fix nil checking in dbutil (typed nils)

db/migrations/000017_remotevars.down.sql

@@ -0,0 +1,2 @@
+ALTER TABLE remote DROP COLUMN statevars;
+

db/migrations/000017_remotevars.up.sql

@@ -0,0 +1,2 @@
+ALTER TABLE remote ADD COLUMN statevars json NOT NULL DEFAULT '{}';
+

db/schema.sql

@@ -58,7 +58,7 @@ CREATE TABLE remote (
     local boolean NOT NULL,
     archived boolean NOT NULL,
     remoteidx int NOT NULL
-);
+, statevars json NOT NULL DEFAULT '{}');
 CREATE TABLE history (
     historyid varchar(36) PRIMARY KEY,
     ts bigint NOT NULL,
@@ -192,10 +192,17 @@ CREATE TABLE IF NOT EXISTS "cmd" (
     rtndiffhasharr json NOT NULL,
     PRIMARY KEY (screenid, cmdid)
 );
-CREATE TABLE screenupdates (
+CREATE TABLE screenupdate (
     updateid integer PRIMARY KEY,
     screenid varchar(36) NOT NULL,
     lineid varchar(36) NOT NULL,
     updatetype varchar(50) NOT NULL,
     updatets bigint NOT NULL
 );
+CREATE TABLE webptypos (
+    screenid varchar(36) NOT NULL,
+    lineid varchar(36) NOT NULL,
+    ptypos bigint NOT NULL,
+    PRIMARY KEY (screenid, lineid)
+);
+CREATE INDEX idx_screenupdate_ids ON screenupdate (screenid, lineid);

pkg/dbutil/dbutil.go

@@ -4,6 +4,7 @@ import (
 	"database/sql/driver"
 	"encoding/json"
 	"fmt"
+	"reflect"
 	"strconv"
 )
 
@@ -130,8 +131,22 @@ func QuickSetJsonArr(ptr interface{}, m map[string]interface{}, name string) {
 	json.Unmarshal(barr, ptr)
 }
 
+func CheckNil(v interface{}) bool {
+	rv := reflect.ValueOf(v)
+	if !rv.IsValid() {
+		return true
+	}
+	switch rv.Kind() {
+	case reflect.Chan, reflect.Func, reflect.Interface, reflect.Map, reflect.Pointer, reflect.Slice:
+		return rv.IsNil()
+
+	default:
+		return false
+	}
+}
+
 func QuickNullableJson(v interface{}) string {
-	if v == nil {
+	if CheckNil(v) {
 		return "null"
 	}
 	barr, _ := json.Marshal(v)
@@ -139,7 +154,7 @@ func QuickNullableJson(v interface{}) string {
 }
 
 func QuickJson(v interface{}) string {
-	if v == nil {
+	if CheckNil(v) {
 		return "{}"
 	}
 	barr, _ := json.Marshal(v)
@@ -147,7 +162,7 @@ func QuickJson(v interface{}) string {
 }
 
 func QuickJsonBytes(v interface{}) []byte {
-	if v == nil {
+	if CheckNil(v) {
 		return []byte("{}")
 	}
 	barr, _ := json.Marshal(v)
@@ -155,7 +170,7 @@ func QuickJsonBytes(v interface{}) []byte {
 }
 
 func QuickJsonArr(v interface{}) string {
-	if v == nil {
+	if CheckNil(v) {
 		return "[]"
 	}
 	barr, _ := json.Marshal(v)
@@ -163,7 +178,7 @@ func QuickJsonArr(v interface{}) string {
 }
 
 func QuickJsonArrBytes(v interface{}) []byte {
-	if v == nil {
+	if CheckNil(v) {
 		return []byte("[]")
 	}
 	barr, _ := json.Marshal(v)
@@ -186,7 +201,7 @@ func QuickScanJson(ptr interface{}, val interface{}) error {
 }
 
 func QuickValueJson(v interface{}) (driver.Value, error) {
-	if v == nil {
+	if CheckNil(v) {
 		return "{}", nil
 	}
 	barr, err := json.Marshal(v)

pkg/dbutil/map.go

@@ -123,7 +123,7 @@ func isStringMapType(t reflect.Type) bool {
 }
 
 func ToDBMap(v DBMappable, useBytes bool) map[string]interface{} {
-	if v == nil {
+	if CheckNil(v) {
 		return nil
 	}
 	rv := reflect.ValueOf(v)
@@ -168,7 +168,7 @@ func ToDBMap(v DBMappable, useBytes bool) map[string]interface{} {
 }
 
 func FromDBMap(v DBMappable, m map[string]interface{}) {
-	if v == nil {
+	if CheckNil(v) {
 		panic("StructFromDBMap, v cannot be nil")
 	}
 	rv := reflect.ValueOf(v)