io

package
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 Go to latest Published: Oct 24, 2018 License: MIT Imports: 11 Imported by: 0

Documentation

Overview

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

Index

Constants

This section is empty.

Variables

View Source 
var (
	ErrIsDir            = errors.New("this dag node is a directory")
	ErrCantReadSymlinks = errors.New("cannot currently read symlinks")
	ErrUnkownNodeType   = errors.New("unknown node type")
)

Common errors

View Source 
var DefaultShardWidth = 256

DefaultShardWidth is the default value used for hamt sharding width.

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

ErrNotADir implies that the given node was not a unixfs directory

View Source 
var UseHAMTSharding = false

UseHAMTSharding is a global flag that signifies whether or not to use the HAMT sharding scheme for directory creation

Functions

func ResolveUnixfsOnce 

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

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

func (*BasicDirectory) Find 

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

Find implements the `Directory` interface. 

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

ForEachLink implements the `Directory` interface.

func (*BasicDirectory) GetCidBuilder added in v1.0.8 

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

GetCidBuilder implements the `Directory` interface.

func (*BasicDirectory) GetNode 

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

GetNode implements the `Directory` interface. 

func (d *BasicDirectory) Links(ctx context.Context) ([]*ipld.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 added in v1.0.8 

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 BufDagReader 

type BufDagReader struct {
	*bytes.Reader
}

BufDagReader implements a DagReader that reads from a byte slice using a bytes.Reader. It is used for RawNodes.

func NewBufDagReader 

func NewBufDagReader(b []byte) *BufDagReader

NewBufDagReader returns a DAG reader for the given byte slice. BufDagReader is used to read RawNodes.

func (*BufDagReader) Close 

func (*BufDagReader) Close() error

Close is a nop.

func (*BufDagReader) CtxReadFull 

func (rd *BufDagReader) CtxReadFull(ctx context.Context, b []byte) (int, error)

CtxReadFull reads the slice onto b.

func (*BufDagReader) Size 

func (rd *BufDagReader) Size() uint64

Size returns the size of the buffer.

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 ipld.Node, serv ipld.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, ipld.Node) error

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

	// Links returns the all the links in the directory node.
	Links(context.Context) ([]*ipld.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.
	Find(context.Context, string) (ipld.Node, error)

	// RemoveChild removes the child with the given name.
	RemoveChild(context.Context, string) error

	// GetNode returns the root of this directory.
	GetNode() (ipld.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 ipld.DAGService) Directory

NewDirectory returns a Directory. It needs a `DAGService` to add the children.

func NewDirectoryFromNode 

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

NewDirectoryFromNode loads a unixfs directory from the given IPLD 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 ipld.Node) error

AddChild implements the `Directory` interface.

func (*HAMTDirectory) Find 

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

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

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

ForEachLink implements the `Directory` interface.

func (*HAMTDirectory) GetCidBuilder added in v1.0.8 

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

GetCidBuilder implements the `Directory` interface.

func (*HAMTDirectory) GetNode 

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

GetNode implements the `Directory` interface. 

func (d *HAMTDirectory) Links(ctx context.Context) ([]*ipld.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 added in v1.0.8 

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

SetCidBuilder implements the `Directory` interface.

type PBDagReader 

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

PBDagReader provides a way to easily read the data contained in a dag.

func NewPBFileReader 

func NewPBFileReader(ctx context.Context, n *mdag.ProtoNode, file *ft.FSNode, serv ipld.NodeGetter) *PBDagReader

NewPBFileReader constructs a new PBFileReader.

func (*PBDagReader) Close 

func (dr *PBDagReader) Close() error

Close closes the reader.

func (*PBDagReader) CtxReadFull 

func (dr *PBDagReader) CtxReadFull(ctx context.Context, b []byte) (int, error)

CtxReadFull reads data from the DAG structured file

func (*PBDagReader) Read 

func (dr *PBDagReader) Read(b []byte) (int, error)

Read reads data from the DAG structured file

func (*PBDagReader) Seek 

func (dr *PBDagReader) Seek(offset int64, whence int) (int64, error)

Seek implements io.Seeker, and will seek to a given offset in the file interface matches standard unix seek TODO: check if we can do relative seeks, to reduce the amount of dagreader recreations that need to happen.

func (*PBDagReader) Size 

func (dr *PBDagReader) Size() uint64

Size return the total length of the data from the DAG structured file.

func (*PBDagReader) WriteTo 

func (dr *PBDagReader) WriteTo(w io.Writer) (int64, error)

WriteTo writes to the given writer.

type ReadSeekCloser 

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

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

Source Files

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