xz: Multiple fixes.

[icculus/xz.git] / src / xz / message.c

///////////////////////////////////////////////////////////////////////////////
//
/// \file       message.c
/// \brief      Printing messages
//
//  Author:     Lasse Collin
//
//  This file has been put into the public domain.
//  You can do whatever you want with this file.
//
///////////////////////////////////////////////////////////////////////////////

#include "private.h"

#ifdef HAVE_SYS_TIME_H
#       include <sys/time.h>
#endif

#include <stdarg.h>


/// Number of the current file
static unsigned int files_pos = 0;

/// Total number of input files; zero if unknown.
static unsigned int files_total;

/// Verbosity level
static enum message_verbosity verbosity = V_WARNING;

/// Filename which we will print with the verbose messages
static const char *filename;

/// True once the a filename has been printed to stderr as part of progress
/// message. If automatic progress updating isn't enabled, this becomes true
/// after the first progress message has been printed due to user sending
/// SIGINFO, SIGUSR1, or SIGALRM. Once this variable is true, we will print
/// an empty line before the next filename to make the output more readable.
static bool first_filename_printed = false;

/// This is set to true when we have printed the current filename to stderr
/// as part of a progress message. This variable is useful only if not
/// updating progress automatically: if user sends many SIGINFO, SIGUSR1, or
/// SIGALRM signals, we won't print the name of the same file multiple times.
static bool current_filename_printed = false;

/// True if we should print progress indicator and update it automatically
/// if also verbose >= V_VERBOSE.
static bool progress_automatic;

/// True if message_progress_start() has been called but
/// message_progress_end() hasn't been called yet.
static bool progress_started = false;

/// This is true when a progress message was printed and the cursor is still
/// on the same line with the progress message. In that case, a newline has
/// to be printed before any error messages.
static bool progress_active = false;

/// Pointer to lzma_stream used to do the encoding or decoding.
static lzma_stream *progress_strm;

/// Expected size of the input stream is needed to show completion percentage
/// and estimate remaining time.
static uint64_t expected_in_size;

/// Time when we started processing the file
static uint64_t start_time;


// Use alarm() and SIGALRM when they are supported. This has two minor
// advantages over the alternative of polling gettimeofday():
//  - It is possible for the user to send SIGINFO, SIGUSR1, or SIGALRM to
//    get intermediate progress information even when --verbose wasn't used
//    or stderr is not a terminal.
//  - alarm() + SIGALRM seems to have slightly less overhead than polling
//    gettimeofday().
#ifdef SIGALRM

/// The signal handler for SIGALRM sets this to true. It is set back to false
/// once the progress message has been updated.
static volatile sig_atomic_t progress_needs_updating = false;

/// Signal handler for SIGALRM
static void
progress_signal_handler(int sig lzma_attribute((unused)))
{
        progress_needs_updating = true;
        return;
}

#else

/// This is true when progress message printing is wanted. Using the same
/// variable name as above to avoid some ifdefs.
static bool progress_needs_updating = false;

/// Elapsed time when the next progress message update should be done.
static uint64_t progress_next_update;

#endif


/// Get the current time as microseconds since epoch
static uint64_t
my_time(void)
{
        struct timeval tv;
        gettimeofday(&tv, NULL);
        return (uint64_t)(tv.tv_sec) * UINT64_C(1000000) + tv.tv_usec;
}


extern void
message_init(void)
{
        // If --verbose is used, we use a progress indicator if and only
        // if stderr is a terminal. If stderr is not a terminal, we print
        // verbose information only after finishing the file. As a special
        // exception, even if --verbose was not used, user can send SIGALRM
        // to make us print progress information once without automatic
        // updating.
        progress_automatic = isatty(STDERR_FILENO);

        // Commented out because COLUMNS is rarely exported to environment.
        // Most users have at least 80 columns anyway, let's think something
        // fancy here if enough people complain.
/*
        if (progress_automatic) {
                // stderr is a terminal. Check the COLUMNS environment
                // variable to see if the terminal is wide enough. If COLUMNS
                // doesn't exist or it has some unparsable value, we assume
                // that the terminal is wide enough.
                const char *columns_str = getenv("COLUMNS");
                if (columns_str != NULL) {
                        char *endptr;
                        const long columns = strtol(columns_str, &endptr, 10);
                        if (*endptr != '\0' || columns < 80)
                                progress_automatic = false;
                }
        }
*/

#ifdef SIGALRM
        // DJGPP lacks SA_RESTART, but it shouldn't give EINTR
        // in most places either.
#       if defined(__DJGPP__) && !defined(SA_RESTART)
#               define SA_RESTART 0
#       endif

        // Establish the signal handlers which set a flag to tell us that
        // progress info should be updated. Since these signals don't
        // require any quick action, we set SA_RESTART. That way we don't
        // need to block them either in signals_block() to keep stdio
        // functions from getting EINTR.
        static const int sigs[] = {
                SIGALRM,
#ifdef SIGINFO
                SIGINFO,
#endif
#ifdef SIGUSR1
                SIGUSR1,
#endif
        };

        struct sigaction sa;
        sigemptyset(&sa.sa_mask);
        sa.sa_flags = SA_RESTART;
        sa.sa_handler = &progress_signal_handler;

        for (size_t i = 0; i < ARRAY_SIZE(sigs); ++i)
                if (sigaction(sigs[i], &sa, NULL))
                        message_signal_handler();
#endif

        return;
}


extern void
message_verbosity_increase(void)
{
        if (verbosity < V_DEBUG)
                ++verbosity;

        return;
}


extern void
message_verbosity_decrease(void)
{
        if (verbosity > V_SILENT)
                --verbosity;

        return;
}


extern enum message_verbosity
message_verbosity_get(void)
{
        return verbosity;
}


extern void
message_set_files(unsigned int files)
{
        files_total = files;
        return;
}


/// Prints the name of the current file if it hasn't been printed already,
/// except if we are processing exactly one stream from stdin to stdout.
/// I think it looks nicer to not print "(stdin)" when --verbose is used
/// in a pipe and no other files are processed.
static void
print_filename(void)
{
        if (files_total != 1 || filename != stdin_filename) {
                signals_block();

                FILE *file = opt_mode == MODE_LIST ? stdout : stderr;

                // If a file was already processed, put an empty line
                // before the next filename to improve readability.
                if (first_filename_printed)
                        fputc('\n', file);

                first_filename_printed = true;
                current_filename_printed = true;

                // If we don't know how many files there will be due
                // to usage of --files or --files0.
                if (files_total == 0)
                        fprintf(file, "%s (%u)\n", filename,
                                        files_pos);
                else
                        fprintf(file, "%s (%u/%u)\n", filename,
                                        files_pos, files_total);

                signals_unblock();
        }

        return;
}


extern void
message_filename(const char *src_name)
{
        // Start numbering the files starting from one.
        ++files_pos;
        filename = src_name;

        if (verbosity >= V_VERBOSE
                        && (progress_automatic || opt_mode == MODE_LIST))
                print_filename();
        else
                current_filename_printed = false;

        return;
}


extern void
message_progress_start(lzma_stream *strm, uint64_t in_size)
{
        // Store the pointer to the lzma_stream used to do the coding.
        // It is needed to find out the position in the stream.
        progress_strm = strm;

        // Store the processing start time of the file and its expected size.
        // If we aren't printing any statistics, then these are unused. But
        // since it is possible that the user sends us a signal to show
        // statistics, we need to have these available anyway.
        start_time = my_time();
        expected_in_size = in_size;

        // Indicate that progress info may need to be printed before
        // printing error messages.
        progress_started = true;

        // If progress indicator is wanted, print the filename and possibly
        // the file count now.
        if (verbosity >= V_VERBOSE && progress_automatic) {
                // Start the timer to display the first progress message
                // after one second. An alternative would be to show the
                // first message almost immediately, but delaying by one
                // second looks better to me, since extremely early
                // progress info is pretty much useless.
#ifdef SIGALRM
                // First disable a possibly existing alarm.
                alarm(0);
                progress_needs_updating = false;
                alarm(1);
#else
                progress_needs_updating = true;
                progress_next_update = 1000000;
#endif
        }

        return;
}


/// Make the string indicating completion percentage.
static const char *
progress_percentage(uint64_t in_pos)
{
        // If the size of the input file is unknown or the size told us is
        // clearly wrong since we have processed more data than the alleged
        // size of the file, show a static string indicating that we have
        // no idea of the completion percentage.
        if (expected_in_size == 0 || in_pos > expected_in_size)
                return "--- %";

        // Never show 100.0 % before we actually are finished.
        double percentage = (double)(in_pos) / (double)(expected_in_size)
                        * 99.9;

        // Use big enough buffer to hold e.g. a multibyte decimal point.
        static char buf[16];
        snprintf(buf, sizeof(buf), "%.1f %%", percentage);

        return buf;
}


/// Make the string containing the amount of input processed, amount of
/// output produced, and the compression ratio.
static const char *
progress_sizes(uint64_t compressed_pos, uint64_t uncompressed_pos, bool final)
{
        // Use big enough buffer to hold e.g. a multibyte thousand separators.
        static char buf[128];
        char *pos = buf;
        size_t left = sizeof(buf);

        // Print the sizes. If this the final message, use more reasonable
        // units than MiB if the file was small.
        const enum nicestr_unit unit_min = final ? NICESTR_B : NICESTR_MIB;
        my_snprintf(&pos, &left, "%s / %s",
                        uint64_to_nicestr(compressed_pos,
                                unit_min, NICESTR_TIB, false, 0),
                        uint64_to_nicestr(uncompressed_pos,
                                unit_min, NICESTR_TIB, false, 1));

        // Avoid division by zero. If we cannot calculate the ratio, set
        // it to some nice number greater than 10.0 so that it gets caught
        // in the next if-clause.
        const double ratio = uncompressed_pos > 0
                        ? (double)(compressed_pos) / (double)(uncompressed_pos)
                        : 16.0;

        // If the ratio is very bad, just indicate that it is greater than
        // 9.999. This way the length of the ratio field stays fixed.
        if (ratio > 9.999)
                snprintf(pos, left, " > %.3f", 9.999);
        else
                snprintf(pos, left, " = %.3f", ratio);

        return buf;
}


/// Make the string containing the processing speed of uncompressed data.
static const char *
progress_speed(uint64_t uncompressed_pos, uint64_t elapsed)
{
        // Don't print the speed immediately, since the early values look
        // somewhat random.
        if (elapsed < 3000000)
                return "";

        static const char unit[][8] = {
                "KiB/s",
                "MiB/s",
                "GiB/s",
        };

        size_t unit_index = 0;

        // Calculate the speed as KiB/s.
        double speed = (double)(uncompressed_pos)
                        / ((double)(elapsed) * (1024.0 / 1e6));

        // Adjust the unit of the speed if needed.
        while (speed > 999.0) {
                speed /= 1024.0;
                if (++unit_index == ARRAY_SIZE(unit))
                        return ""; // Way too fast ;-)
        }

        // Use decimal point only if the number is small. Examples:
        //  - 0.1 KiB/s
        //  - 9.9 KiB/s
        //  - 99 KiB/s
        //  - 999 KiB/s
        // Use big enough buffer to hold e.g. a multibyte decimal point.
        static char buf[16];
        snprintf(buf, sizeof(buf), "%.*f %s",
                        speed > 9.9 ? 0 : 1, speed, unit[unit_index]);
        return buf;
}


/// Make a string indicating elapsed or remaining time. The format is either
/// M:SS or H:MM:SS depending on if the time is an hour or more.
static const char *
progress_time(uint64_t useconds)
{
        // 9999 hours = 416 days
        static char buf[sizeof("9999:59:59")];

        uint32_t seconds = useconds / 1000000;

        // Don't show anything if the time is zero or ridiculously big.
        if (seconds == 0 || seconds > ((9999 * 60) + 59) * 60 + 59)
                return "";

        uint32_t minutes = seconds / 60;
        seconds %= 60;

        if (minutes >= 60) {
                const uint32_t hours = minutes / 60;
                minutes %= 60;
                snprintf(buf, sizeof(buf),
                                "%" PRIu32 ":%02" PRIu32 ":%02" PRIu32,
                                hours, minutes, seconds);
        } else {
                snprintf(buf, sizeof(buf), "%" PRIu32 ":%02" PRIu32,
                                minutes, seconds);
        }

        return buf;
}


/// Return a string containing estimated remaining time when
/// reasonably possible.
static const char *
progress_remaining(uint64_t in_pos, uint64_t elapsed)
{
        // Don't show the estimated remaining time when it wouldn't
        // make sense:
        //  - Input size is unknown.
        //  - Input has grown bigger since we started (de)compressing.
        //  - We haven't processed much data yet, so estimate would be
        //    too inaccurate.
        //  - Only a few seconds has passed since we started (de)compressing,
        //    so estimate would be too inaccurate.
        if (expected_in_size == 0 || in_pos > expected_in_size
                        || in_pos < (UINT64_C(1) << 19) || elapsed < 8000000)
                return "";

        // Calculate the estimate. Don't give an estimate of zero seconds,
        // since it is possible that all the input has been already passed
        // to the library, but there is still quite a bit of output pending.
        uint32_t remaining = (double)(expected_in_size - in_pos)
                        * ((double)(elapsed) / 1e6) / (double)(in_pos);
        if (remaining < 1)
                remaining = 1;

        static char buf[sizeof("9 h 55 min")];

        // Select appropriate precision for the estimated remaining time.
        if (remaining <= 10) {
                // A maximum of 10 seconds remaining.
                // Show the number of seconds as is.
                snprintf(buf, sizeof(buf), "%" PRIu32 " s", remaining);

        } else if (remaining <= 50) {
                // A maximum of 50 seconds remaining.
                // Round up to the next multiple of five seconds.
                remaining = (remaining + 4) / 5 * 5;
                snprintf(buf, sizeof(buf), "%" PRIu32 " s", remaining);

        } else if (remaining <= 590) {
                // A maximum of 9 minutes and 50 seconds remaining.
                // Round up to the next multiple of ten seconds.
                remaining = (remaining + 9) / 10 * 10;
                snprintf(buf, sizeof(buf), "%" PRIu32 " min %" PRIu32 " s",
                                remaining / 60, remaining % 60);

        } else if (remaining <= 59 * 60) {
                // A maximum of 59 minutes remaining.
                // Round up to the next multiple of a minute.
                remaining = (remaining + 59) / 60;
                snprintf(buf, sizeof(buf), "%" PRIu32 " min", remaining);

        } else if (remaining <= 9 * 3600 + 50 * 60) {
                // A maximum of 9 hours and 50 minutes left.
                // Round up to the next multiple of ten minutes.
                remaining = (remaining + 599) / 600 * 10;
                snprintf(buf, sizeof(buf), "%" PRIu32 " h %" PRIu32 " min",
                                remaining / 60, remaining % 60);

        } else if (remaining <= 23 * 3600) {
                // A maximum of 23 hours remaining.
                // Round up to the next multiple of an hour.
                remaining = (remaining + 3599) / 3600;
                snprintf(buf, sizeof(buf), "%" PRIu32 " h", remaining);

        } else if (remaining <= 9 * 24 * 3600 + 23 * 3600) {
                // A maximum of 9 days and 23 hours remaining.
                // Round up to the next multiple of an hour.
                remaining = (remaining + 3599) / 3600;
                snprintf(buf, sizeof(buf), "%" PRIu32 " d %" PRIu32 " h",
                                remaining / 24, remaining % 24);

        } else if (remaining <= 999 * 24 * 3600) {
                // A maximum of 999 days remaining. ;-)
                // Round up to the next multiple of a day.
                remaining = (remaining + 24 * 3600 - 1) / (24 * 3600);
                snprintf(buf, sizeof(buf), "%" PRIu32 " d", remaining);

        } else {
                // The estimated remaining time is too big. Don't show it.
                return "";
        }

        return buf;
}


/// Calculate the elapsed time as microseconds.
static uint64_t
progress_elapsed(void)
{
        return my_time() - start_time;
}


/// Get information about position in the stream. This is currently simple,
/// but it will become more complicated once we have multithreading support.
static void
progress_pos(uint64_t *in_pos,
                uint64_t *compressed_pos, uint64_t *uncompressed_pos)
{
        *in_pos = progress_strm->total_in;

        if (opt_mode == MODE_COMPRESS) {
                *compressed_pos = progress_strm->total_out;
                *uncompressed_pos = progress_strm->total_in;
        } else {
                *compressed_pos = progress_strm->total_in;
                *uncompressed_pos = progress_strm->total_out;
        }

        return;
}


extern void
message_progress_update(void)
{
        if (!progress_needs_updating)
                return;

        // Calculate how long we have been processing this file.
        const uint64_t elapsed = progress_elapsed();

#ifndef SIGALRM
        if (progress_next_update > elapsed)
                return;

        progress_next_update = elapsed + 1000000;
#endif

        // Get our current position in the stream.
        uint64_t in_pos;
        uint64_t compressed_pos;
        uint64_t uncompressed_pos;
        progress_pos(&in_pos, &compressed_pos, &uncompressed_pos);

        // Block signals so that fprintf() doesn't get interrupted.
        signals_block();

        // Print the filename if it hasn't been printed yet.
        if (!current_filename_printed)
                print_filename();

        // Print the actual progress message. The idea is that there is at
        // least three spaces between the fields in typical situations, but
        // even in rare situations there is at least one space.
        const char *cols[5] = {
                progress_percentage(in_pos),
                progress_sizes(compressed_pos, uncompressed_pos, false),
                progress_speed(uncompressed_pos, elapsed),
                progress_time(elapsed),
                progress_remaining(in_pos, elapsed),
        };
        fprintf(stderr, "\r %*s %*s   %*s %10s   %10s\r",
                        tuklib_mbstr_fw(cols[0], 6), cols[0],
                        tuklib_mbstr_fw(cols[1], 35), cols[1],
                        tuklib_mbstr_fw(cols[2], 9), cols[2],
                        cols[3],
                        cols[4]);

#ifdef SIGALRM
        // Updating the progress info was finished. Reset
        // progress_needs_updating to wait for the next SIGALRM.
        //
        // NOTE: This has to be done before alarm(1) or with (very) bad
        // luck we could be setting this to false after the alarm has already
        // been triggered.
        progress_needs_updating = false;

        if (verbosity >= V_VERBOSE && progress_automatic) {
                // Mark that the progress indicator is active, so if an error
                // occurs, the error message gets printed cleanly.
                progress_active = true;

                // Restart the timer so that progress_needs_updating gets
                // set to true after about one second.
                alarm(1);
        } else {
                // The progress message was printed because user had sent us
                // SIGALRM. In this case, each progress message is printed
                // on its own line.
                fputc('\n', stderr);
        }
#else
        // When SIGALRM isn't supported and we get here, it's always due to
        // automatic progress update. We set progress_active here too like
        // described above.
        assert(verbosity >= V_VERBOSE);
        assert(progress_automatic);
        progress_active = true;
#endif

        signals_unblock();

        return;
}


static void
progress_flush(bool finished)
{
        if (!progress_started || verbosity < V_VERBOSE)
                return;

        uint64_t in_pos;
        uint64_t compressed_pos;
        uint64_t uncompressed_pos;
        progress_pos(&in_pos, &compressed_pos, &uncompressed_pos);

        // Avoid printing intermediate progress info if some error occurs
        // in the beginning of the stream. (If something goes wrong later in
        // the stream, it is sometimes useful to tell the user where the
        // error approximately occurred, especially if the error occurs
        // after a time-consuming operation.)
        if (!finished && !progress_active
                        && (compressed_pos == 0 || uncompressed_pos == 0))
                return;

        progress_active = false;

        const uint64_t elapsed = progress_elapsed();

        signals_block();

        // When using the auto-updating progress indicator, the final
        // statistics are printed in the same format as the progress
        // indicator itself.
        if (progress_automatic) {
                const char *cols[5] = {
                        finished ? "100 %" : progress_percentage(in_pos),
                        progress_sizes(compressed_pos, uncompressed_pos, true),
                        progress_speed(uncompressed_pos, elapsed),
                        progress_time(elapsed),
                        finished ? "" : progress_remaining(in_pos, elapsed),
                };
                fprintf(stderr, "\r %*s %*s   %*s %10s   %10s\n",
                                tuklib_mbstr_fw(cols[0], 6), cols[0],
                                tuklib_mbstr_fw(cols[1], 35), cols[1],
                                tuklib_mbstr_fw(cols[2], 9), cols[2],
                                cols[3],
                                cols[4]);
        } else {
                // The filename is always printed.
                fprintf(stderr, "%s: ", filename);

                // Percentage is printed only if we didn't finish yet.
                if (!finished) {
                        // Don't print the percentage when it isn't known
                        // (starts with a dash).
                        const char *percentage = progress_percentage(in_pos);
                        if (percentage[0] != '-')
                                fprintf(stderr, "%s, ", percentage);
                }

                // Size information is always printed.
                fprintf(stderr, "%s", progress_sizes(
                                compressed_pos, uncompressed_pos, true));

                // The speed and elapsed time aren't always shown.
                const char *speed = progress_speed(uncompressed_pos, elapsed);
                if (speed[0] != '\0')
                        fprintf(stderr, ", %s", speed);

                const char *elapsed_str = progress_time(elapsed);
                if (elapsed_str[0] != '\0')
                        fprintf(stderr, ", %s", elapsed_str);

                fputc('\n', stderr);
        }

        signals_unblock();

        return;
}


extern void
message_progress_end(bool success)
{
        assert(progress_started);
        progress_flush(success);
        progress_started = false;
        return;
}


static void
vmessage(enum message_verbosity v, const char *fmt, va_list ap)
{
        if (v <= verbosity) {
                signals_block();

                progress_flush(false);

                fprintf(stderr, "%s: ", progname);
                vfprintf(stderr, fmt, ap);
                fputc('\n', stderr);

                signals_unblock();
        }

        return;
}


extern void
message(enum message_verbosity v, const char *fmt, ...)
{
        va_list ap;
        va_start(ap, fmt);
        vmessage(v, fmt, ap);
        va_end(ap);
        return;
}


extern void
message_warning(const char *fmt, ...)
{
        va_list ap;
        va_start(ap, fmt);
        vmessage(V_WARNING, fmt, ap);
        va_end(ap);

        set_exit_status(E_WARNING);
        return;
}


extern void
message_error(const char *fmt, ...)
{
        va_list ap;
        va_start(ap, fmt);
        vmessage(V_ERROR, fmt, ap);
        va_end(ap);

        set_exit_status(E_ERROR);
        return;
}


extern void
message_fatal(const char *fmt, ...)
{
        va_list ap;
        va_start(ap, fmt);
        vmessage(V_ERROR, fmt, ap);
        va_end(ap);

        tuklib_exit(E_ERROR, E_ERROR, false);
}


extern void
message_bug(void)
{
        message_fatal(_("Internal error (bug)"));
}


extern void
message_signal_handler(void)
{
        message_fatal(_("Cannot establish signal handlers"));
}


extern const char *
message_strm(lzma_ret code)
{
        switch (code) {
        case LZMA_NO_CHECK:
                return _("No integrity check; not verifying file integrity");

        case LZMA_UNSUPPORTED_CHECK:
                return _("Unsupported type of integrity check; "
                                "not verifying file integrity");

        case LZMA_MEM_ERROR:
                return strerror(ENOMEM);

        case LZMA_MEMLIMIT_ERROR:
                return _("Memory usage limit reached");

        case LZMA_FORMAT_ERROR:
                return _("File format not recognized");

        case LZMA_OPTIONS_ERROR:
                return _("Unsupported options");

        case LZMA_DATA_ERROR:
                return _("Compressed data is corrupt");

        case LZMA_BUF_ERROR:
                return _("Unexpected end of input");

        case LZMA_OK:
        case LZMA_STREAM_END:
        case LZMA_GET_CHECK:
        case LZMA_PROG_ERROR:
                return _("Internal error (bug)");
        }

        return NULL;
}


extern void
message_mem_needed(enum message_verbosity v, uint64_t memusage)
{
        if (v > verbosity)
                return;

        // Convert memusage to MiB, rounding up to the next full MiB.
        // This way the user can always use the displayed usage as
        // the new memory usage limit. (If we rounded to the nearest,
        // the user might need to +1 MiB to get high enough limit.)
        memusage = round_up_to_mib(memusage);

        // With US-ASCII:
        // 2^64 with thousand separators + " MiB" suffix + '\0' = 26 + 4 + 1
        // But there may be multibyte chars so reserve enough space.
        char memlimitstr[128];

        // Show the memory usage limit as MiB unless it is less than 1 MiB.
        // This way it's easy to notice errors where one has typed
        // --memory=123 instead of --memory=123MiB.
        uint64_t memlimit = hardware_memlimit_get(opt_mode);
        if (memlimit < (UINT32_C(1) << 20)) {
                snprintf(memlimitstr, sizeof(memlimitstr), "%s B",
                                uint64_to_str(memlimit, 1));
        } else {
                // Round up just like with memusage. If this function is
                // called for informational purposes (to just show the
                // current usage and limit), we should never show that
                // the usage is higher than the limit, which would give
                // a false impression that the memory usage limit isn't
                // properly enforced.
                snprintf(memlimitstr, sizeof(memlimitstr), "%s MiB",
                                uint64_to_str(round_up_to_mib(memlimit), 1));
        }

        message(v, _("%s MiB of memory is required. The limit is %s."),
                        uint64_to_str(memusage, 0), memlimitstr);

        return;
}


/// \brief      Convert uint32_t to a nice string for --lzma[12]=dict=SIZE
///
/// The idea is to use KiB or MiB suffix when possible.
static const char *
uint32_to_optstr(uint32_t num)
{
        static char buf[16];

        if ((num & ((UINT32_C(1) << 20) - 1)) == 0)
                snprintf(buf, sizeof(buf), "%" PRIu32 "MiB", num >> 20);
        else if ((num & ((UINT32_C(1) << 10) - 1)) == 0)
                snprintf(buf, sizeof(buf), "%" PRIu32 "KiB", num >> 10);
        else
                snprintf(buf, sizeof(buf), "%" PRIu32, num);

        return buf;
}


extern void
message_filters_to_str(char buf[FILTERS_STR_SIZE],
                const lzma_filter *filters, bool all_known)
{
        char *pos = buf;
        size_t left = FILTERS_STR_SIZE;

        for (size_t i = 0; filters[i].id != LZMA_VLI_UNKNOWN; ++i) {
                // Add the dashes for the filter option. A space is
                // needed after the first and later filters.
                my_snprintf(&pos, &left, "%s", i == 0 ? "--" : " --");

                switch (filters[i].id) {
                case LZMA_FILTER_LZMA1:
                case LZMA_FILTER_LZMA2: {
                        const lzma_options_lzma *opt = filters[i].options;
                        const char *mode = NULL;
                        const char *mf = NULL;

                        if (all_known) {
                                switch (opt->mode) {
                                case LZMA_MODE_FAST:
                                        mode = "fast";
                                        break;

                                case LZMA_MODE_NORMAL:
                                        mode = "normal";
                                        break;

                                default:
                                        mode = "UNKNOWN";
                                        break;
                                }

                                switch (opt->mf) {
                                case LZMA_MF_HC3:
                                        mf = "hc3";
                                        break;

                                case LZMA_MF_HC4:
                                        mf = "hc4";
                                        break;

                                case LZMA_MF_BT2:
                                        mf = "bt2";
                                        break;

                                case LZMA_MF_BT3:
                                        mf = "bt3";
                                        break;

                                case LZMA_MF_BT4:
                                        mf = "bt4";
                                        break;

                                default:
                                        mf = "UNKNOWN";
                                        break;
                                }
                        }

                        // Add the filter name and dictionary size, which
                        // is always known.
                        my_snprintf(&pos, &left, "lzma%c=dict=%s",
                                        filters[i].id == LZMA_FILTER_LZMA2
                                                ? '2' : '1',
                                        uint32_to_optstr(opt->dict_size));

                        // With LZMA1 also lc/lp/pb are known when
                        // decompressing, but this function is never
                        // used to print information about .lzma headers.
                        assert(filters[i].id == LZMA_FILTER_LZMA2
                                        || all_known);

                        // Print the rest of the options, which are known
                        // only when compressing.
                        if (all_known)
                                my_snprintf(&pos, &left,
                                        ",lc=%" PRIu32 ",lp=%" PRIu32
                                        ",pb=%" PRIu32
                                        ",mode=%s,nice=%" PRIu32 ",mf=%s"
                                        ",depth=%" PRIu32,
                                        opt->lc, opt->lp, opt->pb,
                                        mode, opt->nice_len, mf, opt->depth);
                        break;
                }

                case LZMA_FILTER_X86:
                case LZMA_FILTER_POWERPC:
                case LZMA_FILTER_IA64:
                case LZMA_FILTER_ARM:
                case LZMA_FILTER_ARMTHUMB:
                case LZMA_FILTER_SPARC: {
                        static const char bcj_names[][9] = {
                                "x86",
                                "powerpc",
                                "ia64",
                                "arm",
                                "armthumb",
                                "sparc",
                        };

                        const lzma_options_bcj *opt = filters[i].options;
                        my_snprintf(&pos, &left, "%s", bcj_names[filters[i].id
                                        - LZMA_FILTER_X86]);

                        // Show the start offset only when really needed.
                        if (opt != NULL && opt->start_offset != 0)
                                my_snprintf(&pos, &left, "=start=%" PRIu32,
                                                opt->start_offset);

                        break;
                }

                case LZMA_FILTER_DELTA: {
                        const lzma_options_delta *opt = filters[i].options;
                        my_snprintf(&pos, &left, "delta=dist=%" PRIu32,
                                        opt->dist);
                        break;
                }

                default:
                        // This should be possible only if liblzma is
                        // newer than the xz tool.
                        my_snprintf(&pos, &left, "UNKNOWN");
                        break;
                }
        }

        return;
}


extern void
message_filters_show(enum message_verbosity v, const lzma_filter *filters)
{
        if (v > verbosity)
                return;

        char buf[FILTERS_STR_SIZE];
        message_filters_to_str(buf, filters, true);
        fprintf(stderr, _("%s: Filter chain: %s\n"), progname, buf);
        return;
}


extern void
message_try_help(void)
{
        // Print this with V_WARNING instead of V_ERROR to prevent it from
        // showing up when --quiet has been specified.
        message(V_WARNING, _("Try `%s --help' for more information."),
                        progname);
        return;
}


extern void
message_version(void)
{
        // It is possible that liblzma version is different than the command
        // line tool version, so print both.
        if (opt_robot) {
                printf("XZ_VERSION=%d\nLIBLZMA_VERSION=%d\n",
                                LZMA_VERSION, lzma_version_number());
        } else {
                printf("xz (" PACKAGE_NAME ") " LZMA_VERSION_STRING "\n");
                printf("liblzma %s\n", lzma_version_string());
        }

        tuklib_exit(E_SUCCESS, E_ERROR, verbosity != V_SILENT);
}


extern void
message_help(bool long_help)
{
        printf(_("Usage: %s [OPTION]... [FILE]...\n"
                        "Compress or decompress FILEs in the .xz format.\n\n"),
                        progname);

        // NOTE: The short help doesn't currently have options that
        // take arguments.
        if (long_help)
                puts(_("Mandatory arguments to long options are mandatory "
                                "for short options too.\n"));

        if (long_help)
                puts(_(" Operation mode:\n"));

        puts(_(
"  -z, --compress      force compression\n"
"  -d, --decompress    force decompression\n"
"  -t, --test          test compressed file integrity\n"
"  -l, --list          list information about .xz files"));

        if (long_help)
                puts(_("\n Operation modifiers:\n"));

        puts(_(
"  -k, --keep          keep (don't delete) input files\n"
"  -f, --force         force overwrite of output file and (de)compress links\n"
"  -c, --stdout        write to standard output and don't delete input files"));

        if (long_help)
                puts(_(
"      --no-sparse     do not create sparse files when decompressing\n"
"  -S, --suffix=.SUF   use the suffix `.SUF' on compressed files\n"
"      --files[=FILE]  read filenames to process from FILE; if FILE is\n"
"                      omitted, filenames are read from the standard input;\n"
"                      filenames must be terminated with the newline character\n"
"      --files0[=FILE] like --files but use the null character as terminator"));

        if (long_help) {
                puts(_("\n Basic file format and compression options:\n"));
                puts(_(
"  -F, --format=FMT    file format to encode or decode; possible values are\n"
"                      `auto' (default), `xz', `lzma', and `raw'\n"
"  -C, --check=CHECK   integrity check type: `none' (use with caution),\n"
"                      `crc32', `crc64' (default), or `sha256'"));
        }

        puts(_(
"  -0 ... -9           compression preset; default is 6; take compressor *and*\n"
"                      decompressor memory usage into account before using 7-9!"));

        puts(_(
"  -e, --extreme       try to improve compression ratio by using more CPU time;\n"
"                      does not affect decompressor memory requirements"));

        if (long_help) {
                puts(_( // xgettext:no-c-format
"      --memlimit-compress=LIMIT\n"
"      --memlimit-decompress=LIMIT\n"
"  -M, --memlimit=LIMIT\n"
"                      set memory usage limit for compression, decompression,\n"
"                      or both; LIMIT is in bytes, % of RAM, or 0 for defaults"));

                puts(_(
"      --no-adjust     if compression settings exceed the memory usage limit,\n"
"                      give an error instead of adjusting the settings downwards"));
        }

        if (long_help) {
                puts(_(
"\n Custom filter chain for compression (alternative for using presets):"));

#if defined(HAVE_ENCODER_LZMA1) || defined(HAVE_DECODER_LZMA1) \
                || defined(HAVE_ENCODER_LZMA2) || defined(HAVE_DECODER_LZMA2)
                puts(_(
"\n"
"  --lzma1[=OPTS]      LZMA1 or LZMA2; OPTS is a comma-separated list of zero or\n"
"  --lzma2[=OPTS]      more of the following options (valid values; default):\n"
"                        preset=PRE reset options to a preset (0-9[e])\n"
"                        dict=NUM   dictionary size (4KiB - 1536MiB; 8MiB)\n"
"                        lc=NUM     number of literal context bits (0-4; 3)\n"
"                        lp=NUM     number of literal position bits (0-4; 0)\n"
"                        pb=NUM     number of position bits (0-4; 2)\n"
"                        mode=MODE  compression mode (fast, normal; normal)\n"
"                        nice=NUM   nice length of a match (2-273; 64)\n"
"                        mf=NAME    match finder (hc3, hc4, bt2, bt3, bt4; bt4)\n"
"                        depth=NUM  maximum search depth; 0=automatic (default)"));
#endif

                puts(_(
"\n"
"  --x86[=OPTS]        x86 BCJ filter (32-bit and 64-bit)\n"
"  --powerpc[=OPTS]    PowerPC BCJ filter (big endian only)\n"
"  --ia64[=OPTS]       IA-64 (Itanium) BCJ filter\n"
"  --arm[=OPTS]        ARM BCJ filter (little endian only)\n"
"  --armthumb[=OPTS]   ARM-Thumb BCJ filter (little endian only)\n"
"  --sparc[=OPTS]      SPARC BCJ filter\n"
"                      Valid OPTS for all BCJ filters:\n"
"                        start=NUM  start offset for conversions (default=0)"));

#if defined(HAVE_ENCODER_DELTA) || defined(HAVE_DECODER_DELTA)
                puts(_(
"\n"
"  --delta[=OPTS]      Delta filter; valid OPTS (valid values; default):\n"
"                        dist=NUM   distance between bytes being subtracted\n"
"                                   from each other (1-256; 1)"));
#endif
        }

        if (long_help)
                puts(_("\n Other options:\n"));

        puts(_(
"  -q, --quiet         suppress warnings; specify twice to suppress errors too\n"
"  -v, --verbose       be verbose; specify twice for even more verbose"));

        if (long_help) {
                puts(_(
"  -Q, --no-warn       make warnings not affect the exit status"));
                puts(_(
"      --robot         use machine-parsable messages (useful for scripts)"));
                puts("");
                puts(_(
"      --info-memory   display the total amount of RAM and the currently active\n"
"                      memory usage limits, and exit"));
                puts(_(
"  -h, --help          display the short help (lists only the basic options)\n"
"  -H, --long-help     display this long help and exit"));
        } else {
                puts(_(
"  -h, --help          display this short help and exit\n"
"  -H, --long-help     display the long help (lists also the advanced options)"));
        }

        puts(_(
"  -V, --version       display the version number and exit"));

        puts(_("\nWith no FILE, or when FILE is -, read standard input.\n"));

        // TRANSLATORS: This message indicates the bug reporting address
        // for this package. Please add _another line_ saying
        // "Report translation bugs to <...>\n" with the email or WWW
        // address for translation bugs. Thanks.
        printf(_("Report bugs to <%s> (in English or Finnish).\n"),
                        PACKAGE_BUGREPORT);
        printf(_("%s home page: <%s>\n"), PACKAGE_NAME, PACKAGE_URL);

        tuklib_exit(E_SUCCESS, E_ERROR, verbosity != V_SILENT);
}