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-module(mongoose_node_num_mnesia). |
| 2 |
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| 3 |
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-export([init/0]). |
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-record(node_num, {name :: atom(), |
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num :: mongoose_node_num:node_num() }). |
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| 8 |
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init() -> |
| 9 |
100 |
mongoose_mnesia:create_table(node_num, |
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[{ram_copies, [node()]}, {type, set}, |
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{attributes, record_info(fields, node_num)}]), |
| 12 |
100 |
mnesia:add_table_index(node_num, num), |
| 13 |
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register_node(node()), |
| 14 |
100 |
[#node_num{num = Num}] = mnesia:dirty_read(node_num, node()), |
| 15 |
100 |
mongoose_node_num:set_node_num(Num), |
| 16 |
100 |
ok. |
| 17 |
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-spec register_node(atom()) -> ok. |
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register_node(NodeName) -> |
| 20 |
100 |
{atomic, _} = mnesia:transaction(fun() -> |
| 21 |
100 |
case mnesia:read(node_num, NodeName) of |
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[] -> |
| 23 |
59 |
mnesia:write(#node_num{name = NodeName, num = next_node_num()}); |
| 24 |
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[_] -> ok |
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end |
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end), |
| 27 |
100 |
ok. |
| 28 |
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|
| 29 |
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-spec next_node_num() -> mongoose_node_num:node_num(). |
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next_node_num() -> |
| 31 |
59 |
max_node_num() + 1. |
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| 33 |
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-spec max_node_num() -> mongoose_node_num:node_num(). |
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max_node_num() -> |
| 35 |
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mnesia:foldl(fun(#node_num{num = Num}, Max) -> max(Num, Max) end, 0, node_num). |