104 lines
2.1 KiB
Go
104 lines
2.1 KiB
Go
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// Copyright (C) 2019 Storj Labs, Inc.
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// See LICENSE for copying information.
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package kademlia
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import (
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"math/bits"
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"sort"
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"github.com/zeebo/errs"
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"storj.io/storj/pkg/storj"
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"storj.io/storj/storage"
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)
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func cloneNodeIDs(ids storj.NodeIDList) storj.NodeIDList {
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clone := make(storj.NodeIDList, len(ids))
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copy(clone, ids)
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return clone
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}
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// compareByXor compares left, right xorred by reference
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func compareByXor(left, right, reference storj.NodeID) int {
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for i, r := range reference {
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a, b := left[i]^r, right[i]^r
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if a != b {
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if a < b {
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return -1
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}
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return 1
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}
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}
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return 0
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}
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func sortByXOR(nodeIDs storj.NodeIDList, ref storj.NodeID) {
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sort.Slice(nodeIDs, func(i, k int) bool {
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return compareByXor(nodeIDs[i], nodeIDs[k], ref) < 0
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})
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}
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func keysToNodeIDs(keys storage.Keys) (ids storj.NodeIDList, err error) {
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var idErrs []error
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for _, k := range keys {
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id, err := storj.NodeIDFromBytes(k[:])
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if err != nil {
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idErrs = append(idErrs, err)
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}
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ids = append(ids, id)
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}
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if err := errs.Combine(idErrs...); err != nil {
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return nil, err
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}
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return ids, nil
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}
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func keyToBucketID(key storage.Key) (bID bucketID) {
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copy(bID[:], key)
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return bID
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}
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// xorNodeID returns the xor of each byte in NodeID
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func xorNodeID(a, b storj.NodeID) storj.NodeID {
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r := storj.NodeID{}
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for i, av := range a {
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r[i] = av ^ b[i]
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}
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return r
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}
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// xorBucketID returns the xor of each byte in bucketID
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func xorBucketID(a, b bucketID) bucketID {
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r := bucketID{}
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for i, av := range a {
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r[i] = av ^ b[i]
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}
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return r
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}
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// determineDifferingBitIndex: helper, returns the last bit differs starting from prefix to suffix
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func determineDifferingBitIndex(bID, comparisonID bucketID) (int, error) {
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if bID == comparisonID {
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return -2, RoutingErr.New("compared two equivalent k bucket ids")
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}
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if comparisonID == emptyBucketID {
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comparisonID = firstBucketID
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}
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xorID := xorBucketID(bID, comparisonID)
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if xorID == firstBucketID {
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return -1, nil
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}
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for i, v := range xorID {
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if v != 0 {
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return i*8 + 7 - bits.TrailingZeros8(v), nil
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}
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}
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return -1, nil
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}
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