Add bin and edit workflow

bin/gems/ttfunk-1.8.0/lib/ttfunk/resource_file.rb

@@ -0,0 +1,111 @@
+# frozen_string_literal: true
+
+module TTFunk
+  # Data-fork suitcases resource file
+  class ResourceFile
+    # Resource map
+    #
+    # @return [Hash]
+    attr_reader :map
+
+    # Open a resource file
+    #
+    # @param path [String, Pathname]
+    # @yieldparam resource_file [TTFunk::ResourceFile]
+    # @return [any] result of the block
+    def self.open(path)
+      ::File.open(path, 'rb') { |io|
+        file = new(io)
+        yield(file)
+      }
+    end
+
+    # @param io [IO]
+    def initialize(io)
+      @io = io
+
+      data_offset, map_offset, map_length = @io.read(16).unpack('NNx4N')
+
+      @map = {}
+      # skip header copy, next map handle, file reference, and attrs
+      @io.pos = map_offset + 24
+      type_list_offset, name_list_offset = @io.read(4).unpack('n*')
+
+      type_list_offset += map_offset
+      name_list_offset += map_offset
+
+      @io.pos = type_list_offset
+      max_index = @io.read(2).unpack1('n')
+      0.upto(max_index) do
+        type, max_type_index, ref_list_offset = @io.read(8).unpack('A4nn')
+        @map[type] = { list: [], named: {} }
+
+        parse_from(type_list_offset + ref_list_offset) do
+          0.upto(max_type_index) do
+            id, name_ofs, attr = @io.read(5).unpack('nnC')
+            data_ofs = @io.read(3)
+            data_ofs = data_offset + [0, data_ofs].pack('CA*').unpack1('N')
+            handle = @io.read(4).unpack1('N')
+
+            entry = {
+              id: id,
+              attributes: attr,
+              offset: data_ofs,
+              handle: handle,
+            }
+
+            if name_list_offset + name_ofs < map_offset + map_length
+              parse_from(name_ofs + name_list_offset) do
+                len = @io.read(1).unpack1('C')
+                entry[:name] = @io.read(len)
+              end
+            end
+
+            @map[type][:list] << entry
+            @map[type][:named][entry[:name]] = entry if entry[:name]
+          end
+        end
+      end
+    end
+
+    # Get resource
+    #
+    # @overload [](type, index = 0)
+    #   @param type [String]
+    #   @param inxed [Integer]
+    #   @return [String]
+    # @overload [](type, name)
+    #   @param type [String]
+    #   @param name [String]
+    #   @return [String]
+    def [](type, index = 0)
+      if @map[type]
+        collection = index.is_a?(Integer) ? :list : :named
+        if @map[type][collection][index]
+          parse_from(@map[type][collection][index][:offset]) do
+            length = @io.read(4).unpack1('N')
+            return @io.read(length)
+          end
+        end
+      end
+    end
+
+    # Get resource names
+    #
+    # @param type [String]
+    # @return [Array<String>]
+    def resources_for(type)
+      ((@map[type] && @map[type][:named]) || {}).keys
+    end
+
+    private
+
+    def parse_from(offset)
+      saved = @io.pos
+      @io.pos = offset
+      yield
+    ensure
+      @io.pos = saved
+    end
+  end
+end