1 files changed, 109 insertions, 0 deletions
diff --git a/lib/gitlab/ci/build/artifacts/metadata.rb b/lib/gitlab/ci/build/artifacts/metadata.rb
new file mode 100644
index 00000000000..1344f5d120b
--- /dev/null
+++ b/lib/gitlab/ci/build/artifacts/metadata.rb
@@ -0,0 +1,109 @@
+require 'zlib'
+require 'json'
+
+module Gitlab
+  module Ci
+    module Build
+      module Artifacts
+        class Metadata
+          class ParserError < StandardError; end
+
+          VERSION_PATTERN = /^[\w\s]+(\d+\.\d+\.\d+)/
+          INVALID_PATH_PATTERN = %r{(^\.?\.?/)|(/\.?\.?/)}
+
+          attr_reader :file, :path, :full_version
+
+          def initialize(file, path)
+            @file, @path = file, path
+            @full_version = read_version
+          end
+
+          def version
+            @full_version.match(VERSION_PATTERN)[1]
+          end
+
+          def errors
+            gzip do |gz|
+              read_string(gz) # version
+              errors = read_string(gz)
+              raise ParserError, 'Errors field not found!' unless errors
+
+              begin
+                JSON.parse(errors)
+              rescue JSON::ParserError
+                raise ParserError, 'Invalid errors field!'
+              end
+            end
+          end
+
+          def find_entries!
+            gzip do |gz|
+              2.times { read_string(gz) } # version and errors fields
+              match_entries(gz)
+            end
+          end
+
+          def to_entry
+            entries = find_entries!
+            Entry.new(@path, entries)
+          end
+
+          private
+
+          def match_entries(gz)
+            entries = {}
+            match_pattern = %r{^#{Regexp.escape(@path)}[^/]*/?$}
+
+            until gz.eof? do
+              begin
+                path = read_string(gz).force_encoding('UTF-8')
+                meta = read_string(gz).force_encoding('UTF-8')
+               
+                next unless path.valid_encoding? && meta.valid_encoding?
+                next unless path =~ match_pattern
+                next if path =~ INVALID_PATH_PATTERN
+
+                entries[path] = JSON.parse(meta, symbolize_names: true)
+              rescue JSON::ParserError, Encoding::CompatibilityError
+                next
+              end
+            end
+
+            entries
+          end
+
+          def read_version
+            gzip do |gz|
+              version_string = read_string(gz)
+
+              unless version_string
+                raise ParserError, 'Artifacts metadata file empty!'
+              end
+
+              unless version_string =~ VERSION_PATTERN
+                raise ParserError, 'Invalid version!'
+              end
+
+              version_string.chomp
+            end
+          end
+
+          def read_uint32(gz)
+            binary = gz.read(4)
+            binary.unpack('L>')[0] if binary
+          end
+
+          def read_string(gz)
+            string_size = read_uint32(gz)
+            return nil unless string_size
+            gz.read(string_size)
+          end
+
+          def gzip(&block)
+            Zlib::GzipReader.open(@file, &block)
+          end
+        end
+      end
+    end
+  end
+end