Class: ActionCost::SqlParser

Inherits:
Object
  • Object
show all
Defined in:
lib/action_cost/sql_parser.rb

Constant Summary collapse

VALID_OPERATIONS = 
%w{ select insert update delete }

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(sql) ⇒ SqlParser

Returns a new instance of SqlParser.



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# File 'lib/action_cost/sql_parser.rb', line 7

def initialize(sql)
  @invalid  = false
  @sql      = sql
  @join_tables = []
end

Instance Attribute Details

#invalid ⇒ Object (readonly)

Returns the value of attribute invalid.



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# File 'lib/action_cost/sql_parser.rb', line 3

def invalid
  @invalid
end

#join_tables ⇒ Object (readonly)

Returns the value of attribute join_tables.



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# File 'lib/action_cost/sql_parser.rb', line 3

def join_tables
  @join_tables
end

#operation ⇒ Object (readonly)

Returns the value of attribute operation.



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# File 'lib/action_cost/sql_parser.rb', line 3

def operation
  @operation
end

#table_name ⇒ Object (readonly)

Returns the value of attribute table_name.



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# File 'lib/action_cost/sql_parser.rb', line 3

def table_name
  @table_name
end

Instance Method Details

#log ⇒ Object 



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# File 'lib/action_cost/sql_parser.rb', line 38

def log
  if @invalid
    Rails.logger.debug "action_cost: non parsable query"
  else
    Rails.logger.debug "action_cost: operation=#{@operation} table_name=#{@table_name} " +
                       "join_tables=#{@join_tables.inspect}"
  end
end

#parse ⇒ Object 



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# File 'lib/action_cost/sql_parser.rb', line 13

def parse
  if @sql =~ /^\s*(\w+)/
    op = $1.downcase
    unless VALID_OPERATIONS.include?(op)
      Rails.logger.error "action_cost: unknown operation [#{op}]"
      @invalid = true
      return false
    end
    @operation = op
  else
    Rails.logger.error "action_cost: could not parse [#{@sql}]"
    @invalid = true
    return false
  end

  case @operation
  when 'select' then parse_select
  when 'insert' then parse_insert
  when 'update' then parse_update
  when 'delete' then parse_delete
  end

  return !@invalid
end