diff options
Diffstat (limited to 'vendor/google.golang.org/appengine/datastore/datastore.go')
-rw-r--r-- | vendor/google.golang.org/appengine/datastore/datastore.go | 406 |
1 files changed, 406 insertions, 0 deletions
diff --git a/vendor/google.golang.org/appengine/datastore/datastore.go b/vendor/google.golang.org/appengine/datastore/datastore.go new file mode 100644 index 0000000..9422e41 --- /dev/null +++ b/vendor/google.golang.org/appengine/datastore/datastore.go @@ -0,0 +1,406 @@ +// 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" + "reflect" + + "github.com/golang/protobuf/proto" + "golang.org/x/net/context" + + "google.golang.org/appengine" + "google.golang.org/appengine/internal" + pb "google.golang.org/appengine/internal/datastore" +) + +var ( + // ErrInvalidEntityType is returned when functions like Get or Next are + // passed a dst or src argument of invalid type. + ErrInvalidEntityType = errors.New("datastore: invalid entity type") + // ErrInvalidKey is returned when an invalid key is presented. + ErrInvalidKey = errors.New("datastore: invalid key") + // ErrNoSuchEntity is returned when no entity was found for a given key. + ErrNoSuchEntity = errors.New("datastore: no such entity") +) + +// ErrFieldMismatch is returned when a field is to be loaded into a different +// type than the one it was stored from, or when a field is missing or +// unexported in the destination struct. +// StructType is the type of the struct pointed to by the destination argument +// passed to Get or to Iterator.Next. +type ErrFieldMismatch struct { + StructType reflect.Type + FieldName string + Reason string +} + +func (e *ErrFieldMismatch) Error() string { + return fmt.Sprintf("datastore: cannot load field %q into a %q: %s", + e.FieldName, e.StructType, e.Reason) +} + +// protoToKey converts a Reference proto to a *Key. +func protoToKey(r *pb.Reference) (k *Key, err error) { + appID := r.GetApp() + namespace := r.GetNameSpace() + for _, e := range r.Path.Element { + k = &Key{ + kind: e.GetType(), + stringID: e.GetName(), + intID: e.GetId(), + parent: k, + appID: appID, + namespace: namespace, + } + if !k.valid() { + return nil, ErrInvalidKey + } + } + return +} + +// keyToProto converts a *Key to a Reference proto. +func keyToProto(defaultAppID string, k *Key) *pb.Reference { + appID := k.appID + if appID == "" { + appID = defaultAppID + } + n := 0 + for i := k; i != nil; i = i.parent { + n++ + } + e := make([]*pb.Path_Element, n) + for i := k; i != nil; i = i.parent { + n-- + e[n] = &pb.Path_Element{ + Type: &i.kind, + } + // At most one of {Name,Id} should be set. + // Neither will be set for incomplete keys. + if i.stringID != "" { + e[n].Name = &i.stringID + } else if i.intID != 0 { + e[n].Id = &i.intID + } + } + var namespace *string + if k.namespace != "" { + namespace = proto.String(k.namespace) + } + return &pb.Reference{ + App: proto.String(appID), + NameSpace: namespace, + Path: &pb.Path{ + Element: e, + }, + } +} + +// multiKeyToProto is a batch version of keyToProto. +func multiKeyToProto(appID string, key []*Key) []*pb.Reference { + ret := make([]*pb.Reference, len(key)) + for i, k := range key { + ret[i] = keyToProto(appID, k) + } + return ret +} + +// multiValid is a batch version of Key.valid. It returns an error, not a +// []bool. +func multiValid(key []*Key) error { + invalid := false + for _, k := range key { + if !k.valid() { + invalid = true + break + } + } + if !invalid { + return nil + } + err := make(appengine.MultiError, len(key)) + for i, k := range key { + if !k.valid() { + err[i] = ErrInvalidKey + } + } + return err +} + +// It's unfortunate that the two semantically equivalent concepts pb.Reference +// and pb.PropertyValue_ReferenceValue aren't the same type. For example, the +// two have different protobuf field numbers. + +// referenceValueToKey is the same as protoToKey except the input is a +// PropertyValue_ReferenceValue instead of a Reference. +func referenceValueToKey(r *pb.PropertyValue_ReferenceValue) (k *Key, err error) { + appID := r.GetApp() + namespace := r.GetNameSpace() + for _, e := range r.Pathelement { + k = &Key{ + kind: e.GetType(), + stringID: e.GetName(), + intID: e.GetId(), + parent: k, + appID: appID, + namespace: namespace, + } + if !k.valid() { + return nil, ErrInvalidKey + } + } + return +} + +// keyToReferenceValue is the same as keyToProto except the output is a +// PropertyValue_ReferenceValue instead of a Reference. +func keyToReferenceValue(defaultAppID string, k *Key) *pb.PropertyValue_ReferenceValue { + ref := keyToProto(defaultAppID, k) + pe := make([]*pb.PropertyValue_ReferenceValue_PathElement, len(ref.Path.Element)) + for i, e := range ref.Path.Element { + pe[i] = &pb.PropertyValue_ReferenceValue_PathElement{ + Type: e.Type, + Id: e.Id, + Name: e.Name, + } + } + return &pb.PropertyValue_ReferenceValue{ + App: ref.App, + NameSpace: ref.NameSpace, + Pathelement: pe, + } +} + +type multiArgType int + +const ( + multiArgTypeInvalid multiArgType = iota + multiArgTypePropertyLoadSaver + multiArgTypeStruct + multiArgTypeStructPtr + multiArgTypeInterface +) + +// checkMultiArg checks that v has type []S, []*S, []I, or []P, for some struct +// type S, for some interface type I, or some non-interface non-pointer type P +// such that P or *P implements PropertyLoadSaver. +// +// It returns what category the slice's elements are, and the reflect.Type +// that represents S, I or P. +// +// As a special case, PropertyList is an invalid type for v. +func checkMultiArg(v reflect.Value) (m multiArgType, elemType reflect.Type) { + if v.Kind() != reflect.Slice { + return multiArgTypeInvalid, nil + } + if v.Type() == typeOfPropertyList { + return multiArgTypeInvalid, nil + } + elemType = v.Type().Elem() + if reflect.PtrTo(elemType).Implements(typeOfPropertyLoadSaver) { + return multiArgTypePropertyLoadSaver, elemType + } + switch elemType.Kind() { + case reflect.Struct: + return multiArgTypeStruct, elemType + case reflect.Interface: + return multiArgTypeInterface, elemType + case reflect.Ptr: + elemType = elemType.Elem() + if elemType.Kind() == reflect.Struct { + return multiArgTypeStructPtr, elemType + } + } + return multiArgTypeInvalid, nil +} + +// Get loads the entity stored for k into dst, which must be a struct pointer +// or implement PropertyLoadSaver. If there is no such entity for the key, Get +// returns ErrNoSuchEntity. +// +// The values of dst's unmatched struct fields are not modified, and matching +// slice-typed fields are not reset before appending to them. In particular, it +// is recommended to pass a pointer to a zero valued struct on each Get call. +// +// ErrFieldMismatch is returned when a field is to be loaded into a different +// type than the one it was stored from, or when a field is missing or +// unexported in the destination struct. ErrFieldMismatch is only returned if +// dst is a struct pointer. +func Get(c context.Context, key *Key, dst interface{}) error { + if dst == nil { // GetMulti catches nil interface; we need to catch nil ptr here + return ErrInvalidEntityType + } + err := GetMulti(c, []*Key{key}, []interface{}{dst}) + if me, ok := err.(appengine.MultiError); ok { + return me[0] + } + return err +} + +// GetMulti is a batch version of Get. +// +// dst must be a []S, []*S, []I or []P, for some struct type S, some interface +// type I, or some non-interface non-pointer type P such that P or *P +// implements PropertyLoadSaver. If an []I, each element must be a valid dst +// for Get: it must be a struct pointer or implement PropertyLoadSaver. +// +// As a special case, PropertyList is an invalid type for dst, even though a +// PropertyList is a slice of structs. It is treated as invalid to avoid being +// mistakenly passed when []PropertyList was intended. +func GetMulti(c context.Context, key []*Key, dst interface{}) error { + v := reflect.ValueOf(dst) + multiArgType, _ := checkMultiArg(v) + if multiArgType == multiArgTypeInvalid { + return errors.New("datastore: dst has invalid type") + } + if len(key) != v.Len() { + return errors.New("datastore: key and dst slices have different length") + } + if len(key) == 0 { + return nil + } + if err := multiValid(key); err != nil { + return err + } + req := &pb.GetRequest{ + Key: multiKeyToProto(internal.FullyQualifiedAppID(c), key), + } + res := &pb.GetResponse{} + if err := internal.Call(c, "datastore_v3", "Get", req, res); err != nil { + return err + } + if len(key) != len(res.Entity) { + return errors.New("datastore: internal error: server returned the wrong number of entities") + } + multiErr, any := make(appengine.MultiError, len(key)), false + for i, e := range res.Entity { + if e.Entity == nil { + multiErr[i] = ErrNoSuchEntity + } else { + elem := v.Index(i) + if multiArgType == multiArgTypePropertyLoadSaver || multiArgType == multiArgTypeStruct { + elem = elem.Addr() + } + if multiArgType == multiArgTypeStructPtr && elem.IsNil() { + elem.Set(reflect.New(elem.Type().Elem())) + } + multiErr[i] = loadEntity(elem.Interface(), e.Entity) + } + if multiErr[i] != nil { + any = true + } + } + if any { + return multiErr + } + return nil +} + +// Put saves the entity src into the datastore with key k. src must be a struct +// pointer or implement PropertyLoadSaver; if a struct pointer then any +// unexported fields of that struct will be skipped. If k is an incomplete key, +// the returned key will be a unique key generated by the datastore. +func Put(c context.Context, key *Key, src interface{}) (*Key, error) { + k, err := PutMulti(c, []*Key{key}, []interface{}{src}) + if err != nil { + if me, ok := err.(appengine.MultiError); ok { + return nil, me[0] + } + return nil, err + } + return k[0], nil +} + +// PutMulti is a batch version of Put. +// +// src must satisfy the same conditions as the dst argument to GetMulti. +func PutMulti(c context.Context, key []*Key, src interface{}) ([]*Key, error) { + v := reflect.ValueOf(src) + multiArgType, _ := checkMultiArg(v) + if multiArgType == multiArgTypeInvalid { + return nil, errors.New("datastore: src has invalid type") + } + if len(key) != v.Len() { + return nil, errors.New("datastore: key and src slices have different length") + } + if len(key) == 0 { + return nil, nil + } + appID := internal.FullyQualifiedAppID(c) + if err := multiValid(key); err != nil { + return nil, err + } + req := &pb.PutRequest{} + for i := range key { + elem := v.Index(i) + if multiArgType == multiArgTypePropertyLoadSaver || multiArgType == multiArgTypeStruct { + elem = elem.Addr() + } + sProto, err := saveEntity(appID, key[i], elem.Interface()) + if err != nil { + return nil, err + } + req.Entity = append(req.Entity, sProto) + } + res := &pb.PutResponse{} + if err := internal.Call(c, "datastore_v3", "Put", req, res); err != nil { + return nil, err + } + if len(key) != len(res.Key) { + return nil, errors.New("datastore: internal error: server returned the wrong number of keys") + } + ret := make([]*Key, len(key)) + for i := range ret { + var err error + ret[i], err = protoToKey(res.Key[i]) + if err != nil || ret[i].Incomplete() { + return nil, errors.New("datastore: internal error: server returned an invalid key") + } + } + return ret, nil +} + +// Delete deletes the entity for the given key. +func Delete(c context.Context, key *Key) error { + err := DeleteMulti(c, []*Key{key}) + if me, ok := err.(appengine.MultiError); ok { + return me[0] + } + return err +} + +// DeleteMulti is a batch version of Delete. +func DeleteMulti(c context.Context, key []*Key) error { + if len(key) == 0 { + return nil + } + if err := multiValid(key); err != nil { + return err + } + req := &pb.DeleteRequest{ + Key: multiKeyToProto(internal.FullyQualifiedAppID(c), key), + } + res := &pb.DeleteResponse{} + return internal.Call(c, "datastore_v3", "Delete", req, res) +} + +func namespaceMod(m proto.Message, namespace string) { + // pb.Query is the only type that has a name_space field. + // All other namespace support in datastore is in the keys. + switch m := m.(type) { + case *pb.Query: + if m.NameSpace == nil { + m.NameSpace = &namespace + } + } +} + +func init() { + internal.NamespaceMods["datastore_v3"] = namespaceMod + internal.RegisterErrorCodeMap("datastore_v3", pb.Error_ErrorCode_name) + internal.RegisterTimeoutErrorCode("datastore_v3", int32(pb.Error_TIMEOUT)) +} |