helpers

Documentation

Index

• Variables
• type DagBuilderHelper
  • func (db *DagBuilderHelper) Add(node ipld.Node) error
  • func (db *DagBuilderHelper) Done() bool
  • func (db *DagBuilderHelper) FillNodeLayer(node *FSNodeOverDag) error
  • func (db *DagBuilderHelper) GetCidBuilder() cid.Builder
  • func (db *DagBuilderHelper) GetDagServ() ipld.DAGService
  • func (db *DagBuilderHelper) Maxlinks() int
  • func (db *DagBuilderHelper) NewFSNFromDag(nd *dag.ProtoNode) (*FSNodeOverDag, error)
  • func (db *DagBuilderHelper) NewFSNodeOverDag(fsNodeType pb.Data_DataType) *FSNodeOverDag
  • func (db *DagBuilderHelper) NewLeafDataNode(fsNodeType pb.Data_DataType) (node ipld.Node, dataSize uint64, err error)
  • func (db *DagBuilderHelper) NewLeafNode(data []byte, fsNodeType pb.Data_DataType) (ipld.Node, error)
  • func (db *DagBuilderHelper) Next() ([]byte, error)
  • func (db *DagBuilderHelper) ProcessFileStore(node ipld.Node, dataSize uint64) ipld.Node
• type DagBuilderParams
  • func (dbp *DagBuilderParams) New(spl chunker.Splitter) (*DagBuilderHelper, error)
• type FSNodeOverDag
  • func NewFSNFromDag(nd *dag.ProtoNode) (*FSNodeOverDag, error)
  • func (n *FSNodeOverDag) AddChild(child ipld.Node, fileSize uint64, db *DagBuilderHelper) error
  • func (n *FSNodeOverDag) Commit() (ipld.Node, error)
  • func (n *FSNodeOverDag) FileSize() uint64
  • func (n *FSNodeOverDag) GetChild(ctx context.Context, i int, ds ipld.DAGService) (*FSNodeOverDag, error)
  • func (n *FSNodeOverDag) GetDagNode() (ipld.Node, error)
  • func (n *FSNodeOverDag) NumChildren() int
  • func (n *FSNodeOverDag) RemoveChild(index int, dbh *DagBuilderHelper)
  • func (n *FSNodeOverDag) SetFileData(fileData []byte)

Variables

var BlockSizeLimit = 1048576 // 1 MB

BlockSizeLimit specifies the maximum size an imported block can have.

var DefaultLinksPerBlock = roughLinkBlockSize / roughLinkSize

DefaultLinksPerBlock governs how the importer decides how many links there will be per block. This calculation is based on expected distributions of:

• the expected distribution of block sizes
• the expected distribution of link sizes
• desired access speed

For now, we use:

var roughLinkBlockSize = 1 << 13 // 8KB
var roughLinkSize = 34 + 8 + 5   // sha256 multihash + size + no name
                                 // + protobuf framing
var DefaultLinksPerBlock = (roughLinkBlockSize / roughLinkSize)
                         = ( 8192 / 47 )
                         = (approximately) 174

var ErrMissingFsRef = errors.New("missing file path or URL, can't create filestore reference")

var ErrSizeLimitExceeded = fmt.Errorf("object size limit exceeded")

ErrSizeLimitExceeded signals that a block is larger than BlockSizeLimit.

Types

type DagBuilderHelper

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

DagBuilderHelper wraps together a bunch of objects needed to efficiently create unixfs dag trees

func (*DagBuilderHelper) Add

func (db *DagBuilderHelper) Add(node ipld.Node) error

Add inserts the given node in the DAGService.

func (*DagBuilderHelper) Done

func (db *DagBuilderHelper) Done() bool

Done returns whether or not we're done consuming the incoming data.

func (*DagBuilderHelper) FillNodeLayer

func (db *DagBuilderHelper) FillNodeLayer(node *FSNodeOverDag) error

FillNodeLayer will add datanodes as children to the give node until it is full in this layer or no more data. NOTE: This function creates raw data nodes so it only works for the `trickle.Layout`.

func (*DagBuilderHelper) GetCidBuilder

func (db *DagBuilderHelper) GetCidBuilder() cid.Builder

GetCidBuilder returns the internal `cid.CidBuilder` set in the builder.

func (*DagBuilderHelper) GetDagServ

func (db *DagBuilderHelper) GetDagServ() ipld.DAGService

GetDagServ returns the dagservice object this Helper is using

func (*DagBuilderHelper) Maxlinks

func (db *DagBuilderHelper) Maxlinks() int

Maxlinks returns the configured maximum number for links for nodes built with this helper.

func (*DagBuilderHelper) NewFSNFromDag

func (db *DagBuilderHelper) NewFSNFromDag(nd *dag.ProtoNode) (*FSNodeOverDag, error)

NewFSNFromDag reconstructs a FSNodeOverDag node from a given dag node

func (*DagBuilderHelper) NewFSNodeOverDag

func (db *DagBuilderHelper) NewFSNodeOverDag(fsNodeType pb.Data_DataType) *FSNodeOverDag

NewFSNodeOverDag creates a new `dag.ProtoNode` and `ft.FSNode` decoupled from one onther (and will continue in that way until `Commit` is called), with `fsNodeType` specifying the type of the UnixFS layer node (either `File` or `Raw`).

func (*DagBuilderHelper) NewLeafDataNode

func (db *DagBuilderHelper) NewLeafDataNode(fsNodeType pb.Data_DataType) (node ipld.Node, dataSize uint64, err error)

NewLeafDataNode builds the `node` with the data obtained from the Splitter with the given constraints (BlockSizeLimit, RawLeaves) specified when creating the DagBuilderHelper. It returns `ipld.Node` with the `dataSize` (that will be used to keep track of the DAG file size). The size of the data is computed here because after that it will be hidden by `NewLeafNode` inside a generic `ipld.Node` representation.

func (*DagBuilderHelper) NewLeafNode

func (db *DagBuilderHelper) NewLeafNode(data []byte, fsNodeType pb.Data_DataType) (ipld.Node, error)

NewLeafNode creates a leaf node filled with data. If rawLeaves is defined then a raw leaf will be returned. Otherwise, it will create and return `FSNodeOverDag` with `fsNodeType`.

func (*DagBuilderHelper) Next

func (db *DagBuilderHelper) Next() ([]byte, error)

Next returns the next chunk of data to be inserted into the dag if it returns nil, that signifies that the stream is at an end, and that the current building operation should finish.

func (*DagBuilderHelper) ProcessFileStore

func (db *DagBuilderHelper) ProcessFileStore(node ipld.Node, dataSize uint64) ipld.Node

ProcessFileStore generates, if Filestore is being used, the `FilestoreNode` representation of the `ipld.Node` that contains the file data. If Filestore is not being used just return the same node to continue with its addition to the DAG.

The `db.offset` is updated at this point (instead of when `NewLeafDataNode` is called, both work in tandem but the offset is more related to this function).

type DagBuilderParams

type DagBuilderParams struct {
	// Maximum number of links per intermediate node
	Maxlinks int

	// RawLeaves signifies that the importer should use raw ipld nodes as leaves
	// instead of using the unixfs TRaw type
	RawLeaves bool

	// CID Builder to use if set
	CidBuilder cid.Builder

	// DAGService to write blocks to (required)
	Dagserv ipld.DAGService

	// NoCopy signals to the chunker that it should track fileinfo for
	// filestore adds
	NoCopy bool
}

DagBuilderParams wraps configuration options to create a DagBuilderHelper from a chunker.Splitter.

func (*DagBuilderParams) New

func (dbp *DagBuilderParams) New(spl chunker.Splitter) (*DagBuilderHelper, error)

New generates a new DagBuilderHelper from the given params and a given chunker.Splitter as data source.

type FSNodeOverDag

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

FSNodeOverDag encapsulates an `unixfs.FSNode` that will be stored in a `dag.ProtoNode`. Instead of just having a single `ipld.Node` that would need to be constantly (un)packed to access and modify its internal `FSNode` in the process of creating a UnixFS DAG, this structure stores an `FSNode` cache to manipulate it (add child nodes) directly , and only when the node has reached its final (immutable) state (signaled by calling `Commit()`) is it committed to a single (indivisible) `ipld.Node`.

It is used mainly for internal (non-leaf) nodes, and for some representations of data leaf nodes (that don't use raw nodes or Filestore).

It aims to replace the `UnixfsNode` structure which encapsulated too many possible node state combinations.

TODO: Revisit the name.

func NewFSNFromDag

func NewFSNFromDag(nd *dag.ProtoNode) (*FSNodeOverDag, error)

NewFSNFromDag reconstructs a FSNodeOverDag node from a given dag node

func (*FSNodeOverDag) AddChild

func (n *FSNodeOverDag) AddChild(child ipld.Node, fileSize uint64, db *DagBuilderHelper) error

AddChild adds a `child` `ipld.Node` to both node layers. The `dag.ProtoNode` creates a link to the child node while the `ft.FSNode` stores its file size (that is, not the size of the node but the size of the file data that it is storing at the UnixFS layer). The child is also stored in the `DAGService`.

func (*FSNodeOverDag) Commit

func (n *FSNodeOverDag) Commit() (ipld.Node, error)

Commit unifies (resolves) the cache nodes into a single `ipld.Node` that represents them: the `ft.FSNode` is encoded inside the `dag.ProtoNode`.

TODO: Make it read-only after committing, allow to commit only once.

func (*FSNodeOverDag) FileSize

func (n *FSNodeOverDag) FileSize() uint64

FileSize returns the `Filesize` attribute from the underlying representation of the `ft.FSNode`.

func (*FSNodeOverDag) GetChild

func (n *FSNodeOverDag) GetChild(ctx context.Context, i int, ds ipld.DAGService) (*FSNodeOverDag, error)

GetChild gets the ith child of this node from the given DAGService.

func (*FSNodeOverDag) GetDagNode

func (n *FSNodeOverDag) GetDagNode() (ipld.Node, error)

GetDagNode fills out the proper formatting for the FSNodeOverDag node inside of a DAG node and returns the dag node. TODO: Check if we have committed (passed the UnixFS information to the DAG layer) before returning this.

func (*FSNodeOverDag) NumChildren

func (n *FSNodeOverDag) NumChildren() int

NumChildren returns the number of children of the `ft.FSNode`.

func (*FSNodeOverDag) RemoveChild

func (n *FSNodeOverDag) RemoveChild(index int, dbh *DagBuilderHelper)

RemoveChild deletes the child node at the given index.

func (*FSNodeOverDag) SetFileData

func (n *FSNodeOverDag) SetFileData(fileData []byte)

SetFileData stores the `fileData` in the `ft.FSNode`. It should be used only when `FSNodeOverDag` represents a leaf node (internal nodes don't carry data, just file sizes).