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z5ottu/riak_postcommit_hook_example.erl

Last active September 21, 2024 19:19
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riak_postcommit_hook_example.erl
-module(riak_postcommit_hook_example).
-export([postcommitcounter/1, postcommitmapcounter/1]).
%% Refreshing counters from commithook is very expensive!
%%
%% requirements: bucket-type: maps(Type::map), bucket-type: counters(Type::counters)
%%
%% riak-admin bucket-type create maps '{"props":{"datatype":"map"}}'
%% riak-admin bucket-type activate maps
%% riak-admin bucket-type create counters '{"props":{"datatype":"counter"}}'
%% riak-admin bucket-type activate counters
%%
%% you have to update if you have modified the source:
%%
%% compile the source with same erl version:
%% erlc riak_postcommit_hook_example.erl
%%
%% copy to riak's erlang(PA) directory:
%% // PA directory is configurable: /etc/advanced.config -> {riak_kv, [{add_paths, ["/opt/riak.2.2.3/erl_commit_hooks_and_utils"]} ]}
%% cp riak_postcommit_hook_example.beam /opt/riak.2.2.3/erl_commit_hooks_and_utils
%%
%% reload erl beams:
%% riak-admin erl-reload
%%
%% author: Szloboda Zsolt, z5ottu@gmail.com
%%
postcommitcounter(RObj) ->
{ok, Client} = riak:local_client(),
Bucket = {<<"counters">>, <<"test">>},
Id = <<"all">>,
Counter = case Client:get(Bucket, Id) of
{error, notfound} -> riak_kv_crdt:new(Bucket, Id, riak_dt_pncounter);
{ok, Obj} -> Obj
end,
Op = {crdt_op, riak_dt_pncounter, {increment, 1}, undefined},
Counter2 = riak_kv_crdt:update(Counter, mkhash(), Op),
%%Client:put(Counter2),
%% speedup
riak_kv_w1c_worker:put(Counter2,[]),
RObj.
postcommitmapcounter(RObj) ->
{ok, Client} = riak:local_client(),
Bucket = {<<"maps">>, <<"test">>},
Id = <<"all">>,
{Counter, Context} = case Client:get(Bucket, Id) of
{error, notfound} ->
Obj = riak_kv_crdt:new(Bucket, Id, riak_dt_map),
{Obj, undefined};
{ok, Obj} ->
{{CountContext,_},_} = riak_kv_crdt:value(Obj, riak_dt_map),
{Obj, CountContext}
end,
Op = {crdt_op, riak_dt_map, {update,[{update,{<<"count">>,riak_dt_emcntr},increment}]}, Context},
Counter2 = riak_kv_crdt:update(Counter, mkhash(), Op),
%%Client:put(Counter2),
%% speedup
riak_kv_w1c_worker:put(Counter2,[]),
RObj.
mkhash() ->
integer_to_binary(erlang:phash2({self(), os:timestamp()})).
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