X-Git-Url: https://git.tokkee.org/?a=blobdiff_plain;f=src%2Fpostrr.sql.in;h=9f34f22100cfd04151da1afb56ca23ec2c3538d8;hb=3d39f72435c8664ea9ffce084b1cc8297b6070fd;hp=10aeb777815720620e55c6a71f75ece9504ddadc;hpb=9f6643ebba9ef1a48b4a9e7c90142cfeb3723ddc;p=postrr.git

diff --git a/src/postrr.sql.in b/src/postrr.sql.in
index 10aeb77..9f34f22 100644
--- a/src/postrr.sql.in
+++ b/src/postrr.sql.in
@@ -117,6 +117,11 @@ CREATE CAST (rrtimeslice AS timestamptz)
 	WITH FUNCTION Tstamptz(rrtimeslice);
 	-- EXPLICIT
 
+CREATE OR REPLACE FUNCTION rrtimeslice_cmp(rrtimeslice, rrtimeslice)
+	RETURNS integer
+	AS 'postrr-@POSTRR_MAJOR_VERSION@.@POSTRR_MINOR_VERSION@', 'rrtimeslice_cmp'
+	LANGUAGE 'C' IMMUTABLE STRICT;
+
 CREATE OR REPLACE FUNCTION rrtimeslice_seq_eq(rrtimeslice, rrtimeslice)
 	RETURNS boolean
 	AS 'postrr-@POSTRR_MAJOR_VERSION@.@POSTRR_MINOR_VERSION@', 'rrtimeslice_seq_eq'
@@ -315,6 +320,7 @@ DECLARE
 	ts_str text;
 	v_str text;
 	update_qry text;
+	status integer;
 	newts rrtimeslice;
 	new cdata;
 BEGIN
@@ -325,13 +331,13 @@ BEGIN
 
 	update_qry = 'CData_update(' || vcol || ', ' || v_str || ')';
 
+	-- XXX: handle race conditions
+
 	BEGIN
-		EXECUTE 'UPDATE ' || tbl
-			|| ' SET ' || tscol || ' = ' || ts_str
-			|| ', ' || vcol || ' = ' || update_qry
+		EXECUTE 'SELECT rrtimeslice_cmp(' || tscol || ', ' || ts_str
+			|| ') AS status FROM ' || tbl
 			|| ' WHERE ' || tscol || ' = ' || ts_str
-			|| ' RETURNING ' || tscol || ', ' || vcol
-			INTO STRICT newts, new;
+			INTO STRICT status;
 
 		EXCEPTION
 			WHEN NO_DATA_FOUND THEN
@@ -341,9 +347,29 @@ BEGIN
 					|| ') RETURNING ' || tscol || ', ' || vcol
 					INTO newts, new;
 				-- use strict again; on exception retry?
+				RETURN new;
 			WHEN TOO_MANY_ROWS THEN
 				RAISE EXCEPTION '% is not unique in %.%', ts_str, tbl, tscol;
 	END;
+
+	IF status = 0 THEN
+		-- timestamps match
+		EXECUTE 'UPDATE ' || tbl
+			|| ' SET ' || vcol || ' = ' || update_qry
+			|| ' WHERE ' || tscol || ' = ' || ts_str
+			|| ' RETURNING ' || tscol || ', ' || vcol
+			INTO STRICT newts, new;
+	ELSIF status < 0 THEN
+		-- given timestamp is newer than in the database
+		EXECUTE 'UPDATE ' || tbl
+			|| ' SET ' || tscol || ' = ' || ts_str
+			|| ', ' || vcol || ' = ' || v_str
+			|| ' WHERE ' || tscol || ' = ' || ts_str
+			|| ' RETURNING ' || tscol || ', ' || vcol
+			INTO STRICT newts, new;
+	ELSE
+		RAISE EXCEPTION '% is too old in %.%', ts_str, tbl, tscol;
+	END IF;
 	RETURN new;
 END;
 $$;
@@ -353,20 +379,15 @@ CREATE OR REPLACE FUNCTION PostRR_update(text, timestamptz, double precision)
 	LANGUAGE plpgsql
 	AS $$
 DECLARE
-	rraname ALIAS FOR $1;
-	ts ALIAS FOR $2;
-	value ALIAS FOR $3;
+	-- $1: rraname
+	-- $2: timestamp
+	-- $3: value
 	adef RECORD;
 	new cdata;
 BEGIN
 	FOR adef IN SELECT tbl, tscol, vcol FROM postrr.rrarchives
 			WHERE postrr.rrarchives.rraname = $1 LOOP
-		EXECUTE 'SELECT PostRR_update('
-			|| quote_literal(adef.tbl) || ', '
-			|| quote_literal(adef.tscol) || ', '
-			|| quote_literal(adef.vcol) || ', '
-			|| quote_literal(ts) || ', '
-			|| quote_literal(value) || ')'
+		SELECT PostRR_update(adef.tbl, adef.tscol, adef.vcol, $2, $3)
 			INTO new;
 		RETURN NEXT new;
 	END LOOP;