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Class ::acs::LockfreeCache

::acs::LockfreeCache create ... \
           [ -prefix prefix ]

Lockfree caches are provided either as per-thread caches or per-request caches, sharing the property that accessing these values does not require locks. Typical applications of these caches are the per_request_cache and per_thread_cache.

See Also:

Object ::acs::per_request_cache

Object ::acs::per_thread_cache

Defined in packages/acs-tcl/tcl/acs-cache-procs.tcl

Class Relations

• class: ::nx::Class
• superclass: ::nx::Object

Methods (to be applied on instances)

• eval (scripted, public)

   <instance of acs::LockfreeCache> eval -key key  \
      [ -no_cache no_cache ] [ -no_empty ] \
      [ -from_cache_indicator from_cache_indicator ] cmd

  Use the "prefix" to determine whether the cache is per-thread or per-request.

  Switches:

  -key (required)

  key for caching, should start with package-key and a dot to avoid name clashes

  -no_cache (optional)

  list of returned values that should not be cached

  -no_empty (optional, defaults to "false")

  don't cache empty values. This flag is deprecated, one should use the no_cache flag instead.

  -from_cache_indicator (optional)

  variable name to indicate whether the returned value was from cache or not

  Parameters:

  cmd (required)

  command to be executed.

  Returns:

  return the last value set (don't use "return").

  Testcases:

  No testcase defined.

• flush (scripted, public)

   <instance of acs::LockfreeCache> flush [ -pattern pattern ]

  Flush a cache entry based on the pattern (which might be wild-card-free). Currently, the clusterwide flushing is omitted. We have the per-request cache (clusterwide operations do not make sense for this) and per-thread caching. The per-thread caching application have to be aware that flushing is happening only in one thread, so clusterwide operations will only start to make sense, when the all threads of a server would be cleaned.

  Switches:

  -pattern (optional, defaults to "*")

  Testcases:

  No testcase defined.

• get (scripted, public)

   <instance of acs::LockfreeCache> get -key key  var

  Get entry with the provided key from this cache if it exists. In most cases, the "eval" method should be used.

  Switches:

  -key (required)

  cache key

  Parameters:

  var (required)

  Returns:

  return boolean value indicating success.

  Testcases:

  No testcase defined.

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