Create new BIF ets:update_counter/4

Conflicts:
	erts/emulator/beam/bif.tab
	lib/stdlib/src/ets.erl

3 files changed, 102 insertions, 4 deletions

diff --git a/lib/stdlib/doc/src/ets.xml b/lib/stdlib/doc/src/ets.xml
index 902a921fbf..6b9524ef63 100644
--- a/lib/stdlib/doc/src/ets.xml
+++ b/lib/stdlib/doc/src/ets.xml
@@ -1618,14 +1618,18 @@ true</pre>
     </func>
     <func> 
       <name name="update_counter" arity="3" clause_i="1"/>
+      <name name="update_counter" arity="4" clause_i="1"/>
       <name name="update_counter" arity="3" clause_i="2"/>
+      <name name="update_counter" arity="4" clause_i="2"/>
       <name name="update_counter" arity="3" clause_i="3"/>
+      <name name="update_counter" arity="4" clause_i="3"/>
       <type variable="Tab"/>
       <type variable="Key"/>
       <type variable="UpdateOp" name_i="1"/>
       <type variable="Pos" name_i="1"/>
       <type variable="Threshold" name_i="1"/>
       <type variable="SetValue" name_i="1"/>
+      <type variable="Default"/>
       <fsummary>Update a counter object in an ETS table.</fsummary>
       <desc>
         <p>This function provides an efficient way to update one or more 
@@ -1667,12 +1671,22 @@ true</pre>
           <seealso marker="#lookup/2">lookup/2</seealso> and 
           <seealso marker="#new/2">new/2</seealso>
           for details on the difference).</p>
+        <p>If a default object <c><anno>Default</anno></c> is given, it is used
+          as the object to be updated if the key is missing from the table. The
+          value in place of the key is ignored and replaced by the proper key
+          value. The return value is as if the default object had not been used,
+          that is a single updated element or a list of them.</p>
         <p>The function will fail with reason <c>badarg</c> if:</p>
         <list type="bulleted">
           <item>the table is not of type <c>set</c> or
           <c>ordered_set</c>,</item>
-          <item>no object with the right key exists,</item>
+          <item>no object with the right key exists and no default object were
+            supplied,</item>
           <item>the object has the wrong arity,</item>
+          <item>the default object arity is smaller than
+            <c><![CDATA[<keypos>]]></c></item>
+          <item>any field from the default object being updated is not an
+            integer</item>
           <item>the element to update is not an integer,</item>
           <item>the element to update is also the key, or,</item>
           <item>any of <c><anno>Pos</anno></c>, <c><anno>Incr</anno></c>, <c><anno>Threshold</anno></c> or
diff --git a/lib/stdlib/src/ets.erl b/lib/stdlib/src/ets.erl
index 26b0393b35..f58b274821 100644
--- a/lib/stdlib/src/ets.erl
+++ b/lib/stdlib/src/ets.erl
@@ -72,7 +72,7 @@
          select_count/2, select_delete/2, select_reverse/1,
          select_reverse/2, select_reverse/3, setopts/2, slot/2,
          take/2,
-         update_counter/3, update_element/3]).
+         update_counter/3, update_counter/4, update_element/3]).
 
 -spec all() -> [Tab] when
       Tab :: tab().
@@ -439,6 +439,38 @@ take(_, _) ->
 update_counter(_, _, _) ->
     erlang:nif_error(undef).
 
+-spec update_counter(Tab, Key, UpdateOp, Default) -> Result when
+                        Tab :: tab(),
+                        Key :: term(),
+                        UpdateOp :: {Pos, Incr}
+                                  | {Pos, Incr, Threshold, SetValue},
+                        Pos :: integer(),
+                        Incr :: integer(),
+                        Threshold :: integer(),
+                        SetValue :: integer(),
+                        Result :: integer(),
+                        Default :: tuple();
+                    (Tab, Key, [UpdateOp], Default) -> [Result] when
+                        Tab :: tab(),
+                        Key :: term(),
+                        UpdateOp :: {Pos, Incr}
+                                  | {Pos, Incr, Threshold, SetValue},
+                        Pos :: integer(),
+                        Incr :: integer(),
+                        Threshold :: integer(),
+                        SetValue :: integer(),
+                        Result :: integer(),
+                        Default :: tuple();
+                    (Tab, Key, Incr, Default) -> Result when
+                        Tab :: tab(),
+                        Key :: term(),
+                        Incr :: integer(),
+                        Result :: integer(),
+                        Default :: tuple().
+
+update_counter(_, _, _, _) ->
+    erlang:nif_error(undef).
+
 -spec update_element(Tab, Key, ElementSpec :: {Pos, Value}) -> boolean() when
       Tab :: tab(),
       Key :: term(),
diff --git a/lib/stdlib/test/ets_SUITE.erl b/lib/stdlib/test/ets_SUITE.erl
index 2674f6886f..cc0212ae5e 100644
--- a/lib/stdlib/test/ets_SUITE.erl
+++ b/lib/stdlib/test/ets_SUITE.erl
@@ -47,6 +47,7 @@
 -export([ordered/1, ordered_match/1, interface_equality/1,
 	 fixtable_next/1, fixtable_insert/1, rename/1, rename_unnamed/1, evil_rename/1,
 	 update_element/1, update_counter/1, evil_update_counter/1, partly_bound/1, match_heavy/1]).
+-export([update_counter_with_default/1]).
 -export([member/1]).
 -export([memory/1]).
 -export([select_fail/1]).
@@ -99,7 +100,7 @@
 	 misc1_do/1, safe_fixtable_do/1, info_do/1, dups_do/1, heavy_lookup_do/1,
 	 heavy_lookup_element_do/1, member_do/1, otp_5340_do/1, otp_7665_do/1, meta_wb_do/1,
 	 do_heavy_concurrent/1, tab2file2_do/2, exit_large_table_owner_do/2,
-         types_do/1, sleeper/0, memory_do/1,
+         types_do/1, sleeper/0, memory_do/1, update_counter_with_default_do/1,
 	 ms_tracee_dummy/1, ms_tracee_dummy/2, ms_tracee_dummy/3, ms_tracee_dummy/4
 	]).
 
@@ -136,7 +137,8 @@ all() ->
      {group, heavy}, ordered, ordered_match,
      interface_equality, fixtable_next, fixtable_insert,
      rename, rename_unnamed, evil_rename, update_element,
-     update_counter, evil_update_counter, partly_bound,
+     update_counter, evil_update_counter,
+     update_counter_with_default, partly_bound,
      match_heavy, {group, fold}, member, t_delete_object,
      t_init_table, t_whitebox, t_delete_all_objects,
      t_insert_list, t_test_ms, t_select_delete, t_ets_dets,
@@ -1761,6 +1763,14 @@ update_counter_do(Opts) ->
     OrdSet = ets_new(ordered_set,[ordered_set | Opts]),
     update_counter_for(Set),
     update_counter_for(OrdSet),
+    ets:delete_all_objects(Set),
+    ets:delete_all_objects(OrdSet),
+    ets:safe_fixtable(Set, true),
+    ets:safe_fixtable(OrdSet, true),
+    update_counter_for(Set),
+    update_counter_for(OrdSet),
+    ets:safe_fixtable(Set, false),
+    ets:safe_fixtable(OrdSet, false),
     ets:delete(Set),
     ets:delete(OrdSet),
     update_counter_neg(Opts).
@@ -1780,10 +1790,14 @@ update_counter_for(T) ->
 		      ?line {NewObj, Ret} = uc_mimic(Obj,Arg3),
 		      ArgHash = erlang:phash2({T,a,Arg3}),
 		      %%io:format("update_counter(~p, ~p, ~p) expecting ~p\n",[T,a,Arg3,Ret]),
+                      [DefaultObj] = ets:lookup(T, a),
 		      ?line Ret = ets:update_counter(T,a,Arg3),
+                      Ret = ets:update_counter(T, b, Arg3, DefaultObj),   % Use other key
 		      ?line ArgHash = erlang:phash2({T,a,Arg3}),
 		      %%io:format("NewObj=~p~n ",[NewObj]),
 		      ?line [NewObj] = ets:lookup(T,a),
+                      true = ets:lookup(T, b) =:= [setelement(1, NewObj, b)],
+                      ets:delete(T, b),
 		      Myself(NewObj,Times-1,Arg3,Myself)
 	      end,		  
 
@@ -2008,6 +2022,44 @@ evil_counter_1(Iter, T) ->
     ets:update_counter(T, dracula, 1),
     evil_counter_1(Iter-1, T).
 
+update_counter_with_default(Config) when is_list(Config) ->
+	repeat_for_opts(update_counter_with_default_do).
+
+update_counter_with_default_do(Opts) ->
+    T1 = ets_new(a, [set | Opts]),
+    %% Insert default object.
+    3 = ets:update_counter(T1, foo, 2, {beaufort,1}),
+    %% Increment.
+    5 = ets:update_counter(T1, foo, 2, {cabecou,1}),
+    %% Increment with list.
+    [9] = ets:update_counter(T1, foo, [{2,4}], {camembert,1}),
+    %% Same with non-immediate key.
+    3 = ets:update_counter(T1, {foo,bar}, 2, {{chaource,chevrotin},1}),
+    5 = ets:update_counter(T1, {foo,bar}, 2, {{cantal,comté},1}),
+    [9] = ets:update_counter(T1, {foo,bar}, [{2,4}], {{emmental,de,savoie},1}),
+    %% Same with ordered set.
+    T2 = ets_new(b, [ordered_set | Opts]),
+    3 = ets:update_counter(T2, foo, 2, {maroilles,1}),
+    5 = ets:update_counter(T2, foo, 2, {mimolette,1}),
+    [9] = ets:update_counter(T2, foo, [{2,4}], {morbier,1}),
+    3 = ets:update_counter(T2, {foo,bar}, 2, {{laguiole},1}),
+    5 = ets:update_counter(T2, {foo,bar}, 2, {{saint,nectaire},1}),
+    [9] = ets:update_counter(T2, {foo,bar}, [{2,4}], {{rocamadour},1}),
+    %% Arithmetically-equal keys.
+    3 = ets:update_counter(T2, 1.0, 2, {1,1}),
+    5 = ets:update_counter(T2, 1, 2, {1,1}),
+    7 = ets:update_counter(T2, 1, 2, {1.0,1}),
+    %% Same with reversed type difference.
+    3 = ets:update_counter(T2, 2, 2, {2.0,1}),
+    5 = ets:update_counter(T2, 2.0, 2, {2.0,1}),
+    7 = ets:update_counter(T2, 2.0, 2, {2,1}),
+    %% bar is not an integer.
+    {'EXIT',{badarg,_}} = (catch ets:update_counter(T1, qux, 3, {saint,félicien})),
+    %% No third element in default value.
+    {'EXIT',{badarg,_}} = (catch ets:update_counter(T1, qux, [{3,1}], {roquefort,1})),
+
+    ok.
+
 fixtable_next(doc) ->
     ["Check that a first-next sequence always works on a fixed table"];
 fixtable_next(suite) ->