FileSource.hpp

// SPDX-FileCopyrightText: 2025 Vincent Leroy
// SPDX-License-Identifier: MIT
//
// This file is part of dfx.
//
// Licensed under the MIT License. See the LICENSE file in the project root
// for full license information.
 
#pragma once
 
// Standard includes
#include <chrono>
 
// Project includes
#include <dfx-core/Node.hpp>
#include <dfx-fdwatch/InotifyWatcher.hpp>
#include <dfx-fdwatch/OwnedFd.hpp>
#include <dfx-fdwatch/Timer.hpp>
#include <dfx-magic/Context.hpp>
#include <dfx-utilities/EnumString.hpp>
#include <dfx-utilities/FileSystem.hpp>
 
namespace dfx::Node
{
class FileSource : public Core::Node
{
    DFX_NODE("FileSource")
 
public:
    enum class EmitMode
    {
        Line,
        Block,
        Whole,
    };
 
    enum class Trigger
    {
        OneShot,
        Manual,
        Periodic,
        Tail,
    };
 
public:
    FileSource(Id id, std::string name);
    ~FileSource();
 
protected:
    void startImpl() override;
    void stopImpl() override;
    void initializeImpl(nlohmann::json config) override;
    void handleMessage(Core::InputPort const & port, Core::MessagePtr message) override;
 
private:
    void _doNextRead();
    void _onInotifyEvent(fs::path const & p, uint32_t mask);
 
    std::size_t _readOnceInto(std::vector<uint8_t> & buffer);
 
    bool _sendNextLine();
    bool _sendNextBlock();
 
private:
    Magic::Context _magic;
    FdWatch::OwnedFd _fd;
    FdWatch::Timer _periodicTimer;
    std::unique_ptr<FdWatch::InotifyWatcher> _watcher;
 
private:
    fs::path                  _path;
    EmitMode                  _emitMode = EmitMode::Whole;
    Trigger                   _trigger = Trigger::OneShot;
    std::string               _delimiter = "\n";
    std::size_t               _blockSize = 4096;
    std::chrono::milliseconds _interval{10};
 
private:
    std::vector<uint8_t> _buffer;
};
} // !namespace dfx::Node
 
DECLARE_ENUM_STRING_FUNCTIONS(dfx::Node::FileSource::EmitMode);
DECLARE_ENUM_STRING_FUNCTIONS(dfx::Node::FileSource::Trigger);