From c2ec5589d5eaf9ef791932a187b4527ab737e3c0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bj=C3=B6rn=20Gustavsson?= <bjorn@erlang.org>
Date: Fri, 8 Mar 2013 15:11:05 +0100
Subject: BER: Optimize handling of constraints for INTEGERs
This slight optimization will also eliminate some Dialyzer warnings.
---
lib/asn1/src/asn1ct_gen_ber_bin_v2.erl | 73 ++++++++++++++++++----------------
lib/asn1/src/asn1rtt_ber.erl | 31 +++++++--------
2 files changed, 53 insertions(+), 51 deletions(-)
diff --git a/lib/asn1/src/asn1ct_gen_ber_bin_v2.erl b/lib/asn1/src/asn1ct_gen_ber_bin_v2.erl
index 4073643f9e..c57bb6a335 100644
--- a/lib/asn1/src/asn1ct_gen_ber_bin_v2.erl
+++ b/lib/asn1/src/asn1ct_gen_ber_bin_v2.erl
@@ -458,16 +458,7 @@ gen_dec_prim(Erules,Att,BytesVar,DoTag,TagIn,Form,OptOrMand) ->
%% Constraint = Att#type.constraint,
%% Constraint = [],
Constraint = get_size_constraint(Att#type.constraint),
- ValueRange =
- case get_constraint(Att#type.constraint,'ValueRange') of
- no -> [];
- Tv -> Tv
- end,
- SingleValue =
- case get_constraint(Att#type.constraint,'SingleValue') of
- no -> [];
- Sv -> Sv
- end,
+ IntConstr = int_constr(Att#type.constraint),
AsBin = case get(binary_strings) of
true -> "_as_bin";
_ -> ""
@@ -490,14 +481,27 @@ gen_dec_prim(Erules,Att,BytesVar,DoTag,TagIn,Form,OptOrMand) ->
emit(["decode_boolean(",BytesVar,","]),
need(decode_boolean, 2);
'INTEGER' ->
- emit(["decode_integer(",BytesVar,",",
- {asis,int_constr(SingleValue,ValueRange)},","]),
- need(decode_integer, 3);
+ case IntConstr of
+ [] ->
+ emit(["decode_integer(",BytesVar,","]),
+ need(decode_integer, 2);
+ {_,_} ->
+ emit(["decode_integer(",BytesVar,",",
+ {asis,IntConstr},","]),
+ need(decode_integer, 3)
+ end;
{'INTEGER',NamedNumberList} ->
- emit(["decode_integer(",BytesVar,",",
- {asis,int_constr(SingleValue,ValueRange)},",",
- {asis,NamedNumberList},","]),
- need(decode_integer, 4);
+ case IntConstr of
+ [] ->
+ emit(["decode_named_integer(",BytesVar,",",
+ {asis,NamedNumberList},","]),
+ need(decode_named_integer, 3);
+ {_,_} ->
+ emit(["decode_named_integer(",BytesVar,",",
+ {asis,IntConstr},",",
+ {asis,NamedNumberList},","]),
+ need(decode_named_integer, 4)
+ end;
{'ENUMERATED',NamedNumberList} ->
emit(["decode_enumerated(",BytesVar,",",
{asis,NamedNumberList},","]),
@@ -591,15 +595,23 @@ gen_dec_prim(Erules,Att,BytesVar,DoTag,TagIn,Form,OptOrMand) ->
emit([TagStr,")"])
end.
-
-int_constr([],[]) ->
- [];
-int_constr([],ValueRange) ->
- ValueRange;
-int_constr(SingleValue,[]) ->
- SingleValue;
-int_constr(SV,VR) ->
- [SV,VR].
+%% Simplify an integer constraint so that we can efficiently test it.
+-spec int_constr(term()) -> [] | {integer(),integer()|'MAX'}.
+int_constr(C) ->
+ case asn1ct_imm:effective_constraint(integer, C) of
+ [{_,[]}] ->
+ %% Extension - ignore constraint.
+ [];
+ [{'ValueRange',{'MIN',_}}] ->
+ %% Tricky to implement efficiently - ignore it.
+ [];
+ [{'ValueRange',{_,_}=Range}] ->
+ Range;
+ [{'SingleValue',Sv}] ->
+ {Sv,Sv};
+ [] ->
+ []
+ end.
gen_dec_bit_string(BytesVar, _Constraint, [_|_]=NNL, TagStr) ->
call(decode_named_bit_string,
@@ -1481,15 +1493,6 @@ get_size_constraint(C) ->
{_,{_,_}=Tc} -> Tc
end.
-get_constraint(C,Key) ->
- case lists:keysearch(Key,1,C) of
- false ->
- no;
- {value,{_,V}} ->
- V
- end.
-
-
get_class_fields(#classdef{typespec=ObjClass}) ->
ObjClass#objectclass.fields;
get_class_fields(#objectclass{fields=Fields}) ->
diff --git a/lib/asn1/src/asn1rtt_ber.erl b/lib/asn1/src/asn1rtt_ber.erl
index 509c091355..499db701d9 100644
--- a/lib/asn1/src/asn1rtt_ber.erl
+++ b/lib/asn1/src/asn1rtt_ber.erl
@@ -27,7 +27,8 @@
skip_ExtensionAdditions/2]).
-export([encode_boolean/2,decode_boolean/2,
encode_integer/2,encode_integer/3,
- decode_integer/3,decode_integer/4,
+ decode_integer/2,decode_integer/3,
+ decode_named_integer/3,decode_named_integer/4,
encode_enumerated/2,decode_enumerated/3,
encode_bit_string/4,
decode_named_bit_string/3,
@@ -700,11 +701,20 @@ encode_integer_neg(N, Acc) ->
%% (Buffer, Range, NamedNumberList, HasTag, TotalLen) -> {Integer, Remain, RemovedBytes}
%%===============================================================================
-decode_integer(Tlv, Range, NamedNumberList, TagIn) ->
+decode_named_integer(Tlv, NamedNumberList, TagIn) ->
+ V = match_tags(Tlv, TagIn),
+ Int = decode_integer(V),
+ number2name(Int, NamedNumberList).
+
+decode_named_integer(Tlv, Range, NamedNumberList, TagIn) ->
V = match_tags(Tlv, TagIn),
Int = range_check_integer(decode_integer(V), Range),
number2name(Int, NamedNumberList).
+decode_integer(Tlv, TagIn) ->
+ V = match_tags(Tlv, TagIn),
+ decode_integer(V).
+
decode_integer(Tlv, Range, TagIn) ->
V = match_tags(Tlv, TagIn),
Int = decode_integer(V),
@@ -715,21 +725,10 @@ decode_integer(Bin) ->
<<Int:Len/signed-unit:8>> = Bin,
Int.
+range_check_integer(Int, {Lb,Ub}) when Lb =< Int, Int =< Ub ->
+ Int;
range_check_integer(Int, Range) ->
- case Range of
- [] -> % No length constraint
- Int;
- {Lb,Ub} when Int >= Lb, Ub >= Int -> % variable length constraint
- Int;
- {_,_} ->
- exit({error,{asn1,{integer_range,Range,Int}}});
- Int -> % fixed value constraint
- Int;
- SingleValue when is_integer(SingleValue) ->
- exit({error,{asn1,{integer_range,Range,Int}}});
- _ -> % some strange constraint that we don't support yet
- Int
- end.
+ exit({error,{asn1,{integer_range,Range,Int}}}).
number2name(Int, []) ->
Int;
--
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