Greetings.
I noticed a small inconvenience in the thrift_client Erlang module.
call(Client, Function, Args)
when is_pid(Client), is_atom(Function), is_list(Args) ->
case gen_server:call(Client, {call, Function, Args}) of
R = {ok, _} -> R;
R = {error, _} -> R;
{exception, Exception} -> throw(Exception)
end.
The inconvenience is that we can use atoms as pointers to processes in Erlang.
Say, I write the following wrapper:
-module(hbase).
-export([
start_link/0
]).
start_link() ->
{ok, Client} = thrift_client:start_link("localhost", 9090, hbase_thrift),
register(hbase, Client),
{ok, Client}.
and then I'll want to access hbase like the following:
thrift_client:call(hbase, getTableNames, []).
but the guard at the code above won't allow me to use this
construction. Moreover, we may want to access a pid like this:
{Node, Pid}.
I'd rather remove the is_pid check totally from the code and also add
a possibility to register the thrift client.
Here's the full diff:
--- thrift_client.erl
+++ thrift_client.erl
@@ -22,7 +22,7 @@
-behaviour(gen_server).
%% API
--export([start_link/2, start_link/3, start_link/4,
+-export([start_link/2, start_link/3, start_link/4, start_link/5,
start/3, start/4,
call/3, send_call/3, close/1]).
@@ -46,6 +46,11 @@
start_link(Host, Port, Service) when is_integer(Port), is_atom(Service) ->
start_link(Host, Port, Service, []).
+start_link(RegisterName, Host, Port, Service, Options) ->
+ {ok, Client} = start_link(Host, Port, Service, Options),
+ register(RegisterName, Client),
+ {ok, Client}.
+
start_link(Host, Port, Service, Options) ->
start(Host, Port, Service, [{monitor, link} | Options]).
@@ -141,7 +146,7 @@
end.
call(Client, Function, Args)
- when is_pid(Client), is_atom(Function), is_list(Args) ->
+ when is_atom(Function), is_list(Args) ->
case gen_server:call(Client, {call, Function, Args}) of
R = {ok, _} -> R;
R = {error, _} -> R;
@@ -149,17 +154,17 @@
end.
cast(Client, Function, Args)
- when is_pid(Client), is_atom(Function), is_list(Args) ->
+ when is_atom(Function), is_list(Args) ->
gen_server:cast(Client, {call, Function, Args}).
%% Sends a function call but does not read the result. This is useful
%% if you're trying to log non-oneway function calls to write-only
%% transports like thrift_disk_log_transport.
send_call(Client, Function, Args)
- when is_pid(Client), is_atom(Function), is_list(Args) ->
+ when is_atom(Function), is_list(Args) ->
gen_server:call(Client, {send_call, Function, Args}).
-close(Client) when is_pid(Client) ->
+close(Client) ->
gen_server:cast(Client, close).
%%====================================================================
Just in case, attached the diff as well but not sure if this mailing
list allows attachments.
--
Best regards,
Dmitry Demeshchuk
