LLVM  14.0.0git
Base64.h
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1 //===--- Base64.h - Base64 Encoder/Decoder ----------------------*- C++ -*-===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file provides generic base64 encoder/decoder.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_SUPPORT_BASE64_H
14 #define LLVM_SUPPORT_BASE64_H
15 
16 #include <string>
17 
18 namespace llvm {
19 
20 template <class InputBytes> std::string encodeBase64(InputBytes const &Bytes) {
21  static const char Table[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
22  "abcdefghijklmnopqrstuvwxyz"
23  "0123456789+/";
24  std::string Buffer;
25  Buffer.resize(((Bytes.size() + 2) / 3) * 4);
26 
27  size_t i = 0, j = 0;
28  for (size_t n = Bytes.size() / 3 * 3; i < n; i += 3, j += 4) {
29  uint32_t x = ((unsigned char)Bytes[i] << 16) |
30  ((unsigned char)Bytes[i + 1] << 8) |
31  (unsigned char)Bytes[i + 2];
32  Buffer[j + 0] = Table[(x >> 18) & 63];
33  Buffer[j + 1] = Table[(x >> 12) & 63];
34  Buffer[j + 2] = Table[(x >> 6) & 63];
35  Buffer[j + 3] = Table[x & 63];
36  }
37  if (i + 1 == Bytes.size()) {
38  uint32_t x = ((unsigned char)Bytes[i] << 16);
39  Buffer[j + 0] = Table[(x >> 18) & 63];
40  Buffer[j + 1] = Table[(x >> 12) & 63];
41  Buffer[j + 2] = '=';
42  Buffer[j + 3] = '=';
43  } else if (i + 2 == Bytes.size()) {
44  uint32_t x =
45  ((unsigned char)Bytes[i] << 16) | ((unsigned char)Bytes[i + 1] << 8);
46  Buffer[j + 0] = Table[(x >> 18) & 63];
47  Buffer[j + 1] = Table[(x >> 12) & 63];
48  Buffer[j + 2] = Table[(x >> 6) & 63];
49  Buffer[j + 3] = '=';
50  }
51  return Buffer;
52 }
53 
54 } // end namespace llvm
55 
56 #endif
i
i
Definition: README.txt:29
llvm
---------------------— PointerInfo ------------------------------------—
Definition: AllocatorList.h:23
llvm::encodeBase64
std::string encodeBase64(InputBytes const &Bytes)
Definition: Base64.h:20
uint32_t
j
return j(j<< 16)
x
TODO unsigned x
Definition: README.txt:10
n
The same transformation can work with an even modulo with the addition of a and shrink the compare RHS by the same amount Unless the target supports that transformation probably isn t worthwhile The transformation can also easily be made to work with non zero equality for n
Definition: README.txt:685