Atmosphere/libraries/libstratosphere/include/stratosphere/kvdb/kvdb_bounded_string.hpp
2021-04-26 20:06:28 -07:00

146 lines
5.1 KiB
C++

/*
* Copyright (c) 2018-2020 Atmosphère-NX
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#pragma once
#include <vapours.hpp>
namespace ams::kvdb {
/* Represents a string with a backing buffer of N bytes. */
template<size_t N>
class BoundedString {
static_assert(N > 0, "BoundedString requires non-zero backing buffer!");
private:
char buffer[N];
private:
/* Utility. */
static inline void CheckLength(size_t len) {
AMS_ABORT_UNLESS(len < N);
}
public:
/* Constructors. */
constexpr BoundedString() {
buffer[0] = 0;
}
explicit constexpr BoundedString(const char *s) {
this->Set(s);
}
/* Static constructors. */
static constexpr BoundedString<N> Make(const char *s) {
return BoundedString<N>(s);
}
static constexpr BoundedString<N> MakeFormat(const char *format, ...) __attribute__((format (printf, 1, 2))) {
BoundedString<N> string;
std::va_list args;
va_start(args, format);
CheckLength(util::VSNPrintf(string.buffer, N, format, args));
string.buffer[N - 1] = 0;
va_end(args);
return string;
}
/* Getters. */
size_t GetLength() const {
return util::Strnlen(this->buffer, N);
}
const char *Get() const {
return this->buffer;
}
operator const char *() const {
return this->buffer;
}
/* Setters. */
void Set(const char *s) {
/* Ensure string can fit in our buffer. */
CheckLength(util::Strnlen(s, N));
std::strncpy(this->buffer, s, N);
this->buffer[N - 1] = 0;
}
void SetFormat(const char *format, ...) __attribute__((format (printf, 2, 3))) {
/* Format into the buffer, abort if too large. */
std::va_list args;
va_start(args, format);
CheckLength(util::VSNPrintf(this->buffer, N, format, args));
va_end(args);
}
/* Append to existing. */
void Append(const char *s) {
const size_t length = GetLength();
CheckLength(length + util::Strnlen(s, N));
std::strncat(this->buffer, s, N - length - 1);
}
void Append(char c) {
const size_t length = GetLength();
CheckLength(length + 1);
this->buffer[length] = c;
this->buffer[length + 1] = 0;
}
void AppendFormat(const char *format, ...) __attribute__((format (printf, 2, 3))) {
const size_t length = GetLength();
std::va_list args;
va_start(args, format);
CheckLength(util::VSNPrintf(this->buffer + length, N - length, format, args) + length);
va_end(args);
}
/* Substring utilities. */
void GetSubstring(char *dst, size_t dst_size, size_t offset, size_t length) const {
/* Make sure output buffer can hold the substring. */
AMS_ABORT_UNLESS(offset + length <= GetLength());
AMS_ABORT_UNLESS(dst_size > length);
/* Copy substring to dst. */
std::strncpy(dst, this->buffer + offset, length);
dst[length] = 0;
}
BoundedString<N> GetSubstring(size_t offset, size_t length) const {
BoundedString<N> string;
GetSubstring(string.buffer, N, offset, length);
return string;
}
/* Comparison. */
constexpr bool operator==(const BoundedString<N> &rhs) const {
return std::strncmp(this->buffer, rhs.buffer, N) == 0;
}
constexpr bool operator!=(const BoundedString<N> &rhs) const {
return !(*this == rhs);
}
bool EndsWith(const char *s, size_t offset) const {
return std::strncmp(this->buffer + offset, s, N - offset) == 0;
}
bool EndsWith(const char *s) const {
const size_t suffix_length = util::Strnlen(s, N);
const size_t length = GetLength();
return suffix_length <= length && EndsWith(s, length - suffix_length);
}
};
}