PubSub: Use integer type for timestamps (SQL)

Store PubSub item creation/modification timestamps as integers instead
of "$megasec:$sec:$microsec" strings.  This can improve the performance
of certain SQL queries significantly.

Thanks to Ammonit Measurement GmbH for sponsoring this work.

sql/lite.new.sql

@@ -262,8 +262,8 @@ CREATE TABLE pubsub_item (
   nodeid bigint REFERENCES pubsub_node(nodeid) ON DELETE CASCADE,
   itemid text NOT NULL,
   publisher text NOT NULL,
-  creation varchar(32) NOT NULL,
+  creation BIGINT UNSIGNED NOT NULL,
-  modification varchar(32) NOT NULL,
+  modification BIGINT UNSIGNED NOT NULL,
   payload text NOT NULL DEFAULT ''
 );
 CREATE INDEX i_pubsub_item_itemid ON pubsub_item (itemid);

sql/lite.sql

@@ -238,8 +238,8 @@ CREATE TABLE pubsub_item (
   nodeid bigint REFERENCES pubsub_node(nodeid) ON DELETE CASCADE,
   itemid text NOT NULL,
   publisher text NOT NULL,
-  creation varchar(32) NOT NULL,
+  creation BIGINT UNSIGNED NOT NULL,
-  modification varchar(32) NOT NULL,
+  modification BIGINT UNSIGNED NOT NULL,
   payload text NOT NULL DEFAULT ''
 );
 CREATE INDEX i_pubsub_item_itemid ON pubsub_item (itemid);

sql/mssql.sql

@@ -210,8 +210,8 @@ CREATE TABLE [dbo].[pubsub_item] (
         [nodeid] [bigint] NULL,
         [itemid] [varchar] (255) NOT NULL,
         [publisher] [varchar] (250) NOT NULL,
-        [creation] [varchar] (32) NOT NULL,
+        [creation] [bigint] NOT NULL,
-        [modification] [varchar] (32) NOT NULL,
+        [modification] [bigint] NOT NULL,
         [payload] [text] NOT NULL DEFAULT ''
 ) TEXTIMAGE_ON [PRIMARY];
 

sql/mysql.new.sql

@@ -277,8 +277,8 @@ CREATE TABLE pubsub_item (
   nodeid bigint,
   itemid text NOT NULL,
   publisher text NOT NULL,
-  creation varchar(32) NOT NULL,
+  creation BIGINT UNSIGNED NOT NULL,
-  modification varchar(32) NOT NULL,
+  modification BIGINT UNSIGNED NOT NULL,
   payload mediumtext NOT NULL
 ) ENGINE=InnoDB CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
 CREATE INDEX i_pubsub_item_itemid ON pubsub_item(itemid(36));

sql/mysql.sql

@@ -253,8 +253,8 @@ CREATE TABLE pubsub_item (
   nodeid bigint,
   itemid text NOT NULL,
   publisher text NOT NULL,
-  creation varchar(32) NOT NULL,
+  creation BIGINT UNSIGNED NOT NULL,
-  modification varchar(32) NOT NULL,
+  modification BIGINT UNSIGNED NOT NULL,
   payload mediumtext NOT NULL
 ) ENGINE=InnoDB CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;
 CREATE INDEX i_pubsub_item_itemid ON pubsub_item(itemid(36));

sql/pg.new.sql

@@ -427,8 +427,8 @@ CREATE TABLE pubsub_item (
   nodeid bigint REFERENCES pubsub_node(nodeid) ON DELETE CASCADE,
   itemid text NOT NULL,
   publisher text NOT NULL,
-  creation varchar(32) NOT NULL,
+  creation BIGINT NOT NULL,
-  modification varchar(32) NOT NULL,
+  modification BIGINT NOT NULL,
   payload text NOT NULL DEFAULT ''
 );
 CREATE INDEX i_pubsub_item_itemid ON pubsub_item USING btree (itemid);

sql/pg.sql

@@ -256,8 +256,8 @@ CREATE TABLE pubsub_item (
   nodeid bigint REFERENCES pubsub_node(nodeid) ON DELETE CASCADE,
   itemid text NOT NULL,
   publisher text NOT NULL,
-  creation varchar(32) NOT NULL,
+  creation BIGINT NOT NULL,
-  modification varchar(32) NOT NULL,
+  modification BIGINT NOT NULL,
   payload text NOT NULL DEFAULT ''
 );
 CREATE INDEX i_pubsub_item_itemid ON pubsub_item USING btree (itemid);

src/node_flat_sql.erl

@@ -820,16 +820,16 @@ set_item(Item) ->
     P = encode_jid(JID),
     Payload = Item#pubsub_item.payload,
     XML = str:join([fxml:element_to_binary(X) || X<-Payload], <<>>),
-    SM = encode_now(M),
+    SM = misc:now_to_usec(M),
-    SC = encode_now(C),
+    SC = misc:now_to_usec(C),
     ?SQL_UPSERT_T(
        "pubsub_item",
        ["!nodeid=%(Nidx)d",
         "!itemid=%(ItemId)s",
         "publisher=%(P)s",
-        "modification=%(SM)s",
+        "modification=%(SM)d",
         "payload=%(XML)s",
-        "-creation=%(SC)s"
+        "-creation=%(SC)d"
        ]),
     ok.
 
@@ -1063,20 +1063,27 @@ rsm_page(Count, Index, Offset, Items) ->
 	     first = #rsm_first{index = Offset, data = First},
 	     last = Last}.
 
+%% Convert <<"2021-08-22T19:25:52.817368Z">> to <<"1629660352817368">>.
+-spec encode_stamp(binary()) -> binary().
 encode_stamp(Stamp) ->
     try xmpp_util:decode_timestamp(Stamp) of
 	Now ->
 	    encode_now(Now)
     catch _:{bad_timestamp, _} ->
-	    Stamp % We should return a proper error to the client instead.
+	    <<"0">> % We should return a proper error to the client instead.
     end.
+
+%% Convert <<"1629660352817368">> to <<"2021-08-22T19:25:52.817368Z">>.
+-spec decode_stamp(binary()) -> binary().
 decode_stamp(Stamp) ->
     xmpp_util:encode_timestamp(decode_now(Stamp)).
 
-encode_now({T1, T2, T3}) ->
+%% Convert {1629, 660352, 817368} to <<"1629660352817368">>.
-    <<(misc:i2l(T1, 6))/binary, ":",
+-spec encode_now(erlang:timestamp()) -> binary().
-      (misc:i2l(T2, 6))/binary, ":",
+encode_now(Now) ->
-      (misc:i2l(T3, 6))/binary>>.
+    integer_to_binary(misc:now_to_usec(Now)).
-decode_now(NowStr) ->
+
-    [MS, S, US] = binary:split(NowStr, <<":">>, [global]),
+%% Convert <<"1629660352817368">> to {1629, 660352, 817368}.
-    {binary_to_integer(MS), binary_to_integer(S), binary_to_integer(US)}.
+-spec decode_now(binary()) -> erlang:timestamp().
+decode_now(Str) ->
+    misc:usec_to_now(binary_to_integer(Str)).

src/pubsub_db_sql.erl

@@ -184,15 +184,10 @@ export(_Server) ->
                                 payload = Payload}) ->
             P = jid:encode(JID),
             XML = str:join([fxml:element_to_binary(X) || X<-Payload], <<>>),
-            SM = encode_now(M),
+            SM = misc:now_to_usec(M),
-            SC = encode_now(C),
+            SC = misc:now_to_usec(C),
             [?SQL("insert into pubsub_item(itemid,nodeid,creation,modification,publisher,payload)"
-                  " values (%(ItemId)s, %(Nidx)d, %(SC)s, %(SM)s, %(P)s, %(XML)s);")];
+                  " values (%(ItemId)s, %(Nidx)d, %(SC)d, %(SM)d, %(P)s, %(XML)s);")];
            (_Host, _R) ->
             []
         end}].
-
-encode_now({T1, T2, T3}) ->
-    <<(misc:i2l(T1, 6))/binary, ":",
-      (misc:i2l(T2, 6))/binary, ":",
-      (misc:i2l(T3, 6))/binary>>.