tdlight/tdutils/td/utils/misc.cpp
levlam 2f52861c20 Add hex_encode.
GitOrigin-RevId: f5b42ce196f463d9d5cdb4536ee7b829f198583b
2019-09-02 16:49:18 +03:00

208 lines
4.5 KiB
C++

//
// Copyright Aliaksei Levin (levlam@telegram.org), Arseny Smirnov (arseny30@gmail.com) 2014-2019
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//
#include "td/utils/misc.h"
#include "td/utils/port/thread_local.h"
#include <algorithm>
#include <cstdlib>
#include <locale>
#include <sstream>
namespace td {
char *str_dup(Slice str) {
char *res = static_cast<char *>(std::malloc(str.size() + 1));
if (res == nullptr) {
return nullptr;
}
std::copy(str.begin(), str.end(), res);
res[str.size()] = '\0';
return res;
}
string implode(const vector<string> &v, char delimiter) {
string result;
for (auto &str : v) {
if (!result.empty()) {
result += delimiter;
}
result += str;
}
return result;
}
string lpad0(string str, size_t size) {
if (str.size() >= size) {
return str;
}
return string(size - str.size(), '0') + str;
}
string oneline(Slice str) {
string result;
result.reserve(str.size());
bool after_new_line = true;
for (auto c : str) {
if (c != '\n') {
if (after_new_line) {
if (c == ' ') {
continue;
}
after_new_line = false;
}
result += c;
} else {
after_new_line = true;
result += ' ';
}
}
while (!result.empty() && result.back() == ' ') {
result.pop_back();
}
return result;
}
double to_double(Slice str) {
static TD_THREAD_LOCAL std::stringstream *ss;
if (init_thread_local<std::stringstream>(ss)) {
auto previous_locale = ss->imbue(std::locale::classic());
} else {
ss->str(std::string());
ss->clear();
}
ss->write(str.begin(), narrow_cast<std::streamsize>(str.size()));
double result = 0.0;
*ss >> result;
return result;
}
Result<string> hex_decode(Slice hex) {
if (hex.size() % 2 != 0) {
return Status::Error("Wrong hex string length");
}
string result(hex.size() / 2, '\0');
for (size_t i = 0; i < result.size(); i++) {
int high = hex_to_int(hex[i + i]);
int low = hex_to_int(hex[i + i + 1]);
if (high == 16 || low == 16) {
return Status::Error("Wrong hex string");
}
result[i] = static_cast<char>(high * 16 + low); // TODO implementation-defined
}
return std::move(result);
}
string hex_encode(Slice data) {
const char *hex = "0123456789abcdef";
string res;
res.reserve(2 * data.size());
for (unsigned char c : data) {
res.push_back(hex[c >> 4]);
res.push_back(hex[c & 15]);
}
return res;
}
static bool is_url_char(char c) {
return is_alnum(c) || c == '-' || c == '.' || c == '_' || c == '~';
}
string url_encode(Slice data) {
size_t length = 3 * data.size();
for (auto c : data) {
length -= 2 * is_url_char(c);
}
if (length == data.size()) {
return data.str();
}
string result;
result.reserve(length);
for (auto c : data) {
if (is_url_char(c)) {
result += c;
} else {
auto ch = static_cast<unsigned char>(c);
result += '%';
result += "0123456789ABCDEF"[ch / 16];
result += "0123456789ABCDEF"[ch % 16];
}
}
CHECK(result.size() == length);
return result;
}
string buffer_to_hex(Slice buffer) {
const char *hex = "0123456789ABCDEF";
string res(2 * buffer.size(), '\0');
for (std::size_t i = 0; i < buffer.size(); i++) {
auto c = buffer.ubegin()[i];
res[2 * i] = hex[c & 15];
res[2 * i + 1] = hex[c >> 4];
}
return res;
}
namespace {
template <class F>
string x_decode(Slice s, F &&f) {
string res;
for (size_t n = s.size(), i = 0; i < n; i++) {
if (i + 1 < n && f(s[i])) {
res.append(static_cast<unsigned char>(s[i + 1]), s[i]);
i++;
continue;
}
res.push_back(s[i]);
}
return res;
}
template <class F>
string x_encode(Slice s, F &&f) {
string res;
for (size_t n = s.size(), i = 0; i < n; i++) {
res.push_back(s[i]);
if (f(s[i])) {
unsigned char cnt = 1;
while (cnt < 250 && i + cnt < n && s[i + cnt] == s[i]) {
cnt++;
}
res.push_back(static_cast<char>(cnt));
i += cnt - 1;
}
}
return res;
}
bool is_zero(unsigned char c) {
return c == 0;
}
bool is_zero_or_one(unsigned char c) {
return c == 0 || c == 0xff;
}
} // namespace
std::string zero_encode(Slice data) {
return x_encode(data, is_zero);
}
std::string zero_decode(Slice data) {
return x_decode(data, is_zero);
}
std::string zero_one_encode(Slice data) {
return x_encode(data, is_zero_or_one);
}
std::string zero_one_decode(Slice data) {
return x_decode(data, is_zero_or_one);
}
} // namespace td