diff options
| -rw-r--r-- | src/couchdb/couch_file.erl | 33 | ||||
| -rwxr-xr-x | test/etap/010-file-basics.t | 3 |
2 files changed, 27 insertions, 9 deletions
diff --git a/src/couchdb/couch_file.erl b/src/couchdb/couch_file.erl index a3a728c7..9d2c42ca 100644 --- a/src/couchdb/couch_file.erl +++ b/src/couchdb/couch_file.erl @@ -283,20 +283,28 @@ terminate(_Reason, #file{fd = Fd}) -> handle_call({pread_iolist, Pos}, _From, File) -> - {LenIolist, NextPos} = read_raw_iolist_int(File, Pos, 4), - case iolist_to_binary(LenIolist) of - <<1:1/integer,Len:31/integer>> -> % an MD5-prefixed term - {Md5AndIoList, _} = read_raw_iolist_int(File, NextPos, Len+16), - {Md5, IoList} = extract_md5(Md5AndIoList), + {RawData, NextPos} = try + % up to 8Kbs of read ahead + read_raw_iolist_int(File, Pos, 2 * ?SIZE_BLOCK - (Pos rem ?SIZE_BLOCK)) + catch + _:_ -> + read_raw_iolist_int(File, Pos, 4) + end, + <<Prefix:1/integer, Len:31/integer, RestRawData/binary>> = + iolist_to_binary(RawData), + case Prefix of + 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; - <<0:1/integer,Len:31/integer>> -> - {Iolist, _} = read_raw_iolist_int(File, NextPos, Len), - {reply, {ok, Iolist}, File} + 0 -> + IoList = maybe_read_more_iolist(RestRawData, Len, NextPos, File), + {reply, {ok, IoList}, File} end; handle_call({pread, Pos, Bytes}, _From, #file{fd=Fd,tail_append_begin=TailAppendBegin}=File) -> {ok, Bin} = file:pread(Fd, Pos, Bytes), @@ -503,6 +511,15 @@ load_header(Fd, Block) -> Md5Sig = couch_util:md5(HeaderBin), {ok, HeaderBin}. +maybe_read_more_iolist(Buffer, DataSize, _, _) + when DataSize =< byte_size(Buffer) -> + <<Data:DataSize/binary, _/binary>> = Buffer, + [Data]; +maybe_read_more_iolist(Buffer, DataSize, NextPos, File) -> + {Missing, _} = + read_raw_iolist_int(File, NextPos, DataSize - byte_size(Buffer)), + [Buffer, Missing]. + -spec read_raw_iolist_int(#file{}, Pos::non_neg_integer(), Len::non_neg_integer()) -> {Data::iolist(), CurPos::non_neg_integer()}. read_raw_iolist_int(Fd, {Pos, _Size}, Len) -> % 0110 UPGRADE CODE diff --git a/test/etap/010-file-basics.t b/test/etap/010-file-basics.t index a3599f1a..ed71f5e8 100755 --- a/test/etap/010-file-basics.t +++ b/test/etap/010-file-basics.t @@ -84,7 +84,8 @@ test() -> % append_binary == append_iolist? % Possible bug in pread_iolist or iolist() -> append_binary {ok, IOLPos} = couch_file:append_binary(Fd, ["foo", $m, <<"bam">>]), - etap:is({ok, [<<"foombam">>]}, couch_file:pread_iolist(Fd, IOLPos), + {ok, IoList} = couch_file:pread_iolist(Fd, IOLPos), + etap:is(<<"foombam">>, iolist_to_binary(IoList), "Reading an results in a binary form of the written iolist()"), % XXX: How does on test fsync? |