go-ethereum/trie/slice.go

// Copyright 2014 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.

package trie

import (
	"bytes"
	"math"
)

// Helper function for comparing slices
func CompareIntSlice(a, b []int) bool {
	if len(a) != len(b) {
		return false
	}
	for i, v := range a {
		if v != b[i] {
			return false
		}
	}
	return true
}

// Returns the amount of nibbles that match each other from 0 ...
func MatchingNibbleLength(a, b []byte) int {
	var i, length = 0, int(math.Min(float64(len(a)), float64(len(b))))

	for i < length {
		if a[i] != b[i] {
			break
		}
		i++
	}

	return i
}

func HasTerm(s []byte) bool {
	return s[len(s)-1] == 16
}

func RemTerm(s []byte) []byte {
	if HasTerm(s) {
		return s[:len(s)-1]
	}

	return s
}

func BeginsWith(a, b []byte) bool {
	if len(b) > len(a) {
		return false
	}

	return bytes.Equal(a[:len(b)], b)
}