Class: Ferret::Search::CachingWrapperFilter

Inherits:
Filter
  • Object
show all
Defined in:
lib/ferret/search/caching_wrapper_filter.rb

Overview

Wraps another filter’s result and caches it. The caching behavior is like QueryFilter. The purpose is to allow filters to simply filter, and then wrap with this class to add caching, keeping the two concerns decoupled yet composable.

Instance Method Summary collapse

Constructor Details

#initialize(filter) ⇒ CachingWrapperFilter

filter

Filter to cache results of



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# File 'lib/ferret/search/caching_wrapper_filter.rb', line 10

def initialize(filter) 
  @filter = filter
  @cache = nil
end

Instance Method Details

#bits(reader) ⇒ Object 



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# File 'lib/ferret/search/caching_wrapper_filter.rb', line 15

def bits(reader)
  if (@cache == nil) 
    @cache = Ferret::Utils::WeakKeyHash.new
  end

  @cache.synchronize() do # check cache

    bits = @cache[reader]
    if bits
      return bits
    end
  end

  bits = @filter.bits(reader)

  @cache.synchronize() do # update cache

    @cache[reader] = bits
  end

  return bits
end

#to_s ⇒ Object 



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# File 'lib/ferret/search/caching_wrapper_filter.rb', line 36

def to_s() 
  return "CachingWrapperFilter(#{@filter})"
end