miniflux/vendor/google.golang.org/appengine/datastore/save.go
2017-11-22 22:22:33 -08:00

300 lines
8.1 KiB
Go

// 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 (
"errors"
"fmt"
"math"
"reflect"
"time"
"github.com/golang/protobuf/proto"
"google.golang.org/appengine"
pb "google.golang.org/appengine/internal/datastore"
)
func toUnixMicro(t time.Time) int64 {
// We cannot use t.UnixNano() / 1e3 because we want to handle times more than
// 2^63 nanoseconds (which is about 292 years) away from 1970, and those cannot
// be represented in the numerator of a single int64 divide.
return t.Unix()*1e6 + int64(t.Nanosecond()/1e3)
}
func fromUnixMicro(t int64) time.Time {
return time.Unix(t/1e6, (t%1e6)*1e3).UTC()
}
var (
minTime = time.Unix(int64(math.MinInt64)/1e6, (int64(math.MinInt64)%1e6)*1e3)
maxTime = time.Unix(int64(math.MaxInt64)/1e6, (int64(math.MaxInt64)%1e6)*1e3)
)
// valueToProto converts a named value to a newly allocated Property.
// The returned error string is empty on success.
func valueToProto(defaultAppID, name string, v reflect.Value, multiple bool) (p *pb.Property, errStr string) {
var (
pv pb.PropertyValue
unsupported bool
)
switch v.Kind() {
case reflect.Invalid:
// No-op.
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
pv.Int64Value = proto.Int64(v.Int())
case reflect.Bool:
pv.BooleanValue = proto.Bool(v.Bool())
case reflect.String:
pv.StringValue = proto.String(v.String())
case reflect.Float32, reflect.Float64:
pv.DoubleValue = proto.Float64(v.Float())
case reflect.Ptr:
if k, ok := v.Interface().(*Key); ok {
if k != nil {
pv.Referencevalue = keyToReferenceValue(defaultAppID, k)
}
} else {
unsupported = true
}
case reflect.Struct:
switch t := v.Interface().(type) {
case time.Time:
if t.Before(minTime) || t.After(maxTime) {
return nil, "time value out of range"
}
pv.Int64Value = proto.Int64(toUnixMicro(t))
case appengine.GeoPoint:
if !t.Valid() {
return nil, "invalid GeoPoint value"
}
// NOTE: Strangely, latitude maps to X, longitude to Y.
pv.Pointvalue = &pb.PropertyValue_PointValue{X: &t.Lat, Y: &t.Lng}
default:
unsupported = true
}
case reflect.Slice:
if b, ok := v.Interface().([]byte); ok {
pv.StringValue = proto.String(string(b))
} else {
// nvToProto should already catch slice values.
// If we get here, we have a slice of slice values.
unsupported = true
}
default:
unsupported = true
}
if unsupported {
return nil, "unsupported datastore value type: " + v.Type().String()
}
p = &pb.Property{
Name: proto.String(name),
Value: &pv,
Multiple: proto.Bool(multiple),
}
if v.IsValid() {
switch v.Interface().(type) {
case []byte:
p.Meaning = pb.Property_BLOB.Enum()
case ByteString:
p.Meaning = pb.Property_BYTESTRING.Enum()
case appengine.BlobKey:
p.Meaning = pb.Property_BLOBKEY.Enum()
case time.Time:
p.Meaning = pb.Property_GD_WHEN.Enum()
case appengine.GeoPoint:
p.Meaning = pb.Property_GEORSS_POINT.Enum()
}
}
return p, ""
}
// saveEntity saves an EntityProto into a PropertyLoadSaver or struct pointer.
func saveEntity(defaultAppID string, key *Key, src interface{}) (*pb.EntityProto, error) {
var err error
var props []Property
if e, ok := src.(PropertyLoadSaver); ok {
props, err = e.Save()
} else {
props, err = SaveStruct(src)
}
if err != nil {
return nil, err
}
return propertiesToProto(defaultAppID, key, props)
}
func saveStructProperty(props *[]Property, name string, noIndex, multiple bool, v reflect.Value) error {
p := Property{
Name: name,
NoIndex: noIndex,
Multiple: multiple,
}
switch x := v.Interface().(type) {
case *Key:
p.Value = x
case time.Time:
p.Value = x
case appengine.BlobKey:
p.Value = x
case appengine.GeoPoint:
p.Value = x
case ByteString:
p.Value = x
default:
switch v.Kind() {
case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64:
p.Value = v.Int()
case reflect.Bool:
p.Value = v.Bool()
case reflect.String:
p.Value = v.String()
case reflect.Float32, reflect.Float64:
p.Value = v.Float()
case reflect.Slice:
if v.Type().Elem().Kind() == reflect.Uint8 {
p.NoIndex = true
p.Value = v.Bytes()
}
case reflect.Struct:
if !v.CanAddr() {
return fmt.Errorf("datastore: unsupported struct field: value is unaddressable")
}
sub, err := newStructPLS(v.Addr().Interface())
if err != nil {
return fmt.Errorf("datastore: unsupported struct field: %v", err)
}
return sub.(structPLS).save(props, name, noIndex, multiple)
}
}
if p.Value == nil {
return fmt.Errorf("datastore: unsupported struct field type: %v", v.Type())
}
*props = append(*props, p)
return nil
}
func (s structPLS) Save() ([]Property, error) {
var props []Property
if err := s.save(&props, "", false, false); err != nil {
return nil, err
}
return props, nil
}
func (s structPLS) save(props *[]Property, prefix string, noIndex, multiple bool) error {
for i, t := range s.codec.byIndex {
if t.name == "-" {
continue
}
name := t.name
if prefix != "" {
name = prefix + name
}
v := s.v.Field(i)
if !v.IsValid() || !v.CanSet() {
continue
}
noIndex1 := noIndex || t.noIndex
// For slice fields that aren't []byte, save each element.
if v.Kind() == reflect.Slice && v.Type().Elem().Kind() != reflect.Uint8 {
for j := 0; j < v.Len(); j++ {
if err := saveStructProperty(props, name, noIndex1, true, v.Index(j)); err != nil {
return err
}
}
continue
}
// Otherwise, save the field itself.
if err := saveStructProperty(props, name, noIndex1, multiple, v); err != nil {
return err
}
}
return nil
}
func propertiesToProto(defaultAppID string, key *Key, props []Property) (*pb.EntityProto, error) {
e := &pb.EntityProto{
Key: keyToProto(defaultAppID, key),
}
if key.parent == nil {
e.EntityGroup = &pb.Path{}
} else {
e.EntityGroup = keyToProto(defaultAppID, key.root()).Path
}
prevMultiple := make(map[string]bool)
for _, p := range props {
if pm, ok := prevMultiple[p.Name]; ok {
if !pm || !p.Multiple {
return nil, fmt.Errorf("datastore: multiple Properties with Name %q, but Multiple is false", p.Name)
}
} else {
prevMultiple[p.Name] = p.Multiple
}
x := &pb.Property{
Name: proto.String(p.Name),
Value: new(pb.PropertyValue),
Multiple: proto.Bool(p.Multiple),
}
switch v := p.Value.(type) {
case int64:
x.Value.Int64Value = proto.Int64(v)
case bool:
x.Value.BooleanValue = proto.Bool(v)
case string:
x.Value.StringValue = proto.String(v)
if p.NoIndex {
x.Meaning = pb.Property_TEXT.Enum()
}
case float64:
x.Value.DoubleValue = proto.Float64(v)
case *Key:
if v != nil {
x.Value.Referencevalue = keyToReferenceValue(defaultAppID, v)
}
case time.Time:
if v.Before(minTime) || v.After(maxTime) {
return nil, fmt.Errorf("datastore: time value out of range")
}
x.Value.Int64Value = proto.Int64(toUnixMicro(v))
x.Meaning = pb.Property_GD_WHEN.Enum()
case appengine.BlobKey:
x.Value.StringValue = proto.String(string(v))
x.Meaning = pb.Property_BLOBKEY.Enum()
case appengine.GeoPoint:
if !v.Valid() {
return nil, fmt.Errorf("datastore: invalid GeoPoint value")
}
// NOTE: Strangely, latitude maps to X, longitude to Y.
x.Value.Pointvalue = &pb.PropertyValue_PointValue{X: &v.Lat, Y: &v.Lng}
x.Meaning = pb.Property_GEORSS_POINT.Enum()
case []byte:
x.Value.StringValue = proto.String(string(v))
x.Meaning = pb.Property_BLOB.Enum()
if !p.NoIndex {
return nil, fmt.Errorf("datastore: cannot index a []byte valued Property with Name %q", p.Name)
}
case ByteString:
x.Value.StringValue = proto.String(string(v))
x.Meaning = pb.Property_BYTESTRING.Enum()
default:
if p.Value != nil {
return nil, fmt.Errorf("datastore: invalid Value type for a Property with Name %q", p.Name)
}
}
if p.NoIndex {
e.RawProperty = append(e.RawProperty, x)
} else {
e.Property = append(e.Property, x)
if len(e.Property) > maxIndexedProperties {
return nil, errors.New("datastore: too many indexed properties")
}
}
}
return e, nil
}