Documentation
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Index ¶
Constants ¶
This section is empty.
Variables ¶
var ( ErrReadyNotInitializing = errors.New("Ready was called when Status is not Initializing") ErrMarkForDeletionNotReady = errors.New("MarkForDeletion was called when Status is not either Initializing or Ready") )
var (
ErrIteratorNil = errors.New("iterator is nil")
)
Functions ¶
This section is empty.
Types ¶
type BlobRef ¶
type BlobRef struct {
// Key is the primary key for the blob entry
Key uuid.UUID `datastore:"-"`
// Size is the byte size of the blob
Size int64
// Status is the current status of the blob
Status
// StoreKey is the key of the store that the blob belongs to
StoreKey string
// RecordKey is the key of the record that the blob belongs to
// It can be non-existent (e.g. deleted already) but then the Status
// should not be Blob StatusReady.
RecordKey string
// Chunked is whether the BlobRef is chunked or not.
Chunked bool
// ChunkCount is the number of chunks that should be associated to the BlobRef.
// It is set by either the client when starting a chunk upload or
// the server when committing a chunked upload.
ChunkCount int64
// Checksums have checksums for each blob object associated with the BlobRef entity.
// Record.{MD5,CRC32C} must be used for inline blobs, and
// ChunkRef.{MD5,CRC32C} must be used for chunked blobs.
checksums.Checksums `datastore:",flatten"`
// Timestamps keeps track of creation and modification times and stores a randomly
// generated UUID to maintain consistency.
Timestamps timestamps.Timestamps
}
BlobRef is a metadata document to keep track of blobs stored in an external blob store.
func NewBlobRef ¶
NewBlobRef creates a new BlobRef as follows:
- Set a new UUID to Key
- Initialize Size and ObjectName as specified
- Set Status to BlobRefStatusInitializing
- Set current time to Timestamps (both created and updated at)
func NewChunkedBlobRef ¶
NewChunkedBlobRef creates a new BlobRef object with Size, Chunked, and ChunkCount set to 0, true, and chunkCount respectively. Other behaviors are the same as NewBlobRef
func (*BlobRef) Load ¶
Load implements the Datastore PropertyLoadSaver interface and converts Datstore properties to the Properties field.
func (*BlobRef) LoadKey ¶
LoadKey implements the KeyLoader interface and sets the value to the Key field.
func (*BlobRef) ObjectPath ¶
ObjectPath returns an object path for the backend blob storage.
func (*BlobRef) Save ¶
Save implements the Datastore PropertyLoadSaver interface and converts the properties field in the struct to separate Datastore properties.
func (*BlobRef) ToProto ¶
func (b *BlobRef) ToProto() *pb.BlobMetadata
ToProto returns a BlobMetadata representation of the object.
type BlobRefCursor ¶
type BlobRefCursor struct {
// contains filtered or unexported fields
}
BlobRefCursor is a database cursor for BlobRef.
func NewCursor ¶
func NewCursor(i *ds.Iterator) *BlobRefCursor
func (*BlobRefCursor) Next ¶
func (i *BlobRefCursor) Next() (*BlobRef, error)
Next advances the iterator and returns the next value. Returns nil and and iterator.Done at the end of the iterator. Returns ErrIteratorNil if the iterator is nil.
type Status ¶
type Status int16
Status represents a current blob status.
Life of a Blob ¶
[New Record created] --> [new Status entity with StatusInitializing]
/ \
/ fail \ success
v v
[StatusError] [StatusReady]
| x |
Upload new blob | \ fail | Record deleted or new blob uploaded
or | \ v
delete the record | -------[StatusPendingDeletion]
v /
[Delete the blob entity] <-------------/ Garbage collection
const ( // StatusUnknown represents internal error. StatusUnknown Status = iota // StatusInitializing means the blob is currently being prepared, i.e. // being uploaded to the blob store. StatusInitializing // StatusReady means the blob is committed and ready for use. StatusReady // StatusPendingDeletion means the blob is no longer referenced by // any Record entities and needs to be deleted. StatusPendingDeletion // StatusError means the blob was not uploaded due to client or server // errors and the corresponding record needs to be updated (either by // retrying blob upload or deleting the entry). StatusError )
func (*Status) Fail ¶
func (s *Status) Fail()
Fail marks the Status as StatusError. Any state can transition to StatusError.
func (*Status) MarkForDeletion ¶
MarkForDeletion marks the Status as StatusPendingDeletion. Returns an error if the current Status is not StatusInitializing or StatusReady.
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