svn commit: r728767 - in /couchdb/trunk/src/couchdb: Makefile.am couch_file_stats.erl

[da...@apache.org]

Author: damien
Date: Mon Dec 22 12:41:05 2008
New Revision: 728767

URL: http://svn.apache.org/viewvc?rev=728767&view=rev
Log:
Checking in new erlang source file, used for tracking file stats.

Added:
    couchdb/trunk/src/couchdb/couch_file_stats.erl
Modified:
    couchdb/trunk/src/couchdb/Makefile.am

Modified: couchdb/trunk/src/couchdb/Makefile.am
URL: http://svn.apache.org/viewvc/couchdb/trunk/src/couchdb/Makefile.am?rev=728767&r1=728766&r2=728767&view=diff
==============================================================================
--- couchdb/trunk/src/couchdb/Makefile.am (original)
+++ couchdb/trunk/src/couchdb/Makefile.am Mon Dec 22 12:41:05 2008
@@ -51,6 +51,7 @@
     couch_external_manager.erl \
     couch_external_server.erl \
     couch_file.erl \
+    couch_file_stats.erl \
     couch_httpd.erl \
     couch_httpd_db.erl \
     couch_httpd_external.erl \
@@ -85,6 +86,7 @@
     couch_external_manager.beam \
     couch_external_server.beam \
     couch_file.beam \
+    couch_file_stats.beam \
     couch_httpd.beam \
     couch_httpd_db.beam \
     couch_httpd_external.beam \

Added: couchdb/trunk/src/couchdb/couch_file_stats.erl
URL: http://svn.apache.org/viewvc/couchdb/trunk/src/couchdb/couch_file_stats.erl?rev=728767&view=auto
==============================================================================
--- couchdb/trunk/src/couchdb/couch_file_stats.erl (added)
+++ couchdb/trunk/src/couchdb/couch_file_stats.erl Mon Dec 22 12:41:05 2008
@@ -0,0 +1,68 @@
+% Licensed under the Apache License, Version 2.0 (the "License"); you may not
+% use this file except in compliance with the License.  You may obtain a copy of
+% the License at
+%
+%   http://www.apache.org/licenses/LICENSE-2.0
+%
+% Unless required by applicable law or agreed to in writing, software
+% distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+% WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
+% License for the specific language governing permissions and limitations under
+% the License.
+
+-module(couch_file_stats).
+-behaviour(gen_server).
+
+-export([init/1, terminate/2, handle_call/3, handle_cast/2, code_change/3,
+        handle_info/2]).
+
+-export([start_link/0,track_file/1,get_stats/0]).
+
+-record(stats,{
+    opened=0,
+    closed=0
+    }).
+
+
+track_file(Fd) ->
+    catch gen_server:cast(couch_file_stats, {track, Fd}).
+
+
+get_stats() ->
+    #stats{opened=Opened,closed=Closed}=gen_server:call(couch_file_stats,get),
+    {ok, [{opened,Opened}, {closed,Closed}]}.
+
+
+start_link() ->
+    gen_server:start_link({local, couch_file_stats}, couch_file_stats, [], []).
+
+
+init([]) ->
+    {ok, #stats{}}.
+
+
+terminate(_Reason, _Fd) ->
+    ok.
+
+
+handle_call(get, _From, Stats) ->
+    {reply, Stats, Stats}.
+
+
+handle_cast({track, Fd}, #stats{opened=Opened,closed=Closed}=Stats) ->
+    try erlang:monitor(process, Fd) of
+    _Ref ->
+        {noreply, Stats#stats{opened=Opened+1}}
+    catch
+    _Error ->
+        {noreply, Stats#stats{opened=Opened+1, closed=Closed+1}}
+    end.
+
+
+handle_info({'DOWN',_MonRef,_Type,_Pid,_Info}, #stats{closed=Closed}=Stats) ->
+    {noreply, Stats#stats{closed=Closed+1}}.
+
+
+code_change(_OldVsn, State, _Extra) ->
+    {ok, State}.
+