unixfs

Documentation

Overview

Package unixfs implements a data format for files in the IPFS filesystem It is not the only format in ipfs, but it is the one that the filesystem assumes

Index

• Constants
• Variables
• func BytesForMetadata(m *Metadata) ([]byte, error)
• func DataSize(data []byte) (uint64, error)
• func EmptyDirNode() *dag.ProtoNode
• func FilePBData(data []byte, totalsize uint64) []byte
• func FolderPBData() []byte
• func FromBytes(data []byte) (*pb.Data, error)
• func SymlinkData(path string) ([]byte, error)
• func UnwrapData(data []byte) ([]byte, error)
• func WrapData(b []byte) []byte
• type FSNode
  • func FSNodeFromBytes(b []byte) (*FSNode, error)
  • func NewFSNode(dataType pb.Data_DataType) *FSNode
  • func (n *FSNode) AddBlockSize(s uint64)
  • func (n *FSNode) BlockSize(i int) uint64
  • func (n *FSNode) Data() []byte
  • func (n *FSNode) FileSize() uint64
  • func (n *FSNode) GetBytes() ([]byte, error)
  • func (n *FSNode) NumChildren() int
  • func (n *FSNode) RemoveAllBlockSizes()
  • func (n *FSNode) RemoveBlockSize(i int)
  • func (n *FSNode) SetData(newData []byte)
  • func (n *FSNode) Type() pb.Data_DataType
  • func (n *FSNode) UpdateFilesize(filesizeDiff int64)
• type Metadata
  • func MetadataFromBytes(b []byte) (*Metadata, error)
  • func (m *Metadata) Bytes() ([]byte, error)

Constants

const (
	TRaw       = pb.Data_Raw
	TFile      = pb.Data_File
	TDirectory = pb.Data_Directory
	TMetadata  = pb.Data_Metadata
	TSymlink   = pb.Data_Symlink
	THAMTShard = pb.Data_HAMTShard
)

Shorthands for protobuffer types

Variables

var (
	ErrMalformedFileFormat = errors.New("malformed data in file format")
	ErrUnrecognizedType    = errors.New("unrecognized node type")
)

Common errors

Functions

func BytesForMetadata

func BytesForMetadata(m *Metadata) ([]byte, error)

BytesForMetadata wraps the given Metadata as a profobuf message of Data type, setting the DataType to Metadata. The wrapped bytes are itself the result of calling m.Bytes().

func DataSize

func DataSize(data []byte) (uint64, error)

DataSize returns the size of the contents in protobuf wrapped slice. For raw data it simply provides the length of it. For Data_Files, it will return the associated filesize. Note that Data_Directories will return an error.

func EmptyDirNode

func EmptyDirNode() *dag.ProtoNode

EmptyDirNode creates an empty folder Protonode.

func FilePBData

func FilePBData(data []byte, totalsize uint64) []byte

FilePBData creates a protobuf File with the given byte slice and returns the marshaled protobuf bytes representing it.

func FolderPBData

func FolderPBData() []byte

FolderPBData returns Bytes that represent a Directory.

func FromBytes

func FromBytes(data []byte) (*pb.Data, error)

FromBytes unmarshals a byte slice as protobuf Data.

func SymlinkData

func SymlinkData(path string) ([]byte, error)

SymlinkData returns a `Data_Symlink` protobuf message for the path you specify.

func UnwrapData

func UnwrapData(data []byte) ([]byte, error)

UnwrapData unmarshals a protobuf messages and returns the contents.

func WrapData

func WrapData(b []byte) []byte

WrapData marshals raw bytes into a `Data_Raw` type protobuf message.

Types

type FSNode

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

An FSNode represents a filesystem object using the UnixFS specification.

The `NewFSNode` constructor should be used instead of just calling `new(FSNode)` to guarantee that the required (`Type` and `Filesize`) fields in the `format` structure are initialized before marshaling (in `GetBytes()`).

func FSNodeFromBytes

func FSNodeFromBytes(b []byte) (*FSNode, error)

FSNodeFromBytes unmarshal a protobuf message onto an FSNode.

func NewFSNode

func NewFSNode(dataType pb.Data_DataType) *FSNode

NewFSNode creates a new FSNode structure with the given `dataType`.

It initializes the (required) `Type` field (that doesn't have a `Set()` accessor so it must be specified at creation), otherwise the `Marshal()` method in `GetBytes()` would fail (`required field "Type" not set`).

It also initializes the `Filesize` pointer field to ensure its value is never nil before marshaling, this is not a required field but it is done to be backwards compatible with previous `go-ipfs` versions hash. (If it wasn't initialized there could be cases where `Filesize` could have been left at nil, when the `FSNode` was created but no data or child nodes were set to adjust it, as is the case in `NewLeaf()`.)

func (*FSNode) AddBlockSize

func (n *FSNode) AddBlockSize(s uint64)

AddBlockSize adds the size of the next child block of this node

func (*FSNode) BlockSize

func (n *FSNode) BlockSize(i int) uint64

BlockSize returns the block size indexed by `i`. TODO: Evaluate if this function should be bounds checking.

func (*FSNode) Data

func (n *FSNode) Data() []byte

Data retrieves the `Data` field from the internal `format`.

func (*FSNode) FileSize

func (n *FSNode) FileSize() uint64

FileSize returns the total size of this tree. That is, the size of the data in this node plus the size of all its children.

func (*FSNode) GetBytes

func (n *FSNode) GetBytes() ([]byte, error)

GetBytes marshals this node as a protobuf message.

func (*FSNode) NumChildren

func (n *FSNode) NumChildren() int

NumChildren returns the number of child blocks of this node

func (*FSNode) RemoveAllBlockSizes

func (n *FSNode) RemoveAllBlockSizes()

RemoveAllBlockSizes removes all the child block sizes of this node.

func (*FSNode) RemoveBlockSize

func (n *FSNode) RemoveBlockSize(i int)

RemoveBlockSize removes the given child block's size.

func (*FSNode) SetData

func (n *FSNode) SetData(newData []byte)

SetData sets the `Data` field from the internal `format` updating its `Filesize`.

func (*FSNode) Type

func (n *FSNode) Type() pb.Data_DataType

Type retrieves the `Type` field from the internal `format`.

func (*FSNode) UpdateFilesize

func (n *FSNode) UpdateFilesize(filesizeDiff int64)

UpdateFilesize updates the `Filesize` field from the internal `format` by a signed difference (`filesizeDiff`). TODO: Add assert to check for `Filesize` > 0?

type Metadata

type Metadata struct {
	MimeType string
	Size     uint64
}

Metadata is used to store additional FSNode information.

func MetadataFromBytes

func MetadataFromBytes(b []byte) (*Metadata, error)

MetadataFromBytes Unmarshals a protobuf Data message into Metadata. The provided slice should have been encoded with BytesForMetadata().

func (*Metadata) Bytes

func (m *Metadata) Bytes() ([]byte, error)

Bytes marshals Metadata as a protobuf message of Metadata type.