Class: RedisMemo::Cache

Inherits:
ActiveSupport::Cache::RedisCacheStore
  • Object
show all
Defined in:
lib/redis_memo/cache.rb

Defined Under Namespace

Classes: Rescuable

Constant Summary collapse

THREAD_KEY_LOCAL_CACHE = 
:__redis_memo_cache_local_cache__
THREAD_KEY_LOCAL_DEPENDENCY_CACHE = 
:__redis_memo_local_cache_dependency_cache__
THREAD_KEY_RAISE_ERROR = 
:__redis_memo_cache_raise_error__
@@redis = 
nil
@@redis_store = 
nil
@@redis_store_error_handler = 
proc do |method:, exception:, returning:|
  RedisMemo::DefaultOptions.redis_error_handler&.call(exception, method)
  RedisMemo::DefaultOptions.logger&.warn(exception.full_message)
   RedisMemo.incr_connection_attempts if exception.is_a?(Redis::BaseConnectionError)
   if Thread.current[THREAD_KEY_RAISE_ERROR]
    raise RedisMemo::Cache::Rescuable
  else
    returning
  end
end

Class Method Summary collapse

Class Method Details

.local_cache ⇒ Object

We use our own local_cache instead of the one from RedisCacheStore, because the local_cache in RedisCacheStore stores a dumped ActiveSupport::Cache::Entry object – which is slower comparing to a simple hash storing object references



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# File 'lib/redis_memo/cache.rb', line 52

def self.local_cache
  Thread.current[THREAD_KEY_LOCAL_CACHE]
end

.local_dependency_cache ⇒ Object 



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# File 'lib/redis_memo/cache.rb', line 56

def self.local_dependency_cache
  Thread.current[THREAD_KEY_LOCAL_DEPENDENCY_CACHE]
end

.read_multi(*keys, raw: false, raise_error: false) ⇒ Object

RedisCacheStore doesn’t read from the local cache before reading from redis



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# File 'lib/redis_memo/cache.rb', line 81

def read_multi(*keys, raw: false, raise_error: false)
  return {} if keys.empty?

  Thread.current[THREAD_KEY_RAISE_ERROR] = raise_error

  local_entries = local_cache&.slice(*keys) || {}

  keys_to_fetch = keys
  keys_to_fetch -= local_entries.keys unless local_entries.empty?
  return local_entries if keys_to_fetch.empty?

  remote_entries = redis_store.read_multi(*keys_to_fetch, raw: raw)
  local_cache&.merge!(remote_entries)

  if local_entries.empty?
    remote_entries
  else
    local_entries.merge!(remote_entries)
  end
end

.redis ⇒ Object 



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# File 'lib/redis_memo/cache.rb', line 29

def self.redis
  @@redis ||=
    if RedisMemo::DefaultOptions.connection_pool
      RedisMemo::ConnectionPool.new(**RedisMemo::DefaultOptions.connection_pool)
    else
      RedisMemo::DefaultOptions.redis
    end
end

.redis_store ⇒ Object 



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# File 'lib/redis_memo/cache.rb', line 38

def self.redis_store
  @@redis_store ||= new(
    compress: RedisMemo::DefaultOptions.compress,
    compress_threshold: RedisMemo::DefaultOptions.compress_threshold,
    error_handler: @@redis_store_error_handler,
    expires_in: RedisMemo::DefaultOptions.expires_in,
    redis: redis,
  )
end

.with_local_cache(&blk) ⇒ Object 



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# File 'lib/redis_memo/cache.rb', line 71

def with_local_cache(&blk)
  Thread.current[THREAD_KEY_LOCAL_CACHE] = {}
  Thread.current[THREAD_KEY_LOCAL_DEPENDENCY_CACHE] = {}
  blk.call
ensure
  Thread.current[THREAD_KEY_LOCAL_CACHE] = nil
  Thread.current[THREAD_KEY_LOCAL_DEPENDENCY_CACHE] = nil
end

.write(key, value, disable_async: false, raise_error: false, **options) ⇒ Object 



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# File 'lib/redis_memo/cache.rb', line 102

def write(key, value, disable_async: false, raise_error: false, **options)
  Thread.current[THREAD_KEY_RAISE_ERROR] = raise_error

  if local_cache
    local_cache[key] = value
  end

  async = RedisMemo::DefaultOptions.async
  if async.nil? || disable_async
    redis_store.write(key, value, **options)
  else
    async.call do
      Thread.current[THREAD_KEY_RAISE_ERROR] = raise_error
      redis_store.write(key, value, **options)
    end
  end
end