105 lines
2.7 KiB
Ruby
105 lines
2.7 KiB
Ruby
module ActiveSupport
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module Cache
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module Strategy
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module LocalCache
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# this allows caching of the fact that there is nothing in the remote cache
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NULL = 'remote_cache_store:null'
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def with_local_cache
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Thread.current[thread_local_key] = MemoryStore.new
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yield
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ensure
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Thread.current[thread_local_key] = nil
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end
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def middleware
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@middleware ||= begin
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klass = Class.new
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klass.class_eval(<<-EOS, __FILE__, __LINE__ + 1)
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def initialize(app)
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@app = app
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end
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def call(env)
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Thread.current[:#{thread_local_key}] = MemoryStore.new
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@app.call(env)
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ensure
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Thread.current[:#{thread_local_key}] = nil
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end
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EOS
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klass
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end
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end
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def read(key, options = nil)
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value = local_cache && local_cache.read(key)
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if value == NULL
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nil
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elsif value.nil?
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value = super
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local_cache.mute { local_cache.write(key, value || NULL) } if local_cache
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value.duplicable? ? value.dup : value
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else
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# forcing the value to be immutable
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value.duplicable? ? value.dup : value
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end
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end
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def write(key, value, options = nil)
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value = value.to_s if respond_to?(:raw?) && raw?(options)
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local_cache.mute { local_cache.write(key, value || NULL) } if local_cache
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super
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end
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def delete(key, options = nil)
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local_cache.mute { local_cache.write(key, NULL) } if local_cache
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super
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end
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def exist(key, options = nil)
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value = local_cache.read(key) if local_cache
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if value == NULL
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false
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elsif value
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true
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else
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super
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end
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end
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def increment(key, amount = 1)
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if value = super
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local_cache.mute { local_cache.write(key, value.to_s) } if local_cache
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value
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else
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nil
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end
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end
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def decrement(key, amount = 1)
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if value = super
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local_cache.mute { local_cache.write(key, value.to_s) } if local_cache
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value
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else
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nil
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end
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end
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def clear
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local_cache.clear if local_cache
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super
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end
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private
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def thread_local_key
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@thread_local_key ||= "#{self.class.name.underscore}_local_cache".gsub("/", "_").to_sym
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end
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def local_cache
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Thread.current[thread_local_key]
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end
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end
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end
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end
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end
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