Roy Crihfield
6d20ef7c3b
* stripped down Nodeiterator interface * prefix-bound iterator for traversing a specific range of keys * visitor over subtries divided at a specific depth
50 lines
1.1 KiB
Go
50 lines
1.1 KiB
Go
package iterator
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import (
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"bytes"
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"github.com/ethereum/go-ethereum/trie"
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)
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func CompareNodes(a, b trie.NodeIterator) int {
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if cmp := bytes.Compare(a.Path(), b.Path()); cmp != 0 {
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return cmp
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}
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if a.Leaf() && !b.Leaf() {
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return -1
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} else if b.Leaf() && !a.Leaf() {
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return 1
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}
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if cmp := bytes.Compare(a.Hash().Bytes(), b.Hash().Bytes()); cmp != 0 {
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return cmp
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}
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if a.Leaf() && b.Leaf() {
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return bytes.Compare(a.LeafBlob(), b.LeafBlob())
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}
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return 0
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}
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// hexToKeyBytes turns hex nibbles into key bytes.
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// This can only be used for keys of even length.
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func HexToKeyBytes(hex []byte) []byte {
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if hasTerm(hex) {
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hex = hex[:len(hex)-1]
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}
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if len(hex)&1 != 0 {
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panic("can't convert hex key of odd length")
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}
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key := make([]byte, len(hex)/2)
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decodeNibbles(hex, key)
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return key
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}
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func decodeNibbles(nibbles []byte, bytes []byte) {
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for bi, ni := 0, 0; ni < len(nibbles); bi, ni = bi+1, ni+2 {
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bytes[bi] = nibbles[ni]<<4 | nibbles[ni+1]
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}
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}
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// hasTerm returns whether a hex key has the terminator flag.
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func hasTerm(s []byte) bool {
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return len(s) > 0 && s[len(s)-1] == 16
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}
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