dsio

Documentation

Index

• func Export(it *datastore.Iterator, w io.Writer) (err error)
• func Import(r io.Reader, ds *datastore.Client) (err error)
• func ImportFile(r io.Reader, outCh chan Entity, errCh chan error) (err error)
• func ImportFileReflect(filename string, modelMap []ModelMapping) error
• func ImportStreamReflect(r io.Reader, modelMap []ModelMapping) (err error)
• func Marshal(inCh <-chan Entity, outCh chan<- []byte, errCh chan<- error)
• func MarshalKey(key *datastore.Key) string
• func OpenForReading(filename string) (io.ReadCloser, error)
• func OpenForWriting(filename string) (io.WriteCloser, error)
• func Unmarshal(inCh <-chan []byte, outCh chan<- Entity, errCh chan<- error)
• func UnmarshalKey(s string) (key *datastore.Key)
• type Entity
• type ImportFuncType
• type ModelMapping
• type Reflector
  • func NewReflector(typePtr interface{}) *Reflector
  • func (r *Reflector) MakeCopy() interface{}
  • func (r *Reflector) Reset()
  • func (r *Reflector) Set(field string, value interface{})

Functions

func Export

func Export(it *datastore.Iterator, w io.Writer) (err error)

Export exports the given DataStore entity iterator into the given stream.

func Import

func Import(r io.Reader, ds *datastore.Client) (err error)

Import imports DataStore entities from the export file.

func ImportFile

func ImportFile(r io.Reader, outCh chan Entity, errCh chan error) (err error)

ImportFile reads an export file, writing DataStore entities to outCh. Closes outCh to signal EOF. Waits until errCh is closed. Returns the first encountered error.

func ImportFileReflect

func ImportFileReflect(filename string, modelMap []ModelMapping) error

ImportFileReflect imports a given .ds file using the provided type and import function.

func ImportStreamReflect

func ImportStreamReflect(r io.Reader, modelMap []ModelMapping) (err error)

ImportStreamReflect imports a given .ds stream using the provided type and import function mapping

func Marshal

func Marshal(inCh <-chan Entity, outCh chan<- []byte, errCh chan<- error)

Marshal marshals a stream of DataStore entities into a stream of byte arrays.

func MarshalKey

func MarshalKey(key *datastore.Key) string

func OpenForReading

func OpenForReading(filename string) (io.ReadCloser, error)

OpenForReading opens a file for reading, seamlessly un-gzipping if needed.

func OpenForWriting

func OpenForWriting(filename string) (io.WriteCloser, error)

OpenForWriting opens a file for writing, seamlessly gzipping if needed.

func Unmarshal

func Unmarshal(inCh <-chan []byte, outCh chan<- Entity, errCh chan<- error)

Unmarshal processes export file lines, writing DataStore entities to outCh and any error to errCh. Closes outCh and errCh before returning.

func UnmarshalKey

func UnmarshalKey(s string) (key *datastore.Key)

Types

type Entity

type Entity struct {
	Key        *datastore.Key
	Properties datastore.PropertyList
}

Entity wraps a DataStore entity including its key and all properties as key-value pairs.

type ImportFuncType

type ImportFuncType func(kind string, rows []interface{}) error

ImportFuncType is the type of the import callback.

type ModelMapping

type ModelMapping struct {
	// DataStore entity kind (type name).
	Kind string
	// TypePtr must be a pointer to a struct of the desired type.
	TypePtr interface{}
	// ImportFunc will be called with a slice of pointers to objects of the given type.
	ImportFunc ImportFuncType
	// BatchSize defines the desired number of elements for a single ImportFunc call.
	BatchSize int
}

ModelMapping wraps a single data model type.

type Reflector

type Reflector struct {
	// contains filtered or unexported fields
}

Reflector implements a caching reflection helper.

func NewReflector

func NewReflector(typePtr interface{}) *Reflector

NewReflector returns a new instance of Reflector. Typical use-case flow: r.Reset(), r.Set(), r.Set() ..., r.MakeCopy()

func (*Reflector) MakeCopy

func (r *Reflector) MakeCopy() interface{}

MakeCopy returns a pointer to a copy of the reflected object.

func (*Reflector) Reset

func (r *Reflector) Reset()

Reset default-initializes the reflected object.

func (*Reflector) Set

func (r *Reflector) Set(field string, value interface{})

Set sets a property in the reflected object.