diff options
| -rw-r--r-- | src/cow_hpack.erl | 65 |
1 files changed, 56 insertions, 9 deletions
diff --git a/src/cow_hpack.erl b/src/cow_hpack.erl index 3089d16..0ea4bf8 100644 --- a/src/cow_hpack.erl +++ b/src/cow_hpack.erl @@ -526,14 +526,16 @@ encode(Headers) -> encode(Headers, State=#state{max_size=MaxSize, configured_max_size=MaxSize}) -> encode(Headers, State, huffman, []); encode(Headers, State0=#state{configured_max_size=MaxSize}) -> - {Data, State} = encode(Headers, State0#state{max_size=MaxSize}, huffman, []), + State1 = table_update_size(MaxSize, State0), + {Data, State} = encode(Headers, State1, huffman, []), {[enc_int5(MaxSize, 2#001)|Data], State}. -spec encode(cow_http:headers(), State, opts()) -> {iodata(), State} when State::state(). encode(Headers, State=#state{max_size=MaxSize, configured_max_size=MaxSize}, Opts) -> encode(Headers, State, huffman_opt(Opts), []); encode(Headers, State0=#state{configured_max_size=MaxSize}, Opts) -> - {Data, State} = encode(Headers, State0#state{max_size=MaxSize}, huffman_opt(Opts), []), + State1 = table_update_size(MaxSize, State0), + {Data, State} = encode(Headers, State1, huffman_opt(Opts), []), {[enc_int5(MaxSize, 2#001)|Data], State}. huffman_opt(#{huffman := false}) -> no_huffman; @@ -1016,6 +1018,43 @@ table_update_encode_test() -> {42,{<<":status">>, <<"302">>}}]} = EncState3, ok. +%% Check that encode/2 is using the new table size after calling +%% set_max_size/1 and that adding entries larger than the max size +%% results in an empty table. +table_update_encode_max_size_0_test() -> + %% Encoding starts with default max size + EncState0 = init(), + %% Decoding starts with max size of 0 + DecState0 = init(0), + %% First request. + Headers1 = [ + {<<":method">>, <<"GET">>}, + {<<":scheme">>, <<"http">>}, + {<<":path">>, <<"/">>}, + {<<":authority">>, <<"www.example.com">>} + ], + {Encoded1, EncState1} = encode(Headers1, EncState0), + {Headers1, DecState1} = decode(iolist_to_binary(Encoded1), DecState0), + #state{size=57, dyn_table=[{57,{<<":authority">>, <<"www.example.com">>}}]} = EncState1, + #state{size=0, dyn_table=[]} = DecState1, + %% Settings received after the first request. + EncState2 = set_max_size(0, EncState1), + #state{configured_max_size=0, max_size=4096, + size=57, dyn_table=[{57,{<<":authority">>, <<"www.example.com">>}}]} = EncState2, + %% Second request. + Headers2 = [ + {<<":method">>, <<"GET">>}, + {<<":scheme">>, <<"http">>}, + {<<":path">>, <<"/">>}, + {<<":authority">>, <<"www.example.com">>}, + {<<"cache-control">>, <<"no-cache">>} + ], + {Encoded2, EncState3} = encode(Headers2, EncState2), + {Headers2, DecState2} = decode(iolist_to_binary(Encoded2), DecState1), + #state{configured_max_size=0, max_size=0, size=0, dyn_table=[]} = EncState3, + #state{size=0, dyn_table=[]} = DecState2, + ok. + encode_iolist_test() -> Headers = [ {<<":method">>, <<"GET">>}, @@ -1365,13 +1404,21 @@ table_get_name(Index, #state{dyn_table=DynamicTable}) -> table_insert(Entry = {Name, Value}, State=#state{size=Size, max_size=MaxSize, dyn_table=DynamicTable}) -> EntrySize = byte_size(Name) + byte_size(Value) + 32, - {DynamicTable2, Size2} = if - Size + EntrySize > MaxSize -> - table_resize(DynamicTable, MaxSize - EntrySize, 0, []); - true -> - {DynamicTable, Size} - end, - State#state{size=Size2 + EntrySize, dyn_table=[{EntrySize, Entry}|DynamicTable2]}. + if + EntrySize + Size =< MaxSize -> + %% Add entry without eviction + State#state{size=Size + EntrySize, dyn_table=[{EntrySize, Entry}|DynamicTable]}; + EntrySize =< MaxSize -> + %% Evict, then add entry + {DynamicTable2, Size2} = table_resize(DynamicTable, MaxSize - EntrySize, 0, []), + State#state{size=Size2 + EntrySize, dyn_table=[{EntrySize, Entry}|DynamicTable2]}; + EntrySize > MaxSize -> + %% "an attempt to add an entry larger than the + %% maximum size causes the table to be emptied + %% of all existing entries and results in an + %% empty table" (RFC 7541, 4.4) + State#state{size=0, dyn_table=[]} + end. table_resize([], _, Size, Acc) -> {lists:reverse(Acc), Size}; |