[Compiler] add initial support for incremental build

Incremental build now fully supports static files and images.
XHTML, Bade and Stylus files has only limited support.

refs #11

lib/epuber/compiler.rb

@@ -85,9 +85,16 @@ def compile(build_folder, check: false, write: false, release: false, verbose: f
         # build folder cleanup
         remove_unnecessary_files
         remove_empty_folders
+
+        source_paths = file_resolver.files.select { |a| a.is_a?(FileTypes::SourceFile) }.map { |a| a.source_path }
+        compilation_context.source_file_database.cleanup(source_paths)
+        compilation_context.target_file_database.cleanup(source_paths)
       end
     ensure
       self.class.globals_catcher.clear_all
+
+      compilation_context.source_file_database.save_to_file
+      compilation_context.target_file_database.save_to_file
     end
 
     # Archives current target files to epub
@@ -207,10 +214,12 @@ def parse_target_file_requests
       end
     end
 
-    # @param [FileTypes::AbstractFile] file
+    # @param [Epuber::Compiler::FileTypes::AbstractFile] file
     #
     def process_file(file)
+      file.compilation_context = compilation_context
       file.process(compilation_context)
+      file.compilation_context = nil
     end
 
     # @return nil

lib/epuber/compiler/compilation_context.rb

@@ -16,6 +16,18 @@ class CompilationContext
       #
       attr_accessor :file_resolver
 
+      # This will track source files regardless of current target
+      #
+      # @return [Epuber::Compiler::FileDatabase]
+      #
+      attr_reader :source_file_database
+
+      # This will track source files depend on current target
+      #
+      # @return [Epuber::Compiler::FileDatabase]
+      #
+      attr_reader :target_file_database
+
       # @return [Array<Epuber::Plugin>]
       #
       def plugins
@@ -76,10 +88,16 @@ def verbose?
         verbose
       end
 
+      def debug?
+        !release_build
+      end
 
       def initialize(book, target)
         @book = book
         @target = target
+
+        @source_file_database = FileDatabase.new(Config.instance.file_stat_database_path)
+        @target_file_database = FileDatabase.new(Config.instance.target_file_stat_database_path(target))
       end
     end
   end

lib/epuber/compiler/file_database.rb

@@ -29,24 +29,42 @@ def initialize(path)
 
       # @param [String] file_path
       #
-      def changed?(file_path)
+      def changed?(file_path, transitive: true, default_value: true)
         stat = @all_files[file_path]
-        return false if stat.nil?
+        return default_value if stat.nil?
 
         result = (stat != FileStat.new(file_path))
-        result || stat.dependency_paths.any? { |path| changed?(path) }
+
+        if transitive
+          result ||= stat.dependency_paths.any? do |path|
+            changed?(path, transitive: transitive, default_value: false)
+          end
+        end
+
+        result
+      end
+
+      # @param [String] file_path
+      #
+      # @return [FileStat]
+      #
+      def file_stat_for(file_path)
+        @all_files[file_path]
       end
 
       # @param [String] file_path
       #
-      def up_to_date?(file_path)
-        !changed?(file_path)
+      def up_to_date?(file_path, transitive: true)
+        !changed?(file_path, transitive: transitive)
       end
 
       # @param [String] file_path
       #
       def update_metadata(file_path)
-        @all_files[file_path] = FileStat.new(file_path)
+        old_stat = @all_files[file_path]
+        old_dependencies = old_stat ? old_stat.dependency_paths : []
+
+        @all_files[file_path] = FileStat.new(file_path, dependency_paths: old_dependencies)
       end
 
       # @param [String] file_path  path to file that will be dependent on
@@ -81,6 +99,8 @@ def cleanup(file_paths)
       # @param [String] path
       #
       def save_to_file(path = store_file_path)
+        FileUtils.mkdir_p(File.dirname(path))
+
         File.write(path, @all_files.to_yaml)
       end
 

lib/epuber/compiler/file_stat.rb

@@ -27,15 +27,15 @@ class FileStat
       # @param [String] path
       # @param [File::Stat] stat
       #
-      def initialize(path, stat = nil)
+      def initialize(path, stat = nil, dependency_paths: [])
         @file_path = path
 
         stat ||= File.stat(path)
         @mtime = stat.mtime
         @ctime = stat.ctime
         @size = stat.size
 
-        @dependency_paths = []
+        @dependency_paths = dependency_paths
       end
 
       # @param [String] path

lib/epuber/compiler/file_types/abstract_file.rb

@@ -37,6 +37,9 @@ def properties
         #
         attr_accessor :path_type
 
+        # @return [Epuber::Compiler::CompilationContext] non-nil value only during #process() method
+        #
+        attr_accessor :compilation_context
 
         def ==(other)
           self.class == other.class && final_destination_path == other.final_destination_path

lib/epuber/compiler/file_types/bade_file.rb

@@ -9,14 +9,17 @@ module FileTypes
       require_relative 'xhtml_file'
 
       class BadeFile < XHTMLFile
+        PRECOMPILED_CACHE_NAME = 'bade_precompiled'
+
         # @param [Epuber::Compiler::CompilationContext] compilation_context
         #
         def process(compilation_context)
           target = compilation_context.target
           book = compilation_context.book
           file_resolver = compilation_context.file_resolver
 
-          bade_content = load_source(compilation_context)
+          up_to_date = source_file_up_to_date?
+          precompiled_exists = File.exist?(precompiled_path)
 
           variables = {
             __book: book,
@@ -27,12 +30,36 @@ def process(compilation_context)
             __const: Hash.new { |_hash, key| UI.warning("Undefined constant with key `#{key}`", location: caller_locations[0]) }.merge!(target.constants),
           }
 
-          xhtml_content = Bade::Renderer.from_source(bade_content, source_path)
-                                        .with_locals(variables)
-                                        .render(new_line: '', indent: '')
+          if up_to_date && precompiled_exists && compilation_context.debug?
+            precompiled = Bade::Precompiled.from_yaml_file(precompiled_path)
+
+            renderer = Bade::Renderer.from_precompiled(precompiled)
+                                     .with_locals(variables)
+
+            xhtml_content = renderer.render(new_line: '', indent: '')
+
+          else
+            compilation_context.source_file_database.update_metadata(source_path) if compilation_context.debug?
+
+            bade_content = load_source(compilation_context)
+
+            renderer = Bade::Renderer.from_source(bade_content, source_path)
+                                     .with_locals(variables)
+
+            FileUtils.mkdir_p(File.dirname(precompiled_path))
+            renderer.precompiled.write_yaml_to_file(precompiled_path)
+
+            xhtml_content = renderer.render(new_line: '', indent: '')
+          end
 
           write_compiled(common_process(xhtml_content, compilation_context))
         end
+
+        # @return [String]
+        #
+        def precompiled_path
+          File.join(Config.instance.build_cache_path(PRECOMPILED_CACHE_NAME), source_path + '.precompiled.yml')
+        end
       end
     end
   end

lib/epuber/compiler/file_types/image_file.rb

@@ -9,14 +9,14 @@ module FileTypes
       require_relative 'source_file'
 
       class ImageFile < SourceFile
-        # @param [Compiler::CompilationContext] compilation_context
+        # @param [Compiler::CompilationContext] _compilation_context
         #
-        def process(compilation_context)
+        def process(_compilation_context)
+          return if destination_file_up_to_date?
+
           dest = final_destination_path
           source = abs_source_path
 
-          return if self.class.file_uptodate?(source, dest)
-
           img = Magick::Image::read(source).first
 
           resolution = img.columns * img.rows
@@ -35,6 +35,8 @@ def process(compilation_context)
             # file is already old
             self.class.file_copy!(source, dest)
           end
+
+          update_metadata!
         end
       end
     end

lib/epuber/compiler/file_types/source_file.rb

@@ -26,11 +26,55 @@ def initialize(source_path)
           @source_path = source_path
         end
 
+        # Source file does not change from last build
+        # @warning Using only this method can cause not updating files that are different for targets
+        #
+        # @return [Bool]
+        #
+        def source_file_up_to_date?
+          source_db = compilation_context.source_file_database
+          source_db.up_to_date?(source_path)
+        end
+
+        # Source file does not change from last build of this target
+        #
+        # @return [Bool]
+        #
+        def destination_file_up_to_date?
+          source_db = compilation_context.source_file_database
+          target_db = compilation_context.target_file_database
+
+          destination_file_exist? && # destination file must exist
+            target_db.up_to_date?(source_path) && # source file must be up-to-date from last build of this target
+            source_db.file_stat_for(source_path) == target_db.file_stat_for(source_path)
+        end
+
+        # Final destination path exist
+        #
+        # @return [Bool]
+        #
+        def destination_file_exist?
+          File.exist?(final_destination_path)
+        end
+
+        # Updates information about source file in file databases
+        #
+        # @return [nil]
+        #
+        def update_metadata!
+          compilation_context.source_file_database.update_metadata(source_path)
+          compilation_context.target_file_database.update_metadata(source_path)
+        end
+
         def default_file_copy
-          if self.class.file_copy?(abs_source_path, final_destination_path)
+          ok = destination_file_up_to_date? && destination_file_exist?
+
+          unless ok
             UI.print_processing_debug_info("Copying to #{pkg_destination_path}")
             self.class.file_copy!(abs_source_path, final_destination_path)
           end
+
+          update_metadata!
         end
 
         def write_compiled(content)

lib/epuber/compiler/file_types/static_file.rb

@@ -7,9 +7,9 @@ module FileTypes
       require_relative 'source_file'
 
       class StaticFile < SourceFile
-        # @param [Compiler::CompilationContext] compilation_context
+        # @param [Compiler::CompilationContext] _compilation_context
         #
-        def process(compilation_context)
+        def process(_compilation_context)
           default_file_copy
         end
       end

lib/epuber/compiler/file_types/stylus_file.rb

@@ -12,12 +12,16 @@ class StylusFile < SourceFile
         # @param [Compiler::CompilationContext] compilation_context
         #
         def process(compilation_context)
+          return if destination_file_up_to_date?
+
           Stylus.define('__is_debug', !compilation_context.release_build)
           Stylus.define('__is_verbose_mode', compilation_context.verbose?)
           Stylus.define('__target_name', compilation_context.target.name)
           Stylus.define('__book_title', compilation_context.book.title)
 
           write_compiled(Stylus.compile(File.new(abs_source_path)))
+
+          update_metadata!
         end
       end
     end

lib/epuber/config.rb

@@ -103,6 +103,28 @@ def release_build_path(target)
       File.join(working_path, 'release_build', target.name.to_s)
     end
 
+    # @param [String] cache_name
+    #
+    # @return [String]
+    #
+    def build_cache_path(cache_name)
+      File.join(working_path, 'build_cache', cache_name)
+    end
+
+    # @return [String]
+    #
+    def file_stat_database_path
+      File.join(working_path, 'metadata', 'source_file_stats.yml')
+    end
+
+    # @param [Epuber::Book::Target] target
+    #
+    # @return [String]
+    #
+    def target_file_stat_database_path(target)
+      File.join(working_path, 'metadata', 'target_stats', target.name.to_s, 'file_stats.yml')
+    end
+
     # ---------------------------------------------------------------------------------------------------------------- #
 
     # Singleton

spec/unit/compiler/file/bade_file_spec.rb

@@ -49,6 +49,7 @@ module FileTypes
           ctx = CompilationContext.new(book, book.default_target)
           ctx.file_resolver = FileResolver.new('/', '/.build')
 
+          file.compilation_context = ctx
           file.process(ctx)
 
           expect(File.read('some_file.xhtml')).to eq '<?xml version="1.0" encoding="UTF-8" standalone="no"?>

spec/unit/compiler/file/image_file_spec.rb

@@ -18,6 +18,15 @@ module FileTypes
           @tmp_dir = Dir.mktmpdir
         end
 
+        let (:ctx) do
+          book = Book.new
+
+          ctx = CompilationContext.new(book, book.default_target)
+          ctx.file_resolver = FileResolver.new(@tmp_dir, File.join(@tmp_dir, '/.build'))
+
+          ctx
+        end
+
         it "copy file's content to destination" do
           img_source = File.join(spec_root, '../test_project/images/001_Frie_9780804137508_art_r1_fmt.png')
           img_dest = File.join(@tmp_dir, 'dest_image.png')
@@ -29,6 +38,7 @@ module FileTypes
           file.destination_path = img_dest
           resolve_file_paths(file)
 
+          file.compilation_context = ctx
           file.process(nil)
 
           expect(File.exist?(img_dest)).to be_truthy
@@ -47,6 +57,7 @@ module FileTypes
           file.destination_path = dest
           resolve_file_paths(file)
 
+          file.compilation_context = ctx
           file.process(nil)