io

Documentation

Overview

Package io implements convenience objects for working with the dms3 unixfs data format.

Index

• Variables
• func ResolveUnixfsOnce(ctx context.Context, ds ld.NodeGetter, nd ld.Node, names []string) (*ld.Link, []string, error)
• type BasicDirectory
  • func (d *BasicDirectory) AddChild(ctx context.Context, name string, node ld.Node) error
  • func (d *BasicDirectory) EnumLinksAsync(ctx context.Context) <-chan format.LinkResult
  • func (d *BasicDirectory) Find(ctx context.Context, name string) (ld.Node, error)
  • func (d *BasicDirectory) ForEachLink(ctx context.Context, f func(*ld.Link) error) error
  • func (d *BasicDirectory) GetCidBuilder() cid.Builder
  • func (d *BasicDirectory) GetNode() (ld.Node, error)
  • func (d *BasicDirectory) Links(ctx context.Context) ([]*ld.Link, error)
  • func (d *BasicDirectory) RemoveChild(ctx context.Context, name string) error
  • func (d *BasicDirectory) SetCidBuilder(builder cid.Builder)
  • func (d *BasicDirectory) SwitchToSharding(ctx context.Context) (Directory, error)
• type DagReader
  • func NewDagReader(ctx context.Context, n ld.Node, serv ld.NodeGetter) (DagReader, error)
• type Directory
  • func NewDirectory(dserv ld.DAGService) Directory
  • func NewDirectoryFromNode(dserv ld.DAGService, node ld.Node) (Directory, error)
• type HAMTDirectory
  • func (d *HAMTDirectory) AddChild(ctx context.Context, name string, nd ld.Node) error
  • func (d *HAMTDirectory) EnumLinksAsync(ctx context.Context) <-chan format.LinkResult
  • func (d *HAMTDirectory) Find(ctx context.Context, name string) (ld.Node, error)
  • func (d *HAMTDirectory) ForEachLink(ctx context.Context, f func(*ld.Link) error) error
  • func (d *HAMTDirectory) GetCidBuilder() cid.Builder
  • func (d *HAMTDirectory) GetNode() (ld.Node, error)
  • func (d *HAMTDirectory) Links(ctx context.Context) ([]*ld.Link, error)
  • func (d *HAMTDirectory) RemoveChild(ctx context.Context, name string) error
  • func (d *HAMTDirectory) SetCidBuilder(builder cid.Builder)
• type ReadSeekCloser
• type UpgradeableDirectory
  • func (d *UpgradeableDirectory) AddChild(ctx context.Context, name string, nd ld.Node) error

Variables

var (
	ErrIsDir            = errors.New("this dag node is a directory")
	ErrCantReadSymlinks = errors.New("cannot currently read symlinks")
	ErrUnkownNodeType   = errors.New("unknown node type")
	ErrSeekNotSupported = errors.New("file does not support seeking")
)

Common errors

var DefaultShardWidth = 256

DefaultShardWidth is the default value used for hamt sharding width.

var ErrNotADir = fmt.Errorf("merkledag node was not a directory or shard")

ErrNotADir implies that the given node was not a unixfs directory

var HAMTShardingSize = 0

HAMTShardingSize is a global option that allows switching to a HAMTDirectory when the BasicDirectory grows above the size (in bytes) signalled by this flag. The default size of 0 disables the option. The size is not the *exact* block size of the encoded BasicDirectory but just the estimated size based byte length of links name and CID (BasicDirectory's ProtoNode doesn't use the Data field so this estimate is pretty accurate).

var UseHAMTSharding = true

temporary until upstream decides where to hold this

Functions

func ResolveUnixfsOnce

func ResolveUnixfsOnce(ctx context.Context, ds ld.NodeGetter, nd ld.Node, names []string) (*ld.Link, []string, error)

ResolveUnixfsOnce resolves a single hop of a path through a graph in a unixfs context. This includes handling traversing sharded directories.

Types

type BasicDirectory

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

BasicDirectory is the basic implementation of `Directory`. All the entries are stored in a single node.

func (*BasicDirectory) AddChild

func (d *BasicDirectory) AddChild(ctx context.Context, name string, node ld.Node) error

AddChild implements the `Directory` interface. It adds (or replaces) a link to the given `node` under `name`.

func (*BasicDirectory) EnumLinksAsync

func (d *BasicDirectory) EnumLinksAsync(ctx context.Context) <-chan format.LinkResult

EnumLinksAsync returns a channel which will receive Links in the directory as they are enumerated, where order is not gauranteed

func (*BasicDirectory) Find

func (d *BasicDirectory) Find(ctx context.Context, name string) (ld.Node, error)

Find implements the `Directory` interface.

func (*BasicDirectory) ForEachLink

func (d *BasicDirectory) ForEachLink(ctx context.Context, f func(*ld.Link) error) error

ForEachLink implements the `Directory` interface.

func (*BasicDirectory) GetCidBuilder

func (d *BasicDirectory) GetCidBuilder() cid.Builder

GetCidBuilder implements the `Directory` interface.

func (*BasicDirectory) GetNode

func (d *BasicDirectory) GetNode() (ld.Node, error)

GetNode implements the `Directory` interface.

func (*BasicDirectory) Links

func (d *BasicDirectory) Links(ctx context.Context) ([]*ld.Link, error)

Links implements the `Directory` interface.

func (*BasicDirectory) RemoveChild

func (d *BasicDirectory) RemoveChild(ctx context.Context, name string) error

RemoveChild implements the `Directory` interface.

func (*BasicDirectory) SetCidBuilder

func (d *BasicDirectory) SetCidBuilder(builder cid.Builder)

SetCidBuilder implements the `Directory` interface.

func (*BasicDirectory) SwitchToSharding

func (d *BasicDirectory) SwitchToSharding(ctx context.Context) (Directory, error)

SwitchToSharding returns a HAMT implementation of this directory.

type DagReader

type DagReader interface {
	ReadSeekCloser
	Size() uint64
	CtxReadFull(context.Context, []byte) (int, error)
}

A DagReader provides read-only read and seek acess to a unixfs file. Different implementations of readers are used for the different types of unixfs/protobuf-encoded nodes.

func NewDagReader

func NewDagReader(ctx context.Context, n ld.Node, serv ld.NodeGetter) (DagReader, error)

NewDagReader creates a new reader object that reads the data represented by the given node, using the passed in DAGService for data retrieval.

type Directory

type Directory interface {

	// SetCidBuilder sets the CID Builder of the root node.
	SetCidBuilder(cid.Builder)

	// AddChild adds a (name, key) pair to the root node.
	AddChild(context.Context, string, ld.Node) error

	// ForEachLink applies the given function to Links in the directory.
	ForEachLink(context.Context, func(*ld.Link) error) error

	// EnumLinksAsync returns a channel which will receive Links in the directory
	// as they are enumerated, where order is not gauranteed
	EnumLinksAsync(context.Context) <-chan format.LinkResult

	// Links returns the all the links in the directory node.
	Links(context.Context) ([]*ld.Link, error)

	// Find returns the root node of the file named 'name' within this directory.
	// In the case of HAMT-directories, it will traverse the tree.
	//
	// Returns os.ErrNotExist if the child does not exist.
	Find(context.Context, string) (ld.Node, error)

	// RemoveChild removes the child with the given name.
	//
	// Returns os.ErrNotExist if the child doesn't exist.
	RemoveChild(context.Context, string) error

	// GetNode returns the root of this directory.
	GetNode() (ld.Node, error)

	// GetCidBuilder returns the CID Builder used.
	GetCidBuilder() cid.Builder
}

Directory defines a UnixFS directory. It is used for creating, reading and editing directories. It allows to work with different directory schemes, like the basic or the HAMT implementation.

It just allows to perform explicit edits on a single directory, working with directory trees is out of its scope, they are managed by the MFS layer (which is the main consumer of this interface).

func NewDirectory

func NewDirectory(dserv ld.DAGService) Directory

NewDirectory returns a Directory implemented by UpgradeableDirectory containing a BasicDirectory that can be converted to a HAMTDirectory.

func NewDirectoryFromNode

func NewDirectoryFromNode(dserv ld.DAGService, node ld.Node) (Directory, error)

NewDirectoryFromNode loads a unixfs directory from the given LD node and DAGService.

type HAMTDirectory

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

HAMTDirectory is the HAMT implementation of `Directory`. (See package `hamt` for more information.)

func (*HAMTDirectory) AddChild

func (d *HAMTDirectory) AddChild(ctx context.Context, name string, nd ld.Node) error

AddChild implements the `Directory` interface.

func (*HAMTDirectory) EnumLinksAsync

func (d *HAMTDirectory) EnumLinksAsync(ctx context.Context) <-chan format.LinkResult

EnumLinksAsync returns a channel which will receive Links in the directory as they are enumerated, where order is not gauranteed

func (*HAMTDirectory) Find

func (d *HAMTDirectory) Find(ctx context.Context, name string) (ld.Node, error)

Find implements the `Directory` interface. It will traverse the tree.

func (*HAMTDirectory) ForEachLink

func (d *HAMTDirectory) ForEachLink(ctx context.Context, f func(*ld.Link) error) error

ForEachLink implements the `Directory` interface.

func (*HAMTDirectory) GetCidBuilder

func (d *HAMTDirectory) GetCidBuilder() cid.Builder

GetCidBuilder implements the `Directory` interface.

func (*HAMTDirectory) GetNode

func (d *HAMTDirectory) GetNode() (ld.Node, error)

GetNode implements the `Directory` interface.

func (*HAMTDirectory) Links

func (d *HAMTDirectory) Links(ctx context.Context) ([]*ld.Link, error)

Links implements the `Directory` interface.

func (*HAMTDirectory) RemoveChild

func (d *HAMTDirectory) RemoveChild(ctx context.Context, name string) error

RemoveChild implements the `Directory` interface.

func (*HAMTDirectory) SetCidBuilder

func (d *HAMTDirectory) SetCidBuilder(builder cid.Builder)

SetCidBuilder implements the `Directory` interface.

type ReadSeekCloser

type ReadSeekCloser interface {
	io.Reader
	io.Seeker
	io.Closer
	io.WriterTo
}

A ReadSeekCloser implements interfaces to read, copy, seek and close.

type UpgradeableDirectory

type UpgradeableDirectory struct {
	Directory
}

UpgradeableDirectory wraps a Directory interface and provides extra logic to upgrade from its BasicDirectory implementation to HAMTDirectory.

func (*UpgradeableDirectory) AddChild

func (d *UpgradeableDirectory) AddChild(ctx context.Context, name string, nd ld.Node) error

AddChild implements the `Directory` interface. We check when adding new entries if we should switch to HAMTDirectory according to global option(s).