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diff --git a/lib/kernel/src/raw_file_io_inflate.erl b/lib/kernel/src/raw_file_io_inflate.erl
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+++ b/lib/kernel/src/raw_file_io_inflate.erl
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+%%
+%% %CopyrightBegin%
+%%
+%% Copyright Ericsson AB 2017. All Rights Reserved.
+%%
+%% 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.
+%%
+%% %CopyrightEnd%
+%%
+-module(raw_file_io_inflate).
+
+-behavior(gen_statem).
+
+-export([init/1, callback_mode/0, terminate/3]).
+-export([opening/3, opened_gzip/3, opened_passthrough/3]).
+
+-include("file_int.hrl").
+
+-define(INFLATE_CHUNK_SIZE, (8 bsl 10)).
+-define(GZIP_WBITS, (16 + 15)).
+
+callback_mode() -> state_functions.
+
+init({Owner, Secret, [compressed]}) ->
+ Monitor = monitor(process, Owner),
+ %% We're using the undocumented inflateInit/3 to open the stream in
+ %% 'reset mode', which resets the inflate state at the end of every stream,
+ %% allowing us to read concatenated gzip files.
+ Z = zlib:open(),
+ ok = zlib:inflateInit(Z, ?GZIP_WBITS, reset),
+ Data =
+ #{ owner => Owner,
+ monitor => Monitor,
+ secret => Secret,
+ position => 0,
+ buffer => prim_buffer:new(),
+ zlib => Z },
+ {ok, opening, Data}.
+
+%% The old driver fell back to plain reads if the file didn't start with the
+%% magic gzip bytes.
+choose_decompression_state(PrivateFd) ->
+ State =
+ case ?CALL_FD(PrivateFd, read, [2]) of
+ {ok, <<16#1F, 16#8B>>} -> opened_gzip;
+ _Other -> opened_passthrough
+ end,
+ {ok, 0} = ?CALL_FD(PrivateFd, position, [0]),
+ State.
+
+opening({call, From}, {'$open', Secret, Filename, Modes}, #{ secret := Secret } = Data) ->
+ case raw_file_io:open(Filename, Modes) of
+ {ok, PrivateFd} ->
+ NextState = choose_decompression_state(PrivateFd),
+ NewData = Data#{ handle => PrivateFd },
+ {next_state, NextState, NewData, [{reply, From, ok}]};
+ Other ->
+ {stop_and_reply, normal, [{reply, From, Other}]}
+ end;
+opening(_Event, _Contents, _Data) ->
+ {keep_state_and_data, [postpone]}.
+
+internal_close(From, Data) ->
+ #{ handle := PrivateFd } = Data,
+ Response = ?CALL_FD(PrivateFd, close, []),
+ {stop_and_reply, normal, [{reply, From, Response}]}.
+
+opened_passthrough(info, {'DOWN', Monitor, process, _Owner, _Reason}, #{ monitor := Monitor }) ->
+ {stop, shutdown};
+
+opened_passthrough(info, _Message, _Data) ->
+ keep_state_and_data;
+
+opened_passthrough({call, {Owner, _Tag} = From}, [close], #{ owner := Owner } = Data) ->
+ internal_close(From, Data);
+
+opened_passthrough({call, {Owner, _Tag} = From}, [Method | Args], #{ owner := Owner } = Data) ->
+ #{ handle := PrivateFd } = Data,
+ Response = ?CALL_FD(PrivateFd, Method, Args),
+ {keep_state_and_data, [{reply, From, Response}]};
+
+opened_passthrough({call, _From}, _Command, _Data) ->
+ %% The client functions filter this out, so we'll crash if the user does
+ %% anything stupid on purpose.
+ {shutdown, protocol_violation};
+
+opened_passthrough(_Event, _Request, _Data) ->
+ keep_state_and_data.
+
+%%
+
+opened_gzip(info, {'DOWN', Monitor, process, _Owner, _Reason}, #{ monitor := Monitor }) ->
+ {stop, shutdown};
+
+opened_gzip(info, _Message, _Data) ->
+ keep_state_and_data;
+
+opened_gzip({call, {Owner, _Tag} = From}, [close], #{ owner := Owner } = Data) ->
+ internal_close(From, Data);
+
+opened_gzip({call, {Owner, _Tag} = From}, [position, Mark], #{ owner := Owner } = Data) ->
+ case position(Data, Mark) of
+ {ok, NewData, Result} ->
+ Response = {ok, Result},
+ {keep_state, NewData, [{reply, From, Response}]};
+ Other ->
+ {keep_state_and_data, [{reply, From, Other}]}
+ end;
+
+opened_gzip({call, {Owner, _Tag} = From}, [read, Size], #{ owner := Owner } = Data) ->
+ case read(Data, Size) of
+ {ok, NewData, Result} ->
+ Response = {ok, Result},
+ {keep_state, NewData, [{reply, From, Response}]};
+ Other ->
+ {keep_state_and_data, [{reply, From, Other}]}
+ end;
+
+opened_gzip({call, {Owner, _Tag} = From}, [read_line], #{ owner := Owner } = Data) ->
+ case read_line(Data) of
+ {ok, NewData, Result} ->
+ Response = {ok, Result},
+ {keep_state, NewData, [{reply, From, Response}]};
+ Other ->
+ {keep_state_and_data, [{reply, From, Other}]}
+ end;
+
+opened_gzip({call, {Owner, _Tag} = From}, [write, _IOData], #{ owner := Owner }) ->
+ Response = {error, ebadf},
+ {keep_state_and_data, [{reply, From, Response}]};
+
+opened_gzip({call, {Owner, _Tag} = From}, _Request, #{ owner := Owner }) ->
+ Response = {error, enotsup},
+ {keep_state_and_data, [{reply, From, Response}]};
+
+opened_gzip({call, _From}, _Request, _Data) ->
+ %% The client functions filter this out, so we'll crash if the user does
+ %% anything stupid on purpose.
+ {shutdown, protocol_violation};
+
+opened_gzip(_Event, _Request, _Data) ->
+ keep_state_and_data.
+
+%%
+
+read(#{ buffer := Buffer } = Data, Size) ->
+ try read_1(Data, Buffer, prim_buffer:size(Buffer), Size) of
+ Result -> Result
+ catch
+ error:badarg -> {error, badarg};
+ error:_ -> {error, eio}
+ end.
+read_1(Data, Buffer, BufferSize, ReadSize) when BufferSize >= ReadSize ->
+ #{ position := Position } = Data,
+ Decompressed = prim_buffer:read(Buffer, ReadSize),
+ {ok, Data#{ position => (Position + ReadSize) }, Decompressed};
+read_1(Data, Buffer, BufferSize, ReadSize) when BufferSize < ReadSize ->
+ #{ handle := PrivateFd } = Data,
+ case ?CALL_FD(PrivateFd, read, [?INFLATE_CHUNK_SIZE]) of
+ {ok, Compressed} ->
+ #{ zlib := Z } = Data,
+ Uncompressed = erlang:iolist_to_iovec(zlib:inflate(Z, Compressed)),
+ prim_buffer:write(Buffer, Uncompressed),
+ read_1(Data, Buffer, prim_buffer:size(Buffer), ReadSize);
+ eof when BufferSize > 0 ->
+ read_1(Data, Buffer, BufferSize, BufferSize);
+ Other ->
+ Other
+ end.
+
+read_line(#{ buffer := Buffer } = Data) ->
+ try read_line_1(Data, Buffer, prim_buffer:find_byte_index(Buffer, $\n)) of
+ {ok, NewData, Decompressed} -> {ok, NewData, Decompressed};
+ Other -> Other
+ catch
+ error:badarg -> {error, badarg};
+ error:_ -> {error, eio}
+ end.
+
+read_line_1(Data, Buffer, not_found) ->
+ #{ handle := PrivateFd, zlib := Z } = Data,
+ case ?CALL_FD(PrivateFd, read, [?INFLATE_CHUNK_SIZE]) of
+ {ok, Compressed} ->
+ Uncompressed = erlang:iolist_to_iovec(zlib:inflate(Z, Compressed)),
+ prim_buffer:write(Buffer, Uncompressed),
+ read_line_1(Data, Buffer, prim_buffer:find_byte_index(Buffer, $\n));
+ eof ->
+ case prim_buffer:size(Buffer) of
+ Size when Size > 0 -> {ok, prim_buffer:read(Buffer, Size)};
+ Size when Size =:= 0 -> eof
+ end;
+ Error ->
+ Error
+ end;
+read_line_1(Data, Buffer, {ok, LFIndex}) ->
+ %% Translate CRLF into just LF, completely ignoring which encoding is used,
+ %% but treat the file position as including CR.
+ #{ position := Position } = Data,
+ NewData = Data#{ position => (Position + LFIndex + 1) },
+ CRIndex = (LFIndex - 1),
+ TranslatedLine =
+ case prim_buffer:read(Buffer, LFIndex + 1) of
+ <<Line:CRIndex/binary, "\r\n">> -> <<Line/binary, "\n">>;
+ Line -> Line
+ end,
+ {ok, NewData, TranslatedLine}.
+
+%%
+%% We support seeking in both directions as long as it isn't relative to EOF.
+%%
+%% Seeking backwards is extremely inefficient since we have to seek to the very
+%% beginning and then decompress up to the desired point.
+%%
+
+position(Data, Mark) when is_atom(Mark) ->
+ position(Data, {Mark, 0});
+position(Data, Offset) when is_integer(Offset) ->
+ position(Data, {bof, Offset});
+position(Data, {bof, Offset}) when is_integer(Offset) ->
+ position_1(Data, Offset);
+position(Data, {cur, Offset}) when is_integer(Offset) ->
+ #{ position := Position } = Data,
+ position_1(Data, Position + Offset);
+position(_Data, {eof, Offset}) when is_integer(Offset) ->
+ {error, einval};
+position(_Data, _Other) ->
+ {error, badarg}.
+
+position_1(_Data, Desired) when Desired < 0 ->
+ {error, einval};
+position_1(#{ position := Desired } = Data, Desired) ->
+ {ok, Data, Desired};
+position_1(#{ position := Current } = Data, Desired) when Current < Desired ->
+ case read(Data, min(Desired - Current, ?INFLATE_CHUNK_SIZE)) of
+ {ok, NewData, _Data} -> position_1(NewData, Desired);
+ eof -> {ok, Data, Current};
+ Other -> Other
+ end;
+position_1(#{ position := Current } = Data, Desired) when Current > Desired ->
+ #{ handle := PrivateFd, buffer := Buffer, zlib := Z } = Data,
+ case ?CALL_FD(PrivateFd, position, [bof]) of
+ {ok, 0} ->
+ ok = zlib:inflateReset(Z),
+ prim_buffer:wipe(Buffer),
+ position_1(Data#{ position => 0 }, Desired);
+ Other ->
+ Other
+ end.
+
+terminate(_Reason, _State, _Data) ->
+ ok.
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-07 02:34:47 +0000