logmeow/logcat_thread.h

#pragma once

#include <thread>
#include <variant>
#include "arb.h"
#include "logcat_entry.h"

typedef std::variant<LogEntry, LogcatEntry> LogcatThreadItem;
#define NEWLINE_BUF_SIZE 512 * 1024

enum class LogcatProcessRequest {
    None,
    Start,
    Stop,
};

class LogcatThread {
public:
    // https://stackoverflow.com/a/2173764
    LogcatThread(const LogcatThread&) = delete;
    LogcatThread& operator=(const LogcatThread&) = delete;

    LogcatThread(const std::string* logcat_command);
    ~LogcatThread();
    void request_stop();
    void join();

    AtomicRingBuffer<LogcatThreadItem> atomic_ring_buffer;
    std::atomic<LogcatProcessRequest> logcat_process_request = LogcatProcessRequest::None;
    std::atomic_flag logcat_process_running;

#ifndef NDEBUG
    std::atomic_flag debug_log_request;
#endif

private:
    void _put_if_not_stopped(LogcatThreadItem item);
    void _handle_line(char* buf, size_t length, bool is_stdout);
    void _run(std::stop_token stoken);
    void _run_epoll_round();

    void _try_reap(bool stop_requested);
    bool _handle_stop_request();
    bool _handle_start_request();
    bool _run_process_round(LogcatProcessRequest request);

    int _epoll_fd = -1;
    int _stdout_read_fd = -1;
    int _stdout_write_fd = -1;
    int _stderr_read_fd = -1;
    int _stderr_write_fd = -1;

    char _stdout_buf[NEWLINE_BUF_SIZE];
    size_t _stdout_buf_used = 0;
    char _stderr_buf[NEWLINE_BUF_SIZE];
    size_t _stderr_buf_used = 0;

    pid_t _logcat_pid = -1;
    char _logcat_process_kill_attempts = 0;
    const std::string* _logcat_command;

    Buffer _current_buffer = Buffer::Unknown;
    std::stop_source _stop_source;
    std::thread _thread;
};