Class: Kilden::FlagCache Private

Inherits:
Object
  • Object
show all
Defined in:
lib/kilden/flag_cache.rb

Overview

This class is part of a private API. You should avoid using this class if possible, as it may be removed or be changed in the future.

TTL + LRU cache of /decide responses, keyed by distinct_id (spec ยง8.2: TTL 30s, at most 1000 ids). Ruby's insertion-ordered Hash doubles as the LRU list: delete + reinsert on hit, shift the oldest on overflow.

Constant Summary collapse

TTL =

This constant is part of a private API. You should avoid using this constant if possible, as it may be removed or be changed in the future. 

30
MAX_IDS =

This constant is part of a private API. You should avoid using this constant if possible, as it may be removed or be changed in the future. 

1000

Instance Method Summary collapse

Constructor Details

#initialize(clock: -> { Process.clock_gettime(Process::CLOCK_MONOTONIC) }) ⇒ FlagCache

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Returns a new instance of FlagCache.



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# File 'lib/kilden/flag_cache.rb', line 12

def initialize(clock: -> { Process.clock_gettime(Process::CLOCK_MONOTONIC) })
  @clock = clock
  @entries = {}
  @mutex = Mutex.new
end

Instance Method Details

#clear ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



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# File 'lib/kilden/flag_cache.rb', line 37

def clear
  @mutex.synchronize { @entries.clear }
end

#get(distinct_id) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



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# File 'lib/kilden/flag_cache.rb', line 18

def get(distinct_id)
  @mutex.synchronize do
    entry = @entries.delete(distinct_id)
    return nil unless entry
    return nil if @clock.call >= entry[0]

    @entries[distinct_id] = entry
    entry[1]
  end
end

#set(distinct_id, flags) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future. 



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# File 'lib/kilden/flag_cache.rb', line 29

def set(distinct_id, flags)
  @mutex.synchronize do
    @entries.delete(distinct_id)
    @entries[distinct_id] = [@clock.call + TTL, flags]
    @entries.shift if @entries.size > MAX_IDS
  end
end