Expose pgapp connected workers and fix dialyzer errors

Author: rymir

.gitignore

@@ -2,3 +2,4 @@ ebin/
 *~
 deps/
 *.config
+*.plt

rebar.config

@@ -1,5 +1,5 @@
 {deps,
  [
-  {epgsql,	".*",	{git, "git://github.com/epgsql/epgsql.git",	{tag, "3.1.0"}}},
+  {epgsql,	".*",	{git, "git://github.com/epgsql/epgsql.git",	"792a93c"}},
   {poolboy,	".*",	{git, "git://github.com/devinus/poolboy.git",	{tag, "1.4.2"}}}
  ]}.

src/pgapp.erl

@@ -9,18 +9,24 @@
 -module(pgapp).
 
 %% API
--export([connect/1, connect/2,
-         equery/2, equery/3, equery/4,
-         squery/1, squery/2, squery/3,
-         with_transaction/1, with_transaction/2, with_transaction/3]).
+-export([connect/1, connect/2]).
+-export([equery/2, equery/3, equery/4]).
+-export([squery/1, squery/2, squery/3]).
+-export([with_transaction/1, with_transaction/2, with_transaction/3]).
+-export([connected_workers/1]).
 
 %%%===================================================================
 %%% API
 %%%===================================================================
 
+-spec connect(Settings :: list()) -> {ok, WorkerPid} when
+              WorkerPid :: pid().
 connect(Settings) ->
     connect(epgsql_pool, Settings).
 
+-spec connect(PoolName :: atom(),
+              Settings :: list()) -> {ok, WorkerPid} when
+              WorkerPid :: pid().
 connect(PoolName, Settings) ->
     PoolSize    = proplists:get_value(size, Settings, 5),
     MaxOverflow = proplists:get_value(max_overflow, Settings, 5),
@@ -89,6 +95,13 @@ with_transaction(PoolName, Fun) when is_function(Fun, 0) ->
 with_transaction(PoolName, Fun, Timeout) when is_function(Fun, 0) ->
     pgapp_worker:with_transaction(PoolName, Fun, Timeout).
 
+-spec connected_workers(PoolName :: atom()) -> {ok, ConnectedWorkerPids} when
+                        ConnectedWorkerPids :: list(pid()).
+connected_workers(PoolName) ->
+    WorkerPids = gen_server:call(PoolName, get_avail_workers),
+    {ok, [WorkerPid || WorkerPid <- WorkerPids,
+          pgapp_worker:is_connected(WorkerPid)]}.
+
 %%--------------------------------------------------------------------
 %% @doc
 %% @spec

src/pgapp_worker.erl

@@ -8,9 +8,10 @@
 -behaviour(gen_server).
 -behaviour(poolboy_worker).
 
--export([squery/1, squery/2, squery/3,
-         equery/2, equery/3, equery/4,
-         with_transaction/2, with_transaction/3]).
+-export([squery/1, squery/2, squery/3]).
+-export([equery/2, equery/3, equery/4]).
+-export([with_transaction/2, with_transaction/3]).
+-export([is_connected/1]).
 
 -export([start_link/1]).
 
@@ -29,34 +30,37 @@
 -define(STATE_VAR, '$pgapp_state').
 
 squery(Sql) ->
+    squery(Sql, ?TIMEOUT).
+
+squery(PoolName, Sql) when is_atom(PoolName) ->
+    squery(PoolName, Sql, ?TIMEOUT);
+squery(Sql, Timeout) ->
     case get(?STATE_VAR) of
         undefined ->
-            squery(epgsql_pool, Sql);
+            squery(epgsql_pool, Sql, Timeout);
         Conn ->
             epgsql:squery(Conn, Sql)
     end.
 
-squery(PoolName, Sql) ->
-    squery(PoolName, Sql, ?TIMEOUT).
-
 squery(PoolName, Sql, Timeout) ->
     poolboy:transaction(PoolName,
                         fun (Worker) ->
                                 gen_server:call(Worker, {squery, Sql}, Timeout)
                         end, Timeout).
 
-
 equery(Sql, Params) ->
+    equery(Sql, Params, ?TIMEOUT).
+
+equery(PoolName, Sql, Params) when is_atom(PoolName) ->
+    equery(PoolName, Sql, Params, ?TIMEOUT);
+equery(Sql, Params, Timeout) ->
     case get(?STATE_VAR) of
         undefined ->
-            equery(epgsql_pool, Sql, Params);
+            equery(epgsql_pool, Sql, Params, Timeout);
         Conn ->
             epgsql:equery(Conn, Sql, Params)
     end.
 
-equery(PoolName, Sql, Params) ->
-    equery(PoolName, Sql, Params, ?TIMEOUT).
-
 equery(PoolName, Sql, Params, Timeout) ->
     poolboy:transaction(PoolName,
                         fun (Worker) ->
@@ -74,6 +78,9 @@ with_transaction(PoolName, Fun, Timeout) ->
                                                 {transaction, Fun}, Timeout)
                         end, Timeout).
 
+is_connected(WorkerPid) ->
+    gen_server:call(WorkerPid, {is_connected}, ?TIMEOUT).
+
 start_link(Args) ->
     gen_server:start_link(?MODULE, Args, []).
 
@@ -93,7 +100,12 @@ handle_call({transaction, Fun}, _From,
     put(?STATE_VAR, Conn),
     Result = epgsql:with_transaction(Conn, fun(_) -> Fun() end),
     erase(?STATE_VAR),
-    {reply, Result, State}.
+    {reply, Result, State};
+
+handle_call({is_connected}, _From, #state{conn = undefined} = State) ->
+    {reply, false, State};
+handle_call({is_connected}, _From, #state{conn = _Conn} = State) ->
+    {reply, true, State}.
 
 handle_cast(reconnect, State) ->
     {noreply, connect(State)}.