mcc v1.1.1 Mcc.Async.Writer

Async writer module.

The writer is a group of GenServer process, which support write mcc cache table asynchronously.

Why we need the module?

As we all know, in general, the write operations are heavy, especially if using transaction to write cache. Rely on async writer, the upper application can get the data from source database and retrun as soon as possible rather than wait for the write operation to complete. When async write, this module will dispatch the keys to different GenServer process depend on hash of key. So that, the async writer will avoid the single point from the GenServer process.

Link to this section Summary

Functions

Returns a specification to start this module under a supervisor

Invoked when the server is started. start_link/3 or start/3 will block until it returns

Async put operation

Start the GenServer process and link it

Link to this section Functions

Link to this function

child_spec(arg)

Returns a specification to start this module under a supervisor.

See Supervisor.

Invoked when the server is started. start_link/3 or start/3 will block until it returns.

args is the argument term (second argument) passed to start_link/3.

Returning {:ok, state} will cause start_link/3 to return {:ok, pid} and the process to enter its loop.

Returning {:ok, state, timeout} is similar to {:ok, state} except handle_info(:timeout, state) will be called after timeout milliseconds if no messages are received within the timeout.

Returning {:ok, state, :hibernate} is similar to {:ok, state} except the process is hibernated before entering the loop. See c:handle_call/3 for more information on hibernation.

Returning {:ok, state, {:continue, continue}} is similar to {:ok, state} except that immediately after entering the loop the c:handle_continue/2 callback will be invoked with the value continue as first argument.

Returning :ignore will cause start_link/3 to return :ignore and the process will exit normally without entering the loop or calling c:terminate/2. If used when part of a supervision tree the parent supervisor will not fail to start nor immediately try to restart the GenServer. The remainder of the supervision tree will be started and so the GenServer should not be required by other processes. It can be started later with Supervisor.restart_child/2 as the child specification is saved in the parent supervisor. The main use cases for this are:

  • The GenServer is disabled by configuration but might be enabled later.
  • An error occurred and it will be handled by a different mechanism than the Supervisor. Likely this approach involves calling Supervisor.restart_child/2 after a delay to attempt a restart.

Returning {:stop, reason} will cause start_link/3 to return {:error, reason} and the process to exit with reason reason without entering the loop or calling c:terminate/2.

Callback implementation for GenServer.init/1.

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put(key, mod, func, args)
put(any(), module(), function(), [any()]) :: :ok

Async put operation.

This function support upper application write the cache table using async approach, and the key will be dispatched to different GenServer process depend on hash of the key.

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start_link(id)
start_link(atom()) :: GenServer.on_start()

Start the GenServer process and link it.