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authorHans Bolinder <[email protected]>2017-11-07 17:22:16 +0100
committerHans Bolinder <[email protected]>2017-11-28 13:03:46 +0100
commitfc80770ba7645d71a159c807c6aba7956a2eb394 (patch)
treeac75c7cf36e041cd0a16274e01de1ee8317f2b44 /lib
parent3d28da78f3e8bab7a13f4f928cdd7747ab943197 (diff)
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stdlib: Use binary_to_list in base64 when it is faster
It is sometimes faster to use binary_to_list on input, at least when not considering time for garbage collections. The three functions all return a list, and the temporary list created by binary_to_list should be reclaimed very fast. The implementation from before is thus kept.
Diffstat (limited to 'lib')
-rw-r--r--lib/stdlib/src/base64.erl134
1 files changed, 11 insertions, 123 deletions
diff --git a/lib/stdlib/src/base64.erl b/lib/stdlib/src/base64.erl
index 6311f3c86b..6ff6020e53 100644
--- a/lib/stdlib/src/base64.erl
+++ b/lib/stdlib/src/base64.erl
@@ -34,7 +34,7 @@
Base64String :: ascii_string().
encode_to_string(Bin) when is_binary(Bin) ->
- encode_binary_to_string(Bin);
+ encode_to_string(binary_to_list(Bin));
encode_to_string(List) when is_list(List) ->
encode_list_to_string(List).
@@ -47,22 +47,6 @@ encode(Bin) when is_binary(Bin) ->
encode(List) when is_list(List) ->
encode_list(List, <<>>).
-encode_binary_to_string(<<>>) ->
- [];
-encode_binary_to_string(<<B1:8>>) ->
- [b64e(B1 bsr 2),
- b64e((B1 band 3) bsl 4), $=, $=];
-encode_binary_to_string(<<B1:8, B2:8>>) ->
- [b64e(B1 bsr 2),
- b64e(((B1 band 3) bsl 4) bor (B2 bsr 4)),
- b64e((B2 band 15) bsl 2), $=];
-encode_binary_to_string(<<B1:8, B2:8, B3:8, Ls/bits>>) ->
- BB = (B1 bsl 16) bor (B2 bsl 8) bor B3,
- [b64e(BB bsr 18),
- b64e((BB bsr 12) band 63),
- b64e((BB bsr 6) band 63),
- b64e(BB band 63) | encode_binary_to_string(Ls)].
-
encode_list_to_string([]) ->
[];
encode_list_to_string([B1]) ->
@@ -141,7 +125,7 @@ mime_decode(List) when is_list(List) ->
DataString :: ascii_string().
decode_to_string(Bin) when is_binary(Bin) ->
- decode_binary_to_string(Bin);
+ decode_to_string(binary_to_list(Bin));
decode_to_string(List) when is_list(List) ->
decode_list_to_string(List).
@@ -150,7 +134,7 @@ decode_to_string(List) when is_list(List) ->
DataString :: ascii_string().
mime_decode_to_string(Bin) when is_binary(Bin) ->
- mime_decode_binary_to_string(Bin);
+ mime_decode_to_string(binary_to_list(Bin));
mime_decode_to_string(List) when is_list(List) ->
mime_decode_list_to_string(List).
@@ -339,67 +323,6 @@ mime_decode_list_to_string_after_eq([], B1, B2, eq) ->
mime_decode_list_to_string_after_eq([], B1, B2, B3) ->
binary_to_list(<<B1:6,B2:6,(B3 bsr 2):4>>).
-mime_decode_binary_to_string(<<0:8, Cs/bits>>) ->
- mime_decode_binary_to_string(Cs);
-mime_decode_binary_to_string(<<C1:8, Cs/bits>>) ->
- case b64d(C1) of
- B1 when is_integer(B1) -> mime_decode_binary_to_string(Cs, B1);
- _ -> mime_decode_binary_to_string(Cs) % eq is padding
- end;
-mime_decode_binary_to_string(<<>>) ->
- [].
-
-mime_decode_binary_to_string(<<0:8, Cs/bits>>, B1) ->
- mime_decode_binary_to_string(Cs, B1);
-mime_decode_binary_to_string(<<C2:8, Cs/bits>>, B1) ->
- case b64d(C2) of
- B2 when is_integer(B2) ->
- mime_decode_binary_to_string(Cs, B1, B2);
- _ -> mime_decode_binary_to_string(Cs, B1) % eq is padding
- end.
-
-mime_decode_binary_to_string(<<0:8, Cs/bits>>, B1, B2) ->
- mime_decode_binary_to_string(Cs, B1, B2);
-mime_decode_binary_to_string(<<C3:8, Cs/bits>>, B1, B2) ->
- case b64d(C3) of
- B3 when is_integer(B3) ->
- mime_decode_binary_to_string(Cs, B1, B2, B3);
- eq=B3 -> mime_decode_binary_to_string_after_eq(Cs, B1, B2, B3);
- _ -> mime_decode_binary_to_string(Cs, B1, B2)
- end.
-
-mime_decode_binary_to_string(<<0:8, Cs/bits>>, B1, B2, B3) ->
- mime_decode_binary_to_string(Cs, B1, B2, B3);
-mime_decode_binary_to_string(<<C4:8, Cs/bits>>, B1, B2, B3) ->
- case b64d(C4) of
- B4 when is_integer(B4) ->
- Bits4x6 = (B1 bsl 18) bor (B2 bsl 12) bor (B3 bsl 6) bor B4,
- Octet1 = Bits4x6 bsr 16,
- Octet2 = (Bits4x6 bsr 8) band 16#ff,
- Octet3 = Bits4x6 band 16#ff,
- [Octet1, Octet2, Octet3 | mime_decode_binary_to_string(Cs)];
- eq ->
- mime_decode_binary_to_string_after_eq(Cs, B1, B2, B3);
- _ -> mime_decode_binary_to_string(Cs, B1, B2, B3)
- end.
-
-mime_decode_binary_to_string_after_eq(<<0:8, Cs/bits>>, B1, B2, B3) ->
- mime_decode_binary_to_string_after_eq(Cs, B1, B2, B3);
-mime_decode_binary_to_string_after_eq(<<C:8, Cs/bits>>=Cs0, B1, B2, B3) ->
- case b64d(C) of
- B when is_integer(B) ->
- %% More valid data, skip the eq as invalid
- case B3 of
- eq -> mime_decode_binary_to_string(Cs, B1, B2, B);
- _ -> mime_decode_binary_to_string(Cs0, B1, B2, B3)
- end;
- _ -> mime_decode_binary_to_string_after_eq(Cs, B1, B2, B3)
- end;
-mime_decode_binary_to_string_after_eq(<<>>, B1, B2, eq) ->
- binary_to_list(<<B1:6,(B2 bsr 4):2>>);
-mime_decode_binary_to_string_after_eq(<<>>, B1, B2, B3) ->
- binary_to_list(<<B1:6,B2:6,(B3 bsr 2):4>>).
-
decode_list([C1 | Cs], A) ->
case b64d(C1) of
ws -> decode_list(Cs, A);
@@ -456,6 +379,14 @@ decode_binary(<<C4:8, Cs/bits>>, A, B1, B2, B3) ->
B4 -> decode_binary(Cs, <<A/binary,B1:6,B2:6,B3:6,B4:6>>)
end.
+only_ws_binary(<<>>, A) ->
+ A;
+only_ws_binary(<<C:8, Cs/bits>>, A) ->
+ case b64d(C) of
+ ws -> only_ws_binary(Cs, A);
+ _ -> erlang:error(function_clause)
+ end.
+
decode_list_to_string([C1 | Cs]) ->
case b64d(C1) of
ws -> decode_list_to_string(Cs);
@@ -500,49 +431,6 @@ only_ws([C | Cs], A) ->
_ -> erlang:error(function_clause)
end.
-decode_binary_to_string(<<C1:8, Cs/bits>>) ->
- case b64d(C1) of
- ws -> decode_binary_to_string(Cs);
- B1 -> decode_binary_to_string(Cs, B1)
- end;
-decode_binary_to_string(<<>>) ->
- [].
-
-decode_binary_to_string(<<C2:8, Cs/bits>>, B1) ->
- case b64d(C2) of
- ws -> decode_binary_to_string(Cs, B1);
- B2 -> decode_binary_to_string(Cs, B1, B2)
- end.
-
-decode_binary_to_string(<<C3:8, Cs/bits>>, B1, B2) ->
- case b64d(C3) of
- ws -> decode_binary_to_string(Cs, B1, B2);
- B3 -> decode_binary_to_string(Cs, B1, B2, B3)
- end.
-
-decode_binary_to_string(<<C4:8, Cs/bits>>, B1, B2, B3) ->
- case b64d(C4) of
- ws -> decode_binary_to_string(Cs, B1, B2, B3);
- eq when B3 =:= eq ->
- only_ws_binary(Cs, binary_to_list(<<B1:6,(B2 bsr 4):2>>));
- eq ->
- only_ws_binary(Cs, binary_to_list(<<B1:6,B2:6,(B3 bsr 2):4>>));
- B4 ->
- Bits4x6 = (B1 bsl 18) bor (B2 bsl 12) bor (B3 bsl 6) bor B4,
- Octet1 = Bits4x6 bsr 16,
- Octet2 = (Bits4x6 bsr 8) band 16#ff,
- Octet3 = Bits4x6 band 16#ff,
- [Octet1, Octet2, Octet3 | decode_binary_to_string(Cs)]
- end.
-
-only_ws_binary(<<>>, A) ->
- A;
-only_ws_binary(<<C:8, Cs/bits>>, A) ->
- case b64d(C) of
- ws -> only_ws_binary(Cs, A);
- _ -> erlang:error(function_clause)
- end.
-
%%%========================================================================
%%% Internal functions
%%%========================================================================