use the metrics application

There is no point to maintain an duplicae code here since we maintain the
metrics application afterall.

doc/edoc-info

@@ -1,9 +1,8 @@
 %% encoding: UTF-8
 {application,hackney}.
 {modules,[hackney,hackney_app,hackney_bstr,hackney_connect,hackney_cookie,
-          hackney_date,hackney_dummy_metrics,hackney_exometer_metrics,
-          hackney_folsom_metrics,hackney_headers,hackney_http,
-          hackney_http_connect,hackney_manager,hackney_multipart,hackney_pool,
-          hackney_pool_handler,hackney_request,hackney_response,
-          hackney_socks5,hackney_ssl_transport,hackney_stream,hackney_sup,
+          hackney_date,hackney_headers,hackney_http,hackney_http_connect,
+          hackney_manager,hackney_multipart,hackney_pool,hackney_pool_handler,
+          hackney_request,hackney_response,hackney_socks5,
+          hackney_ssl_transport,hackney_stream,hackney_sup,
           hackney_tcp_transport,hackney_trace,hackney_url,hackney_util]}.

include/hackney.hrl

@@ -42,4 +42,4 @@
         connection = nil,
         method = nil,
         path,
-        ctype = nil}).
+        ctype = nil}).

rebar.config

@@ -17,6 +17,7 @@
         {idna, "1.1.0"},
         {mimerl, "1.0.2"},
         {certifi, "0.3.0"},
+        {metrics, "1.0.0"},
         {ssl_verify_hostname, "1.0.5"}
        ]}.
 
@@ -38,4 +39,4 @@
              {test, [
                {deps, [{cowboy, "1.0.4"}]}
              ]}
-           ]}.
+           ]}.

rebar.config.script

@@ -19,6 +19,10 @@ Rebar2Deps0 = [{idna, ".*",
                {git, "https://github.com/certifi/erlang-certifi",
                 {tag, "0.3.0"}}},
 
+              {metrics, ".*",
+               {git, "https://github.com/benoitc/metrics",
+                {tag, "1.0.0"}}},
+
               {ssl_verify_hostname, ".*",
                {git, "https://github.com/deadtrickster/ssl_verify_hostname.erl",
                 {tag, "1.0.5"}}}],

rebar.lock

@@ -1,4 +1,5 @@
 [{<<"certifi">>,{pkg,<<"certifi">>,<<"0.3.0">>},0},
  {<<"idna">>,{pkg,<<"idna">>,<<"1.1.0">>},0},
+ {<<"metrics">>,{pkg,<<"metrics">>,<<"1.0.0">>},0},
  {<<"mimerl">>,{pkg,<<"mimerl">>,<<"1.0.2">>},0},
  {<<"ssl_verify_hostname">>,{pkg,<<"ssl_verify_hostname">>,<<"1.0.5">>},0}].

src/hackney.app.src

@@ -15,7 +15,7 @@
                  idna,
                  mimerl,
                  certifi]},
- {included_applications, [ssl_verify_hostname]},
+ {included_applications, [ssl_verify_hostname, metrics]},
  {mod, { hackney_app, []}},
  {env, [{timeout, 150000},
         {max_connections, 50},

src/hackney_manager.erl

@@ -45,7 +45,7 @@
 -define(REFS, hackney_manager_refs).
 
 -record(mstate, {pids=dict:new(),
-                 mod_metrics}).
+                 metrics}).
 
 
 new_request(#client{request_ref=Ref}=Client)
@@ -283,14 +283,14 @@ init(_) ->
     ets:new(?REFS, [named_table, set, protected]),
 
     %% initialize metrics
-    Mod = init_metrics(),
+    Metrics = init_metrics(),
 
     process_flag(trap_exit, true),
     %% return {ok, {Pids, Refs}}
     %% Pids are the managed pids
     %% Refs are the managed requests
     {ok, #mstate{pids=dict:new(),
-                 mod_metrics=Mod}}.
+                 metrics=Metrics}}.
 
 
 handle_call({new_request, Pid, Ref, Client}, _From, #mstate{pids=Pids}=State) ->
@@ -581,24 +581,24 @@ wait_async_response(Stream) ->
 
 init_metrics() ->
     %% get metrics module
-    Mod = hackney_util:mod_metrics(),
+    Engine = metrics:init(hackney_util:mod_metrics()),
 
     %% initialise metrics
-    Mod:new(counter, [hackney, nb_requests]),
-    Mod:new(counter, [hackney, total_requests]),
-    Mod:new(counter, [hackney, finished_requests]),
-    Mod.
+    metrics:new(Engine, counter, [hackney, nb_requests]),
+    metrics:new(Engine, counter, [hackney, total_requests]),
+    metrics:new(Engine, counter, [hackney, finished_requests]),
+    Engine.
 
-start_request(#request_info{host=Host}, #mstate{mod_metrics=Mod}) ->
-    Mod:increment_counter([hackney, Host, nb_requests]),
-    Mod:increment_counter([hackney, nb_requests]),
-    Mod:increment_counter([hackney, total_requests]).
+start_request(#request_info{host=Host}, #mstate{metrics=Engine}) ->
+    metrics:increment_counter(Engine, [hackney, Host, nb_requests]),
+    metrics:increment_counter(Engine, [hackney, nb_requests]),
+    metrics:increment_counter(Engine, [hackney, total_requests]).
 
 
 finish_request(#request_info{start_time=Begin, host=Host},
-               #mstate{mod_metrics=Mod}) ->
+               #mstate{metrics=Engine}) ->
     RequestTime = timer:now_diff(os:timestamp(), Begin)/1000,
-    Mod:update_histogram([hackney, Host, request_time], RequestTime),
-    Mod:decrement_counter([hackney, Host, nb_requests]),
-    Mod:decrement_counter([hackney, nb_requests]),
-    Mod:increment_counter([hackney, finished_requests]).
+    metrics:update_histogram(Engine, [hackney, Host, request_time], RequestTime),
+    metrics:decrement_counter(Engine, [hackney, Host, nb_requests]),
+    metrics:decrement_counter(Engine, [hackney, nb_requests]),
+    metrics:increment_counter(Engine, [hackney, finished_requests]).

src/hackney_util.erl

@@ -102,18 +102,11 @@ privdir() ->
 
 mod_metrics() ->
     case application:get_env(hackney, mod_metrics) of
-        {ok, folsom} -> hackney_folsom_metrics;
-        {ok, exometer} -> hackney_exometer_metrics;
-        {ok, dummy} -> hackney_dummy_metrics;
-        {ok, Mod} ->
-            _ = code:ensure_loaded(Mod),
-            case erlang:function_exported(Mod, new, 2) of
-                false ->
-                    {error, badarg};
-                true ->
-                    Mod
-            end;
-        _ -> hackney_dummy_metrics
+        {ok, folsom} -> metrics_folsom;
+        {ok, exometer} -> metrics_exometers;
+        {ok, dummy} -> metrics_dumy;
+        {ok, Mod} -> Mod;
+        _ -> metrics_dummy
     end.
 
 

src/http/hackney_response.erl

@@ -118,11 +118,11 @@ wait_headers({header, {Key, Value}=KV, Parser}, Client, Status, Headers) ->
                  [KV | Headers]);
 
 wait_headers({headers_complete, Parser}, Client, Status, Headers) ->
-    Mod = Client#client.mod_metrics,
     ResponseTime = timer:now_diff(os:timestamp(),
                                   Client#client.start_time)/1000,
-    Mod:update_histogram([hackney, Client#client.host, response_time],
-                         ResponseTime),
+    metrics:update_histogram(Client#client.mod_metrics,
+                             [hackney, Client#client.host, response_time],
+                             ResponseTime),
     {ok, Status, lists:reverse(Headers), Client#client{parser=Parser}}.
 
 stream_body(Client=#client{response_state=done}) ->