CMake/Source/cmBase32.cxx

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Simplify CMake per-source license notices Per-source copyright/license notice headers that spell out copyright holder names and years are hard to maintain and often out-of-date or plain wrong. Precise contributor information is already maintained automatically by the version control tool. Ultimately it is the receiver of a file who is responsible for determining its licensing status, and per-source notices are merely a convenience. Therefore it is simpler and more accurate for each source to have a generic notice of the license name and references to more detailed information on copyright holders and full license terms. Our `Copyright.txt` file now contains a list of Contributors whose names appeared source-level copyright notices. It also references version control history for more precise information. Therefore we no longer need to spell out the list of Contributors in each source file notice. Replace CMake per-source copyright/license notice headers with a short description of the license and links to `Copyright.txt` and online information available from "https://cmake.org/licensing". The online URL also handles cases of modules being copied out of our source into other projects, so we can drop our notices about replacing links with full license text. Run the `Utilities/Scripts/filter-notices.bash` script to perform the majority of the replacements mechanically. Manually fix up shebang lines and trailing newlines in a few files. Manually update the notices in a few files that the script does not handle.
2016-09-27 22:01:08 +03:00
/* Distributed under the OSI-approved BSD 3-Clause License. See accompanying
file Copyright.txt or https://cmake.org/licensing for details. */
2016-09-01 14:08:18 +03:00
#include "cmBase32.h"
// -- Static functions
static const unsigned char Base32EncodeTable[33] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
inline unsigned char Base32EncodeChar(int schar)
{
return Base32EncodeTable[schar];
}
void Base32Encode5(const unsigned char src[5], char dst[8])
{
// [0]:5 bits
dst[0] = Base32EncodeChar((src[0] >> 3) & 0x1F);
// [0]:3 bits + [1]:2 bits
dst[1] = Base32EncodeChar(((src[0] << 2) & 0x1C) + ((src[1] >> 6) & 0x03));
// [1]:5 bits
dst[2] = Base32EncodeChar((src[1] >> 1) & 0x1F);
// [1]:1 bit + [2]:4 bits
dst[3] = Base32EncodeChar(((src[1] << 4) & 0x10) + ((src[2] >> 4) & 0x0F));
// [2]:4 bits + [3]:1 bit
dst[4] = Base32EncodeChar(((src[2] << 1) & 0x1E) + ((src[3] >> 7) & 0x01));
// [3]:5 bits
dst[5] = Base32EncodeChar((src[3] >> 2) & 0x1F);
// [3]:2 bits + [4]:3 bit
dst[6] = Base32EncodeChar(((src[3] << 3) & 0x18) + ((src[4] >> 5) & 0x07));
// [4]:5 bits
dst[7] = Base32EncodeChar((src[4] << 0) & 0x1F);
}
// -- Class methods
cmBase32Encoder::cmBase32Encoder()
{
}
cmBase32Encoder::~cmBase32Encoder()
{
}
std::string cmBase32Encoder::encodeString(const unsigned char* input,
size_t len, bool padding)
{
std::string res;
static const size_t blockSize = 5;
static const size_t bufferSize = 8;
char buffer[bufferSize];
const unsigned char* end = input + len;
while ((input + blockSize) <= end) {
Base32Encode5(input, buffer);
res.append(buffer, bufferSize);
input += blockSize;
}
size_t remain(end - input);
if (remain != 0) {
// Temporary source buffer filled up with 0s
unsigned char extended[blockSize];
for (size_t ii = 0; ii != remain; ++ii) {
extended[ii] = input[ii];
}
for (size_t ii = remain; ii != blockSize; ++ii) {
extended[ii] = 0;
}
Base32Encode5(extended, buffer);
size_t numPad(0);
switch (remain) {
case 1:
numPad = 6;
break;
case 2:
numPad = 4;
break;
case 3:
numPad = 3;
break;
case 4:
numPad = 1;
break;
default:
break;
}
res.append(buffer, bufferSize - numPad);
if (padding) {
for (size_t ii = 0; ii != numPad; ++ii) {
res.push_back(paddingChar);
}
}
}
return res;
}