Switch to using the dep tool and update all the dependencies

vendor/google.golang.org/appengine/datastore/load.go

@@ -0,0 +1,334 @@
+// Copyright 2011 Google Inc. All rights reserved.
+// Use of this source code is governed by the Apache 2.0
+// license that can be found in the LICENSE file.
+
+package datastore
+
+import (
+	"fmt"
+	"reflect"
+	"time"
+
+	"google.golang.org/appengine"
+	pb "google.golang.org/appengine/internal/datastore"
+)
+
+var (
+	typeOfBlobKey    = reflect.TypeOf(appengine.BlobKey(""))
+	typeOfByteSlice  = reflect.TypeOf([]byte(nil))
+	typeOfByteString = reflect.TypeOf(ByteString(nil))
+	typeOfGeoPoint   = reflect.TypeOf(appengine.GeoPoint{})
+	typeOfTime       = reflect.TypeOf(time.Time{})
+)
+
+// typeMismatchReason returns a string explaining why the property p could not
+// be stored in an entity field of type v.Type().
+func typeMismatchReason(p Property, v reflect.Value) string {
+	entityType := "empty"
+	switch p.Value.(type) {
+	case int64:
+		entityType = "int"
+	case bool:
+		entityType = "bool"
+	case string:
+		entityType = "string"
+	case float64:
+		entityType = "float"
+	case *Key:
+		entityType = "*datastore.Key"
+	case time.Time:
+		entityType = "time.Time"
+	case appengine.BlobKey:
+		entityType = "appengine.BlobKey"
+	case appengine.GeoPoint:
+		entityType = "appengine.GeoPoint"
+	case ByteString:
+		entityType = "datastore.ByteString"
+	case []byte:
+		entityType = "[]byte"
+	}
+	return fmt.Sprintf("type mismatch: %s versus %v", entityType, v.Type())
+}
+
+type propertyLoader struct {
+	// m holds the number of times a substruct field like "Foo.Bar.Baz" has
+	// been seen so far. The map is constructed lazily.
+	m map[string]int
+}
+
+func (l *propertyLoader) load(codec *structCodec, structValue reflect.Value, p Property, requireSlice bool) string {
+	var v reflect.Value
+	// Traverse a struct's struct-typed fields.
+	for name := p.Name; ; {
+		decoder, ok := codec.byName[name]
+		if !ok {
+			return "no such struct field"
+		}
+		v = structValue.Field(decoder.index)
+		if !v.IsValid() {
+			return "no such struct field"
+		}
+		if !v.CanSet() {
+			return "cannot set struct field"
+		}
+
+		if decoder.substructCodec == nil {
+			break
+		}
+
+		if v.Kind() == reflect.Slice {
+			if l.m == nil {
+				l.m = make(map[string]int)
+			}
+			index := l.m[p.Name]
+			l.m[p.Name] = index + 1
+			for v.Len() <= index {
+				v.Set(reflect.Append(v, reflect.New(v.Type().Elem()).Elem()))
+			}
+			structValue = v.Index(index)
+			requireSlice = false
+		} else {
+			structValue = v
+		}
+		// Strip the "I." from "I.X".
+		name = name[len(codec.byIndex[decoder.index].name):]
+		codec = decoder.substructCodec
+	}
+
+	var slice reflect.Value
+	if v.Kind() == reflect.Slice && v.Type().Elem().Kind() != reflect.Uint8 {
+		slice = v
+		v = reflect.New(v.Type().Elem()).Elem()
+	} else if requireSlice {
+		return "multiple-valued property requires a slice field type"
+	}
+
+	// Convert indexValues to a Go value with a meaning derived from the
+	// destination type.
+	pValue := p.Value
+	if iv, ok := pValue.(indexValue); ok {
+		meaning := pb.Property_NO_MEANING
+		switch v.Type() {
+		case typeOfBlobKey:
+			meaning = pb.Property_BLOBKEY
+		case typeOfByteSlice:
+			meaning = pb.Property_BLOB
+		case typeOfByteString:
+			meaning = pb.Property_BYTESTRING
+		case typeOfGeoPoint:
+			meaning = pb.Property_GEORSS_POINT
+		case typeOfTime:
+			meaning = pb.Property_GD_WHEN
+		}
+		var err error
+		pValue, err = propValue(iv.value, meaning)
+		if err != nil {
+			return err.Error()
+		}
+	}
+
+	switch v.Kind() {
+	case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
+		x, ok := pValue.(int64)
+		if !ok && pValue != nil {
+			return typeMismatchReason(p, v)
+		}
+		if v.OverflowInt(x) {
+			return fmt.Sprintf("value %v overflows struct field of type %v", x, v.Type())
+		}
+		v.SetInt(x)
+	case reflect.Bool:
+		x, ok := pValue.(bool)
+		if !ok && pValue != nil {
+			return typeMismatchReason(p, v)
+		}
+		v.SetBool(x)
+	case reflect.String:
+		switch x := pValue.(type) {
+		case appengine.BlobKey:
+			v.SetString(string(x))
+		case ByteString:
+			v.SetString(string(x))
+		case string:
+			v.SetString(x)
+		default:
+			if pValue != nil {
+				return typeMismatchReason(p, v)
+			}
+		}
+	case reflect.Float32, reflect.Float64:
+		x, ok := pValue.(float64)
+		if !ok && pValue != nil {
+			return typeMismatchReason(p, v)
+		}
+		if v.OverflowFloat(x) {
+			return fmt.Sprintf("value %v overflows struct field of type %v", x, v.Type())
+		}
+		v.SetFloat(x)
+	case reflect.Ptr:
+		x, ok := pValue.(*Key)
+		if !ok && pValue != nil {
+			return typeMismatchReason(p, v)
+		}
+		if _, ok := v.Interface().(*Key); !ok {
+			return typeMismatchReason(p, v)
+		}
+		v.Set(reflect.ValueOf(x))
+	case reflect.Struct:
+		switch v.Type() {
+		case typeOfTime:
+			x, ok := pValue.(time.Time)
+			if !ok && pValue != nil {
+				return typeMismatchReason(p, v)
+			}
+			v.Set(reflect.ValueOf(x))
+		case typeOfGeoPoint:
+			x, ok := pValue.(appengine.GeoPoint)
+			if !ok && pValue != nil {
+				return typeMismatchReason(p, v)
+			}
+			v.Set(reflect.ValueOf(x))
+		default:
+			return typeMismatchReason(p, v)
+		}
+	case reflect.Slice:
+		x, ok := pValue.([]byte)
+		if !ok {
+			if y, yok := pValue.(ByteString); yok {
+				x, ok = []byte(y), true
+			}
+		}
+		if !ok && pValue != nil {
+			return typeMismatchReason(p, v)
+		}
+		if v.Type().Elem().Kind() != reflect.Uint8 {
+			return typeMismatchReason(p, v)
+		}
+		v.SetBytes(x)
+	default:
+		return typeMismatchReason(p, v)
+	}
+	if slice.IsValid() {
+		slice.Set(reflect.Append(slice, v))
+	}
+	return ""
+}
+
+// loadEntity loads an EntityProto into PropertyLoadSaver or struct pointer.
+func loadEntity(dst interface{}, src *pb.EntityProto) (err error) {
+	props, err := protoToProperties(src)
+	if err != nil {
+		return err
+	}
+	if e, ok := dst.(PropertyLoadSaver); ok {
+		return e.Load(props)
+	}
+	return LoadStruct(dst, props)
+}
+
+func (s structPLS) Load(props []Property) error {
+	var fieldName, reason string
+	var l propertyLoader
+	for _, p := range props {
+		if errStr := l.load(s.codec, s.v, p, p.Multiple); errStr != "" {
+			// We don't return early, as we try to load as many properties as possible.
+			// It is valid to load an entity into a struct that cannot fully represent it.
+			// That case returns an error, but the caller is free to ignore it.
+			fieldName, reason = p.Name, errStr
+		}
+	}
+	if reason != "" {
+		return &ErrFieldMismatch{
+			StructType: s.v.Type(),
+			FieldName:  fieldName,
+			Reason:     reason,
+		}
+	}
+	return nil
+}
+
+func protoToProperties(src *pb.EntityProto) ([]Property, error) {
+	props, rawProps := src.Property, src.RawProperty
+	out := make([]Property, 0, len(props)+len(rawProps))
+	for {
+		var (
+			x       *pb.Property
+			noIndex bool
+		)
+		if len(props) > 0 {
+			x, props = props[0], props[1:]
+		} else if len(rawProps) > 0 {
+			x, rawProps = rawProps[0], rawProps[1:]
+			noIndex = true
+		} else {
+			break
+		}
+
+		var value interface{}
+		if x.Meaning != nil && *x.Meaning == pb.Property_INDEX_VALUE {
+			value = indexValue{x.Value}
+		} else {
+			var err error
+			value, err = propValue(x.Value, x.GetMeaning())
+			if err != nil {
+				return nil, err
+			}
+		}
+		out = append(out, Property{
+			Name:     x.GetName(),
+			Value:    value,
+			NoIndex:  noIndex,
+			Multiple: x.GetMultiple(),
+		})
+	}
+	return out, nil
+}
+
+// propValue returns a Go value that combines the raw PropertyValue with a
+// meaning. For example, an Int64Value with GD_WHEN becomes a time.Time.
+func propValue(v *pb.PropertyValue, m pb.Property_Meaning) (interface{}, error) {
+	switch {
+	case v.Int64Value != nil:
+		if m == pb.Property_GD_WHEN {
+			return fromUnixMicro(*v.Int64Value), nil
+		} else {
+			return *v.Int64Value, nil
+		}
+	case v.BooleanValue != nil:
+		return *v.BooleanValue, nil
+	case v.StringValue != nil:
+		if m == pb.Property_BLOB {
+			return []byte(*v.StringValue), nil
+		} else if m == pb.Property_BLOBKEY {
+			return appengine.BlobKey(*v.StringValue), nil
+		} else if m == pb.Property_BYTESTRING {
+			return ByteString(*v.StringValue), nil
+		} else {
+			return *v.StringValue, nil
+		}
+	case v.DoubleValue != nil:
+		return *v.DoubleValue, nil
+	case v.Referencevalue != nil:
+		key, err := referenceValueToKey(v.Referencevalue)
+		if err != nil {
+			return nil, err
+		}
+		return key, nil
+	case v.Pointvalue != nil:
+		// NOTE: Strangely, latitude maps to X, longitude to Y.
+		return appengine.GeoPoint{Lat: v.Pointvalue.GetX(), Lng: v.Pointvalue.GetY()}, nil
+	}
+	return nil, nil
+}
+
+// indexValue is a Property value that is created when entities are loaded from
+// an index, such as from a projection query.
+//
+// Such Property values do not contain all of the metadata required to be
+// faithfully represented as a Go value, and are instead represented as an
+// opaque indexValue. Load the properties into a concrete struct type (e.g. by
+// passing a struct pointer to Iterator.Next) to reconstruct actual Go values
+// of type int, string, time.Time, etc.
+type indexValue struct {
+	value *pb.PropertyValue
+}