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/* Copyright 2024 Ján Sučan <jan@jansucan.com>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include "buffered_stream.h"
#include <endian.h>
#include <vector>
namespace FormatV2
{
const std::string FileSignature{"diff-dd image"};
const uint8_t FileVersion{2};
const size_t RecordHeaderSize{sizeof(uint64_t) + sizeof(uint32_t)};
struct RecordData {
size_t size;
std::shared_ptr<char[]> data;
};
class Error : public DiffddError
{
public:
explicit Error(const std::string &message) : DiffddError(message) {}
};
class Writer
{
public:
Writer(std::ostream &ostream, size_t buffer_size)
: m_writer{BufferedStream::Writer{ostream, buffer_size}}
{
writeFileHeader();
};
void writeDiffRecord(
uint64_t offset, size_t size,
std::vector<RecordData> data) // cppcheck-suppress passedByValue
{
writeOffset(offset);
writeSize(size);
for (auto it = data.begin(); it != data.end(); ++it) {
writeData(*it);
}
}
private:
BufferedStream::Writer m_writer;
void writeFileHeader()
{
m_writer.write(FileSignature.data(), FileSignature.size());
uint8_t val{FileVersion};
m_writer.write(reinterpret_cast<char *>(&val), sizeof(val));
};
void writeOffset(uint64_t offset)
{
uint64_t val{htobe64(offset)};
m_writer.write(reinterpret_cast<char *>(&val), sizeof(val));
};
void writeSize(size_t size)
{
uint32_t val{htobe32(size)};
m_writer.write(reinterpret_cast<char *>(&val), sizeof(val));
};
void writeData(RecordData data)
{
m_writer.write(reinterpret_cast<char *>(data.data.get()), data.size);
};
};
class Reader
{
public:
Reader(std::istream &istream, size_t buffer_size)
: m_reader{BufferedStream::Reader{istream, buffer_size, 1}}, m_eof{
false}
{
readFileHeader();
};
bool eof() { return m_eof; };
void readFileHeader()
{
auto rawSignature{std::make_unique<char[]>(FileSignature.size())};
size_t r{m_reader.read(FileSignature.size(), rawSignature.get())};
if (r < FileSignature.size()) {
throw new Error("cannot read file header signature");
}
const std::string signature{rawSignature.get(), FileSignature.size()};
if (signature != FileSignature) {
throw new Error("wrong file header signature");
}
uint8_t version;
r = {
m_reader.read(sizeof(version), reinterpret_cast<char *>(&version))};
if (r < sizeof(version)) {
throw new Error("cannot read file header version");
}
if (version != FileVersion) {
throw new Error("wrong file header version");
}
};
uint64_t readOffset()
{
uint64_t raw_offset;
const size_t r{m_reader.read(sizeof(raw_offset),
reinterpret_cast<char *>(&raw_offset))};
if (r != sizeof(raw_offset)) {
m_eof = true;
}
return be64toh(raw_offset);
};
size_t readSize()
{
uint32_t raw_size;
const size_t r{m_reader.read(sizeof(raw_size),
reinterpret_cast<char *>(&raw_size))};
if (r != sizeof(raw_size)) {
m_eof = true;
}
return be32toh(raw_size);
};
RecordData readRecordData(size_t size)
{
const BufferedStream::DataPart dp = m_reader.readMultipart(size);
return RecordData{
.size = dp.size,
.data = dp.data,
};
};
private:
BufferedStream::Reader m_reader;
bool m_eof;
};
} // namespace FormatV2
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