Class: CanvasSync::Importers::BulkImporter

Inherits:
Object
  • Object
show all
Defined in:
lib/canvas_sync/importers/bulk_importer.rb

Defined Under Namespace

Classes: NullRowBuffer, RowBuffer, UserRowBuffer

Constant Summary collapse

DEFAULT_BATCH_SIZE =

The batch import size can be customized by setting the ‘BULK_IMPORTER_BATCH_SIZE’ environment variable

10_000

Class Method Summary collapse

Class Method Details

.batch_size ⇒ Object 



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# File 'lib/canvas_sync/importers/bulk_importer.rb', line 127

def self.batch_size
  batch_size = ENV["BULK_IMPORTER_BATCH_SIZE"].to_i
  batch_size > 0 ? batch_size : DEFAULT_BATCH_SIZE
end

.condition_sql(klass, columns, report_start = nil) ⇒ Object

This method generates SQL that looks like: (users.sis_id, users.email) IS DISTINCT FROM (EXCLUDED.sis_id, EXCLUDED.email)

This prevents activerecord-import from setting the ‘updated_at` column for rows that haven’t actually changed. This allows you to query for rows that have changed by doing something like:

started_at = Time.now run_the_users_sync! changed = User.where(“updated_at >= ?”, started_at)



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# File 'lib/canvas_sync/importers/bulk_importer.rb', line 117

def self.condition_sql(klass, columns, report_start = nil)
  columns_str = columns.map { |c| "#{klass.quoted_table_name}.#{c}" }.join(", ")
  excluded_str = columns.map { |c| "EXCLUDED.#{c}" }.join(", ")
  condition_sql = "(#{columns_str}) IS DISTINCT FROM (#{excluded_str})"
  if klass.column_names.include?("updated_at") && report_start
    condition_sql += " AND #{klass.quoted_table_name}.updated_at < '#{report_start}'"
  end
  condition_sql
end

.import(report_file_path, mapping, klass, conflict_target, import_args: {}) {|row| ... } ⇒ Object

Does a bulk import of a set of models using the activerecord-import gem.

Parameters:

  • report_file_path (String) —

    path to the report CSV

  • mapping (Hash) —

    a hash of the values to import. See ‘model_mappings.yml` for a format example

  • klass (Object) —

    e.g., User

  • conflict_target (Symbol) —

    the csv column name that maps to the database column that will determine if we need to update or insert a given row. e.g.,: canvas_user_id

  • import_args (Hash) (defaults to: {}) —

    Any arguments passed here will be passed through to ActiveRecord::BulkImport. Note: passing the key [:on_duplicate_key_ignore] will override the default behavior of [:on_duplicate_key_update]

Yield Parameters:

  • row (Array) —

    if a block is passed in it will yield the current row from the CSV. This can be used if you need to filter or massage the data in any way.



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# File 'lib/canvas_sync/importers/bulk_importer.rb', line 20

def self.import(report_file_path, mapping, klass, conflict_target, import_args: {}, &blk) # rubocop:disable Metrics/AbcSize, Metrics/CyclomaticComplexity, Metrics/PerceivedComplexity, Metrics/LineLength
  ClassCallbackExecutor.run_if_defined(klass, :sync_import) do
    perform_in_batches(report_file_path, mapping, klass, conflict_target, import_args: import_args, &blk)
  end
end

.perform_import(klass, columns, rows, conflict_target, import_args = {}) ⇒ Object 



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# File 'lib/canvas_sync/importers/bulk_importer.rb', line 92

def self.perform_import(klass, columns, rows, conflict_target, import_args={})
  return if rows.length.zero?
  columns = columns.dup

  update_conditions = {
    condition: condition_sql(klass, columns, import_args[:sync_start_time]),
    columns: columns
  }
  update_conditions[:conflict_target] = conflict_target if conflict_target.present?

  options = { validate: false, on_duplicate_key_update: update_conditions }.merge(import_args)
  options.delete(:on_duplicate_key_update) if options.key?(:on_duplicate_key_ignore)
  klass.import(columns, rows, options)
end

.perform_in_batches(report_file_path, raw_mapping, klass, conflict_target, import_args: {}) ⇒ Object 



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# File 'lib/canvas_sync/importers/bulk_importer.rb', line 26

def self.perform_in_batches(report_file_path, raw_mapping, klass, conflict_target, import_args: {})
  mapping = {}.with_indifferent_access
  raw_mapping.each do |db_col, opts|
    next if opts[:deprecated] && !klass.column_names.include?(db_col.to_s)

    mapping[db_col] = opts
  end

  csv_column_names = mapping.values.map { |value| value[:report_column].to_s }
  database_column_names = mapping.keys

  conflict_target = Array(conflict_target).map(&:to_s)
  conflict_target_indices = conflict_target.map{|ct| database_column_names.index(ct) }

  row_ids = {}
  batcher = CanvasSync::BatchProcessor.new(of: batch_size) do |batch|
    row_ids = {}
    perform_import(klass, database_column_names, batch, conflict_target, import_args)
  end

  row_buffer_out = ->(row) {
    formatted_row = mapping.map do |db_col, col_def|
      value = nil
      value = row[col_def[:report_column]] if col_def[:report_column]

      if col_def[:type]
        if col_def[:type].to_sym == :datetime
          # TODO: add some timezone config to the mapping.
          # In cases where the timestamp or date doesn't include a timezone, you should be able to specify one
          value = DateTime.parse(value).utc rescue nil # rubocop:disable Style/RescueModifier
        end
      end

      value = col_def[:transform].call(value, row) if col_def[:transform]

      value
    end

    if conflict_target.present?
      key = conflict_target_indices.map{|ct| formatted_row[ct] }
      next if row_ids[key]

      row_ids[key] = true
    end

    batcher << formatted_row
  }

  row_buffer = nil
  if defined?(User) && klass == User && csv_column_names.include?('user_id')
    row_buffer = UserRowBuffer.new(&row_buffer_out)
  else
    row_buffer = NullRowBuffer.new(&row_buffer_out)
  end

  CSV.foreach(report_file_path, headers: true, header_converters: :symbol) do |row|
    row = yield(row) if block_given?
    next if row.nil?

    row_buffer << row
  end

  row_buffer.flush
  batcher.flush
end