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Contents
# frozen_string_literal: true
module JSI
module Util::Private
class MemoMap
def initialize(key_by: nil, &block)
@key_by = key_by
@block = block || raise(ArgumentError, "no block given")
# each result has its own mutex to update its memoized value thread-safely
@result_mutexes = {}
# another mutex to thread-safely initialize each result mutex
@result_mutexes_mutex = Mutex.new
@results = {}
end
def key_for(inputs)
if @key_by
@key_by.call(**inputs)
else
inputs
end
end
end
class MemoMap::Mutable < MemoMap
Result = AttrStruct[*%w(
value
inputs
inputs_hash
)]
class Result
end
def [](**inputs)
key = key_for(inputs)
result_mutex = @result_mutexes_mutex.synchronize do
@result_mutexes[key] ||= Mutex.new
end
result_mutex.synchronize do
inputs_hash = inputs.hash
if @results.key?(key) && inputs_hash == @results[key].inputs_hash && inputs == @results[key].inputs
@results[key].value
else
value = @block.call(**inputs)
@results[key] = Result.new(value: value, inputs: inputs, inputs_hash: inputs_hash)
value
end
end
end
end
class MemoMap::Immutable < MemoMap
def [](**inputs)
key = key_for(inputs)
result_mutex = @result_mutexes_mutex.synchronize do
@result_mutexes[key] ||= Mutex.new
end
result_mutex.synchronize do
if @results.key?(key)
@results[key]
else
@results[key] = @block.call(**inputs)
end
end
end
end
end
end
Version data entries
19 entries across 19 versions & 2 rubygems