Magisk/native/jni/utils/misc.hpp

#pragma once

#include <pthread.h>
#include <string>
#include <functional>
#include <string_view>

#define UID_ROOT   0
#define UID_SHELL  2000

class mutex_guard {
public:
    explicit mutex_guard(pthread_mutex_t &m): mutex(&m) {
        pthread_mutex_lock(mutex);
    }

    explicit mutex_guard(pthread_mutex_t *m): mutex(m) {
        pthread_mutex_lock(mutex);
    }

    ~mutex_guard() {
        pthread_mutex_unlock(mutex);
    }

private:
    pthread_mutex_t *mutex;
};

template <class Func>
class run_finally {
public:
    explicit run_finally(const Func &fn) : fn(fn) {}
    ~run_finally() { fn(); }
private:
    const Func &fn;
};

template <typename T>
class reversed_container {
public:
    reversed_container(T &base) : base(base) {}
    decltype(std::declval<T>().rbegin()) begin() { return base.rbegin(); }
    decltype(std::declval<T>().crbegin()) begin() const { return base.crbegin(); }
    decltype(std::declval<T>().crbegin()) cbegin() const { return base.crbegin(); }
    decltype(std::declval<T>().rend()) end() { return base.rend(); }
    decltype(std::declval<T>().crend()) end() const { return base.crend(); }
    decltype(std::declval<T>().crend()) cend() const { return base.crend(); }
private:
    T &base;
};

template <typename T>
reversed_container<T> reversed(T &base) {
    return reversed_container<T>(base);
}

int parse_int(const char *s);
static inline int parse_int(const std::string &s) { return parse_int(s.data()); }
static inline int parse_int(std::string_view s) { return parse_int(s.data()); }

using thread_entry = void *(*)(void *);
int new_daemon_thread(thread_entry entry, void *arg = nullptr, const pthread_attr_t *attr = nullptr);
int new_daemon_thread(std::function<void()> &&entry);

static inline bool str_contains(std::string_view s, std::string_view ss) {
    return s.find(ss) != std::string::npos;
}
static inline bool str_starts(std::string_view s, std::string_view ss) {
    return s.rfind(ss, 0) == 0;
}
static inline bool str_ends(std::string_view s, std::string_view ss) {
    return s.size() >= ss.size() && s.compare(s.size() - ss.size(), std::string::npos, ss) == 0;
}

int fork_dont_care();
int fork_no_orphan();
void init_argv0(int argc, char **argv);
void set_nice_name(const char *name);
uint32_t binary_gcd(uint32_t u, uint32_t v);
int switch_mnt_ns(int pid);
int gen_rand_str(char *buf, int len, bool varlen = true);
std::string &replace_all(std::string &str, std::string_view from, std::string_view to);

struct exec_t {
    bool err = false;
    int fd = -2;
    void (*pre_exec)() = nullptr;
    int (*fork)() = xfork;
    const char **argv = nullptr;
};

int exec_command(exec_t &exec);
template <class ...Args>
int exec_command(exec_t &exec, Args &&...args) {
    const char *argv[] = {args..., nullptr};
    exec.argv = argv;
    return exec_command(exec);
}
int exec_command_sync(exec_t &exec);
template <class ...Args>
int exec_command_sync(exec_t &exec, Args &&...args) {
    const char *argv[] = {args..., nullptr};
    exec.argv = argv;
    return exec_command_sync(exec);
}
template <class ...Args>
int exec_command_sync(Args &&...args) {
    exec_t exec{};
    return exec_command_sync(exec, args...);
}
template <class ...Args>
void exec_command_async(Args &&...args) {
    const char *argv[] = {args..., nullptr};
    exec_t exec {
        .argv = argv,
        .fork = fork_dont_care
    };
    exec_command(exec);
}