parser: add nowait keyword, add for update no wait grammar, and relat…

…ed error… (pingcap#582)

ast/dml.go

@@ -421,6 +421,7 @@ const (
 	SelectLockNone SelectLockType = iota
 	SelectLockForUpdate
 	SelectLockInShareMode
+	SelectLockForUpdateNoWait
 )
 
 // String implements fmt.Stringer.
@@ -432,6 +433,8 @@ func (slt SelectLockType) String() string {
 		return "for update"
 	case SelectLockInShareMode:
 		return "in share mode"
+	case SelectLockForUpdateNoWait:
+		return "for update nowait"
 	}
 	return "unsupported select lock type"
 }
@@ -881,7 +884,7 @@ func (n *SelectStmt) Restore(ctx *RestoreCtx) error {
 	case SelectLockInShareMode:
 		ctx.WriteKeyWord(" LOCK ")
 		ctx.WriteKeyWord(n.LockTp.String())
-	case SelectLockForUpdate:
+	case SelectLockForUpdate, SelectLockForUpdateNoWait:
 		ctx.WritePlain(" ")
 		ctx.WriteKeyWord(n.LockTp.String())
 	}

ast/util.go

@@ -17,7 +17,7 @@ package ast
 func IsReadOnly(node Node) bool {
 	switch st := node.(type) {
 	case *SelectStmt:
-		if st.LockTp == SelectLockForUpdate {
+		if st.LockTp == SelectLockForUpdate || st.LockTp == SelectLockForUpdateNoWait {
 			return false
 		}
 

misc.go

@@ -666,6 +666,7 @@ var tokenMap = map[string]int{
 	"BINDINGS":                 bindings,
 	"EXPR_PUSHDOWN_BLACKLIST":  exprPushdownBlacklist,
 	"OPT_RULE_BLACKLIST":       optRuleBlacklist,
+	"NOWAIT":                   nowait,
 }
 
 // See https://dev.mysql.com/doc/refman/5.7/en/function-resolution.html for details

model/model_test.go

@@ -101,7 +101,7 @@ func (*testModelSuite) TestModelBasic(c *C) {
 	c.Assert(tp.String(), Equals, "BTREE")
 	tp = IndexTypeHash
 	c.Assert(tp.String(), Equals, "HASH")
-	tp = 1E5
+	tp = 1e5
 	c.Assert(tp.String(), Equals, "")
 	has := index.HasPrefixIndex()
 	c.Assert(has, Equals, true)

mysql/errcode.go

@@ -903,6 +903,7 @@ const (
 	ErrBadUser                                                      = 3162
 	ErrInvalidEncryptionOption                                      = 3184
 	ErrRoleNotGranted                                               = 3530
+	ErrLockAcquireFailAndNoWaitSet                                  = 3572
 	ErrWindowNoSuchWindow                                           = 3579
 	ErrWindowCircularityInWindowGraph                               = 3580
 	ErrWindowNoChildPartitioning                                    = 3581

mysql/errname.go

@@ -920,6 +920,7 @@ var MySQLErrName = map[uint16]string{
 	ErrWindowFunctionIgnoresFrame:                            "Window function '%s' ignores the frame clause of window '%s' and aggregates over the whole partition",
 	ErrRoleNotGranted:                                        "%s is is not granted to %s",
 	ErrMaxExecTimeExceeded:                                   "Query execution was interrupted, max_execution_time exceeded.",
+	ErrLockAcquireFailAndNoWaitSet:                           "Statement aborted because lock(s) could not be acquired immediately and NOWAIT is set.",
 
 	// MariaDB errors.
 	ErrOnlyOneDefaultPartionAllowed:         "Only one DEFAULT partition allowed",