From 8eadd0297d9676a9004673f9efa2574283942f9f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Wed, 16 Apr 2014 14:35:23 +0200
Subject: BER: Optimize decoding of ENUMERATED

---
 lib/asn1/src/asn1ct_gen_ber_bin_v2.erl | 28 ++++++++++++++++++++++-
 lib/asn1/src/asn1rtt_ber.erl           | 41 ++--------------------------------
 2 files changed, 29 insertions(+), 40 deletions(-)

(limited to 'lib/asn1')

diff --git a/lib/asn1/src/asn1ct_gen_ber_bin_v2.erl b/lib/asn1/src/asn1ct_gen_ber_bin_v2.erl
index 4c08f24619..bf5d649029 100644
--- a/lib/asn1/src/asn1ct_gen_ber_bin_v2.erl
+++ b/lib/asn1/src/asn1ct_gen_ber_bin_v2.erl
@@ -537,7 +537,7 @@ gen_dec_prim(Att, BytesVar, DoTag) ->
 					    [{curr,val},{asis,NNL}]}])
 			     end);
 	{'ENUMERATED',NNL} ->
-	    call(decode_enumerated, [BytesVar,{asis,NNL},TagStr]);
+	    gen_dec_enumerated(BytesVar, NNL, TagStr);
 	'REAL' ->
 	    asn1ct_name:new(tmpbuf),
 	    emit(["begin",nl,
@@ -677,6 +677,32 @@ check_constraint(F, Args, Constr, PreConstr0, ReturnVal0) ->
 		  "end",nl,
 		 "end"])
     end.
+
+gen_dec_enumerated(BytesVar, NNL0, TagStr) ->
+    asn1ct_name:new(enum),
+    emit(["case ",
+	  {call,ber,decode_integer,[BytesVar,TagStr]},
+	  " of",nl]),
+    NNL = case NNL0 of
+	      {L1,L2} ->
+		  L1 ++ L2 ++ [accept];
+	      [_|_] ->
+		  NNL0 ++ [error]
+	  end,
+    gen_dec_enumerated_1(NNL),
+    emit("end").
+
+gen_dec_enumerated_1([accept]) ->
+    asn1ct_name:new(default),
+    emit([{curr,default}," -> {asn1_enum,",{curr,default},"}",nl]);
+gen_dec_enumerated_1([error]) ->
+    asn1ct_name:new(default),
+    emit([{curr,default}," -> exit({error,{asn1,{illegal_enumerated,",
+	  {curr,default},"}}})",nl]);
+gen_dec_enumerated_1([{V,K}|T]) ->
+    emit([{asis,K}," -> ",{asis,V},";",nl]),
+    gen_dec_enumerated_1(T).
+
     
 %% Object code generating for encoding and decoding
 %% ------------------------------------------------
diff --git a/lib/asn1/src/asn1rtt_ber.erl b/lib/asn1/src/asn1rtt_ber.erl
index c65e7dea11..0c3c31e1d8 100644
--- a/lib/asn1/src/asn1rtt_ber.erl
+++ b/lib/asn1/src/asn1rtt_ber.erl
@@ -28,7 +28,7 @@
 	 encode_integer/2,encode_integer/3,
 	 decode_integer/2,
 	 number2name/2,
-	 encode_enumerated/2,decode_enumerated/3,
+	 encode_enumerated/2,
 	 encode_unnamed_bit_string/2,encode_unnamed_bit_string/3,
 	 encode_named_bit_string/3,encode_named_bit_string/4,
 	 encode_bit_string/4,
@@ -700,10 +700,7 @@ encode_integer_neg(N, Acc) ->
 %%===============================================================================
 
 decode_integer(Tlv, TagIn) ->
-    V = match_tags(Tlv, TagIn),
-    decode_integer(V).
-
-decode_integer(Bin) ->
+    Bin = match_tags(Tlv, TagIn),
     Len = byte_size(Bin),
     <<Int:Len/signed-unit:8>> = Bin,
     Int.
@@ -725,40 +722,6 @@ number2name(Int, NamedNumberList) ->
 encode_enumerated(Val, TagIn) when is_integer(Val) ->
     encode_tags(TagIn, encode_integer(Val)).
 
-%%============================================================================
-%% decode enumerated value
-%%   (Buffer, Range, NamedNumberList, HasTag, TotalLen) ->  Value
-%%===========================================================================
-decode_enumerated(Tlv, NamedNumberList, Tags) ->
-    Buffer = match_tags(Tlv, Tags),
-    decode_enumerated_notag(Buffer, NamedNumberList, Tags).
-
-decode_enumerated_notag(Buffer, {NamedNumberList,ExtList}, _Tags) ->
-    IVal = decode_integer(Buffer),
-    case decode_enumerated1(IVal, NamedNumberList) of
-	{asn1_enum,IVal} ->
-	    decode_enumerated1(IVal,ExtList);
-	EVal ->
-	    EVal
-    end;
-decode_enumerated_notag(Buffer, NNList, _Tags) ->
-    IVal = decode_integer(Buffer),
-    case decode_enumerated1(IVal, NNList) of
-	{asn1_enum,_} ->
-	    exit({error,{asn1, {illegal_enumerated, IVal}}});
-	EVal ->
-	    EVal
-    end.
-
-decode_enumerated1(Val, NamedNumberList) ->
-    %% it must be a named integer
-    case lists:keyfind(Val, 2, NamedNumberList) of
-	{NamedVal, _} ->
-	    NamedVal;
-	_ ->
-	    {asn1_enum,Val}
-    end.
-
 %%============================================================================
 %% Bitstring value, ITU_T X.690 Chapter 8.6
 %%
-- 
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