From 29f04eb3e864003cd0ca5b3b38b9f3f2c86aa25c Mon Sep 17 00:00:00 2001 From: Filipe David Borba Manana Date: Wed, 8 Dec 2010 17:03:08 +0000 Subject: [PATCH] Calculate and verify MD5 digests outside of a couch_file server This has a significant positive impact on the performance, both for readers and writers, when there are several requests in parallel acessing the same database or view index file. $ node tests/compare_write_and_read.js --wclients 100 --rclients 200 \ -name1 md5_out -name2 trunk \ -url1 http://localhost:5984/ -url2 http://localhost:5985/ \ --duration 120 run 1) http://graphs.mikeal.couchone.com/#/graph/5c859b3e7d1b9bd0488cfe271105130c run 2) http://graphs.mikeal.couchone.com/#/graph/5c859b3e7d1b9bd0488cfe2711051bba Closes COUCHDB-980 git-svn-id: https://svn.apache.org/repos/asf/couchdb/trunk@1043524 13f79535-47bb-0310-9956-ffa450edef68 --- src/couchdb/couch_file.erl | 23 +++++++++++++++-------- 1 file changed, 15 insertions(+), 8 deletions(-) diff --git a/src/couchdb/couch_file.erl b/src/couchdb/couch_file.erl index 25cfc22ffb6..4b2879e5596 100644 --- a/src/couchdb/couch_file.erl +++ b/src/couchdb/couch_file.erl @@ -123,7 +123,19 @@ pread_binary(Fd, Pos) -> pread_iolist(Fd, Pos) -> - gen_server:call(Fd, {pread_iolist, Pos}, infinity). + case gen_server:call(Fd, {pread_iolist, Pos}, infinity) of + {ok, IoList, <<>>} -> + {ok, IoList}; + {ok, IoList, Md5} -> + case couch_util:md5(IoList) of + Md5 -> + {ok, IoList}; + _ -> + exit({file_corruption, <<"file corruption">>}) + end; + Error -> + Error + end. %%---------------------------------------------------------------------- %% Purpose: The length of a file, in bytes. @@ -297,15 +309,10 @@ handle_call({pread_iolist, Pos}, _From, File) -> 1 -> {Md5, IoList} = extract_md5( maybe_read_more_iolist(RestRawData, 16 + Len, NextPos, File)), - case couch_util:md5(IoList) of - Md5 -> - {reply, {ok, IoList}, File}; - _ -> - {stop, file_corruption, {error,file_corruption}, File} - end; + {reply, {ok, IoList, Md5}, File}; 0 -> IoList = maybe_read_more_iolist(RestRawData, Len, NextPos, File), - {reply, {ok, IoList}, File} + {reply, {ok, IoList, <<>>}, File} end; handle_call(bytes, _From, #file{fd = Fd} = File) ->