refactoring build into db/folder/file services

app/models/db_folder.rb

@@ -7,7 +7,7 @@ class DbFolder < ActiveRecord::Base
   has_many :subfolders, class_name: 'DbFolder', foreign_key: 'parent_id'
   has_many :db_files
 
-  def defined_attributes
+  def self.defined_attributes
     [:name, :description, :hidden]
   end
 

app/services/db/update_db.rb

 # frozen_string_literal: true
 
 # Handles construction of database objects
-class UpdateDb # rubocop:disable Metrics/ClassLength
+class UpdateDb
   attr_accessor :warnings, :errors
 
   def initialize(db:)
@@ -18,10 +18,18 @@ class UpdateDb # rubocop:disable Metrics/ClassLength
     # create the entry array from the schema
     entries = __create_entries(db_adapter.schema)
 
+    updater = UpdateFolder.new(@root_folder, entries)
+    updater.run()
+    @errors << updater.errors
+    @warnings << updater.warnings
+
     # parse the entries array
     # Note: @root_folder gets linked in on
     #       the first call to __build_folder
-    __parse_folder_entries(parent: nil, entries: entries)
+    # Don't save the result if there were errors
+    if !@errors.empty?
+      return false
+    end
     @db.save
   end
 
@@ -41,166 +49,4 @@ class UpdateDb # rubocop:disable Metrics/ClassLength
     end
   end
 
-  # Creates or updates the folder defined by these entries.
-  # Then adds in any subfolders or subfiles
-  def __parse_folder_entries(parent:, entries:, default_name: '')
-    # generate the folder path
-    path = __build_path(entries)
-    # find the info stream entry if it exists
-    info = __read_info_entry(entries) || { name: default_name }
-    # create or update the folder
-    folder = __build_folder(parent: parent, path: path, info: info)
-    # group the folder entries
-    groups = __group_entries(entries)
-    # process the groups as subfolders or files
-    __process_folder_contents(folder, groups)
-    # return the updated folder
-    folder
-  end
-
-  # if this folder has an info stream, find that entry and
-  # use its metadata to update the folder's attributes
-  def __read_info_entry(entries)
-    info_entry = entries.detect do |entry|
-      entry[:chunks] == ['info']
-    end
-    info_entry ||= {}
-    # if there is an info entry, remove it from the array
-    # so we don't process it as a seperate file
-    entries.delete(info_entry)
-    # return the attributes
-    info_entry[:attributes]
-  end
-
-  # all entries agree on a common path
-  # up to the point where they still have
-  # chunks. Get this common path by popping
-  # the chunks off the first entry's path
-  def __build_path(entries)
-    parts = entries[0][:path].split('/')
-    parts.pop(entries[0][:chunks].length)
-    parts.join('/') # stitch parts together to form a path
-  end
-
-  # create or update a DbFolder object at the
-  # specified path. If the parent parameter is nil
-  # then the folder must be the Db's root folder
-  def __build_folder(parent:, path:, info:)
-    return @root_folder if parent.nil?
-    folder = parent.subfolders.find_by_path(path)
-    folder ||= DbFolder.new(parent: parent, path: path)
-    folder.update_attributes(
-      info.slice(*folder.defined_attributes))
-    folder.save!
-    folder
-  end
-
-  # collect the folder's entries into a set of groups
-  # based off the next item in their :chunk array
-  # returns entry_groups which is a Hash with
-  # :key = name of the common chunk
-  # :value = the entry, less the common chunk
-  def __group_entries(entries)
-    entry_groups = {}
-    entries.map do |entry|
-      # group streams by their base paths (ignore ~decim endings)
-      group_name = entry[:chunks].pop.gsub(decimation_tag, '')
-      __add_to_group(entry_groups, group_name, entry)
-    end
-    entry_groups
-  end
-
-  # regex matching the ~decimXX ending on a stream path
-  def decimation_tag
-    /~decim-([\d]+)$/
-  end
-
-  # helper function to __group_entries that handles
-  # sorting entries into the entry_groups Hash
-  def __add_to_group(entry_groups, group_name, entry)
-    entry_groups[group_name] ||= []
-    if entry[:chunks] == ['info'] # put the info stream in front
-      entry_groups[group_name].prepend(entry)
-    else
-      entry_groups[group_name].append(entry)
-    end
-  end
-
-  # convert the groups into subfolders and files
-  def __process_folder_contents(folder, groups)
-    groups.each do |name, entry_group|
-      if file?(entry_group)
-        __build_file(folder: folder, entry_group: entry_group,
-                     default_name: name)
-      else # its a folder
-        __parse_folder_entries(parent: folder, entries: entry_group,
-                               default_name: name)
-      end
-    end
-  end
-
-  # determine if the entry groups constitute a single file
-  def file?(entry_group)
-    # if any entry_group has chunks left, this is a folder
-    entry_group.select { |entry|
-      !entry[:chunks].empty?
-    }.count == 0
-  end
-
-  # create or update a DbFile object at the
-  # specified path.
-  def __build_file(folder:, entry_group:,
-                   default_name:)
-    base = __base_entry(entry_group)
-    unless base # corrupt file, don't process
-      @warnings << "#{entry_group.count} orphan decimations in #{folder.name}"
-      return
-    end
-    # find or create the file
-    file = folder.db_files.find_by_path(base[:path])
-    file ||= DbFile.new(db_folder: folder, path: base[:path])
-    # if the file doesn't have a name, use the default
-    base[:attributes][:name] ||= default_name
-    # automatically updates the streams for this file
-    file.update_attributes(base[:attributes])
-    file.save!
-    __build_decimations(file: file,
-                        entry_group: entry_group - [base])
-    __build_streams(file: file, stream_data: base[:streams])
-  end
-
-  # find the base stream in this entry_group
-  # this is the stream that doesn't have a decimXX tag
-  # adds a warning and returns nil if base entry is missing
-  def __base_entry(entry_group)
-    base_entry = entry_group.select { |entry|
-      entry[:path].match(decimation_tag).nil?
-    }.first
-    return nil unless base_entry
-    base_entry
-  end
-
-  # create or update DbDecimations for the
-  # specified DbFile
-  def __build_decimations(file:, entry_group:)
-    entry_group.each do |entry|
-      level = entry[:path].match(decimation_tag)[1].to_i
-      decim = file.db_decimations.find_by_level(level)
-      decim ||= DbDecimation.new(db_file: file, level: level)
-      decim.update_attributes(entry[:attributes])
-      decim.save!
-    end
-  end
-
-  # create or update DbStreams for the
-  # specified DbFile
-  def __build_streams(file:, stream_data:)
-    return if stream_data.empty?
-    stream_data.each do |entry|
-      stream = file.db_streams.find_by_column(entry[:column])
-      stream ||= DbStream.new(db_file: file)
-      stream.update_attributes(entry)
-      stream.save!
-    end
-  end
 end

app/services/db_file/update_file.rb

+# frozen_string_literal: true
+
+# Handles construction of DbFolder objects
+class UpdateFile
+  attr_accessor :warnings, :errors
+
+  def initialize(file, base_entry, decimation_entries)
+    @file = file
+    @base_entry = base_entry
+    @decimation_entries = decimation_entries
+    @warnings = []
+    @errors = []
+  end
+
+  def run()
+    return __update_file(@file, @base_entry, @decimation_entries)
+  end
+
+  # create or update a DbFile object at the
+  # specified path.
+  def __update_file(file, base_entry, decimation_entries:)
+    file.update_attributes(base_entry[:attributes])
+    file.save!
+    __build_decimations(file: file,
+                        entry_group: decimation_entries)
+    __build_streams(file: file, stream_data: base_entry[:streams])
+  end
+
+
+  # create or update DbDecimations for the
+  # specified DbFile
+  def __build_decimations(file:, entry_group:)
+    entry_group.each do |entry|
+      level = entry[:path].match(decimation_tag)[1].to_i
+      decim = file.db_decimations.find_by_level(level)
+      decim ||= DbDecimation.new(db_file: file, level: level)
+      decim.update_attributes(entry[:attributes])
+      decim.save!
+    end
+  end
+
+  # create or update DbStreams for the
+  # specified DbFile
+  def __build_streams(file:, stream_data:)
+    return if stream_data.empty?
+    stream_data.each do |entry|
+      stream = file.db_streams.find_by_column(entry[:column])
+      stream ||= DbStream.new(db_file: file)
+      stream.update_attributes(entry)
+      stream.save!
+    end
+  end
+end
\ No newline at end of file

app/services/db_folder/update_folder.rb

+# frozen_string_literal: true
+
+# Handles construction of DbFolder objects
+class UpdateFolder
+  attr_accessor :warnings, :errors
+
+
+  def initialize(folder, entries)
+    @folder = folder
+    @entries = entries
+    @warnings = []
+    @errors = []
+  end
+
+  # returns the updated DbFolder object
+  def run()
+    # update the folder attributes from metadata
+    info = __read_info_entry(@entries) || {}
+    @folder.update_attributes(
+      info.slice(*DbFolder.defined_attributes))
+    # process the contents of the folder
+    __parse_folder_entries(@folder, @entries)
+    # save the result
+    @folder.save!
+  end
+
+  protected
+
+  # if this folder has an info stream, find that entry and
+  # use its metadata to update the folder's attributes
+  def __read_info_entry(entries)
+    info_entry = entries.detect do |entry|
+      entry[:chunks] == ['info']
+    end
+    info_entry ||= {}
+    # if there is an info entry, remove it from the array
+    # so we don't process it as a seperate file
+    entries.delete(info_entry)
+    # return the attributes
+    info_entry[:attributes]
+  end
+
+  # Creates or updates the folder defined by these entries.
+  # Then adds in any subfolders or subfiles
+  def __parse_folder_entries(folder, entries)
+    # group the folder entries
+    groups = __group_entries(entries)
+    # process the groups as subfolders or files
+    __process_folder_contents(folder, groups)
+    # return the updated folder
+    folder
+  end
+
+
+
+  # collect the folder's entries into a set of groups
+  # based off the next item in their :chunk array
+  # returns entry_groups which is a Hash with
+  # :key = name of the common chunk
+  # :value = the entry, less the common chunk
+  def __group_entries(entries)
+    entry_groups = {}
+    entries.map do |entry|
+      # group streams by their base paths (ignore ~decim endings)
+      group_name = entry[:chunks].pop.gsub(decimation_tag, '')
+      __add_to_group(entry_groups, group_name, entry)
+    end
+    entry_groups
+  end
+
+  # regex matching the ~decimXX ending on a stream path
+  def decimation_tag
+    /~decim-([\d]+)$/
+  end
+
+  # helper function to __group_entries that handles
+  # sorting entries into the entry_groups Hash
+  def __add_to_group(entry_groups, group_name, entry)
+    entry_groups[group_name] ||= []
+    if entry[:chunks] == ['info'] # put the info stream in front
+      entry_groups[group_name].prepend(entry)
+    else
+      entry_groups[group_name].append(entry)
+    end
+  end
+
+  # convert the groups into subfolders and files
+  def __process_folder_contents(folder, groups)
+    groups.each do |name, entry_group|
+      if file?(entry_group)
+        file = __build_file(folder, entry_group, name)
+        base = __base_entry(entry_group)
+        updater = UpdateFile.new(file, base, entry_group-[base])
+      else # its a folder
+        subfolder = __build_folder(folder, entry_group, name)
+        updater = UpdateFolder.new(subfolder, entry_group)
+      end
+      updater.run()
+      @warnings << updater.warnings
+      @errors << updater.errors
+    end
+  end
+
+  # determine if the entry groups constitute a single file
+  def file?(entry_group)
+    # if any entry_group has chunks left, this is a folder
+    entry_group.select { |entry|
+      !entry[:chunks].empty?
+    }.count == 0
+  end
+
+  # create or update a DbFile object at the
+  # specified path.
+  def __build_file(folder, entry_group,
+                   default_name)
+    base = __base_entry(entry_group)
+    unless base # corrupt file, don't process
+      @warnings << "#{entry_group.count} orphan decimations in #{folder.name}"
+      return
+    end
+    # find or create the file
+    file = folder.db_files.find_by_path(base[:path])
+    file ||= DbFile.new(db_folder: folder, path: base[:path], name: default_name)
+    file
+  end
+
+  # find the base stream in this entry_group
+  # this is the stream that doesn't have a decimXX tag
+  # adds a warning and returns nil if base entry is missing
+  def __base_entry(entry_group)
+    base_entry = entry_group.select { |entry|
+      entry[:path].match(decimation_tag).nil?
+    }.first
+    return nil unless base_entry
+    base_entry
+  end
+
+  # create or update a DbFolder object at the
+  # specified path.
+  def __build_folder(parent, entries, default_name)
+    path = __build_path(entries)
+    folder = parent.subfolders.find_by_path(path)
+    folder ||= DbFolder.new(parent: parent, path: path, name: default_name)
+    folder
+  end
+
+  # all entries agree on a common path
+  # up to the point where they still have
+  # chunks. Get this common path by popping
+  # the chunks off the first entry's path
+  def __build_path(entries)
+    parts = entries[0][:path].split('/')
+    parts.pop(entries[0][:chunks].length)
+    parts.join('/') # stitch parts together to form a path
+  end
+
+
+end
\ No newline at end of file

config/application.rb

@@ -22,9 +22,9 @@ module ControlPanel
 
     # Do not swallow errors in after_commit/after_rollback callbacks.
     config.active_record.raise_in_transactional_callbacks = true
-    
+
     # Add folders under the services directory
-    ['nilm','db','folder'].each do |service|
+    ['nilm','db','db_folder','db_file'].each do |service|
       config.autoload_paths << Rails.root.join("app/services/#{service}")
     end
   end

spec/services/db/update_db_spec.rb

@@ -126,5 +126,19 @@ describe 'UpdateDb' do
         expect(file.db_folder.parent.parent).to eq(@root)
       end
     end
+
+    # updates to remote db
+    describe 'given changes to remote db' do
+      it 'removes missing files'
+      it 'removes missing folders'
+      it 'adds new files'
+      it 'adds new folders'
+    end
+    describe 'given changes to remote metadata' do
+      it 'updates file info'
+      it 'updates folder info'
+      it 'adds new streams'
+      it 'removes missing streams'
+    end
   end
 end