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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-16 19:23:18 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-16 19:23:18 +0000
commit43a123c1ae6613b3efeed291fa552ecd909d3acf (patch)
treefd92518b7024bc74031f78a1cf9e454b65e73665 /src/hash/crc32/example_test.go
parentInitial commit. (diff)
downloadgolang-1.20-43a123c1ae6613b3efeed291fa552ecd909d3acf.tar.xz
golang-1.20-43a123c1ae6613b3efeed291fa552ecd909d3acf.zip
Adding upstream version 1.20.14.upstream/1.20.14upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
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+// Copyright 2015 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package crc32_test
+
+import (
+ "fmt"
+ "hash/crc32"
+)
+
+func ExampleMakeTable() {
+ // In this package, the CRC polynomial is represented in reversed notation,
+ // or LSB-first representation.
+ //
+ // LSB-first representation is a hexadecimal number with n bits, in which the
+ // most significant bit represents the coefficient of x⁰ and the least significant
+ // bit represents the coefficient of xⁿ⁻¹ (the coefficient for xⁿ is implicit).
+ //
+ // For example, CRC32-Q, as defined by the following polynomial,
+ // x³²+ x³¹+ x²⁴+ x²²+ x¹⁶+ x¹⁴+ x⁸+ x⁷+ x⁵+ x³+ x¹+ x⁰
+ // has the reversed notation 0b11010101100000101000001010000001, so the value
+ // that should be passed to MakeTable is 0xD5828281.
+ crc32q := crc32.MakeTable(0xD5828281)
+ fmt.Printf("%08x\n", crc32.Checksum([]byte("Hello world"), crc32q))
+ // Output:
+ // 2964d064
+}