ipld-eth-server/vendor/github.com/ipfs/go-merkledag/raw.go

104 lines
2.6 KiB
Go

package merkledag
import (
"encoding/json"
"fmt"
"github.com/ipfs/go-block-format"
cid "github.com/ipfs/go-cid"
u "github.com/ipfs/go-ipfs-util"
ipld "github.com/ipfs/go-ipld-format"
)
// RawNode represents a node which only contains data.
type RawNode struct {
blocks.Block
}
// NewRawNode creates a RawNode using the default sha2-256 hash function.
func NewRawNode(data []byte) *RawNode {
h := u.Hash(data)
c := cid.NewCidV1(cid.Raw, h)
blk, _ := blocks.NewBlockWithCid(data, c)
return &RawNode{blk}
}
// DecodeRawBlock is a block decoder for raw IPLD nodes conforming to `node.DecodeBlockFunc`.
func DecodeRawBlock(block blocks.Block) (ipld.Node, error) {
if block.Cid().Type() != cid.Raw {
return nil, fmt.Errorf("raw nodes cannot be decoded from non-raw blocks: %d", block.Cid().Type())
}
// Once you "share" a block, it should be immutable. Therefore, we can just use this block as-is.
return &RawNode{block}, nil
}
var _ ipld.DecodeBlockFunc = DecodeRawBlock
// NewRawNodeWPrefix creates a RawNode using the provided cid builder
func NewRawNodeWPrefix(data []byte, builder cid.Builder) (*RawNode, error) {
builder = builder.WithCodec(cid.Raw)
c, err := builder.Sum(data)
if err != nil {
return nil, err
}
blk, err := blocks.NewBlockWithCid(data, c)
if err != nil {
return nil, err
}
return &RawNode{blk}, nil
}
// Links returns nil.
func (rn *RawNode) Links() []*ipld.Link {
return nil
}
// ResolveLink returns an error.
func (rn *RawNode) ResolveLink(path []string) (*ipld.Link, []string, error) {
return nil, nil, ErrLinkNotFound
}
// Resolve returns an error.
func (rn *RawNode) Resolve(path []string) (interface{}, []string, error) {
return nil, nil, ErrLinkNotFound
}
// Tree returns nil.
func (rn *RawNode) Tree(p string, depth int) []string {
return nil
}
// Copy performs a deep copy of this node and returns it as an ipld.Node
func (rn *RawNode) Copy() ipld.Node {
copybuf := make([]byte, len(rn.RawData()))
copy(copybuf, rn.RawData())
nblk, err := blocks.NewBlockWithCid(rn.RawData(), rn.Cid())
if err != nil {
// programmer error
panic("failure attempting to clone raw block: " + err.Error())
}
return &RawNode{nblk}
}
// Size returns the size of this node
func (rn *RawNode) Size() (uint64, error) {
return uint64(len(rn.RawData())), nil
}
// Stat returns some Stats about this node.
func (rn *RawNode) Stat() (*ipld.NodeStat, error) {
return &ipld.NodeStat{
CumulativeSize: len(rn.RawData()),
DataSize: len(rn.RawData()),
}, nil
}
// MarshalJSON is required for our "ipfs dag" commands.
func (rn *RawNode) MarshalJSON() ([]byte, error) {
return json.Marshal(string(rn.RawData()))
}
var _ ipld.Node = (*RawNode)(nil)