llvm-for-llvmta/include/llvm/Support/Base64.h

57 lines
1.8 KiB
C++

//===--- Base64.h - Base64 Encoder/Decoder ----------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file provides generic base64 encoder/decoder.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_SUPPORT_BASE64_H
#define LLVM_SUPPORT_BASE64_H
#include <string>
namespace llvm {
template <class InputBytes> std::string encodeBase64(InputBytes const &Bytes) {
static const char Table[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz"
"0123456789+/";
std::string Buffer;
Buffer.resize(((Bytes.size() + 2) / 3) * 4);
size_t i = 0, j = 0;
for (size_t n = Bytes.size() / 3 * 3; i < n; i += 3, j += 4) {
uint32_t x = ((unsigned char)Bytes[i] << 16) |
((unsigned char)Bytes[i + 1] << 8) |
(unsigned char)Bytes[i + 2];
Buffer[j + 0] = Table[(x >> 18) & 63];
Buffer[j + 1] = Table[(x >> 12) & 63];
Buffer[j + 2] = Table[(x >> 6) & 63];
Buffer[j + 3] = Table[x & 63];
}
if (i + 1 == Bytes.size()) {
uint32_t x = ((unsigned char)Bytes[i] << 16);
Buffer[j + 0] = Table[(x >> 18) & 63];
Buffer[j + 1] = Table[(x >> 12) & 63];
Buffer[j + 2] = '=';
Buffer[j + 3] = '=';
} else if (i + 2 == Bytes.size()) {
uint32_t x =
((unsigned char)Bytes[i] << 16) | ((unsigned char)Bytes[i + 1] << 8);
Buffer[j + 0] = Table[(x >> 18) & 63];
Buffer[j + 1] = Table[(x >> 12) & 63];
Buffer[j + 2] = Table[(x >> 6) & 63];
Buffer[j + 3] = '=';
}
return Buffer;
}
} // end namespace llvm
#endif