simple_record.rb

# Usage:
# require 'simple_record'
#
# class MyModel < SimpleRecord::Base
#
#   has_attributes :name, :age
#   are_ints :age
#
# end
#
# AWS_ACCESS_KEY_ID='XXXXX'
# AWS_SECRET_ACCESS_KEY='YYYYY'
# SimpleRecord.establish_connection(AWS_ACCESS_KEY_ID,AWS_SECRET_ACCESS_KEY)
#
## Save an object
# mm = MyModel.new
# mm.name = "Travis"
# mm.age = 32
# mm.save
# id = mm.id
# # Get the object back
# mm2 = MyModel.select(id)
# puts 'got=' + mm2.name + ' and he/she is ' + mm.age.to_s + ' years old'
#
# Forked off old ActiveRecord2sdb library.

require 'aws'
require 'base64'
require 'active_support'
require 'active_support/core_ext'
require File.expand_path(File.dirname(__FILE__) + "/simple_record/attributes")
require File.expand_path(File.dirname(__FILE__) + "/simple_record/active_sdb")
require File.expand_path(File.dirname(__FILE__) + "/simple_record/callbacks")
require File.expand_path(File.dirname(__FILE__) + "/simple_record/encryptor")
require File.expand_path(File.dirname(__FILE__) + "/simple_record/exceptions")
require File.expand_path(File.dirname(__FILE__) + "/simple_record/errors")
require File.expand_path(File.dirname(__FILE__) + "/simple_record/json")
require File.expand_path(File.dirname(__FILE__) + "/simple_record/logging")
require File.expand_path(File.dirname(__FILE__) + "/simple_record/password")
require File.expand_path(File.dirname(__FILE__) + "/simple_record/rails2")
require File.expand_path(File.dirname(__FILE__) + "/simple_record/results_array")
require File.expand_path(File.dirname(__FILE__) + "/simple_record/stats")
require File.expand_path(File.dirname(__FILE__) + "/simple_record/translations")
require_relative 'simple_record/sharding'


module SimpleRecord

  @@options       = {}
  @@stats         = SimpleRecord::Stats.new
  @@logging       = false
  @@s3            = nil
  @@auto_close_s3 = false
  @@logger        = Logger.new(STDOUT)
  @@logger.level  = Logger::INFO

  class << self;
    attr_accessor :aws_access_key, :aws_secret_key

    # Deprecated
    def enable_logging
      @@logging      = true
      @@logger.level = Logger::DEBUG
    end

    # Deprecated
    def disable_logging
      @@logging = false
    end

    # Deprecated
    def logging?
      @@logging
    end

    def logger
      @@logger
    end

    # This can be used to log queries and what not to a file.
    # Params:
    # :select=>{:filename=>"file_to_write_to", :format=>"csv"}
    def log_usage(types={})
      @usage_logging_options = {} unless @usage_logging_options
      return if types.nil?
      types.each_pair do |type, options|
        options[:lines_between_flushes] = 100 unless options[:lines_between_flushes]
        @usage_logging_options[type] = options
      end
      #puts 'SimpleRecord.usage_logging_options=' + SimpleRecord.usage_logging_options.inspect
    end

    def close_usage_log(type)
      return unless @usage_logging_options[type]
      @usage_logging_options[type][:file].close if @usage_logging_options[type][:file]
    end

    def usage_logging_options
      @usage_logging_options
    end

    def stats
      @@stats
    end


    # Create a new handle to an Sdb account. All handles share the same per process or per thread
    # HTTP connection to Amazon Sdb. Each handle is for a specific account.
    # The +params+ are passed through as-is to Aws::SdbInterface.new
    # Params:
    #    { :server       => 'sdb.amazonaws.com'  # Amazon service host: 'sdb.amazonaws.com'(default)
    #      :port         => 443                  # Amazon service port: 80(default) or 443
    #      :protocol     => 'https'              # Amazon service protocol: 'http'(default) or 'https'
    #      :signature_version => '0'             # The signature version : '0' or '1'(default)
    #      :connection_mode  => :default         # options are
    #                                                  :default (will use best known safe (as in won't need explicit close) option, may change in the future)
    #                                                  :per_request (opens and closes a connection on every request to SDB)
    #                                                  :single (one thread across entire app)
    #                                                  :per_thread (one connection per thread)
    #                                                  :pool (uses a connection pool with a maximum number of connections - NOT IMPLEMENTED YET)
    #      :logger       => Logger Object        # Logger instance: logs to STDOUT if omitted
    def establish_connection(aws_access_key=nil, aws_secret_key=nil, options={})
      @aws_access_key = aws_access_key
      @aws_secret_key = aws_secret_key
      @@options.merge!(options)
      #puts 'SimpleRecord.establish_connection with options: ' + @@options.inspect
      SimpleRecord::ActiveSdb.establish_connection(aws_access_key, aws_secret_key, @@options)
      if options[:connection_mode] == :per_thread
        @@auto_close_s3 = true
        # todo: should we init this only when needed?
      end
      s3_ops = {:connection_mode=>options[:connection_mode] || :default}
      @@s3   = Aws::S3.new(SimpleRecord.aws_access_key, SimpleRecord.aws_secret_key, s3_ops)

      if options[:created_col]
        SimpleRecord::Base.has_dates options[:created_col]
      end
      if options[:updated_col]
        SimpleRecord::Base.has_dates options[:updated_col]
      end


    end

    # Call this to close the connection to SimpleDB.
    # If you're using this in Rails with per_thread connection mode, you should do this in
    # an after_filter for each request.
    def close_connection()
      SimpleRecord::ActiveSdb.close_connection
      @@s3.close_connection if @@auto_close_s3
    end

    # If you'd like to specify the s3 connection to use for LOBs, you can pass it in here.
    # We recommend that this connection matches the type of connection you're using for SimpleDB,
    # at least if you're using per_thread connection mode.
    def s3=(s3)
      @@s3 = s3
    end

    def s3
      @@s3
    end

    def options
      @@options
    end

  end

  class Base < SimpleRecord::ActiveSdb::Base


#        puts 'Is ActiveModel defined? ' + defined?(ActiveModel).inspect
    if defined?(ActiveModel)
      extend ActiveModel::Naming
      include ActiveModel::Conversion
      include ActiveModel::Validations
    else
      attr_accessor :errors
      include SimpleRecord::Rails2
    end

    include SimpleRecord::Translations
#        include SimpleRecord::Attributes
    extend SimpleRecord::Attributes::ClassMethods
    include SimpleRecord::Attributes
    extend SimpleRecord::Sharding::ClassMethods
    include SimpleRecord::Sharding
    include SimpleRecord::Callbacks
    include SimpleRecord::Json
    include SimpleRecord::Logging
    extend SimpleRecord::Logging::ClassMethods

    def self.extended(base)

    end

    def initialize(attrs={})
      # todo: Need to deal with objects passed in. iterate through belongs_to perhaps and if in attrs, set the objects id rather than the object itself

      initialize_base(attrs)

      # Convert attributes to sdb values
      attrs.each_pair do |name, value|
        set(name, value, true)
      end
    end

    def initialize_base(attrs={})

      #we have to handle the virtuals.
      Attributes.handle_virtuals(attrs)

      clear_errors

      @dirty         = {}

      @attributes    = {} # sdb values
      @attributes_rb = {} # ruby values
      @lobs          = {}
      @new_record    = true

    end

    def initialize_from_db(attrs={})
      initialize_base(attrs)
      attrs.each_pair do |k, v|
        @attributes[k.to_s] = v
      end
    end


    def self.inherited(base)
#      puts 'SimpleRecord::Base is inherited by ' + base.inspect
      Callbacks.setup_callbacks(base)

#            base.has_strings :id
      base.has_dates :created, :updated
      base.before_create :set_created, :set_updated
      base.before_update :set_updated

    end


    def persisted?
      !@new_record && !destroyed?
    end

    def destroyed?
      @deleted
    end

    def defined_attributes_local
      # todo: store this somewhere so it doesn't keep going through this
      ret = self.class.defined_attributes
      ret.merge!(self.class.superclass.defined_attributes) if self.class.superclass.respond_to?(:defined_attributes)
    end


    class << self;
      attr_accessor :domain_prefix
    end

    #@domain_name_for_class = nil

    @@cache_store = nil
    # Set the cache to use
    def self.cache_store=(cache)
      @@cache_store = cache
    end

    def self.cache_store
      return @@cache_store
    end

    # If you want a domain prefix for all your models, set it here.
    def self.set_domain_prefix(prefix)
      #puts 'set_domain_prefix=' + prefix
      self.domain_prefix = prefix
    end

    # Same as set_table_name
    def self.set_table_name(table_name)
      set_domain_name table_name
    end

    # Sets the domain name for this class
    def self.set_domain_name(table_name)
      super
    end


    def domain
      self.class.domain
    end

    def self.domain
      unless @domain
        # This strips off the module if there is one.
        n2 = name.split('::').last || name
#                puts 'n2=' + n2
        if n2.respond_to?(:tableize)
          @domain = n2.tableize
        else
          @domain = n2.downcase
        end
        set_domain_name @domain
      end
      domain_name_for_class = (SimpleRecord::Base.domain_prefix || "") + @domain.to_s
      domain_name_for_class
    end

    def has_id_on_end(name_s)
      name_s = name_s.to_s
      name_s.length > 3 && name_s[-3..-1] == "_id"
    end

    def get_att_meta(name)
      name_s   = name.to_s
      att_meta = defined_attributes_local[name.to_sym]
      if att_meta.nil? && has_id_on_end(name_s)
        att_meta = defined_attributes_local[name_s[0..-4].to_sym]
      end
      return att_meta
    end

    def sdb_att_name(name)
      att_meta = get_att_meta(name)
      if att_meta.type == :belongs_to && !has_id_on_end(name.to_s)
        return "#{name}_id"
      end
      name.to_s
    end

    def strip_array(arg)
      if arg.is_a? Array
        if arg.length==1
          ret = arg[0]
        else
          ret = arg
        end
      else
        ret = arg
      end
      return ret
    end


    def make_dirty(arg, value)
      sdb_att_name = sdb_att_name(arg)
      arg          = arg.to_s

#            puts "Marking #{arg} dirty with #{value}" if SimpleRecord.logging?
      if @dirty.include?(sdb_att_name)
        old = @dirty[sdb_att_name]
#                puts "#{sdb_att_name} was already dirty #{old}"
        @dirty.delete(sdb_att_name) if value == old
      else
        old = get_attribute(arg)
#                puts "dirtifying #{sdb_att_name} old=#{old.inspect} to new=#{value.inspect}" if SimpleRecord.logging?
        @dirty[sdb_att_name] = old if value != old
      end
    end

    def clear_errors
#      @errors=SimpleRecord_errors.new
      if not (defined?(ActiveModel))
        @errors=SimpleRecord_errors.new
      else
        @errors = ActiveModel::Errors.new(self)
      end
    end

    def []=(attribute, values)
      make_dirty(attribute, values)
      super
    end

    def [](attribute)
      super
    end


    def set_created
      set(SimpleRecord.options[:created_col] || :created, Time.now)
    end

    def set_updated
      set(SimpleRecord.options[:updated_col] || :updated, Time.now)
    end

    # an aliased method since many people use created_at/updated_at naming convention
    def created_at
      self.created
    end

    # an aliased method since many people use created_at/updated_at naming convention
    def updated_at
      self.updated
    end

    def read_attribute_for_validation(key)
      @attributes[key.to_s]
    end

    def cache_store
      @@cache_store
    end

    def domain_ok(ex, options={})
      if (ex.message().index("NoSuchDomain") != nil)
        dom = options[:domain] || domain
        self.class.create_domain(dom)
        return true
      end
      return false
    end


    def new_record?
      # todo: new_record in activesdb should align with how we're defining a new record here, ie: if id is nil
      super
    end


    @create_domain_called = false

    # Options:
    #   - :except => Array of attributes to NOT save
    #   - :dirty => true - Will only store attributes that were modified. To make it save regardless and have it update the :updated value, include this and set it to false.
    #   - :domain => Explicitly define domain to use.
    #
    def save(options={})
#            puts 'SAVING: ' + self.inspect if SimpleRecord.logging?
      # todo: Clean out undefined values in @attributes (in case someone set the attributes hash with values that they hadn't defined)
      clear_errors
      # todo: decide whether this should go before pre_save or after pre_save? pre_save dirties "updated" and perhaps other items due to callbacks
      if options[:dirty]
#                puts '@dirtyA=' + @dirty.inspect
        return true if @dirty.size == 0 # Nothing to save so skip it
      end
      is_create = self[:id].nil?
      ok        = pre_save(options) # Validates and sets ID
      if ok
        begin
          dirty = @dirty
#                    puts 'dirty before=' + @dirty.inspect
          if options[:dirty]
#                        puts '@dirty=' + @dirty.inspect
            return true if @dirty.size == 0 # This should probably never happen because after pre_save, created/updated dates are changed
            options[:dirty_atts] = @dirty
          end
          to_delete                = get_atts_to_delete
          SimpleRecord.stats.saves += 1

          if self.class.is_sharded?
            options[:domain] = sharded_domain
          end

          if super(options)
            self.class.cache_results(self)
            delete_niled(to_delete)
            save_lobs(dirty)
            after_save_cleanup
            if (is_create ? run_after_create : run_after_update) && run_after_save
#                            puts 'all good?'
              return true
            else
              return false
            end
          else
            return false
          end
        rescue Aws::AwsError => ex
          # puts "RESCUED in save: " + $!
          # Domain is created in aws lib now using :create_domain=>true
#                    if (domain_ok(ex, options))
#                        if !@create_domain_called
#                            @create_domain_called = true
#                            save(options)
#                        else
#                            raise $!
#                        end
#                    else
#                        raise $!
#                    end
          raise ex
        end
      else
        #@debug = "not saved"
        return false
      end
    end

    def save_lobs(dirty=nil)
#            puts 'dirty.inspect=' + dirty.inspect
      dirty = @dirty if dirty.nil?
      all_clobs   = {}
      dirty_clobs = {}
      defined_attributes_local.each_pair do |k, v|
        # collect up the clobs in case it's a single put
        if v.type == :clob
          val          = @lobs[k]
          all_clobs[k] = val
          if dirty.include?(k.to_s)
            dirty_clobs[k] = val
          else
#                        puts 'NOT DIRTY'
          end

        end
      end
      if dirty_clobs.size > 0
        if self.class.get_sr_config[:single_clob]
          # all clobs in one chunk
          # using json for now, could change later
          val = all_clobs.to_json
          puts 'val=' + val.inspect
          put_lob(single_clob_id, val, :s3_bucket=>:new)
        else
          dirty_clobs.each_pair do |k, val|
            put_lob(s3_lob_id(k), val)
          end
        end
      end
    end

    def delete_lobs
      defined_attributes_local.each_pair do |k, v|
        if v.type == :clob
          if self.class.get_sr_config[:single_clob]
            s3_bucket(false, :s3_bucket=>:new).delete_key(single_clob_id)
            SimpleRecord.stats.s3_deletes += 1
            return
          else
            s3_bucket.delete_key(s3_lob_id(k))
            SimpleRecord.stats.s3_deletes += 1
          end
        end
      end
    end


    def put_lob(k, val, options={})
      begin
        s3_bucket(false, options).put(k, val)
      rescue Aws::AwsError => ex
        if ex.include? /NoSuchBucket/
          s3_bucket(true, options).put(k, val)
        else
          raise ex
        end
      end
      SimpleRecord.stats.s3_puts += 1
    end


    def is_dirty?(name)
      # todo: should change all the dirty stuff to symbols?
#            puts '@dirty=' + @dirty.inspect
#            puts 'name=' +name.to_s
      @dirty.include? name.to_s
    end

    def s3

      return SimpleRecord.s3 if SimpleRecord.s3
      # todo: should optimize this somehow, like use the same connection_mode as used in SR
      # or keep open while looping in ResultsArray.
      Aws::S3.new(SimpleRecord.aws_access_key, SimpleRecord.aws_secret_key)
    end

    # options:
    #   :s3_bucket => :old/:new/"#{any_bucket_name}". :new if want to use new bucket. Defaults to :old for backwards compatability.
    def s3_bucket(create=false, options={})
      s3.bucket(s3_bucket_name(options[:s3_bucket]), create)
    end

    def s3_bucket_name(s3_bucket_option=:old)
      if s3_bucket_option == :new || SimpleRecord.options[:s3_bucket] == :new
        # this is the bucket that will be used going forward for anything related to s3
        ret = "simple_record_#{SimpleRecord.aws_access_key}"
      elsif !SimpleRecord.options[:s3_bucket].nil? && SimpleRecord.options[:s3_bucket] != :old
        ret = SimpleRecord.options[:s3_bucket]
      else
        ret = SimpleRecord.aws_access_key + "_lobs"
      end
      ret
    end

    def s3_lob_id(name)
      # if s3_bucket is not nil and not :old, then we use the new key.
      if !SimpleRecord.options[:s3_bucket].nil? && SimpleRecord.options[:s3_bucket] != :old
        "lobs/#{self.id}_#{name}"
      else
        self.id + "_" + name.to_s
      end
    end

    def single_clob_id
      "lobs/#{self.id}_single_clob"
    end

    def save!(options={})
      save(options) || raise(RecordNotSaved)
    end

    def self.create(attributes={})
#            puts "About to create in domain #{domain}"
      super
    end

    def self.create!(attributes={})
      item = self.new(attributes)
      item.save!
      item
    end

    def save_with_validation!(options={})
      if valid?
        save
      else
        raise RecordInvalid.new(self)
      end
    end


    def self.get_encryption_key()
      key = SimpleRecord.options[:encryption_key]
#            if key.nil?
#                puts 'WARNING: Encrypting attributes with your AWS Access Key. You should use your own :encryption_key so it doesn\'t change'
#                key = connection.aws_access_key_id # default to aws access key. NOT recommended in case you start using a new key
#            end
      return key
    end

    def validate
      true
    end

    def validate_on_create
      true
    end

    def validate_on_update
      true
    end


    def pre_save(options)

      is_create = self[:id].nil?
      ok        = run_before_validation && (is_create ? run_before_validation_on_create : run_before_validation_on_update)
      return false unless ok

#      validate()
#      is_create ? validate_on_create : validate_on_update
      if !valid?
        return false
      end
#
##      puts 'AFTER VALIDATIONS, ERRORS=' + errors.inspect
#      if (!errors.nil? && errors.size > 0)
##        puts 'THERE ARE ERRORS, returning false'
#        return false
#      end

      ok = run_after_validation && (is_create ? run_after_validation_on_create : run_after_validation_on_update)
      return false unless ok

      ok = respond_to?('before_save') ? before_save : true
      if ok
        if is_create && respond_to?('before_create')
          ok = before_create
        elsif !is_create && respond_to?('before_update')
          ok = before_update
        end
      end
      if ok
        ok = run_before_save && (is_create ? run_before_create : run_before_update)
      end
      if ok
        # Now translate all fields into SimpleDB friendly strings
#                convert_all_atts_to_sdb()
      end
      prepare_for_update
      ok
    end


    def get_atts_to_delete
      to_delete = []
      changes.each_pair do |key, v|
        if v[1].nil?
          to_delete << key
          @attributes.delete(key)
        end
      end
#            @attributes.each do |key, value|
##                puts 'key=' + key.inspect + ' value=' + value.inspect
#                if value.nil? || (value.is_a?(Array) && value.size == 0) || (value.is_a?(Array) && value.size == 1 && value[0] == nil)
#                    to_delete << key
#                    @attributes.delete(key)
#                end
#            end
      return to_delete
    end

    # Run pre_save on each object, then runs batch_put_attributes
    # Returns
    def self.batch_save(objects, options={})
      options[:create_domain] = true if options[:create_domain].nil?
      results = []
      to_save = []
      if objects && objects.size > 0
        objects.each do |o|
          ok = o.pre_save(options)
          raise "Pre save failed on object [" + o.inspect + "]" if !ok
          results << ok
          next if !ok # todo: this shouldn't be here should it?  raises above
          o.pre_save2
          to_save << Aws::SdbInterface::Item.new(o.id, o.attributes, true)
          if to_save.size == 25 # Max amount SDB will accept
            connection.batch_put_attributes(domain, to_save, options)
            to_save.clear
          end
        end
      end
      connection.batch_put_attributes(domain, to_save, options) if to_save.size > 0
      objects.each do |o|
        o.save_lobs(nil)
      end
      results
    end

    # Pass in an array of objects
    def self.batch_delete(objects, options={})
      if objects
        # 25 item limit, we should maybe handle this limit in here.
        connection.batch_delete_attributes @domain, objects.collect { |x| x.id }
      end
    end

    #
    # Usage: ClassName.delete id
    #
    def self.delete(id)
      connection.delete_attributes(domain, id)
      @deleted = true
    end

    # Pass in the same OPTIONS you'd pass into a find(:all, OPTIONS)
    def self.delete_all(options)
      # could make this quicker by just getting item_names and deleting attributes rather than creating objects
      obs = self.find(:all, options)
      i   = 0
      obs.each do |a|
        a.delete
        i+=1
      end
      return i
    end

    # Pass in the same OPTIONS you'd pass into a find(:all, OPTIONS)
    def self.destroy_all(options)
      obs = self.find(:all, options)
      i   = 0
      obs.each do |a|
        a.destroy
        i+=1
      end
      return i
    end

    def delete(options={})
      if self.class.is_sharded?
        options[:domain] = sharded_domain
      end
      super(options)

      # delete lobs now too
      delete_lobs
    end

    def destroy
      return run_before_destroy && delete && run_after_destroy
    end


    def delete_niled(to_delete)
#            puts 'to_delete=' + to_delete.inspect
      if to_delete.size > 0
#      puts 'Deleting attributes=' + to_delete.inspect
        SimpleRecord.stats.deletes += 1
        delete_attributes to_delete
        to_delete.each do |att|
          att_meta = get_att_meta(att)
          if att_meta.type == :clob
            s3_bucket.key(s3_lob_id(att)).delete
          end
        end
      end
    end

    def reload
      super()
    end


    def update_attributes(atts)
      set_attributes(atts)
      save
    end

    def update_attributes!(atts)
      set_attributes(atts)
      save!
    end


    def self.quote_regexp(a, re)
      a =~ re
      #was there a match?
      if $&
        before=$`
        middle=$&
        after =$'

        before =~ /'$/ #is there already a quote immediately before the match?
        unless $&
          return "#{before}'#{middle}'#{quote_regexp(after, re)}" #if not, put quotes around the match
        else
          return "#{before}#{middle}#{quote_regexp(after, re)}" #if so, assume it is quoted already and move on
        end
      else
        #no match, just return the string
        return a
      end
    end

    @@regex_no_id = /.*Couldn't find.*with ID.*/

    #
    # Usage:
    # Find by ID:
    #   MyModel.find(ID)
    #
    # Query example:
    #   MyModel.find(:all, :conditions=>["name = ?", name], :order=>"created desc", :limit=>10)
    #
    # Extra options:
    #   :per_token => the number of results to return per next_token, max is 2500.
    #   :consistent_read => true/false  --  as per http://developer.amazonwebservices.com/connect/entry.jspa?externalID=3572
    #   :retries => maximum number of times to retry this query on an error response.
    #   :shard => shard name or array of shard names to use on this query.
    def self.find(*params)
      #puts 'params=' + params.inspect

      q_type           = :all
      select_attributes=[]
      if params.size > 0
        q_type = params[0]
      end
      options = {}
      if params.size > 1
        options = params[1]
      end

      if !options[:shard_find] && is_sharded?
        # then break off and get results across all shards
        return find_sharded(*params)
      end

      # Pad and Offset number attributes
      params_dup = params.dup
      if params.size > 1
        options = params[1]
        #puts 'options=' + options.inspect
        #puts 'after collect=' + options.inspect
        convert_condition_params(options)
        per_token       = options[:per_token]
        consistent_read = options[:consistent_read]
        if per_token || consistent_read then
          op_dup                   = options.dup
          op_dup[:limit]           = per_token # simpledb uses Limit as a paging thing, not what is normal
          op_dup[:consistent_read] = consistent_read
          params_dup[1]            = op_dup
        end
      end
#            puts 'params2=' + params.inspect

      ret = q_type == :all ? [] : nil
      begin
        results=find_with_metadata(*params_dup)
#                puts "RESULT=" + results.inspect
        write_usage(:select, domain, q_type, options, results)
        #puts 'params3=' + params.inspect
        SimpleRecord.stats.selects += 1
        if q_type == :count
          ret = results[:count]
        elsif q_type == :first
          ret = results[:items].first
          # todo: we should store request_id and box_usage with the object maybe?
          cache_results(ret)
        elsif results[:single]
          ret = results[:single]
          cache_results(ret)
        else
          if results[:items] #.is_a?(Array)
            cache_results(results[:items])
            ret = SimpleRecord::ResultsArray.new(self, params, results, next_token)
          end
        end
      rescue Aws::AwsError, SimpleRecord::ActiveSdb::ActiveSdbError => ex
#                puts "RESCUED: " + ex.message
        if (ex.message().index("NoSuchDomain") != nil)
          # this is ok
        elsif (ex.message() =~ @@regex_no_id)
          ret = nil
        else
          raise ex
        end
      end
#            puts 'single2=' + ret.inspect
      return ret
    end

    def self.select(*params)
      return find(*params)
    end

    def self.all(*args)
      find(:all, *args)
    end

    def self.first(*args)
      find(:first, *args)
    end

    def self.count(*args)
      find(:count, *args)
    end

    # This gets less and less efficient the higher the page since SimpleDB has no way
    # to start at a specific row. So it will iterate from the first record and pull out the specific pages.
    def self.paginate(options={})
#            options = args.pop
#            puts 'paginate options=' + options.inspect if SimpleRecord.logging?
      page               = options[:page] || 1
      per_page           = options[:per_page] || 50
#            total    = options[:total_entries].to_i
      options[:page]     = page.to_i # makes sure it's to_i
      options[:per_page] = per_page.to_i
      options[:limit]    = options[:page] * options[:per_page]
#            puts 'paging options=' + options.inspect
      fr                 = find(:all, options)
      return fr

    end


    def self.convert_condition_params(options)
      return if options.nil?
      conditions = options[:conditions]
      if !conditions.nil? && conditions.size > 1
        # all after first are values
        conditions.collect! { |x|
          Translations.pad_and_offset(x)
        }
      end

    end

    def self.cache_results(results)
      if !cache_store.nil? && !results.nil?
        if results.is_a?(Array)
          # todo: cache each result
          results.each do |item|
            class_name = item.class.name
            id         = item.id
            cache_key  = self.cache_key(class_name, id)
            #puts 'caching result at ' + cache_key + ': ' + results.inspect
            cache_store.write(cache_key, item, :expires_in =>30)
          end
        else
          class_name = results.class.name
          id         = results.id
          cache_key  = self.cache_key(class_name, id)
          #puts 'caching result at ' + cache_key + ': ' + results.inspect
          cache_store.write(cache_key, results, :expires_in =>30)
        end
      end
    end

    def self.cache_key(class_name, id)
      return class_name + "/" + id.to_s
    end

    @@debug=""

    def self.debug
      @@debug
    end

    def self.sanitize_sql(*params)
      return ActiveRecord::Base.sanitize_sql(*params)
    end

    def self.table_name
      return domain
    end

    def changed
      return @dirty.keys
    end

    def changed?
      return @dirty.size > 0
    end

    def changes
      ret = {}
      #puts 'in CHANGES=' + @dirty.inspect
      @dirty.each_pair { |key, value| ret[key] = [value, get_attribute(key)] }
      return ret
    end

    def after_save_cleanup
      @dirty = {}
    end

    def hash
      # same as ActiveRecord
      id.hash
    end


  end


  class Activerecordtosdb_subrecord_array
    def initialize(subname, referencename, referencevalue)
      @subname       =subname.classify
      @referencename =referencename.tableize.singularize + "_id"
      @referencevalue=referencevalue
    end

    # Performance optimization if you know the array should be empty

    def init_empty
      @records = []
    end

    def load
      if @records.nil?
        @records = find_all
      end
      return @records
    end

    def [](key)
      return load[key]
    end

    def first
      load[0]
    end

    def <<(ob)
      return load << ob
    end

    def count
      return load.count
    end

    def size
      return count
    end

    def each(*params, &block)
      return load.each(*params) { |record| block.call(record) }
    end

    def find_all(*params)
      find(:all, *params)
    end

    def empty?
      return load.empty?
    end

    def build(*params)
      params[0][@referencename]=@referencevalue
      eval(@subname).new(*params)
    end

    def create(*params)
      params[0][@referencename]=@referencevalue
      record                   = eval(@subname).new(*params)
      record.save
    end

    def find(*params)
      query=[:first, {}]
      #{:conditions=>"id=>1"}
      if params[0]
        if params[0]==:all
          query[0]=:all
        end
      end

      if params[1]
        query[1]=params[1]
        if query[1][:conditions]
          query[1][:conditions]=SimpleRecord::Base.sanitize_sql(query[1][:conditions])+" AND "+ SimpleRecord::Base.sanitize_sql(["#{@referencename} = ?", @referencevalue])
          #query[1][:conditions]=Activerecordtosdb.sanitize_sql(query[1][:conditions])+" AND id='#{@id}'"
        else
          query[1][:conditions]=["#{@referencename} = ?", @referencevalue]
          #query[1][:conditions]="id='#{@id}'"
        end
      else
        query[1][:conditions]=["#{@referencename} = ?", @referencevalue]
        #query[1][:conditions]="id='#{@id}'"
      end

      return eval(@subname).find(*query)
    end

  end

  # This is simply a place holder so we don't keep doing gets to s3 or simpledb if already checked.
  class RemoteNil

  end


end