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authorBjörn Gustavsson <[email protected]>2012-12-12 12:20:22 +0100
committerBjörn Gustavsson <[email protected]>2012-12-19 11:52:12 +0100
commitb8c35cfdb858cc68a40d21e58b54e2362f3a456a (patch)
tree12714552a8430888c0957de67456967f8dc87c68 /lib/asn1/src
parent1749a097ef9871124e6d2eecf2c6644f0c133fcc (diff)
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per: Slightly optimize encoding of fixed OCTET STRINGs
Do the following optimizations: * Optimize construction of OCTET STRINGs of size 2 by using the 45 opcode instead of the 10 opcode for each character. * Use exact comparison (implicit by matching) instead of '=='. * Use list literals when more than one integer is added to a list (e.g. [[45,16,2],...] instead of [45,16,2,...]). Results in fewer BEAM instructions and less garbage. * Cons instead of building a nested list when possible. Example: [20,TempLen|TmpVal] instead of [20,TempLen,TmpVal]. * Omit the "2" opcode (align to byte boundary) before the "20" and "21" opcodes (because they imply alignment). * Assign the value to be encoded to a temporary variable, to avoid calling element/2 more than once.
Diffstat (limited to 'lib/asn1/src')
-rw-r--r--lib/asn1/src/asn1ct_gen_per_rt2ct.erl57
1 files changed, 34 insertions, 23 deletions
diff --git a/lib/asn1/src/asn1ct_gen_per_rt2ct.erl b/lib/asn1/src/asn1ct_gen_per_rt2ct.erl
index fa9c3645b3..e6ffc0fb47 100644
--- a/lib/asn1/src/asn1ct_gen_per_rt2ct.erl
+++ b/lib/asn1/src/asn1ct_gen_per_rt2ct.erl
@@ -405,35 +405,46 @@ emit_enc_octet_string(_Erules,Constraint,Value) ->
asn1ct_name:new(tmpval),
emit({" begin",nl}),
emit({" [",{curr,tmpval},"] = ",Value,",",nl}),
- emit({" [10,8,",{curr,tmpval},"]",nl}),
+ emit([" [[10,8],",{curr,tmpval},"]",nl]),
emit(" end");
2 ->
asn1ct_name:new(tmpval),
- emit({" begin",nl}),
- emit({" [",{curr,tmpval},",",{next,tmpval},"] = ",
- Value,",",nl}),
- emit({" [[10,8,",{curr,tmpval},"],[10,8,",
- {next,tmpval},"]]",nl}),
- emit(" end"),
- asn1ct_name:new(tmpval);
- Sv when is_integer(Sv),Sv < 256 ->
+ emit([" begin",nl,
+ " ",{curr,tmpval}," = ",Value,",",nl,
+ " case length(",{curr,tmpval},") of",nl,
+ " 2 ->",nl,
+ " [[45,16,2]|",{curr,tmpval},"];",nl,
+ " _ ->",nl,
+ " exit({error,{value_out_of_bounds,",
+ {curr,tmpval},"}})",nl,
+ " end",nl,
+ " end"]);
+ Sv when is_integer(Sv), Sv < 256 ->
asn1ct_name:new(tmpval),
- emit({" begin",nl}),
- emit({" case length(",Value,") of",nl}),
- emit([" ",{curr,tmpval}," when ",{curr,tmpval}," == ",Sv," ->"]),
- emit([" [2,20,",{curr,tmpval},",",Value,"];",nl]),
- emit({" _ -> exit({error,{value_out_of_bounds,",
- Value,"}})", nl," end",nl}),
- emit(" end");
+ asn1ct_name:new(tmplen),
+ emit([" begin",nl,
+ " ",{curr,tmpval}," = ",Value,",",nl,
+ " case length(",{curr,tmpval},") of",nl,
+ " ",Sv,"=",{curr,tmplen}," ->",nl,
+ " [20,",{curr,tmplen},"|",{curr,tmpval},"];",nl,
+ " _ ->",nl,
+ " exit({error,{value_out_of_bounds,",
+ {curr,tmpval},"}})",nl,
+ " end",nl,
+ " end"]);
Sv when is_integer(Sv),Sv =< 65535 ->
asn1ct_name:new(tmpval),
- emit({" begin",nl}),
- emit({" case length(",Value,") of",nl}),
- emit([" ",{curr,tmpval}," when ",{curr,tmpval}," == ",Sv," ->"]),
- emit([" [<<21,",{curr,tmpval},":16>>|",Value,"];",nl]),
- emit({" _ -> exit({error,{value_out_of_bounds,",
- Value,"}})",nl," end",nl}),
- emit(" end");
+ asn1ct_name:new(tmplen),
+ emit([" begin",nl,
+ " ",{curr,tmpval}," = ",Value,",",nl,
+ " case length(",{curr,tmpval},") of",nl,
+ " ",Sv,"=",{curr,tmplen}," ->",nl,
+ " [<<21,",{curr,tmplen},":16>>|",Value,"];",nl,
+ " _ ->",nl,
+ " exit({error,{value_out_of_bounds,",
+ {curr,tmpval},"}})",nl,
+ " end",nl,
+ " end"]);
C ->
emit({" ?RT_PER:encode_octet_string(",{asis,C},",false,",Value,")",nl})
end.