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authorFilipe David Manana <[email protected]>2011-05-16 17:00:25 +0100
committerFilipe David Manana <[email protected]>2011-08-27 21:16:21 -0700
commit1b2cea397131a36a39b18c6ce8c6944bf11db4c7 (patch)
treee3f6ec427883d36e3ab8104ee73eb1c9c5966fcb /erts
parent9a52e239698ae62cddbc0d780502c72458867b6f (diff)
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Add erlang:external_size/2 BIF
This BIF's second parameter is a list of options. Currently the only allowed option is {minor_version, Version} where version is either 0 (default) or 1.
Diffstat (limited to 'erts')
-rw-r--r--erts/doc/src/erlang.xml50
-rw-r--r--erts/emulator/beam/bif.tab2
-rw-r--r--erts/emulator/beam/external.c49
-rw-r--r--erts/emulator/beam/external.h1
-rw-r--r--erts/emulator/test/binary_SUITE.erl16
5 files changed, 116 insertions, 2 deletions
diff --git a/erts/doc/src/erlang.xml b/erts/doc/src/erlang.xml
index ad7a57bd73..84d4160e6a 100644
--- a/erts/doc/src/erlang.xml
+++ b/erts/doc/src/erlang.xml
@@ -1035,6 +1035,56 @@ b</pre>
</desc>
</func>
<func>
+ <name>erlang:external_size(Term) -> integer() >= 0</name>
+ <fsummary>Calculate the maximum size for a term encoded in the Erlang
+ external term format</fsummary>
+ <type>
+ <v>Term = term()</v>
+ </type>
+ <desc>
+ <p>Calculates, without doing the encoding, the maximum byte size for
+ a term encoded in the Erlang external term format. The following
+ condition applies always:</p>
+ <p>
+ <pre>
+> <input>Size1 = byte_size(term_to_binary(Term)),</input>
+> <input>Size2 = erlang:external_size(Term),</input>
+> <input>true = Size1 =&lt; Size2.</input>
+true
+ </pre>
+ </p>
+ <p>This is equivalent to a call to: <code>erlang:external_size(Term, [])
+ </code></p>
+ </desc>
+ </func>
+ <func>
+ <name>erlang:external_size(Term, [Option]) -> integer() >= 0</name>
+ <fsummary>Calculate the maximum size for a term encoded in the Erlang
+ external term format</fsummary>
+ <type>
+ <v>Term = term()</v>
+ <v>Option = {minor_version, Version}</v>
+ </type>
+ <desc>
+ <p>Calculates, without doing the encoding, the maximum byte size for
+ a term encoded in the Erlang external term format. The following
+ condition applies always:</p>
+ <p>
+ <pre>
+> <input>Size1 = byte_size(term_to_binary(Term, Options)),</input>
+> <input>Size2 = erlang:external_size(Term, Options),</input>
+> <input>true = Size1 =&lt; Size2.</input>
+true
+ </pre>
+ </p>
+ <p>The option <c>{minor_version, Version}</c> specifies how floats
+ are encoded. See
+ <seealso marker="#term_to_binary/2">term_to_binary/2</seealso> for
+ a more detailed description.
+ </p>
+ </desc>
+ </func>
+ <func>
<name>float(Number) -> float()</name>
<fsummary>Convert a number to a float</fsummary>
<type>
diff --git a/erts/emulator/beam/bif.tab b/erts/emulator/beam/bif.tab
index b171e99e03..831c0b1ce6 100644
--- a/erts/emulator/beam/bif.tab
+++ b/erts/emulator/beam/bif.tab
@@ -87,6 +87,8 @@ bif erlang:exit/2
bif 'erl.lang.proc':signal/2 ebif_signal_2 exit_2
bif erlang:external_size/1
bif 'erl.lang.term':external_size/1 ebif_external_size_1
+bif erlang:external_size/2
+bif 'erl.lang.term':external_size/2 ebif_external_size_2
ubif erlang:float/1
ubif 'erl.lang.number':to_float/1 ebif_to_float_1 float_1
bif erlang:float_to_list/1
diff --git a/erts/emulator/beam/external.c b/erts/emulator/beam/external.c
index 1a102f7187..6953e7fe7d 100644
--- a/erts/emulator/beam/external.c
+++ b/erts/emulator/beam/external.c
@@ -459,6 +459,12 @@ Uint erts_encode_ext_size(Eterm term)
+ 1 /* VERSION_MAGIC */;
}
+Uint erts_encode_ext_size_2(Eterm term, unsigned dflags)
+{
+ return encode_size_struct2(NULL, term, TERM_TO_BINARY_DFLAGS|dflags)
+ + 1 /* VERSION_MAGIC */;
+}
+
Uint erts_encode_ext_size_ets(Eterm term)
{
return encode_size_struct2(NULL, term, TERM_TO_BINARY_DFLAGS|DFLAGS_INTERNAL_TAGS);
@@ -1262,6 +1268,49 @@ external_size_1(Process* p, Eterm Term)
}
Eterm
+external_size_2(Process* p, Eterm Term, Eterm Flags)
+{
+ Uint size;
+ Uint flags = TERM_TO_BINARY_DFLAGS;
+
+ while (is_list(Flags)) {
+ Eterm arg = CAR(list_val(Flags));
+ Eterm* tp;
+
+ if (is_tuple(arg) && *(tp = tuple_val(arg)) == make_arityval(2)) {
+ if (tp[1] == am_minor_version && is_small(tp[2])) {
+ switch (signed_val(tp[2])) {
+ case 0:
+ break;
+ case 1:
+ flags |= DFLAG_NEW_FLOATS;
+ break;
+ default:
+ goto error;
+ }
+ } else {
+ goto error;
+ }
+ } else {
+ error:
+ BIF_ERROR(p, BADARG);
+ }
+ Flags = CDR(list_val(Flags));
+ }
+ if (is_not_nil(Flags)) {
+ goto error;
+ }
+
+ size = erts_encode_ext_size_2(Term, flags);
+ if (IS_USMALL(0, size)) {
+ BIF_RET(make_small(size));
+ } else {
+ Eterm* hp = HAlloc(p, BIG_UINT_HEAP_SIZE);
+ BIF_RET(uint_to_big(size, hp));
+ }
+}
+
+Eterm
erts_term_to_binary(Process* p, Eterm Term, int level, Uint flags)
{
Uint size;
diff --git a/erts/emulator/beam/external.h b/erts/emulator/beam/external.h
index d8287b96a4..72fe74baf2 100644
--- a/erts/emulator/beam/external.h
+++ b/erts/emulator/beam/external.h
@@ -160,6 +160,7 @@ Uint erts_encode_dist_ext_size(Eterm, Uint32, ErtsAtomCacheMap *);
void erts_encode_dist_ext(Eterm, byte **, Uint32, ErtsAtomCacheMap *);
Uint erts_encode_ext_size(Eterm);
+Uint erts_encode_ext_size_2(Eterm, unsigned);
Uint erts_encode_ext_size_ets(Eterm);
void erts_encode_ext(Eterm, byte **);
byte* erts_encode_ext_ets(Eterm, byte *, struct erl_off_heap_header** ext_off_heap);
diff --git a/erts/emulator/test/binary_SUITE.erl b/erts/emulator/test/binary_SUITE.erl
index 4e82381fba..fed5854112 100644
--- a/erts/emulator/test/binary_SUITE.erl
+++ b/erts/emulator/test/binary_SUITE.erl
@@ -478,6 +478,11 @@ terms(Config) when is_list(Config) ->
Sz when is_integer(Sz), size(Bin) =< Sz ->
ok
end,
+ Bin1 = term_to_binary(Term, [{minor_version, 1}]),
+ case erlang:external_size(Bin1, [{minor_version, 1}]) of
+ Sz1 when is_integer(Sz1), size(Bin1) =< Sz1 ->
+ ok
+ end,
Term = binary_to_term(Bin),
Term = binary_to_term(Bin, [safe]),
Unaligned = make_unaligned_sub_binary(Bin),
@@ -510,7 +515,12 @@ terms_float(Config) when is_list(Config) ->
Term = binary_to_term(Bin0),
Bin1 = term_to_binary(Term, [{minor_version,1}]),
Term = binary_to_term(Bin1),
- true = size(Bin1) < size(Bin0)
+ true = size(Bin1) < size(Bin0),
+ Size0 = erlang:external_size(Term),
+ Size00 = erlang:external_size(Term, [{minor_version, 0}]),
+ Size1 = erlang:external_size(Term, [{minor_version, 1}]),
+ true = (Size0 =:= Size00),
+ true = Size1 < Size0
end).
external_size(Config) when is_list(Config) ->
@@ -526,7 +536,9 @@ external_size(Config) when is_list(Config) ->
io:format(" Aligned size: ~p\n", [Sz1]),
io:format("Unaligned size: ~p\n", [Sz2]),
?line ?t:fail()
- end.
+ end,
+ ?line erlang:external_size(Bin) =:= erlang:external_size(Bin, [{minor_version, 1}]),
+ ?line erlang:external_size(Unaligned) =:= erlang:external_size(Unaligned, [{minor_version, 1}]).
external_size_1(Term, Size0, Limit) when Size0 < Limit ->
case erlang:external_size(Term) of