lnav/src/lnav_util.hh

/**
 * Copyright (c) 2007-2012, Timothy Stack
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 * * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * * Neither the name of Timothy Stack nor the names of its contributors
 * may be used to endorse or promote products derived from this software
 * without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ''AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * @file lnav_util.hh
 *
 * Dumping ground for useful functions with no other home.
 */

#ifndef lnav_util_hh
#define lnav_util_hh

#include <future>
#include <numeric>
#include <string>
#include <type_traits>
#include <vector>

#include <fcntl.h>
#include <poll.h>
#include <sys/resource.h>
#include <sys/time.h>
#include <sys/types.h>
#include <time.h>

#include "base/intern_string.hh"
#include "base/lnav.console.hh"
#include "base/result.h"
#include "byte_array.hh"
#include "config.h"
#include "fmt/format.h"
#include "optional.hpp"
#include "ptimec.hh"
#include "spookyhash/SpookyV2.h"

#if SIZEOF_OFF_T == 8
#    define FORMAT_OFF_T "%lld"
#elif SIZEOF_OFF_T == 4
#    define FORMAT_OFF_T "%ld"
#else
#    error "off_t has unhandled size..."
#endif

class hasher {
public:
    hasher()
    {
        this->h_context.Init(0, 0);
    }

    hasher& update(const std::string& str)
    {
        this->h_context.Update(str.data(), str.length());

        return *this;
    }

    hasher& update(const string_fragment& str)
    {
        this->h_context.Update(str.data(), str.length());

        return *this;
    }

    hasher& update(const char* bits, size_t len)
    {
        this->h_context.Update(bits, len);

        return *this;
    }

    template<typename T,
             typename = std::enable_if<std::is_arithmetic<T>::value>>
    hasher& update(T value)
    {
        this->h_context.Update(&value, sizeof(value));

        return *this;
    }

    std::string to_string()
    {
        byte_array<2, uint64> bits;

        this->h_context.Final(bits.out(0), bits.out(1));
        return bits.to_string();
    }

private:
    SpookyHash h_context;
};

bool change_to_parent_dir();

bool next_format(const char* const fmt[], int& index, int& locked_index);

namespace std {
inline string
to_string(const string& s)
{
    return s;
}
inline string
to_string(const char* s)
{
    return s;
}
}  // namespace std

inline bool
is_glob(const std::string& fn)
{
    return (fn.find('*') != std::string::npos
            || fn.find('?') != std::string::npos
            || fn.find('[') != std::string::npos);
};

short pollfd_revents(const std::vector<struct pollfd>& pollfds, int fd);

inline bool
pollfd_ready(const std::vector<struct pollfd>& pollfds,
             int fd,
             short events = POLLIN | POLLHUP)
{
    return std::any_of(
        pollfds.begin(), pollfds.end(), [fd, events](const auto& entry) {
            return entry.fd == fd && entry.revents & events;
        });
};

inline void
rusagesub(const struct rusage& left,
          const struct rusage& right,
          struct rusage& diff_out)
{
    timersub(&left.ru_utime, &right.ru_utime, &diff_out.ru_utime);
    timersub(&left.ru_stime, &right.ru_stime, &diff_out.ru_stime);
    diff_out.ru_maxrss = left.ru_maxrss - right.ru_maxrss;
    diff_out.ru_ixrss = left.ru_ixrss - right.ru_ixrss;
    diff_out.ru_idrss = left.ru_idrss - right.ru_idrss;
    diff_out.ru_isrss = left.ru_isrss - right.ru_isrss;
    diff_out.ru_minflt = left.ru_minflt - right.ru_minflt;
    diff_out.ru_majflt = left.ru_majflt - right.ru_majflt;
    diff_out.ru_nswap = left.ru_nswap - right.ru_nswap;
    diff_out.ru_inblock = left.ru_inblock - right.ru_inblock;
    diff_out.ru_oublock = left.ru_oublock - right.ru_oublock;
    diff_out.ru_msgsnd = left.ru_msgsnd - right.ru_msgsnd;
    diff_out.ru_msgrcv = left.ru_msgrcv - right.ru_msgrcv;
    diff_out.ru_nvcsw = left.ru_nvcsw - right.ru_nvcsw;
    diff_out.ru_nivcsw = left.ru_nivcsw - right.ru_nivcsw;
}

inline void
rusageadd(const struct rusage& left,
          const struct rusage& right,
          struct rusage& diff_out)
{
    timeradd(&left.ru_utime, &right.ru_utime, &diff_out.ru_utime);
    timeradd(&left.ru_stime, &right.ru_stime, &diff_out.ru_stime);
    diff_out.ru_maxrss = left.ru_maxrss + right.ru_maxrss;
    diff_out.ru_ixrss = left.ru_ixrss + right.ru_ixrss;
    diff_out.ru_idrss = left.ru_idrss + right.ru_idrss;
    diff_out.ru_isrss = left.ru_isrss + right.ru_isrss;
    diff_out.ru_minflt = left.ru_minflt + right.ru_minflt;
    diff_out.ru_majflt = left.ru_majflt + right.ru_majflt;
    diff_out.ru_nswap = left.ru_nswap + right.ru_nswap;
    diff_out.ru_inblock = left.ru_inblock + right.ru_inblock;
    diff_out.ru_oublock = left.ru_oublock + right.ru_oublock;
    diff_out.ru_msgsnd = left.ru_msgsnd + right.ru_msgsnd;
    diff_out.ru_msgrcv = left.ru_msgrcv + right.ru_msgrcv;
    diff_out.ru_nvcsw = left.ru_nvcsw + right.ru_nvcsw;
    diff_out.ru_nivcsw = left.ru_nivcsw + right.ru_nivcsw;
}

bool is_dev_null(const struct stat& st);
bool is_dev_null(int fd);

template<typename A>
struct final_action {  // slightly simplified
    A act;
    final_action(A a) : act{a} {}
    ~final_action()
    {
        act();
    }
};

template<typename A>
final_action<A>
finally(A act)  // deduce action type
{
    return final_action<A>{act};
}

std::string ok_prefix(std::string msg);
std::string err_prefix(std::string msg);
Result<std::string, lnav::console::user_message> err_to_ok(
    lnav::console::user_message msg);

void write_line_to(FILE* outfile, const attr_line_t& al);

namespace lnav {

std::string to_json(const std::string& str);
std::string to_json(const lnav::console::user_message& um);
std::string to_json(const attr_line_t& al);

template<typename T>
Result<T, std::vector<lnav::console::user_message>> from_json(
    const std::string& json);

}  // namespace lnav

#endif