Add encoder/decoder checks and fix julian date test

sql/functions/check_time_encoder_decoder.sql

@@ -0,0 +1,81 @@
+CREATE FUNCTION @[email protected]_time_encoder_decoder(
+    p_time_encoder TEXT
+    , p_time_decoder TEXT
+    , p_control_type TEXT
+    , p_start_timestamp TIMESTAMPTZ
+)
+    RETURNS VOID
+    LANGUAGE plpgsql STABLE
+    AS $$
+DECLARE
+
+v_control_type_oid      REGTYPE;
+v_i_check_rec           RECORD;
+v_i_fname_parsed        TEXT[];
+v_i_found_proc_row      pg_catalog.pg_proc%ROWTYPE;
+v_i_null_returned_null  BOOLEAN;
+v_roundtrip_result      TIMESTAMPTZ;
+
+BEGIN
+/*
+ * Performs sanity checks on provided time encoder and decoder functions.
+ */
+
+SELECT p_control_type::regtype INTO STRICT v_control_type_oid;
+
+FOR v_i_check_rec IN
+    WITH loops(fname, ftypin, ftypout) AS (VALUES
+        (p_time_encoder, 'TIMESTAMPTZ'::regtype, v_control_type_oid),
+        (p_time_decoder, v_control_type_oid, 'TIMESTAMPTZ'::regtype)
+    )
+    SELECT * FROM loops
+LOOP
+    -- Make sure the function name is valid and schema qualified
+    v_i_fname_parsed := parse_ident(v_i_check_rec.fname);
+    IF cardinality(v_i_fname_parsed) <> 2 THEN
+        RAISE EXCEPTION 'The function name % is not a valid fully qualified name.', v_i_check_rec.fname;
+    END IF;
+
+    -- Check the functions exist with exact parameter/return types
+    BEGIN
+        SELECT * INTO STRICT v_i_found_proc_row
+        FROM pg_catalog.pg_proc p
+        JOIN pg_catalog.pg_namespace n ON p.pronamespace = n.oid
+        WHERE n.nspname = v_i_fname_parsed[1] AND proname = v_i_fname_parsed[2]
+        AND pronargs >= 1 and proargtypes[0] = v_i_check_rec.ftypin
+        AND prorettype = v_i_check_rec.ftypout;
+        EXCEPTION
+            WHEN NO_DATA_FOUND THEN
+                RAISE EXCEPTION 'No function named % matching argument % and returning %.', v_i_check_rec.fname, v_i_check_rec.ftypin, ftypout;
+            WHEN TOO_MANY_ROWS THEN
+                RAISE EXCEPTION 'Function %(%) -> % is ambiguous, this should not happen.', v_i_check_rec.fname, v_i_check_rec.ftypin, ftypout;
+    END;
+
+    -- Check that the function is declared IMMUTABLE
+    IF v_i_found_proc_row.provolatile <> 'i' THEN
+        RAISE EXCEPTION 'Function % must be declared IMMUTABLE (got %).', v_i_check_rec.fname, CASE v_i_found_proc_row.provolatile WHEN 's' THEN 'STABLE' WHEN 'v' THEN 'VOLATILE' END;
+    END IF;
+
+    -- Check that the functions return NULL when passed a NULL
+    EXECUTE FORMAT('SELECT %s(NULL) IS NULL', v_i_check_rec.fname) INTO v_i_null_returned_null;
+
+    IF NOT v_i_null_returned_null THEN
+        RAISE EXCEPTION 'Function % does not return NULL when called on NULL.', v_i_check_rec.fname;
+    END IF;
+
+    -- Show performance warning for default of PARALLEL UNSAFE
+    IF v_i_found_proc_row.proparallel <> 's' THEN
+        RAISE NOTICE 'Function % is not declared parallel safe, this may affect performance if you use it for predicates. See the documentation for CREATE FUNCTION.', v_i_check_rec.fname;
+    END IF;
+
+END LOOP;
+
+-- test roundtrip
+EXECUTE FORMAT('SELECT %s(%s(%L))', p_time_decoder, p_time_encoder, p_start_timestamp) INTO v_roundtrip_result;
+
+IF p_start_timestamp <> v_roundtrip_result THEN
+    RAISE EXCEPTION 'Encoding and then decoding the start of the first partition range (%) got a different value (%). Make sure the encoding is correct and aligns with the partition interval.', p_start_timestamp, v_roundtrip_result;
+END IF;
+
+END
+$$;

sql/functions/create_parent.sql

@@ -348,6 +348,10 @@ IF v_control_type IN ('time', 'text', 'uuid') OR (v_control_type = 'id' AND p_ep
     INTO v_base_timestamp, v_datetime_string
     FROM @[email protected]_time_partition_info(v_time_interval, v_start_time, p_date_trunc_interval);
 
+    IF p_epoch = 'func' THEN
+        PERFORM @[email protected]_time_encoder_decoder(p_time_encoder, p_time_decoder, v_control_exact_type, v_base_timestamp);
+    END IF;
+
     RAISE DEBUG 'create_parent(): parent_table: %, v_base_timestamp: %', p_parent_table, v_base_timestamp;
 
     v_partition_time_array := array_append(v_partition_time_array, v_base_timestamp);

test/test-id-func-julian-monthly.sql

@@ -12,14 +12,14 @@ SELECT plan(121);
 CREATE SCHEMA partman_test;
 CREATE SCHEMA partman_retention_test;
 
--- Convert to and from Julian days using Postgres builtin functions, aligned to noon UTC
+-- Convert to and from Julian days using Postgres builtin functions
 CREATE FUNCTION partman_test.timestamp_to_julian_day(ts TIMESTAMPTZ)
     RETURNS INTEGER LANGUAGE SQL IMMUTABLE PARALLEL SAFE AS
-    $$SELECT EXTRACT(julian FROM ts at time zone 'UTC+12')::INTEGER$$;
+    $$SELECT EXTRACT(julian FROM ts at time zone 'UTC')::INTEGER$$;
 
 CREATE FUNCTION partman_test.julian_day_to_timestamp(jul_day integer)
     RETURNS TIMESTAMPTZ LANGUAGE SQL IMMUTABLE PARALLEL SAFE AS
-    $$SELECT ('J' || jul_day)::TIMESTAMP AT TIME ZONE 'UTC+12'$$;
+    $$SELECT ('J' || jul_day)::TIMESTAMP AT TIME ZONE 'UTC'$$;
 
 CREATE TABLE partman_test.time_taptest_table
     (col1 int