ipldutil

Documentation

Index

• func DecodeNode(encoded []byte) (ipld.Node, error)
• func EncodeNode(node ipld.Node) ([]byte, error)
• func ParseSelector(selector ipld.Node) (selector.Selector, error)
• func Traverse(ctx context.Context, loader ipld.Loader, ...) error
• func WalkMatching(node ipld.Node, s selector.Selector, fn traversal.VisitFn) error
• type ContextCancelError
  • func (cp ContextCancelError) Error() string
• type TraversalBuilder
  • func (tb TraversalBuilder) Start(parentCtx context.Context) Traverser
• type Traverser

Functions

func DecodeNode

func DecodeNode(encoded []byte) (ipld.Node, error)

func EncodeNode

func EncodeNode(node ipld.Node) ([]byte, error)

func ParseSelector

func ParseSelector(selector ipld.Node) (selector.Selector, error)

func Traverse

func Traverse(ctx context.Context, loader ipld.Loader, chooser traversal.LinkTargetNodePrototypeChooser, root ipld.Link, s selector.Selector, fn traversal.AdvVisitFn) error

func WalkMatching

func WalkMatching(node ipld.Node, s selector.Selector, fn traversal.VisitFn) error

Types

type ContextCancelError

type ContextCancelError struct{}

ContextCancelError is a sentinel that indicates the passed in context was cancelled

func (ContextCancelError) Error

func (cp ContextCancelError) Error() string

type TraversalBuilder

type TraversalBuilder struct {
	Root     ipld.Link
	Selector ipld.Node
	Visitor  traversal.AdvVisitFn
	Chooser  traversal.LinkTargetNodePrototypeChooser
}

TraversalBuilder defines parameters for an iterative traversal

func (TraversalBuilder) Start

func (tb TraversalBuilder) Start(parentCtx context.Context) Traverser

Start initiates the traversal (run in a go routine because the regular selector traversal expects a call back)

type Traverser

type Traverser interface {
	// IsComplete returns the completion state (boolean) and if so, the final error result from IPLD
	IsComplete() (bool, error)
	// Current request returns the current link waiting to be loaded
	CurrentRequest() (ipld.Link, ipld.LinkContext)
	// Advance advances the traversal successfully by supplying the given reader as the result of the next IPLD load
	Advance(reader io.Reader) error
	// Error errors the traversal by returning the given error as the result of the next IPLD load
	Error(err error)
	// Shutdown cancels the traversal
	Shutdown(ctx context.Context)
}

Traverser is an interface for performing a selector traversal that operates iteratively -- it stops and waits for a manual load every time a block boundary is encountered