length] if length && out.length > length
+
+          out
+        end
+
+        def readline
+          out = ""
+
+          until eof?
+            data = get_chunk
+            new_line = data.index("\n")
+
+            if !new_line.nil?
+              out << data[0..new_line]
+              @tell += new_line + 1
+              break
+            else
+              out << data
+              @tell += data.bytesize
+            end
+          end
+
+          out
+        end
+
+        def write(data)
+          raise NotImplementedError
+        end
+
+        def truncate(offset)
+          raise NotImplementedError
+        end
+
+        def flush
+          raise NotImplementedError
+        end
+
+        def present?
+          true
+        end
+
+        private
+
+        ##
+        # The below methods are not implemented in IO class
+        #
+        def in_range?
+          @chunk_range&.include?(tell)
+        end
+
+        def get_chunk
+          unless in_range?
+            response = Net::HTTP.start(uri.hostname, uri.port, use_ssl: uri.scheme == 'https') do |http|
+              http.request(request)
+            end
+
+            raise FailedToGetChunkError unless response.code == '200' || response.code == '206'
+
+            @chunk = response.body.force_encoding(Encoding::BINARY)
+            @chunk_range = response.content_range
+
+            ##
+            # Note: If provider does not return content_range, then we set it as we requested
+            # Provider: minio
+            # - When the file size is larger than requested Content-range, the Content-range is included in responces with Net::HTTPPartialContent 206
+            # - When the file size is smaller than requested Content-range, the Content-range is included in responces with Net::HTTPPartialContent 206
+            # Provider: AWS
+            # - When the file size is larger than requested Content-range, the Content-range is included in responces with Net::HTTPPartialContent 206
+            # - When the file size is smaller than requested Content-range, the Content-range is included in responces with Net::HTTPPartialContent 206
+            # Provider: GCS
+            # - When the file size is larger than requested Content-range, the Content-range is included in responces with Net::HTTPPartialContent 206
+            # - When the file size is smaller than requested Content-range, the Content-range is included in responces with Net::HTTPOK 200
+            @chunk_range ||= (chunk_start...(chunk_start + @chunk.length))
+          end
+
+          @chunk[chunk_offset..BUFFER_SIZE]
+        end
+
+        def request
+          Net::HTTP::Get.new(uri).tap do |request|
+            request.set_range(chunk_start, BUFFER_SIZE)
+          end
+        end
+
+        def chunk_offset
+          tell % BUFFER_SIZE
+        end
+
+        def chunk_start
+          (tell / BUFFER_SIZE) * BUFFER_SIZE
+        end
+
+        def chunk_end
+          [chunk_start + BUFFER_SIZE, size].min
+        end
+      end
+    end
+  end
+end