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// Copyright (c) 2009-present The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or https://opensource.org/license/mit/.
#include <span.h>
#include <streams.h>
#include <util/fs_helpers.h>
#include <array>
AutoFile::AutoFile(std::FILE* file, std::vector<std::byte> data_xor)
: m_file{file}, m_xor{std::move(data_xor)}
{
if (!IsNull()) {
auto pos{std::ftell(m_file)};
if (pos >= 0) m_position = pos;
}
}
std::size_t AutoFile::detail_fread(Span<std::byte> dst)
{
if (!m_file) throw std::ios_base::failure("AutoFile::read: file handle is nullptr");
size_t ret = std::fread(dst.data(), 1, dst.size(), m_file);
if (!m_xor.empty()) {
if (!m_position.has_value()) throw std::ios_base::failure("AutoFile::read: position unknown");
util::Xor(dst.subspan(0, ret), m_xor, *m_position);
}
if (m_position.has_value()) *m_position += ret;
return ret;
}
void AutoFile::seek(int64_t offset, int origin)
{
if (IsNull()) {
throw std::ios_base::failure("AutoFile::seek: file handle is nullptr");
}
if (std::fseek(m_file, offset, origin) != 0) {
throw std::ios_base::failure(feof() ? "AutoFile::seek: end of file" : "AutoFile::seek: fseek failed");
}
if (origin == SEEK_SET) {
m_position = offset;
} else if (origin == SEEK_CUR && m_position.has_value()) {
*m_position += offset;
} else {
int64_t r{std::ftell(m_file)};
if (r < 0) {
throw std::ios_base::failure("AutoFile::seek: ftell failed");
}
m_position = r;
}
}
int64_t AutoFile::tell()
{
if (!m_position.has_value()) throw std::ios_base::failure("AutoFile::tell: position unknown");
return *m_position;
}
void AutoFile::read(Span<std::byte> dst)
{
if (detail_fread(dst) != dst.size()) {
throw std::ios_base::failure(feof() ? "AutoFile::read: end of file" : "AutoFile::read: fread failed");
}
}
void AutoFile::ignore(size_t nSize)
{
if (!m_file) throw std::ios_base::failure("AutoFile::ignore: file handle is nullptr");
unsigned char data[4096];
while (nSize > 0) {
size_t nNow = std::min<size_t>(nSize, sizeof(data));
if (std::fread(data, 1, nNow, m_file) != nNow) {
throw std::ios_base::failure(feof() ? "AutoFile::ignore: end of file" : "AutoFile::ignore: fread failed");
}
nSize -= nNow;
if (m_position.has_value()) *m_position += nNow;
}
}
void AutoFile::write(Span<const std::byte> src)
{
if (!m_file) throw std::ios_base::failure("AutoFile::write: file handle is nullptr");
if (m_xor.empty()) {
if (std::fwrite(src.data(), 1, src.size(), m_file) != src.size()) {
throw std::ios_base::failure("AutoFile::write: write failed");
}
if (m_position.has_value()) *m_position += src.size();
} else {
if (!m_position.has_value()) throw std::ios_base::failure("AutoFile::write: position unknown");
std::array<std::byte, 4096> buf;
while (src.size() > 0) {
auto buf_now{Span{buf}.first(std::min<size_t>(src.size(), buf.size()))};
std::copy(src.begin(), src.begin() + buf_now.size(), buf_now.begin());
util::Xor(buf_now, m_xor, *m_position);
if (std::fwrite(buf_now.data(), 1, buf_now.size(), m_file) != buf_now.size()) {
throw std::ios_base::failure{"XorFile::write: failed"};
}
src = src.subspan(buf_now.size());
*m_position += buf_now.size();
}
}
}
bool AutoFile::Commit()
{
return ::FileCommit(m_file);
}
bool AutoFile::Truncate(unsigned size)
{
return ::TruncateFile(m_file, size);
}
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