Files
scylladb/sstables/checksummed_data_source.cc
Ernest Zaslavsky 8d49bb8af2 sstables: Start using make_data_or_index_source in sstable
Convert all necessary methods to be awaitable. Start using `make_data_or_index_source`
when creating data_source for data and index components.

For proper working of compressed/checksummed input streams, start passing
stream creator functors to `make_(checksummed/compressed)_file_(k_l/m)_format_input_stream`.
2025-07-15 10:10:23 +03:00

238 lines
10 KiB
C++

/*
* Copyright (C) 2024-present ScyllaDB
*/
/*
* SPDX-License-Identifier: LicenseRef-ScyllaDB-Source-Available-1.0
*/
#include <cstdint>
#include <seastar/core/bitops.hh>
#include <seastar/core/fstream.hh>
#include <seastar/core/future.hh>
#include <seastar/core/temporary_buffer.hh>
#include "types.hh"
#include "exceptions.hh"
#include "checksum_utils.hh"
#include "data_source_types.hh"
#include "checksummed_data_source.hh"
namespace sstables {
extern logging::logger sstlog;
// File data source implementation for SSTables with attached checksum
// data and no compression
template <ChecksumUtils ChecksumType, bool check_digest>
class checksummed_file_data_source_impl : public data_source_impl {
std::function<future<input_stream<char>>()> _stream_creator;
std::optional<input_stream<char>> _input_stream;
const checksum& _checksum;
[[no_unique_address]] digest_members<check_digest> _digests;
integrity_error_handler _error_handler;
uint64_t _chunk_size_trailing_zeros;
uint64_t _file_len;
uint64_t _underlying_pos;
uint64_t _pos;
uint64_t _beg_pos;
uint64_t _end_pos;
public:
checksummed_file_data_source_impl(stream_creator_fn stream_creator, uint64_t file_len,
const checksum& checksum, uint64_t pos, size_t len,
file_input_stream_options options,
std::optional<uint32_t> digest,
integrity_error_handler error_handler)
: _checksum(checksum)
, _error_handler(error_handler)
, _file_len(file_len)
, _pos(pos)
, _beg_pos(pos)
, _end_pos(pos + len)
{
// _beg_pos and _end_pos specify positions in the stream.
// These are not necessarily aligned on chunk boundaries.
// To be able to verify the checksums, we need to translate
// them into a range of chunks that contain the given
// address range, and open a file input stream to read that
// range. The _underlying_pos always points to the current
// chunk-aligned position of the file input stream.
uint64_t chunk_size = checksum.chunk_size;
if (chunk_size == 0 || (chunk_size & (chunk_size - 1)) != 0) {
on_internal_error(sstlog, format("Invalid chunk size: {}", chunk_size));
}
_chunk_size_trailing_zeros = count_trailing_zeros(chunk_size);
if (_pos > _file_len) {
on_internal_error(sstlog, "attempt to read beyond end");
}
if (len == 0 || _pos == _file_len) {
// Nothing to read
_end_pos = _pos;
return;
}
if (len > _file_len - _pos) {
_end_pos = _file_len;
}
if constexpr (check_digest) {
if (!digest) {
on_internal_error(sstlog, "Requested digest check but no digest was provided.");
}
if (_end_pos - _pos < _file_len) {
sstlog.debug("Checksummed reader cannot calculate digest with partial read: current pos={}, end pos={}, file len={}. Disabling digest check.",
_pos, _end_pos, _file_len);
_digests = {false};
} else {
_digests = {true, *digest, ChecksumType::init_checksum()};
}
}
auto start = align_down(_beg_pos, chunk_size);
auto end = std::min(_file_len, align_up(_end_pos, chunk_size));
_stream_creator = [stream_creator, start, length = end - start, options] mutable {
return stream_creator(start, length, std::move(options));
};
_underlying_pos = start;
}
virtual future<temporary_buffer<char>> get() override {
uint64_t chunk_size = _checksum.chunk_size;
if (_pos >= _end_pos) {
co_return temporary_buffer<char>();
}
if (!_input_stream) {
_input_stream = co_await _stream_creator();
}
// Read the next chunk. We need to skip part of the first
// chunk, but then continue to read from beginning of chunks.
// Also, we need to take into account that the last chunk can
// be smaller than `chunk_size`.
if (_pos != _beg_pos && (_pos & (chunk_size - 1)) != 0) {
throw std::runtime_error(format("Checksummed reader not aligned to chunk boundary: pos={}, chunk_size={}", _pos, chunk_size));
}
auto buf = co_await _input_stream->read_exactly(chunk_size);
uint32_t chunk_index = _pos >> _chunk_size_trailing_zeros;
if (buf.size() != chunk_size) {
auto actual_end = _underlying_pos + buf.size();
if (chunk_index + 1 < _checksum.checksums.size()) {
throw malformed_sstable_exception(seastar::format("Checksummed reader hit premature end-of-file at file offset {}: expected {} chunks of size {} but data file has {}",
actual_end, _checksum.checksums.size(), chunk_size, chunk_index + 1));
} else if (actual_end < _file_len) {
// Truncation on last chunk. Update _end_pos so that future
// calls to get() return immediately.
_end_pos = actual_end;
}
}
if (chunk_index >= _checksum.checksums.size()) {
throw malformed_sstable_exception(seastar::format("Chunk count mismatch between CRC and Data.db: expected {} but data file has more", _checksum.checksums.size()));
}
auto expected_checksum = _checksum.checksums[chunk_index];
auto actual_checksum = ChecksumType::checksum(buf.get(), buf.size());
if (expected_checksum != actual_checksum) {
_error_handler(seastar::format(
"Checksummed chunk of size {} at file offset {} failed checksum: expected={}, actual={}",
buf.size(), _underlying_pos, expected_checksum, actual_checksum));
}
if constexpr (check_digest) {
if (_digests.can_calculate_digest) {
_digests.actual_digest = checksum_combine_or_feed<ChecksumType>(_digests.actual_digest, actual_checksum, buf.begin(), buf.size());
}
}
buf.trim_front(_pos & (chunk_size - 1));
_pos += buf.size();
_underlying_pos += chunk_size;
if constexpr (check_digest) {
if (_digests.can_calculate_digest && _pos == _file_len && _digests.expected_digest != _digests.actual_digest) {
_error_handler(seastar::format("Digest mismatch: expected={}, actual={}", _digests.expected_digest, _digests.actual_digest));
}
}
co_return buf;
}
virtual future<> close() override {
if (!_input_stream) {
return make_ready_future<>();
}
return _input_stream->close();
}
virtual future<temporary_buffer<char>> skip(uint64_t n) override {
if constexpr (check_digest) {
if (_digests.can_calculate_digest) {
sstlog.debug("Checksummed reader cannot calculate digest with skipped data: current pos={}, end pos={}, skip len={}. Disabling digest check.", _pos, _end_pos, n);
_digests.can_calculate_digest = false;
}
}
uint64_t chunk_size = _checksum.chunk_size;
if (_pos + n > _end_pos) {
on_internal_error(sstlog, format("Skipping over the end position is disallowed: current pos={}, end pos={}, skip len={}", _pos, _end_pos, n));
}
_pos += n;
if (_pos == _end_pos) {
co_return temporary_buffer<char>();
}
auto underlying_n = align_down(_pos, chunk_size) - _underlying_pos;
_beg_pos = _pos;
_underlying_pos += underlying_n;
if (!_input_stream) {
_input_stream = co_await _stream_creator();
}
co_await _input_stream->skip(underlying_n);
co_return temporary_buffer<char>();
}
};
template <ChecksumUtils ChecksumType, bool check_digest>
class checksummed_file_data_source : public data_source {
public:
checksummed_file_data_source(stream_creator_fn stream_creator, uint64_t file_len, const checksum& checksum,
uint64_t offset, size_t len, file_input_stream_options options,
std::optional<uint32_t> digest, integrity_error_handler error_handler)
: data_source(std::make_unique<checksummed_file_data_source_impl<ChecksumType, check_digest>>(
std::move(stream_creator), file_len, checksum, offset, len, std::move(options), digest,
error_handler))
{}
};
template <ChecksumUtils ChecksumType>
inline input_stream<char> make_checksummed_file_input_stream(
stream_creator_fn stream_creator, uint64_t file_len, const checksum& checksum, uint64_t offset,
size_t len, file_input_stream_options options, std::optional<uint32_t> digest,
integrity_error_handler error_handler)
{
if (digest) {
return input_stream<char>(checksummed_file_data_source<ChecksumType, true>(
std::move(stream_creator), file_len, checksum, offset, len, std::move(options), digest,
error_handler));
}
return input_stream<char>(checksummed_file_data_source<ChecksumType, false>(
std::move(stream_creator), file_len, checksum, offset, len, std::move(options), digest, error_handler));
}
input_stream<char> make_checksummed_file_k_l_format_input_stream(
stream_creator_fn stream_creator, uint64_t file_len, const checksum& checksum, uint64_t offset,
size_t len, file_input_stream_options options, std::optional<uint32_t> digest,
integrity_error_handler error_handler)
{
return make_checksummed_file_input_stream<adler32_utils>(std::move(stream_creator), file_len,
checksum, offset, len, std::move(options), digest, error_handler);
}
input_stream<char> make_checksummed_file_m_format_input_stream(
stream_creator_fn stream_creator, uint64_t file_len, const checksum& checksum, uint64_t offset,
size_t len, file_input_stream_options options, std::optional<uint32_t> digest,
integrity_error_handler error_handler)
{
return make_checksummed_file_input_stream<crc32_utils>(std::move(stream_creator), file_len,
checksum, offset, len, std::move(options), digest, error_handler);
}
void throwing_integrity_error_handler(sstring msg) {
throw sstables::malformed_sstable_exception(msg);
};
}