some small codec optimisations

- encode and decode field types as characters rather than strings
- construct shallower iolists by cons'ing instead of appending
- avoid construction of intermediate binary for tables and arrays

2 files changed, 45 insertions, 46 deletions

diff --git a/src/rabbit_binary_generator.erl b/src/rabbit_binary_generator.erl
index ae5bbf51..8eaac10d 100644
--- a/src/rabbit_binary_generator.erl
+++ b/src/rabbit_binary_generator.erl
@@ -119,52 +119,51 @@ create_frame(TypeInt, ChannelInt, Payload) ->
 table_field_to_binary({FName, T, V}) ->
     [short_string_to_binary(FName) | field_value_to_binary(T, V)].
 
-field_value_to_binary(longstr,   V) -> ["S", long_string_to_binary(V)];
-field_value_to_binary(signedint, V) -> ["I", <<V:32/signed>>];
+field_value_to_binary(longstr,   V) -> [$S | long_string_to_binary(V)];
+field_value_to_binary(signedint, V) -> [$I | <<V:32/signed>>];
 field_value_to_binary(decimal,   V) -> {Before, After} = V,
-                                       ["D", Before, <<After:32>>];
-field_value_to_binary(timestamp, V) -> ["T", <<V:64>>];
-field_value_to_binary(table,     V) -> ["F", table_to_binary(V)];
-field_value_to_binary(array,     V) -> ["A", array_to_binary(V)];
-field_value_to_binary(byte,      V) -> ["b", <<V:8/unsigned>>];
-field_value_to_binary(double,    V) -> ["d", <<V:64/float>>];
-field_value_to_binary(float,     V) -> ["f", <<V:32/float>>];
-field_value_to_binary(long,      V) -> ["l", <<V:64/signed>>];
-field_value_to_binary(short,     V) -> ["s", <<V:16/signed>>];
-field_value_to_binary(bool,      V) -> ["t", if V -> 1; true -> 0 end];
-field_value_to_binary(binary,    V) -> ["x", long_string_to_binary(V)];
-field_value_to_binary(void,     _V) -> ["V"].
+                                       [$D | [Before, <<After:32>>]];
+field_value_to_binary(timestamp, V) -> [$T | <<V:64>>];
+field_value_to_binary(table,     V) -> [$F | table_to_binary(V)];
+field_value_to_binary(array,     V) -> [$A | array_to_binary(V)];
+field_value_to_binary(byte,      V) -> [$b | <<V:8/unsigned>>];
+field_value_to_binary(double,    V) -> [$d | <<V:64/float>>];
+field_value_to_binary(float,     V) -> [$f | <<V:32/float>>];
+field_value_to_binary(long,      V) -> [$l | <<V:64/signed>>];
+field_value_to_binary(short,     V) -> [$s | <<V:16/signed>>];
+field_value_to_binary(bool,      V) -> [$t | [if V -> 1; true -> 0 end]];
+field_value_to_binary(binary,    V) -> [$x | long_string_to_binary(V)];
+field_value_to_binary(void,     _V) -> [$V].
 
 table_to_binary(Table) when is_list(Table) ->
-    BinTable = generate_table(Table),
-    [<<(size(BinTable)):32>>, BinTable].
+    BinTable = generate_table_iolist(Table),
+    [<<(iolist_size(BinTable)):32>> | BinTable].
 
 array_to_binary(Array) when is_list(Array) ->
-    BinArray = generate_array(Array),
-    [<<(size(BinArray)):32>>, BinArray].
+    BinArray = generate_array_iolist(Array),
+    [<<(iolist_size(BinArray)):32>> | BinArray].
 
 generate_table(Table) when is_list(Table) ->
-    list_to_binary(lists:map(fun table_field_to_binary/1, Table)).
+    list_to_binary(generate_table_iolist(Table)).
 
-generate_array(Array) when is_list(Array) ->
-    list_to_binary(lists:map(fun ({T, V}) -> field_value_to_binary(T, V) end,
-                             Array)).
+generate_table_iolist(Table) ->
+    lists:map(fun table_field_to_binary/1, Table).
+
+generate_array_iolist(Array) ->
+    lists:map(fun ({T, V}) -> field_value_to_binary(T, V) end, Array).
 
-short_string_to_binary(String) when is_binary(String) ->
-    Len = size(String),
-    if Len < 256 -> [<<Len:8>>, String];
-       true      -> exit(content_properties_shortstr_overflow)
-    end;
 short_string_to_binary(String) ->
-    Len = length(String),
-    if Len < 256 -> [<<Len:8>>, String];
+    Len = string_length(String),
+    if Len < 256 -> [<<Len:8>> | String];
        true      -> exit(content_properties_shortstr_overflow)
     end.
 
-long_string_to_binary(String) when is_binary(String) ->
-    [<<(size(String)):32>>, String];
 long_string_to_binary(String) ->
-    [<<(length(String)):32>>, String].
+    Len = string_length(String),
+    [<<Len:32>> | String].
+
+string_length(String) when is_binary(String) ->   size(String);
+string_length(String)                        -> length(String).
 
 check_empty_frame_size() ->
     %% Intended to ensure that EMPTY_FRAME_SIZE is defined correctly.
diff --git a/src/rabbit_binary_parser.erl b/src/rabbit_binary_parser.erl
index dc6d090f..2d703033 100644
--- a/src/rabbit_binary_parser.erl
+++ b/src/rabbit_binary_parser.erl
@@ -50,35 +50,35 @@ parse_array(<<ValueAndRest/binary>>) ->
     {Type, Value, Rest} = parse_field_value(ValueAndRest),
     [{Type, Value} | parse_array(Rest)].
 
-parse_field_value(<<"S", VLen:32/unsigned, V:VLen/binary, R/binary>>) ->
+parse_field_value(<<$S, VLen:32/unsigned, V:VLen/binary, R/binary>>) ->
     {longstr, V, R};
 
-parse_field_value(<<"I", V:32/signed, R/binary>>) ->
+parse_field_value(<<$I, V:32/signed, R/binary>>) ->
     {signedint, V, R};
 
-parse_field_value(<<"D", Before:8/unsigned, After:32/unsigned, R/binary>>) ->
+parse_field_value(<<$D, Before:8/unsigned, After:32/unsigned, R/binary>>) ->
     {decimal, {Before, After}, R};
 
-parse_field_value(<<"T", V:64/unsigned, R/binary>>) ->
+parse_field_value(<<$T, V:64/unsigned, R/binary>>) ->
     {timestamp, V, R};
 
-parse_field_value(<<"F", VLen:32/unsigned, Table:VLen/binary, R/binary>>) ->
+parse_field_value(<<$F, VLen:32/unsigned, Table:VLen/binary, R/binary>>) ->
     {table, parse_table(Table), R};
 
-parse_field_value(<<"A", VLen:32/unsigned, Array:VLen/binary, R/binary>>) ->
+parse_field_value(<<$A, VLen:32/unsigned, Array:VLen/binary, R/binary>>) ->
     {array, parse_array(Array), R};
 
-parse_field_value(<<"b", V:8/unsigned, R/binary>>) -> {byte,        V, R};
-parse_field_value(<<"d", V:64/float,   R/binary>>) -> {double,      V, R};
-parse_field_value(<<"f", V:32/float,   R/binary>>) -> {float,       V, R};
-parse_field_value(<<"l", V:64/signed,  R/binary>>) -> {long,        V, R};
-parse_field_value(<<"s", V:16/signed,  R/binary>>) -> {short,       V, R};
-parse_field_value(<<"t", V:8/unsigned, R/binary>>) -> {bool, (V /= 0), R};
+parse_field_value(<<$b, V:8/unsigned, R/binary>>) -> {byte,        V, R};
+parse_field_value(<<$d, V:64/float,   R/binary>>) -> {double,      V, R};
+parse_field_value(<<$f, V:32/float,   R/binary>>) -> {float,       V, R};
+parse_field_value(<<$l, V:64/signed,  R/binary>>) -> {long,        V, R};
+parse_field_value(<<$s, V:16/signed,  R/binary>>) -> {short,       V, R};
+parse_field_value(<<$t, V:8/unsigned, R/binary>>) -> {bool, (V /= 0), R};
 
-parse_field_value(<<"x", VLen:32/unsigned, V:VLen/binary, R/binary>>) ->
+parse_field_value(<<$x, VLen:32/unsigned, V:VLen/binary, R/binary>>) ->
     {binary, V, R};
 
-parse_field_value(<<"V", R/binary>>) ->
+parse_field_value(<<$V, R/binary>>) ->
     {void, undefined, R}.
 
 ensure_content_decoded(Content = #content{properties = Props})