blobstore

Documentation

Index

• Variables
• type BlobInfo
• type BlobReader
• type BlobRef
  • func (ref *BlobRef) IsValid() bool
• type BlobWriter
• type Blobs
• type DiskInfo
• type FileInfo
• type FormatVersion
• type SkipPrefixFn

Variables

var ErrInvalidBlobRef = errs.Class("invalid blob ref")

ErrInvalidBlobRef is returned when an blob reference is invalid.

Types

type BlobInfo

type BlobInfo interface {
	// BlobRef returns the relevant BlobRef for the blob.
	BlobRef() BlobRef
	// StorageFormatVersion indicates the storage format version used to store the blob.
	StorageFormatVersion() FormatVersion
	// FullPath gives the full path to the on-disk blob file.
	FullPath(ctx context.Context) (string, error)
	// Stat does a stat on the on-disk blob file.
	Stat(ctx context.Context) (FileInfo, error)
}

BlobInfo allows lazy inspection of a blob and its underlying file during iteration with WalkNamespace-type methods.

type BlobReader

type BlobReader interface {
	io.Reader
	io.ReaderAt
	io.Seeker
	io.Closer
	// Size returns the size of the blob.
	Size() (int64, error)
	// StorageFormatVersion returns the storage format version associated with the blob.
	StorageFormatVersion() FormatVersion
}

BlobReader is an interface that groups Read, ReadAt, Seek and Close.

type BlobRef

type BlobRef struct {
	Namespace []byte
	Key       []byte
}

BlobRef is a reference to a blob.

func (*BlobRef) IsValid

func (ref *BlobRef) IsValid() bool

IsValid returns whether both namespace and key are specified.

type BlobWriter

type BlobWriter interface {
	io.Writer
	io.Seeker
	// Cancel discards the blob.
	Cancel(context.Context) error
	// Commit ensures that the blob is readable by others.
	Commit(context.Context) error
	// Size returns the size of the blob
	Size() (int64, error)
	// ReserveHeader reserves header area at the beginning of the blob.
	ReserveHeader(int64) error
	// StorageFormatVersion returns the storage format version associated with the blob.
	StorageFormatVersion() FormatVersion
}

BlobWriter defines the interface that must be satisfied for a general blob storage provider. BlobWriter instances are returned by the Create() method on Blobs instances.

type Blobs

type Blobs interface {
	// Create creates a new blob that can be written.
	Create(ctx context.Context, ref BlobRef) (BlobWriter, error)
	// Open opens a reader with the specified namespace and key.
	Open(ctx context.Context, ref BlobRef) (BlobReader, error)
	// OpenWithStorageFormat opens a reader for the already-located blob, avoiding the potential
	// need to check multiple storage formats to find the blob.
	OpenWithStorageFormat(ctx context.Context, ref BlobRef, formatVer FormatVersion) (BlobReader, error)
	// Delete deletes the blob with the namespace and key.
	Delete(ctx context.Context, ref BlobRef) error
	// DeleteWithStorageFormat deletes a blob of a specific storage format.
	DeleteWithStorageFormat(ctx context.Context, ref BlobRef, formatVer FormatVersion, sizeHint int64) error
	// DeleteNamespace deletes blobs folder for a specific namespace.
	DeleteNamespace(ctx context.Context, ref []byte) (err error)
	// DeleteTrashNamespace deletes the trash folder for a given namespace.
	DeleteTrashNamespace(ctx context.Context, namespace []byte) (err error)
	// Trash marks a file for pending deletion.
	Trash(ctx context.Context, ref BlobRef, timestamp time.Time) error
	// TrashWithStorageFormat marks a blob with a specific storage format for pending deletion.
	TrashWithStorageFormat(ctx context.Context, ref BlobRef, formatVer FormatVersion, timestamp time.Time) error
	// RestoreTrash restores all files in the trash for a given namespace and returns the keys restored.
	RestoreTrash(ctx context.Context, namespace []byte) ([][]byte, error)
	// EmptyTrash removes all files in trash that were moved to trash prior to trashedBefore and returns the total bytes emptied and keys deleted.
	EmptyTrash(ctx context.Context, namespace []byte, trashedBefore time.Time) (int64, [][]byte, error)
	// TryRestoreTrashBlob attempts to restore a blob from the trash.
	// It returns nil if the blob was restored, or an error if the blob was not
	// in the trash or could not be restored.
	TryRestoreTrashBlob(ctx context.Context, ref BlobRef) error
	// Stat looks up disk metadata on the blob file.
	Stat(ctx context.Context, ref BlobRef) (BlobInfo, error)
	// StatWithStorageFormat looks up disk metadata for the blob file with the given storage format
	// version. This avoids the potential need to check multiple storage formats for the blob
	// when the format is already known.
	StatWithStorageFormat(ctx context.Context, ref BlobRef, formatVer FormatVersion) (BlobInfo, error)

	// DiskInfo returns information about the disk.
	DiskInfo(ctx context.Context) (DiskInfo, error)
	// SpaceUsedForTrash returns the total space used by the trash.
	SpaceUsedForTrash(ctx context.Context) (int64, error)
	// SpaceUsedForBlobs adds up how much is used in all namespaces.
	SpaceUsedForBlobs(ctx context.Context) (int64, error)
	// SpaceUsedForBlobsInNamespace adds up how much is used in the given namespace.
	SpaceUsedForBlobsInNamespace(ctx context.Context, namespace []byte) (int64, error)

	// ListNamespaces finds all namespaces in which keys might currently be stored.
	ListNamespaces(ctx context.Context) ([][]byte, error)
	// WalkNamespace executes walkFunc for each locally stored blob, stored with
	// storage format V1 or greater, in the given namespace. If walkFunc returns a non-nil
	// error, WalkNamespace will stop iterating and return the error immediately. The ctx
	// parameter is intended to allow canceling iteration early.
	WalkNamespace(ctx context.Context, namespace []byte, skipPrefixFn SkipPrefixFn, walkFunc func(BlobInfo) error) error

	// CheckWritability tests writability of the storage directory by creating and deleting a file.
	CheckWritability(ctx context.Context) error
	// CreateVerificationFile creates a file to be used for storage directory verification.
	CreateVerificationFile(ctx context.Context, id storj.NodeID) error
	// VerifyStorageDir verifies that the storage directory is correct by checking for the existence and validity
	// of the verification file.
	VerifyStorageDir(ctx context.Context, id storj.NodeID) error

	// Close closes the blob store and any resources associated with it.
	Close() error
}

Blobs is a blob storage interface.

architecture: Database

type DiskInfo

type DiskInfo struct {
	TotalSpace     int64
	AvailableSpace int64
}

DiskInfo contains information about the disk.

type FileInfo

type FileInfo interface {
	ModTime() time.Time
	Size() int64
}

FileInfo contains information about the pieces files, what we care about.

type FormatVersion

type FormatVersion int

FormatVersion represents differing storage format version values. Different Blobs implementors might interpret different FormatVersion values differently, but they share a type so that there can be a common StorageFormatVersion() call on the interface.

Changes in FormatVersion might affect how a Blobs or BlobReader or BlobWriter instance works, or they might only be relevant to some higher layer. A FormatVersion must be specified when writing a new blob, and the blob storage interface must store that value with the blob somehow, so that the same FormatVersion is returned later when reading that stored blob.

type SkipPrefixFn

type SkipPrefixFn func(prefix string) bool

SkipPrefixFn returns true if a prefix should be skipped.