merkledag: keep links sorted by name
May not be necessary to sort when adding each link-- doing so would be unnecessarily expensive O(n^2) when constructing nodes -- though n wont be big.
Juan Batiz-Benet committed
Jan 6, 2015 at 13:07 UTC
cd65ec614b5506013c86e02236ce6267d22fc77e
2 files changed
+11
merkledag/coding.go
+5
@@ -2,6 +2,7 @@ package merkledag
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import (
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"fmt"
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+ "sort"
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mh "github.com/jbenet/go-ipfs/Godeps/_workspace/src/github.com/jbenet/go-multihash"
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@@ -30,6 +31,7 @@ func (n *Node) Unmarshal(encoded []byte) error {
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}
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n.Links[i].Hash = h
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}
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+ sort.Stable(LinkSlice(n.Links)) // keep links sorted
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n.Data = pbn.GetData()
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return nil
@@ -59,6 +61,8 @@ func (n *Node) Marshal() ([]byte, error) {
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func (n *Node) getPBNode() *pb.PBNode {
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pbn := &pb.PBNode{}
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pbn.Links = make([]*pb.PBLink, len(n.Links))
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+
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+ sort.Stable(LinkSlice(n.Links)) // keep links sorted
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for i, l := range n.Links {
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pbn.Links[i] = &pb.PBLink{}
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pbn.Links[i].Name = &l.Name
@@ -73,6 +77,7 @@ func (n *Node) getPBNode() *pb.PBNode {
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// Encoded returns the encoded raw data version of a Node instance.
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// It may use a cached encoded version, unless the force flag is given.
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func (n *Node) Encoded(force bool) ([]byte, error) {
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+ sort.Stable(LinkSlice(n.Links)) // keep links sorted
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if n.encoded == nil || force {
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var err error
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n.encoded, err = n.Marshal()
merkledag/merkledag.go
+6
@@ -66,6 +66,12 @@ type Link struct {
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Node *Node
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}
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+type LinkSlice []*Link
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+
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+func (ls LinkSlice) Len() int { return len(ls) }
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+func (ls LinkSlice) Swap(a, b int) { ls[a], ls[b] = ls[b], ls[a] }
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+func (ls LinkSlice) Less(a, b int) bool { return ls[a].Name < ls[b].Name }
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+
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// MakeLink creates a link to the given node
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func MakeLink(n *Node) (*Link, error) {
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s, err := n.Size()