bd2b1a0521
Knowing serialized size of the node is useful for preallocating byte-slice in advance. Signed-off-by: Evgeniy Stratonikov <evgeniy@nspcc.ru>
98 lines
2.1 KiB
Go
98 lines
2.1 KiB
Go
package mpt
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import (
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"encoding/json"
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"errors"
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"github.com/nspcc-dev/neo-go/pkg/io"
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"github.com/nspcc-dev/neo-go/pkg/util"
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)
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const (
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// childrenCount represents a number of children of a branch node.
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childrenCount = 17
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// lastChild is the index of the last child.
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lastChild = childrenCount - 1
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)
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// BranchNode represents MPT's branch node.
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type BranchNode struct {
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BaseNode
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Children [childrenCount]Node
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}
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var _ Node = (*BranchNode)(nil)
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// NewBranchNode returns new branch node.
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func NewBranchNode() *BranchNode {
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b := new(BranchNode)
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for i := 0; i < childrenCount; i++ {
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b.Children[i] = EmptyNode{}
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}
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return b
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}
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// Type implements Node interface.
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func (b *BranchNode) Type() NodeType { return BranchT }
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// Hash implements BaseNode interface.
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func (b *BranchNode) Hash() util.Uint256 {
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return b.getHash(b)
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}
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// Bytes implements BaseNode interface.
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func (b *BranchNode) Bytes() []byte {
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return b.getBytes(b)
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}
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// Size implements Node interface.
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func (b *BranchNode) Size() int {
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sz := childrenCount
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for i := range b.Children {
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if !isEmpty(b.Children[i]) {
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sz += util.Uint256Size
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}
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}
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return sz
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}
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// EncodeBinary implements io.Serializable.
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func (b *BranchNode) EncodeBinary(w *io.BinWriter) {
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for i := 0; i < childrenCount; i++ {
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encodeBinaryAsChild(b.Children[i], w)
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}
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}
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// DecodeBinary implements io.Serializable.
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func (b *BranchNode) DecodeBinary(r *io.BinReader) {
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for i := 0; i < childrenCount; i++ {
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no := new(NodeObject)
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no.DecodeBinary(r)
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b.Children[i] = no.Node
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}
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}
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// MarshalJSON implements json.Marshaler.
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func (b *BranchNode) MarshalJSON() ([]byte, error) {
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return json.Marshal(b.Children)
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}
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// UnmarshalJSON implements json.Unmarshaler.
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func (b *BranchNode) UnmarshalJSON(data []byte) error {
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var obj NodeObject
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if err := obj.UnmarshalJSON(data); err != nil {
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return err
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} else if u, ok := obj.Node.(*BranchNode); ok {
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*b = *u
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return nil
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}
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return errors.New("expected branch node")
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}
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// splitPath splits path for a branch node.
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func splitPath(path []byte) (byte, []byte) {
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if len(path) != 0 {
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return path[0], path[1:]
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}
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return lastChild, path
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}
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