Utility functions for Erlang-based Riak demos. These ignore error handling and use strings instead of binaries for readability. Using the anonymous functions makes for a cleaner read.

helperfuns.erl

%% Useful in Erlang shell. These assume an already-defined handle named "Riak"

Get = fun(X, Y) -> helpers:get(Riak, X, Y) end.
RawGet = fun(X, Y) -> helpers:raw_get(Riak, X, Y) end.
Put = fun(X) -> helpers:put(Riak, X) end.
Update = fun(X, Y, Z) -> helpers:update(Riak, X, Y, Z) end.
Resolve = fun(X, Y) -> helpers:update(Riak, X, Y) end.
New = fun(X, Y, Z) -> helpers:new(X, Y, Z) end.

%% Add an object to Riak and retrieve it:
%% 8> Object = New("legacy", "breakfast", "bacon & eggs"),
%% 8> Put(Object).
%% ok
%% 9> Get("legacy", "breakfast").
%% ["bacon & eggs"]

%% Pull vector clock from <<"groceries">>/<<"breakfast">> object already in Riak and use its vector clock to resolve any siblings:
%% Object = RawGet("groceries", "breakfast"),
%% Resolve(Object, "pancakes, bacon & eggs, and orange juice").

%% Could/should abstract away the New/Put cycle by defining Store("bucket", "key", "value")

helpers.erl

-module(helpers).
-compile(export_all).

raw_get(Riak, Bucket, Key) ->
    {ok, Obj} = riakc_pb_socket:get(Riak, l2b(Bucket), l2b(Key)),
    Obj.

get(Riak, Bucket, Key) ->
    {ok, Obj} = riakc_pb_socket:get(Riak, l2b(Bucket), l2b(Key)),
    lists:map(fun(X) -> binary_to_list(X) end, riakc_obj:get_values(Obj)).

update(Riak, Bucket, Key, Value) ->
    {ok, Obj} = riakc_pb_socket:get(Riak, l2b(Bucket), l2b(Key)),
    update(Riak, Obj, Value).

update(Riak, Object, Value) ->
    helpers:put(Riak,
                riakc_obj:set_vclock(
                  replace(Object, Value),
                  riakc_obj:vclock(Object))).

l2b(String) ->
    unicode:characters_to_binary(String).

replace(Object, Value) ->
    new(riakc_obj:bucket(Object), riakc_obj:key(Object), l2b(Value)).

new(Bucket, Key, Value) when is_list(Bucket) ->
    riakc_obj:new(l2b(Bucket), l2b(Key), l2b(Value));
new(Bucket, Key, Value) ->
    riakc_obj:new(Bucket, Key, Value).

put(Riak, Bucket, Key, Value) ->
    {ok, Obj} = new(Bucket, Key, Value),
    riakc_pb_socket:put(Riak, Obj).

put(Riak, Object) ->
    riakc_pb_socket:put(Riak, Object).