Atmosphere/libraries/libstratosphere/include/stratosphere/kvdb/kvdb_bounded_string.hpp

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C++

/*
* Copyright (c) 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 m_buffer[N];
public:
/* Constructors. */
constexpr BoundedString() {
m_buffer[0] = 0;
}
explicit constexpr BoundedString(const char *s) {
AMS_ABORT_UNLESS(static_cast<size_t>(util::Strnlen(s, N)) < N);
util::Strlcpy(m_buffer, s, N);
}
/* Static constructors. */
static constexpr BoundedString<N> Make(const char *s) {
return BoundedString<N>(s);
}
static BoundedString<N> MakeFormat(const char *format, ...) __attribute__((format (printf, 1, 2))) {
BoundedString<N> string;
std::va_list vl;
va_start(vl, format);
AMS_ABORT_UNLESS(static_cast<size_t>(util::VSNPrintf(string.m_buffer, N, format, vl)) < N);
va_end(vl);
return string;
}
/* Getters. */
constexpr size_t GetLength() const {
return util::Strnlen(m_buffer, N);
}
constexpr const char *Get() const {
return m_buffer;
}
constexpr operator const char *() const {
return m_buffer;
}
/* Assignment. */
constexpr BoundedString<N> &Assign(const char *s) {
AMS_ABORT_UNLESS(static_cast<size_t>(util::Strnlen(s, N)) < N);
util::Strlcpy(m_buffer, s, N);
return *this;
}
BoundedString<N> &AssignFormat(const char *format, ...) __attribute__((format (printf, 2, 3))) {
std::va_list vl;
va_start(vl, format);
AMS_ABORT_UNLESS(static_cast<size_t>(util::VSNPrintf(m_buffer, N, format, vl)) < N);
va_end(vl);
return *this;
}
/* Append to existing. */
BoundedString<N> &Append(const char *s) {
const size_t length = GetLength();
AMS_ABORT_UNLESS(length + static_cast<size_t>(util::Strnlen(s, N)) < N);
std::strncat(m_buffer, s, N - length - 1);
return *this;
}
BoundedString<N> &Append(char c) {
const size_t length = GetLength();
AMS_ABORT_UNLESS(length + 1 < N);
m_buffer[length] = c;
m_buffer[length + 1] = 0;
return *this;
}
BoundedString<N> &AppendFormat(const char *format, ...) __attribute__((format (printf, 2, 3))) {
const size_t length = GetLength();
std::va_list vl;
va_start(vl, format);
AMS_ABORT_UNLESS(static_cast<size_t>(util::VSNPrintf(m_buffer + length, N - length, format, vl)) < static_cast<size_t>(N - length));
va_end(vl);
return *this;
}
/* 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, m_buffer + offset, length);
dst[length] = 0;
}
BoundedString<N> MakeSubString(size_t offset, size_t length) const {
BoundedString<N> string;
GetSubString(string.m_buffer, N, offset, length);
return string;
}
/* Comparison. */
constexpr bool Equals(const char *s, size_t offset = 0) const {
if (std::is_constant_evaluated()) {
return util::Strncmp(m_buffer + offset, s, N - offset) == 0;
} else {
return std::strncmp(m_buffer + offset, s, N - offset) == 0;
}
}
constexpr bool operator==(const BoundedString<N> &rhs) const {
return this->Equals(rhs.m_buffer);
}
constexpr bool operator!=(const BoundedString<N> &rhs) const {
return !(*this == rhs);
}
constexpr bool EqualsPostfix(const char *s) const {
const size_t suffix_length = util::Strnlen(s, N);
const size_t length = GetLength();
return suffix_length <= length && this->Equals(s, length - suffix_length);
}
};
}