Packages
ra
1.0.7
3.1.9
3.1.8
3.1.7
3.1.6
3.1.5
3.1.4
3.1.3
3.1.2
3.1.1
3.1.0
3.0.2
3.0.1
3.0.0
3.0.0-beta.1
2.17.3
2.17.2
2.17.1
2.17.0
2.16.13
2.16.12
2.16.11
2.16.10
2.16.9
2.16.8
2.16.7
2.16.6
2.16.5
2.16.4
2.16.3
2.16.2
2.16.1
2.16.0
2.16.0-pre.12
2.16.0-pre.11
2.16.0-pre.10
2.16.0-pre.9
2.16.0-pre.8
2.16.0-pre.7
2.16.0-pre.6
2.16.0-pre.5
2.16.0-pre.4
2.16.0-pre.3
2.16.0-pre.2
2.16.0-pre.1
2.15.4
2.15.3
2.15.2
2.15.1
2.15.0
2.14.0
2.13.6
2.13.5
2.13.4
2.13.3
2.13.2
2.13.1
2.13.0
2.13.0-pre.1
2.12.0
2.11.0
2.11.0-pre.1
2.10.2-pre.2
2.10.2-pre.1
2.10.1
2.10.0
2.10.0-pre.3
2.10.0-pre.2
2.10.0-pre.1
2.9.10-pre.1
2.9.1
2.9.1-pre.2
2.9.1-pre.1
2.9.0
2.8.0
retired
2.7.3
2.7.2
2.7.1
2.7.0
2.7.0-pre.3
2.7.0-pre.2
2.7.0-pre.1
2.6.3
2.6.2
2.6.1
2.6.0-pre.1
2.5.1
2.5.1-pre.1
2.5.0
2.4.9
2.4.8
2.4.7
2.4.6
2.4.5
2.4.4
2.4.3
2.4.2
retired
2.4.1
2.4.0
2.3.0
2.2.0
2.1.0
2.0.13
2.0.12
2.0.11
2.0.10
2.0.9
2.0.8
2.0.7
2.0.6
2.0.5
2.0.4
2.0.3
2.0.2
2.0.1
2.0.0
1.1.9
1.1.8
1.1.7
1.1.6
1.1.5
1.1.4
1.1.3
1.1.2
1.1.1
1.1.0
1.0.8
1.0.7
1.0.6
1.0.5
1.0.4
1.0.3
1.0.2
1.0.1
1.0.0
0.9.6
0.9.5
0.9.4
0.9.2
0.3.3
retired
0.3.2
retired
0.3.1
retired
Raft library
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Files
src/ra_dbg.erl
%% @doc utilities to debug ra
-module(ra_dbg).
%% API
-export([replay_log/3, replay_log/4]).
%% exported for tests
-export([filter_duplicate_entries/1]).
%% @doc Replays log file for a given state machine module with an initial state.
%%
%% @param The location of the WAL file.
%% @param The Erlang module of the state machine.
%% @param The initial state.
%%
%% @returns The state once the log has been replayed.
-spec replay_log(string(), module(), term()) ->
term().
replay_log(WalFile, Module, InitialState) ->
replay_log(WalFile, Module, InitialState, fun(_, _) -> noop end).
%% @doc Replays log file for a given state machine module with an initial state.
%%
%% @param The location of the WAL file.
%% @param The Erlang module of the state machine.
%% @param The initial state.
%% @param A function to react to state and effects after each applied command
%%
%% @returns The state once the log has been replayed.
-spec replay_log(string(), module(), term(), Fun) -> term() when
Fun :: fun((State :: term(), Effects :: term()) -> term()).
replay_log(WalFile, Module, InitialState, Func) ->
Wal = filter_duplicate_entries(ra_log_wal:wal2list(WalFile)),
WalFunc = fun({Index, Term, {'$usr', Metadata, Command, _}}, Acc) ->
Metadata1 = Metadata#{index => Index,
term => Term},
case Module:apply(Metadata1, Command, Acc) of
{NewAcc, _Reply} ->
Func(NewAcc, undefined),
NewAcc;
{NewAcc, _Reply, Effects} ->
Func(NewAcc, Effects),
NewAcc
end;
(_, Acc) ->
Acc
end,
lists:foldl(WalFunc, InitialState, Wal).
filter_duplicate_entries(WalInReverseOrder) ->
{_IndexRegistry, OrderedAndFilteredWal} = lists:foldl(fun({Index, _Term, _Command} = Entry, {IndexRegistry, WalAcc}) ->
case maps:is_key(Index, IndexRegistry) of
true ->
{IndexRegistry, WalAcc};
false ->
{maps:put(Index, true, IndexRegistry), lists:append([Entry], WalAcc)}
end
end, {#{}, []}, WalInReverseOrder),
OrderedAndFilteredWal.