move zio/zngio.Validate to zed.(*Value).Validate (#4291)

This function lives in zio/zngio for historical reasons but is more
accessible as a method on zed.Value.

value.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"errors"
 	"fmt"
+	"runtime/debug"
 
 	"github.com/brimdata/zed/pkg/field"
 	"github.com/brimdata/zed/pkg/nano"
@@ -320,3 +321,60 @@ func (v *Value) Under() *Value {
 		typ, bytes = union.Untag(bytes)
 	}
 }
+
+// Validate checks that v.Bytes is structurally consistent
+// with v.Type.  It does not check that the actual leaf
+// values when parsed are type compatible with the leaf types.
+func (v *Value) Validate() (err error) {
+	defer func() {
+		if r := recover(); r != nil {
+			err = fmt.Errorf("panic: %+v\n%s", r, debug.Stack())
+		}
+	}()
+	return v.Walk(func(typ Type, body zcode.Bytes) error {
+		if typset, ok := typ.(*TypeSet); ok {
+			if err := checkSet(typset, body); err != nil {
+				return err
+			}
+			return SkipContainer
+		}
+		if typ, ok := typ.(*TypeEnum); ok {
+			if err := checkEnum(typ, body); err != nil {
+				return err
+			}
+			return SkipContainer
+		}
+		return nil
+	})
+}
+
+func checkSet(typ *TypeSet, body zcode.Bytes) error {
+	if body == nil {
+		return nil
+	}
+	it := body.Iter()
+	var prev zcode.Bytes
+	for !it.Done() {
+		tagAndBody := it.NextTagAndBody()
+		if prev != nil {
+			switch bytes.Compare(prev, tagAndBody) {
+			case 0:
+				return errors.New("invalid ZNG: duplicate set element")
+			case 1:
+				return errors.New("invalid ZNG: set elements not sorted")
+			}
+		}
+		prev = tagAndBody
+	}
+	return nil
+}
+
+func checkEnum(typ *TypeEnum, body zcode.Bytes) error {
+	if body == nil {
+		return nil
+	}
+	if selector := DecodeUint(body); int(selector) >= len(typ.Symbols) {
+		return errors.New("enum selector out of range")
+	}
+	return nil
+}

zio/zngio/validate_test.go → value_test.go

@@ -1,4 +1,4 @@
-package zngio
+package zed_test
 
 import (
 	"testing"
@@ -8,7 +8,7 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
-func TestValidate(t *testing.T) {
+func TestValueValidate(t *testing.T) {
 	r := zed.NewValue(
 		zed.NewTypeRecord(0, []zed.Column{
 			zed.NewColumn("f", zed.NewTypeSet(0, zed.TypeString)),
@@ -22,7 +22,7 @@ func TestValidate(t *testing.T) {
 		// Don't normalize.
 		b.EndContainer()
 		r.Bytes = b.Bytes()
-		assert.EqualError(t, Validate(r), "invalid ZNG: duplicate set element")
+		assert.EqualError(t, r.Validate(), "invalid ZNG: duplicate set element")
 	})
 	t.Run("set/error/unsorted-elements", func(t *testing.T) {
 		var b zcode.Builder
@@ -33,7 +33,7 @@ func TestValidate(t *testing.T) {
 		// Don't normalize.
 		b.EndContainer()
 		r.Bytes = b.Bytes()
-		assert.EqualError(t, Validate(r), "invalid ZNG: set elements not sorted")
+		assert.EqualError(t, r.Validate(), "invalid ZNG: set elements not sorted")
 	})
 	t.Run("set/primitive-elements", func(t *testing.T) {
 		var b zcode.Builder
@@ -45,7 +45,7 @@ func TestValidate(t *testing.T) {
 		b.TransformContainer(zed.NormalizeSet)
 		b.EndContainer()
 		r.Bytes = b.Bytes()
-		assert.NoError(t, Validate(r))
+		assert.NoError(t, r.Validate())
 	})
 	t.Run("set/complex-elements", func(t *testing.T) {
 		var b zcode.Builder
@@ -64,6 +64,6 @@ func TestValidate(t *testing.T) {
 				}))),
 			}),
 			b.Bytes())
-		assert.NoError(t, Validate(r))
+		assert.NoError(t, r.Validate())
 	})
 }

zio/zeekio/parser_test.go

@@ -7,7 +7,6 @@ import (
 
 	"github.com/brimdata/zed"
 	"github.com/brimdata/zed/pkg/nano"
-	"github.com/brimdata/zed/zio/zngio"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -130,7 +129,7 @@ func TestNestedRecords(t *testing.T) {
 	parser := startLegacyTest(t, fields, types, "")
 	record, err := sendLegacyValues(parser, vals)
 	require.NoError(t, err)
-	require.NoError(t, zngio.Validate(record))
+	require.NoError(t, record.Validate())
 
 	// First check that the descriptor was created correctly
 	cols := zed.TypeRecordOf(record.Type).Columns

zio/zngio/scanner.go

@@ -323,7 +323,7 @@ func (w *worker) decodeVal(buf *buffer, valRef *zed.Value) error {
 	valRef.Type = typ
 	valRef.Bytes = b
 	if w.validate {
-		if err := Validate(valRef); err != nil {
+		if err := valRef.Validate(); err != nil {
 			return err
 		}
 	}