Class: RailsConsolePro::Services::ColumnStatsCalculator

Inherits:
Object
  • Object
show all
Defined in:
lib/rails_console_pro/services/column_stats_calculator.rb

Overview

Service for calculating column statistics

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(model_class, connection, table_name, safe_count_proc, config) ⇒ ColumnStatsCalculator 



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# File 'lib/rails_console_pro/services/column_stats_calculator.rb', line 11

def initialize(model_class, connection, table_name, safe_count_proc, config)
  @model_class = model_class
  @connection = connection
  @table_name = table_name
  @safe_count = safe_count_proc
  @config = config
end

Class Method Details

.calculate(model_class, connection, table_name, safe_count_proc, config) ⇒ Object 



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# File 'lib/rails_console_pro/services/column_stats_calculator.rb', line 7

def self.calculate(model_class, connection, table_name, safe_count_proc, config)
  new(model_class, connection, table_name, safe_count_proc, config).calculate
end

Instance Method Details

#calculate ⇒ Object 



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# File 'lib/rails_console_pro/services/column_stats_calculator.rb', line 19

def calculate
  # Skip for large tables (already checked in execute_stats, but defensive)
  return {} if ModelValidator.large_table?(@model_class)
  
  column_names = ModelValidator.safe_column_names(@model_class)
  return {} unless column_names.any?

  column_stats = {}
  total_count = @safe_count.call
  
  # Skip distinct count for very large tables (performance)
  skip_distinct_threshold = @config.stats_skip_distinct_threshold
  skip_distinct = total_count >= skip_distinct_threshold

  column_names.each do |column_name|
    stats = {}
    
    # Count nulls (safe with error handling)
    begin
      null_count = @model_class.where("#{@connection.quote_column_name(column_name)} IS NULL").count
      stats[:null_count] = null_count if null_count > 0
    rescue => e
      # Skip if column doesn't support null checks or query fails
    end

    # Count distinct values (only for smaller tables)
    unless skip_distinct
      begin
        distinct_count = @model_class.distinct.count(column_name)
        stats[:distinct_count] = distinct_count if distinct_count > 0
      rescue => e
        # Skip if calculation fails
      end
    end

    column_stats[column_name] = stats if stats.any?
  end

  column_stats
rescue => e
  {} # Return empty hash on any error
end