diff options
Diffstat (limited to 'src/file_handle_cache.erl')
| -rw-r--r-- | src/file_handle_cache.erl | 161 |
1 files changed, 124 insertions, 37 deletions
diff --git a/src/file_handle_cache.erl b/src/file_handle_cache.erl index 3a7a692c..2922e146 100644 --- a/src/file_handle_cache.erl +++ b/src/file_handle_cache.erl @@ -178,6 +178,9 @@ write_buffer_size, write_buffer_size_limit, write_buffer, + read_buffer, + read_buffer_size, + read_buffer_size_limit, at_eof, path, mode, @@ -237,7 +240,8 @@ -spec(register_callback/3 :: (atom(), atom(), [any()]) -> 'ok'). -spec(open/3 :: (file:filename(), [any()], - [{'write_buffer', (non_neg_integer() | 'infinity' | 'unbuffered')}]) + [{'write_buffer', (non_neg_integer() | 'infinity' | 'unbuffered')} | + {'read_buffer', (non_neg_integer() | 'unbuffered')}]) -> val_or_error(ref())). -spec(close/1 :: (ref()) -> ok_or_error()). -spec(read/2 :: (ref(), non_neg_integer()) -> @@ -331,16 +335,44 @@ close(Ref) -> read(Ref, Count) -> with_flushed_handles( - [Ref], + [Ref], keep, fun ([#handle { is_read = false }]) -> {error, not_open_for_reading}; - ([Handle = #handle { hdl = Hdl, offset = Offset }]) -> - case prim_file:read(Hdl, Count) of - {ok, Data} = Obj -> Offset1 = Offset + iolist_size(Data), - {Obj, - [Handle #handle { offset = Offset1 }]}; - eof -> {eof, [Handle #handle { at_eof = true }]}; - Error -> {Error, [Handle]} + ([Handle = #handle{read_buffer = Buf, + read_buffer_size = BufSz, + offset = Offset}]) when BufSz >= Count -> + <<Hd:Count/binary, Tl/binary>> = Buf, + {{ok, Hd}, [Handle#handle{offset = Offset + Count, + read_buffer = Tl, + read_buffer_size = BufSz - Count}]}; + ([Handle = #handle{read_buffer = Buf, + read_buffer_size = BufSz, + read_buffer_size_limit = BufSzLimit, + hdl = Hdl, + offset = Offset}]) -> + WantedCount = Count - BufSz, + case prim_file_read(Hdl, lists:max([BufSzLimit, WantedCount])) of + {ok, Data} -> + ReadCount = size(Data), + case ReadCount < WantedCount of + true -> + OffSet1 = Offset + BufSz + ReadCount, + {{ok, <<Buf/binary, Data/binary>>}, + [reset_read_buffer( + Handle#handle{offset = OffSet1})]}; + false -> + <<Hd:WantedCount/binary, Tl/binary>> = Data, + OffSet1 = Offset + BufSz + WantedCount, + BufSz1 = ReadCount - WantedCount, + {{ok, <<Buf/binary, Hd/binary>>}, + [Handle#handle{offset = OffSet1, + read_buffer = Tl, + read_buffer_size = BufSz1}]} + end; + eof -> + {eof, [Handle #handle { at_eof = true }]}; + Error -> + {Error, [reset_read_buffer(Handle)]} end end). @@ -355,7 +387,7 @@ append(Ref, Data) -> write_buffer_size_limit = 0, at_eof = true } = Handle1} -> Offset1 = Offset + iolist_size(Data), - {prim_file:write(Hdl, Data), + {prim_file_write(Hdl, Data), [Handle1 #handle { is_dirty = true, offset = Offset1 }]}; {{ok, _Offset}, #handle { write_buffer = WriteBuffer, write_buffer_size = Size, @@ -377,12 +409,12 @@ append(Ref, Data) -> sync(Ref) -> with_flushed_handles( - [Ref], + [Ref], keep, fun ([#handle { is_dirty = false, write_buffer = [] }]) -> ok; ([Handle = #handle { hdl = Hdl, is_dirty = true, write_buffer = [] }]) -> - case prim_file:sync(Hdl) of + case prim_file_sync(Hdl) of ok -> {ok, [Handle #handle { is_dirty = false }]}; Error -> {Error, [Handle]} end @@ -397,7 +429,7 @@ needs_sync(Ref) -> position(Ref, NewOffset) -> with_flushed_handles( - [Ref], + [Ref], keep, fun ([Handle]) -> {Result, Handle1} = maybe_seek(NewOffset, Handle), {Result, [Handle1]} end). @@ -465,8 +497,8 @@ clear(Ref) -> fun ([#handle { at_eof = true, write_buffer_size = 0, offset = 0 }]) -> ok; ([Handle]) -> - case maybe_seek(bof, Handle #handle { write_buffer = [], - write_buffer_size = 0 }) of + case maybe_seek(bof, Handle#handle{write_buffer = [], + write_buffer_size = 0}) of {{ok, 0}, Handle1 = #handle { hdl = Hdl }} -> case prim_file:truncate(Hdl) of ok -> {ok, [Handle1 #handle { at_eof = true }]}; @@ -539,6 +571,21 @@ info(Items) -> gen_server2:call(?SERVER, {info, Items}, infinity). %% Internal functions %%---------------------------------------------------------------------------- +prim_file_read(Hdl, Size) -> + file_handle_cache_stats:update( + read, Size, fun() -> prim_file:read(Hdl, Size) end). + +prim_file_write(Hdl, Bytes) -> + file_handle_cache_stats:update( + write, iolist_size(Bytes), fun() -> prim_file:write(Hdl, Bytes) end). + +prim_file_sync(Hdl) -> + file_handle_cache_stats:update(sync, fun() -> prim_file:sync(Hdl) end). + +prim_file_position(Hdl, NewOffset) -> + file_handle_cache_stats:update( + seek, fun() -> prim_file:position(Hdl, NewOffset) end). + is_reader(Mode) -> lists:member(read, Mode). is_writer(Mode) -> lists:member(write, Mode). @@ -550,8 +597,15 @@ append_to_write(Mode) -> end. with_handles(Refs, Fun) -> + with_handles(Refs, reset, Fun). + +with_handles(Refs, ReadBuffer, Fun) -> case get_or_reopen([{Ref, reopen} || Ref <- Refs]) of - {ok, Handles} -> + {ok, Handles0} -> + Handles = case ReadBuffer of + reset -> [reset_read_buffer(H) || H <- Handles0]; + keep -> Handles0 + end, case Fun(Handles) of {Result, Handles1} when is_list(Handles1) -> lists:zipwith(fun put_handle/2, Refs, Handles1), @@ -564,8 +618,11 @@ with_handles(Refs, Fun) -> end. with_flushed_handles(Refs, Fun) -> + with_flushed_handles(Refs, reset, Fun). + +with_flushed_handles(Refs, ReadBuffer, Fun) -> with_handles( - Refs, + Refs, ReadBuffer, fun (Handles) -> case lists:foldl( fun (Handle, {ok, HandlesAcc}) -> @@ -611,20 +668,23 @@ reopen([], Tree, RefHdls) -> {ok, lists:reverse(RefHdls)}; reopen([{Ref, NewOrReopen, Handle = #handle { hdl = closed, path = Path, - mode = Mode, + mode = Mode0, offset = Offset, last_used_at = undefined }} | RefNewOrReopenHdls] = ToOpen, Tree, RefHdls) -> - case prim_file:open(Path, case NewOrReopen of - new -> Mode; - reopen -> [read | Mode] - end) of + Mode = case NewOrReopen of + new -> Mode0; + reopen -> file_handle_cache_stats:update(reopen), + [read | Mode0] + end, + case prim_file:open(Path, Mode) of {ok, Hdl} -> Now = now(), {{ok, _Offset}, Handle1} = - maybe_seek(Offset, Handle #handle { hdl = Hdl, - offset = 0, - last_used_at = Now }), + maybe_seek(Offset, reset_read_buffer( + Handle#handle{hdl = Hdl, + offset = 0, + last_used_at = Now})), put({Ref, fhc_handle}, Handle1), reopen(RefNewOrReopenHdls, gb_trees:insert(Now, Ref, Tree), [{Ref, Handle1} | RefHdls]); @@ -709,6 +769,11 @@ new_closed_handle(Path, Mode, Options) -> infinity -> infinity; N when is_integer(N) -> N end, + ReadBufferSize = + case proplists:get_value(read_buffer, Options, unbuffered) of + unbuffered -> 0; + N2 when is_integer(N2) -> N2 + end, Ref = make_ref(), put({Ref, fhc_handle}, #handle { hdl = closed, offset = 0, @@ -716,6 +781,9 @@ new_closed_handle(Path, Mode, Options) -> write_buffer_size = 0, write_buffer_size_limit = WriteBufferSize, write_buffer = [], + read_buffer_size = 0, + read_buffer_size_limit = ReadBufferSize, + read_buffer = <<>>, at_eof = false, path = Path, mode = Mode, @@ -742,7 +810,7 @@ soft_close(Handle) -> is_dirty = IsDirty, last_used_at = Then } = Handle1 } -> ok = case IsDirty of - true -> prim_file:sync(Hdl); + true -> prim_file_sync(Hdl); false -> ok end, ok = prim_file:close(Hdl), @@ -776,17 +844,31 @@ hard_close(Handle) -> Result end. -maybe_seek(NewOffset, Handle = #handle { hdl = Hdl, offset = Offset, - at_eof = AtEoF }) -> +maybe_seek(NewOffset, Handle = #handle{hdl = Hdl, + offset = Offset, + read_buffer = Buf, + read_buffer_size = BufSz, + at_eof = AtEoF}) -> {AtEoF1, NeedsSeek} = needs_seek(AtEoF, Offset, NewOffset), - case (case NeedsSeek of - true -> prim_file:position(Hdl, NewOffset); - false -> {ok, Offset} - end) of - {ok, Offset1} = Result -> - {Result, Handle #handle { offset = Offset1, at_eof = AtEoF1 }}; - {error, _} = Error -> - {Error, Handle} + case NeedsSeek of + true when is_number(NewOffset) andalso + NewOffset >= Offset andalso NewOffset =< BufSz + Offset -> + Diff = NewOffset - Offset, + <<_:Diff/binary, Rest/binary>> = Buf, + {{ok, NewOffset}, Handle#handle{offset = NewOffset, + at_eof = AtEoF1, + read_buffer = Rest, + read_buffer_size = BufSz - Diff}}; + true -> + case prim_file_position(Hdl, NewOffset) of + {ok, Offset1} = Result -> + {Result, reset_read_buffer(Handle#handle{offset = Offset1, + at_eof = AtEoF1})}; + {error, _} = Error -> + {Error, Handle} + end; + false -> + {{ok, Offset}, Handle} end. needs_seek( AtEoF, _CurOffset, cur ) -> {AtEoF, false}; @@ -817,7 +899,7 @@ write_buffer(Handle = #handle { hdl = Hdl, offset = Offset, write_buffer = WriteBuffer, write_buffer_size = DataSize, at_eof = true }) -> - case prim_file:write(Hdl, lists:reverse(WriteBuffer)) of + case prim_file_write(Hdl, lists:reverse(WriteBuffer)) of ok -> Offset1 = Offset + DataSize, {ok, Handle #handle { offset = Offset1, is_dirty = true, @@ -826,6 +908,10 @@ write_buffer(Handle = #handle { hdl = Hdl, offset = Offset, {Error, Handle} end. +reset_read_buffer(Handle) -> + Handle#handle{read_buffer = <<>>, + read_buffer_size = 0}. + infos(Items, State) -> [{Item, i(Item, State)} || Item <- Items]. i(total_limit, #fhc_state{limit = Limit}) -> Limit; @@ -843,6 +929,7 @@ used(#fhc_state{open_count = C1, %%---------------------------------------------------------------------------- init([AlarmSet, AlarmClear]) -> + file_handle_cache_stats:init(), Limit = case application:get_env(file_handles_high_watermark) of {ok, Watermark} when (is_integer(Watermark) andalso Watermark > 0) -> |