piazza_core v0.3.0 Piazza.Crypto.License

Genserver for managing the license verification lifecycle. The protocol is basically:

  1. On start, decode the license and pass to either on_failure or on_verify depending on the result.
  2. At a fixed interval, reverify the license, in case it's expired/changed.

The verification interval can be configured with

config :piazza_core, :license_interval, interval_in_ms

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.

Link to this section Functions

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child_spec(init_arg)

Returns a specification to start this module under a supervisor.

See Supervisor.

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fetch(pid \\ __MODULE__)

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

init_arg 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 that it also sets a timeout. See the "Timeouts" section in the module documentation for more information.

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.

Link to this function

start_link(license, public_key, on_failure, on_verify \\ fn _, state -> state end)