github.com/m10x/go/src@v0.0.0-20220112094212-ba61592315da/net/netip/leaf_alts.go (about) 1 // Copyright 2021 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 // Stuff that exists in std, but we can't use due to being a dependency 6 // of net, for go/build deps_test policy reasons. 7 8 package netip 9 10 func stringsLastIndexByte(s string, b byte) int { 11 for i := len(s) - 1; i >= 0; i-- { 12 if s[i] == b { 13 return i 14 } 15 } 16 return -1 17 } 18 19 func beUint64(b []byte) uint64 { 20 _ = b[7] // bounds check hint to compiler; see golang.org/issue/14808 21 return uint64(b[7]) | uint64(b[6])<<8 | uint64(b[5])<<16 | uint64(b[4])<<24 | 22 uint64(b[3])<<32 | uint64(b[2])<<40 | uint64(b[1])<<48 | uint64(b[0])<<56 23 } 24 25 func bePutUint64(b []byte, v uint64) { 26 _ = b[7] // early bounds check to guarantee safety of writes below 27 b[0] = byte(v >> 56) 28 b[1] = byte(v >> 48) 29 b[2] = byte(v >> 40) 30 b[3] = byte(v >> 32) 31 b[4] = byte(v >> 24) 32 b[5] = byte(v >> 16) 33 b[6] = byte(v >> 8) 34 b[7] = byte(v) 35 } 36 37 func bePutUint32(b []byte, v uint32) { 38 _ = b[3] // early bounds check to guarantee safety of writes below 39 b[0] = byte(v >> 24) 40 b[1] = byte(v >> 16) 41 b[2] = byte(v >> 8) 42 b[3] = byte(v) 43 } 44 45 func leUint16(b []byte) uint16 { 46 _ = b[1] // bounds check hint to compiler; see golang.org/issue/14808 47 return uint16(b[0]) | uint16(b[1])<<8 48 } 49 50 func lePutUint16(b []byte, v uint16) { 51 _ = b[1] // early bounds check to guarantee safety of writes below 52 b[0] = byte(v) 53 b[1] = byte(v >> 8) 54 }