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macula
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7.0.0
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5.2.2
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5.2.0
5.1.0
5.0.0
4.8.0
4.7.1
4.7.0
4.6.0
4.5.0
4.4.10
4.4.9
4.4.8
4.4.7
4.4.6
4.4.5
4.4.4
4.4.3
4.4.2
4.4.1
4.4.0
4.3.1
4.3.0
4.2.9
4.2.8
4.2.7
4.2.6
4.2.5
4.2.4
4.2.3
4.2.2
4.2.1
4.2.0
4.1.1
4.1.0
4.0.0
3.16.0
3.15.3
3.15.2
3.15.1
3.14.0
3.13.0
3.12.1
3.12.0
3.11.1
3.11.0
3.10.3
3.10.2
3.10.1
3.9.0
3.8.0
3.7.0
3.5.0
3.4.0
3.3.0
3.2.0
3.1.0
3.0.0
2.1.1
2.1.0
2.0.0
1.5.2
1.5.1
1.4.30
1.4.29
1.4.28
1.4.27
1.4.26
1.4.25
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1.4.21
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1.4.17
1.4.16
1.4.15
1.4.14
1.4.13
1.4.11
1.4.10
1.4.9
1.4.8
1.4.7
1.4.6
1.4.5
1.4.4
1.4.3
1.4.2
1.4.1
1.4.0
1.3.1
1.3.0
1.2.0
1.1.0
1.0.10
1.0.9
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
0.48.6
0.48.5
0.48.4
0.48.3
0.48.2
0.48.1
0.48.0
0.47.1
0.47.0
0.46.3
0.46.1
0.46.0
0.45.3
0.45.2
0.45.1
0.45.0
0.44.2
0.44.1
0.44.0
0.43.3
0.43.2
0.43.1
0.43.0
0.42.9
0.42.8
0.42.7
0.42.6
0.42.5
0.42.4
0.42.3
0.42.2
0.42.1
0.42.0
0.41.1
0.41.0
0.40.1
0.40.0
0.39.9
0.39.8
0.39.7
0.39.6
0.39.5
0.39.4
0.39.3
0.39.2
0.39.1
0.39.0
0.38.8
0.38.7
0.38.6
0.38.5
0.38.4
0.38.3
0.38.2
0.38.1
0.38.0
0.37.7
0.37.6
0.37.5
0.37.4
0.37.3
0.37.2
0.37.1
0.37.0
0.36.6
0.36.5
0.36.4
0.36.3
0.36.2
0.36.1
0.36.0
0.35.4
0.35.3
0.35.2
0.35.1
0.35.0
0.34.1
0.34.0
0.33.1
0.33.0
0.32.5
0.32.4
0.32.3
0.32.2
0.32.1
0.32.0
0.31.9
0.31.8
0.31.7
0.31.6
0.31.5
0.31.4
0.31.3
0.31.2
0.31.1
0.31.0
0.30.10
0.30.9
0.30.8
0.30.7
0.30.6
0.30.5
0.30.4
0.30.3
0.30.2
0.30.1
0.30.0
0.29.0
0.28.3
0.28.2
0.28.1
0.28.0
0.27.1
0.27.0
0.26.1
0.26.0
0.25.6
0.25.5
0.25.4
0.25.3
0.25.2
0.25.1
0.25.0
0.24.6
0.24.5
0.24.4
0.24.3
0.24.2
0.24.1
0.24.0
0.23.3
0.23.2
0.23.1
0.23.0
0.22.12
0.22.11
0.22.10
0.22.9
0.22.8
0.22.7
0.22.6
0.22.5
0.22.4
0.22.3
0.22.2
0.22.1
0.22.0
0.21.7
0.21.6
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0.21.2
0.21.1
0.21.0
0.20.25
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0.20.2
0.20.1
0.20.0
0.19.2
0.19.1
0.19.0
0.18.1
0.18.0
0.17.4
0.17.3
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0.17.1
0.17.0
0.16.6
0.16.5
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0.16.3
0.16.2
0.16.1
0.16.0
0.15.1
0.15.0
0.14.3
0.14.2
0.14.1
0.14.0
0.12.6
0.12.5
0.12.3
0.11.3
0.10.2
0.10.1
0.10.0
0.9.2
0.9.1
0.9.0
0.8.25
0.8.24
0.8.23
0.8.22
0.8.21
0.8.20
0.8.19
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0.8.9
0.8.8
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0.8.6
0.8.5
0.8.4
0.8.3
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0.8.1
0.8.0
0.7.30
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0.6.3
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0.6.1
0.6.0
0.5.0
0.4.4
0.4.3
0.4.2
0.4.1
0.4.0
0.3.4
0.3.3
0.3.2
0.3.1
Macula HTTP/3 Mesh SDK — connect, subscribe, publish, call, advertise
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Files
src/macula_platform_system/macula_crdt.erl
%% @doc Conflict-Free Replicated Data Types (CRDTs) for shared state
%% Implements LWW-Register (Last-Write-Wins Register) for eventual consistency
-module(macula_crdt).
%% API exports
-export([
new_lww_register/0,
new_lww_register/1,
lww_set/3,
lww_get/1,
lww_merge/2,
lww_timestamp/1,
lww_value/1
]).
%% Type definitions
-type timestamp() :: non_neg_integer().
-type lww_register() :: #{
value => term(),
timestamp => timestamp(),
node => node()
}.
-export_type([lww_register/0, timestamp/0]).
%%==============================================================================
%% LWW-Register (Last-Write-Wins Register)
%%==============================================================================
%% A simple CRDT that resolves conflicts by keeping the value with
%% the highest timestamp. Ties are broken by node name (lexicographic order).
%% @doc Create a new empty LWW-Register
-spec new_lww_register() -> lww_register().
new_lww_register() ->
#{
value => undefined,
timestamp => 0,
node => node()
}.
%% @doc Create a new LWW-Register with initial value
-spec new_lww_register(term()) -> lww_register().
new_lww_register(Value) ->
#{
value => Value,
timestamp => erlang:system_time(microsecond),
node => node()
}.
%% @doc Set a value in the LWW-Register with timestamp
-spec lww_set(lww_register(), term(), timestamp()) -> lww_register().
lww_set(_Register, Value, Timestamp) when is_integer(Timestamp), Timestamp >= 0 ->
#{
value => Value,
timestamp => Timestamp,
node => node()
}.
%% @doc Get the current value of the LWW-Register
-spec lww_get(lww_register()) -> term().
lww_get(#{value := Value}) ->
Value.
%% @doc Get the timestamp of the LWW-Register
-spec lww_timestamp(lww_register()) -> timestamp().
lww_timestamp(#{timestamp := Timestamp}) ->
Timestamp.
%% @doc Get the value of the LWW-Register (alias for lww_get)
-spec lww_value(lww_register()) -> term().
lww_value(Register) ->
lww_get(Register).
%% @doc Merge two LWW-Registers
%% Keeps the value with the highest timestamp
%% Ties broken by node name (lexicographic order)
-spec lww_merge(lww_register(), lww_register()) -> lww_register().
lww_merge(
#{timestamp := T1} = R1,
#{timestamp := T2}
) when T1 > T2 ->
R1;
lww_merge(
#{timestamp := T1},
#{timestamp := T2} = R2
) when T1 < T2 ->
R2;
lww_merge(
#{timestamp := T, node := N1} = R1,
#{timestamp := T, node := N2} = R2
) ->
%% Same timestamp - use lexicographic order of node names
case N1 < N2 of
true -> R1;
false -> R2
end.
%%==============================================================================
%% Internal Functions
%%==============================================================================
%% Future: G-Counter (Grow-only Counter)
%% Future: PN-Counter (Positive-Negative Counter)
%% Future: OR-Set (Observed-Remove Set)
%% Future: LWW-Element-Set (Last-Write-Wins Element Set)