Files
scylladb/sstables/random_access_reader.hh
Avi Kivity f3eade2f62 treewide: relicense to ScyllaDB-Source-Available-1.0
Drop the AGPL license in favor of a source-available license.
See the blog post [1] for details.

[1] https://www.scylladb.com/2024/12/18/why-were-moving-to-a-source-available-license/
2024-12-18 17:45:13 +02:00

59 lines
1.4 KiB
C++

/*
* Copyright (C) 2018-present ScyllaDB
*/
/*
* SPDX-License-Identifier: LicenseRef-ScyllaDB-Source-Available-1.0
*/
#pragma once
#include "utils/assert.hh"
#include <memory>
#include <seastar/core/file.hh>
#include <seastar/core/fstream.hh>
#include <seastar/core/future.hh>
#include <seastar/core/gate.hh>
#include <seastar/core/iostream.hh>
#include <seastar/core/temporary_buffer.hh>
#include "seastarx.hh"
namespace sstables {
class random_access_reader {
std::unique_ptr <input_stream<char>> _in;
protected:
virtual input_stream<char> open_at(uint64_t pos) = 0;
void set(input_stream<char> in) {
SCYLLA_ASSERT(!_in);
_in = std::make_unique<input_stream<char>>(std::move(in));
}
public:
future <temporary_buffer<char>> read_exactly(size_t n) noexcept;
future<> seek(uint64_t pos) noexcept;
bool eof() const noexcept { return _in->eof(); }
virtual future<> close() noexcept;
virtual ~random_access_reader() {}
};
class file_random_access_reader : public random_access_reader {
file _file;
uint64_t _file_size;
size_t _buffer_size;
unsigned _read_ahead;
public:
virtual input_stream<char> open_at(uint64_t pos) override;
explicit file_random_access_reader(file f, uint64_t file_size, size_t buffer_size = 8192, unsigned read_ahead = 4);
virtual future<> close() noexcept override;
};
}