Class: RecordCache::Index

Inherits:
Object
  • Object
show all
Includes:
Deferrable
Defined in:
lib/record_cache/index.rb

Constant Summary collapse

NULL = 
'NULL'
@@disable_db = 
false

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(opts) ⇒ Index

Returns a new instance of Index.



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# File 'lib/record_cache/index.rb', line 11

def initialize(opts)
  raise ':by => index_field required for cache'       if opts[:by].nil?
  raise 'explicit name or prefix required with scope' if opts[:scope] and opts[:name].nil? and opts[:prefix].nil?

  @auto_name     = opts[:name].nil?
  @write_ahead   = opts[:write_ahead]
  @cache         = opts[:cache].kind_of?(Symbol) ? Memcache.pool[opts[:cache]] : (opts[:cache] || CACHE)
  @expiry        = opts[:expiry]
  @model_class   = opts[:class]
  @set_class     = opts[:set_class] || "#{@model_class}Set"
  @index_field   = opts[:by].to_s
  @fields        = opts[:fields].collect {|field| field.to_s}
  @prefix        = opts[:prefix]
  @name          = ( opts[:name] || [prefix, 'by', index_field].compact.join('_') ).to_s
  @order_by      = opts[:order_by]
  @limit         = opts[:limit]
  @disallow_null = opts[:null] == false
  @scope_query   = opts[:scope] || {}
end

Instance Attribute Details

#expiry ⇒ Object (readonly)

Returns the value of attribute expiry.



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# File 'lib/record_cache/index.rb', line 7

def expiry
  @expiry
end

#fields ⇒ Object (readonly)

Returns the value of attribute fields.



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# File 'lib/record_cache/index.rb', line 7

def fields
  @fields
end

#index_field ⇒ Object (readonly)

Returns the value of attribute index_field.



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# File 'lib/record_cache/index.rb', line 7

def index_field
  @index_field
end

#limit ⇒ Object (readonly)

Returns the value of attribute limit.



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# File 'lib/record_cache/index.rb', line 7

def limit
  @limit
end

#model_class ⇒ Object (readonly)

Returns the value of attribute model_class.



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# File 'lib/record_cache/index.rb', line 7

def model_class
  @model_class
end

#name ⇒ Object (readonly)

Returns the value of attribute name.



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# File 'lib/record_cache/index.rb', line 7

def name
  @name
end

#order_by ⇒ Object (readonly)

Returns the value of attribute order_by.



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# File 'lib/record_cache/index.rb', line 7

def order_by
  @order_by
end

#prefix ⇒ Object (readonly)

Returns the value of attribute prefix.



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# File 'lib/record_cache/index.rb', line 7

def prefix
  @prefix
end

Class Method Details

.disable_db ⇒ Object 



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# File 'lib/record_cache/index.rb', line 224

def self.disable_db
  @@disable_db = true
end

.enable_db ⇒ Object 



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# File 'lib/record_cache/index.rb', line 228

def self.enable_db
  @@disable_db = false
end

Instance Method Details

#auto_name? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/record_cache/index.rb', line 43

def auto_name?;     @auto_name;     end

#cache ⇒ Object 



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# File 'lib/record_cache/index.rb', line 35

def cache
  if RecordCache.config[:thread_safe]
    Thread.current[:record_cache] ||= @cache.clone
  else
    @cache
  end
end

#cached_set(id) ⇒ Object 



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# File 'lib/record_cache/index.rb', line 251

def cached_set(id)
  # Used for debugging. Gives you the RecordCache::Set that is currently in the cache.
  id = stringify([id]).first
  cache.in_namespace(namespace) do
    cache.get(id)
  end
end

#disallow_null? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/record_cache/index.rb', line 45

def disallow_null?; @disallow_null; end

#field_lookup(keys, model_class, field, flag = nil) ⇒ Object 



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# File 'lib/record_cache/index.rb', line 141

def field_lookup(keys, model_class, field, flag = nil)
  keys = [*keys]
  keys = stringify(keys)
  field = field.to_s if field
  records_by_key = get_records(keys)

  field_by_index = {}
  all_fields = []
  keys.each do |key|
    records = records_by_key[key]
    fields = field ? records.fields(field, model_class) : records.all_fields(model_class, :except => index_field)
    if flag == :all
      all_fields.concat(fields)
    elsif flag == :first
      next if fields.empty?
      field_by_index[index_column.type_cast(key)] = fields.first
    else
      field_by_index[index_column.type_cast(key)] = fields
    end
  end
  if flag == :all
    all_fields.uniq
  else
    field_by_index
  end
end

#fields_hash ⇒ Object 



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# File 'lib/record_cache/index.rb', line 64

def fields_hash
  if @fields_hash.nil?
    fields = full_record? ? model_class.column_names : self.fields
    md5 = Digest::MD5::new
    md5 << fields.sort.join(',')
    @fields_hash = md5.hexdigest
  end
  @fields_hash
end

#find_by_field(keys, model_class, type) ⇒ Object 



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# File 'lib/record_cache/index.rb', line 108

def find_by_field(keys, model_class, type)
  keys = [keys] if not keys.kind_of?(Array)
  keys = stringify(keys)
  records_by_key = get_records(keys)

  case type
  when :first
    keys.each do |key|
      model = records_by_key[key].instantiate_first(model_class, full_record?)
      return model if model
    end
    return nil
  when :all
    models = []
    keys.each do |key|
      models.concat( records_by_key[key].instantiate(model_class, full_record?) )
    end
    models
  when :set, :ids
    ids = []
    keys.each do |key|
      ids.concat( records_by_key[key].ids(model_class) )
    end
    type == :set ? set_class.new(ids) : ids
  when :raw
    raw_records = []
    keys.each do |key|
      raw_records.concat( records_by_key[key].records(model_class) )
    end
    raw_records
  end
end

#find_by_ids(ids, model_class) ⇒ Object 



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# File 'lib/record_cache/index.rb', line 74

def find_by_ids(ids, model_class)
  expects_array = ids.first.kind_of?(Array)
  ids = ids.flatten.compact.collect {|id| id.to_i}
  ids = stringify(ids)

  if ids.empty?
    return [] if expects_array
    raise ActiveRecord::RecordNotFound, "Couldn't find #{model_class} without an ID"
  end

  records_by_id = get_records(ids)

  models = ids.collect do |id|
    records = records_by_id[id]
    model   = records.instantiate_first(model_class, full_record?) if records

    # try to get record from db again before we throw an exception
    if model.nil?
      invalidate(id)
      records = get_records([id])[id]
      model   = records.instantiate_first(model_class, full_record?) if records
    end

    raise ActiveRecord::RecordNotFound, "Couldn't find #{model_class} with ID #{id}" unless model
    model
  end

  if models.size == 1 and not expects_array
    models.first
  else
    models
  end
end

#find_method_name(type) ⇒ Object 



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# File 'lib/record_cache/index.rb', line 232

def find_method_name(type)
  if name =~ /(^|_)by_/
    if type == :first
      "find_#{name}"
    else
      "find_#{type}_#{name}"
    end
  else
    case type
    when :all
      "find_#{name}"
    when :first
      "find_#{type}_#{name.singularize}"
    else
      "find_#{name.singularize}_#{type}"
    end
  end
end

#full_record? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/record_cache/index.rb', line 47

def full_record?
  fields.empty?
end

#includes_id? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/record_cache/index.rb', line 51

def includes_id?
  full_record? or fields.include?('id')
end

#invalidate(*keys) ⇒ Object 



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# File 'lib/record_cache/index.rb', line 168

def invalidate(*keys)
  return if model_class.record_cache_config[:disable_write]

  keys = stringify(keys)
  cache.in_namespace(namespace) do
    keys.each do |key|
      cache.delete(key)
    end
  end
end

#invalidate_from_conditions(conditions) ⇒ Object 



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# File 'lib/record_cache/index.rb', line 186

def invalidate_from_conditions(conditions)
  invalidate_from_conditions_lambda(conditions).call
end

#invalidate_from_conditions_lambda(conditions) ⇒ Object 



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# File 'lib/record_cache/index.rb', line 179

def invalidate_from_conditions_lambda(conditions)
  sql = "SELECT #{index_field} FROM #{table_name} "
  model_class.send(:add_conditions!, sql, conditions, model_class.send(:scope, :find))
  ids = db.select_values(sql)
  lambda { invalidate(*ids) }
end

#invalidate_model(model) ⇒ Object 



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# File 'lib/record_cache/index.rb', line 190

def invalidate_model(model)
  attribute     = model.read_attribute(index_field)
  attribute_was = model.attr_was(index_field)
  if scope.match_previous?(model)
    if write_ahead?
      remove_from_cache(model)
    else
      now_and_later do
        invalidate(attribute_was)
      end
    end
  end

  if scope.match_current?(model)
    if write_ahead?
      add_to_cache(model)
    elsif not (scope.match_previous?(model) and attribute_was == attribute)
      now_and_later do
        invalidate(attribute)
      end
    end
  end
end

#namespace ⇒ Object 



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# File 'lib/record_cache/index.rb', line 59

def namespace
  record_cache_class = model_class.record_cache_class
  "#{record_cache_class.name}_#{record_cache_class.version}_#{RecordCache.version}_#{fields_hash}:#{name}"
end

#scope ⇒ Object 



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# File 'lib/record_cache/index.rb', line 219

def scope
  @scope ||= Scope.new(model_class, scope_query)
end

#scope_query ⇒ Object 



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# File 'lib/record_cache/index.rb', line 214

def scope_query
  @scope_query[:type] ||= model_class.to_s if sub_class?
  @scope_query
end

#set_class ⇒ Object 



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# File 'lib/record_cache/index.rb', line 55

def set_class
  @set_class.constantize
end

#to_s ⇒ Object 



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# File 'lib/record_cache/index.rb', line 31

def to_s
  "<RecordCache::Index #{@model_class} by #{@index_field} (#{@name})>"
end

#write_ahead? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/record_cache/index.rb', line 44

def write_ahead?;   @write_ahead;   end