Raft v0.2.1 Raft.Log
The Log
module provides an api for all log operations. Since the log process
is the only process that can access the underlying log store we cache several
values in the log process state.
Link to this section Summary
Functions
Appends new entries to the log and returns the latest index
Deletes all logs in the range inclusivesly
Gets the current configuration
Gets the entry at the given index
Gets the current metadata for the server
Gets the current term
Invoked when the server is started. start_link/3
or start/3
will
block until it returns
Returns the last entry in the log. If there are no entries then it returns an
:error
Returns the index of the last entry in the log
Returns the term of the last entry in the log. If the log is empty returns 0
Sets metadata
Link to this section Types
Link to this section Functions
append(atom(), [Raft.Log.Entry.t()]) :: {:ok, index()} | {:error, term()}
Appends new entries to the log and returns the latest index.
Deletes all logs in the range inclusivesly
Gets the current configuration.
get_entry(atom(), index()) :: {:ok, Raft.Log.Entry.t()} | {:error, :not_found}
Gets the entry at the given index.
Gets the current metadata for the server.
Gets the current term.
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 :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 (re)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 callingSupervisor.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
.
Returns the last entry in the log. If there are no entries then it returns an
:error
.
Returns the index of the last entry in the log.
Returns the term of the last entry in the log. If the log is empty returns 0.
Sets metadata.