Module: Sequel::Plugins::StaticCache::ClassMethods

Defined in:
lib/sequel/plugins/static_cache.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#cacheObject (readonly)

A frozen ruby hash holding all of the model's frozen instances, keyed by frozen primary key.


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# File 'lib/sequel/plugins/static_cache.rb', line 73

def cache
  @cache
end

Instance Method Details

#all(&block) ⇒ Object

An array of all of the model's instances, without issuing a database query. If a block is given, yields each instance to the block.


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# File 'lib/sequel/plugins/static_cache.rb', line 77

def all(&block)
  array = @static_cache_frozen ? @all.dup : to_a
  array.each(&block) if block
  array
end

#as_hash(key_column = nil, value_column = nil, opts = OPTS) ⇒ Object

Use the cache instead of a query to get the results.


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# File 'lib/sequel/plugins/static_cache.rb', line 144

def as_hash(key_column = nil, value_column = nil, opts = OPTS)
  if key_column.nil? && value_column.nil?
    if @static_cache_frozen && !opts[:hash]
      return Hash[cache]
    else
      key_column = primary_key
    end
  end

  h = opts[:hash] || {}
  if value_column
    if value_column.is_a?(Array)
      if key_column.is_a?(Array)
        @all.each{|r| h[r.values.values_at(*key_column)] = r.values.values_at(*value_column)}
      else
        @all.each{|r| h[r[key_column]] = r.values.values_at(*value_column)}
      end
    else
      if key_column.is_a?(Array)
        @all.each{|r| h[r.values.values_at(*key_column)] = r[value_column]}
      else
        @all.each{|r| h[r[key_column]] = r[value_column]}
      end
    end
  elsif key_column.is_a?(Array)
    @all.each{|r| h[r.values.values_at(*key_column)] = static_cache_object(r)}
  else
    @all.each{|r| h[r[key_column]] = static_cache_object(r)}
  end
  h
end

#cache_get_pk(pk) ⇒ Object

Return the frozen object with the given pk, or nil if no such object exists in the cache, without issuing a database query.


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# File 'lib/sequel/plugins/static_cache.rb', line 108

def cache_get_pk(pk)
  static_cache_object(cache[pk])
end

#count(*a, &block) ⇒ Object

Get the number of records in the cache, without issuing a database query.


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# File 'lib/sequel/plugins/static_cache.rb', line 98

def count(*a, &block)
  if a.empty? && !block
    @all.size
  else
    super
  end
end

#each(&block) ⇒ Object

Yield each of the model's frozen instances to the block, without issuing a database query.


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# File 'lib/sequel/plugins/static_cache.rb', line 114

def each(&block)
  if @static_cache_frozen
    @all.each(&block)
  else
    @all.each{|o| yield(static_cache_object(o))}
  end
end

#first(*args) ⇒ Object

If a block is given, multiple arguments are given, or a single non-Integer argument is given, performs the default behavior of issuing a database query. Otherwise, uses the cached values to return either the first cached instance (no arguments) or an array containing the number of instances specified (single integer argument).


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# File 'lib/sequel/plugins/static_cache.rb', line 89

def first(*args)
  if defined?(yield) || args.length > 1 || (args.length == 1 && !args[0].is_a?(Integer))
    super
  else
    @all.first(*args)
  end
end

#load_cacheObject

Reload the cache for this model by retrieving all of the instances in the dataset freezing them, and populating the cached array and hash.


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# File 'lib/sequel/plugins/static_cache.rb', line 213

def load_cache
  @all = load_static_cache_rows
  h = {}
  @all.each do |o|
    o.errors.freeze
    h[o.pk.freeze] = o.freeze
  end
  @cache = h.freeze
end

#map(column = nil, &block) ⇒ Object

Use the cache instead of a query to get the results.


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# File 'lib/sequel/plugins/static_cache.rb', line 123

def map(column=nil, &block)
  if column
    raise(Error, "Cannot provide both column and block to map") if block
    if column.is_a?(Array)
      @all.map{|r| r.values.values_at(*column)}
    else
      @all.map{|r| r[column]}
    end
  elsif @static_cache_frozen
    @all.map(&block)
  elsif block
    @all.map{|o| yield(static_cache_object(o))}
  else
    all.map
  end
end

#static_cache_allow_modifications?Boolean

Ask whether modifications to this class are allowed.

Returns:

  • (Boolean)

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# File 'lib/sequel/plugins/static_cache.rb', line 207

def static_cache_allow_modifications?
  !@static_cache_frozen
end

#to_hash(*a) ⇒ Object

Alias of as_hash for backwards compatibility.


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# File 'lib/sequel/plugins/static_cache.rb', line 177

def to_hash(*a)
  as_hash(*a)
end

#to_hash_groups(key_column, value_column = nil, opts = OPTS) ⇒ Object

Use the cache instead of a query to get the results


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# File 'lib/sequel/plugins/static_cache.rb', line 182

def to_hash_groups(key_column, value_column = nil, opts = OPTS)
  h = opts[:hash] || {}
  if value_column
    if value_column.is_a?(Array)
      if key_column.is_a?(Array)
        @all.each{|r| (h[r.values.values_at(*key_column)] ||= []) << r.values.values_at(*value_column)}
      else
        @all.each{|r| (h[r[key_column]] ||= []) << r.values.values_at(*value_column)}
      end
    else
      if key_column.is_a?(Array)
        @all.each{|r| (h[r.values.values_at(*key_column)] ||= []) << r[value_column]}
      else
        @all.each{|r| (h[r[key_column]] ||= []) << r[value_column]}
      end
    end
  elsif key_column.is_a?(Array)
    @all.each{|r| (h[r.values.values_at(*key_column)] ||= []) << static_cache_object(r)}
  else
    @all.each{|r| (h[r[key_column]] ||= []) << static_cache_object(r)}
  end
  h
end