monojob.c

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/*
 * Copyright (C) 2007 Michael Brown <mbrown@fensystems.co.uk>.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of the
 * License, or any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 *
 * You can also choose to distribute this program under the terms of
 * the Unmodified Binary Distribution Licence (as given in the file
 * COPYING.UBDL), provided that you have satisfied its requirements.
 */

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );

#include <string.h>
#include <stdio.h>
#include <errno.h>
#include <ipxe/process.h>
#include <ipxe/console.h>
#include <ipxe/keys.h>
#include <ipxe/job.h>
#include <ipxe/monojob.h>
#include <ipxe/timer.h>

/** @file
 *
 * Single foreground job
 *
 */

static int monojob_rc;

static void monojob_close ( struct interface *intf, int rc ) {
        monojob_rc = rc;
        intf_restart ( intf, rc );
}

static struct interface_operation monojob_intf_op[] = {
        INTF_OP ( intf_close, struct interface *, monojob_close ),
};

static struct interface_descriptor monojob_intf_desc =
        INTF_DESC_PURE ( monojob_intf_op );

struct interface monojob = INTF_INIT ( monojob_intf_desc );

/**
 * Clear previously displayed message
 *
 * @v len               Length of previously displayed message
 */
static void monojob_clear ( size_t len ) {
        unsigned int i;

        for ( i = 0 ; i < len ; i++ )
                putchar ( '\b' );
        for ( i = 0 ; i < len ; i++ )
                putchar ( ' ' );
        for ( i = 0 ; i < len ; i++ )
                putchar ( '\b' );
}

/**
 * Wait for single foreground job to complete
 *
 * @v string            Job description to display, or NULL to be silent
 * @v timeout           Timeout period, in ticks (0=indefinite)
 * @ret rc              Job final status code
 */
int monojob_wait ( const char *string, unsigned long timeout ) {
        struct job_progress progress;
        unsigned long last_check;
        unsigned long last_progress;
        unsigned long last_display;
        unsigned long now;
        unsigned long elapsed;
        unsigned long completed = 0;
        unsigned long scaled_completed;
        unsigned long scaled_total;
        unsigned int percentage;
        size_t clear_len = 0;
        int ongoing_rc;
        int key;
        int rc;

        if ( string )
                printf ( "%s...", string );
        monojob_rc = -EINPROGRESS;
        last_check = last_progress = last_display = currticks();
        while ( monojob_rc == -EINPROGRESS ) {

                /* Allow job to progress */
                step();
                now = currticks();

                /* Continue until a timer tick occurs (to minimise
                 * time wasted checking for progress and keypresses).
                 */
                elapsed = ( now - last_check );
                if ( ! elapsed )
                        continue;
                last_check = now;

                /* Check for keypresses */
                if ( iskey() ) {
                        key = getchar();
                        if ( key == CTRL_C ) {
                                monojob_rc = -ECANCELED;
                                break;
                        }
                }

                /* Monitor progress */
                ongoing_rc = job_progress ( &monojob, &progress );

                /* Reset timeout if progress has been made */
                if ( completed != progress.completed )
                        last_progress = now;
                completed = progress.completed;

                /* Check for timeout, if applicable */
                elapsed = ( now - last_progress );
                if ( timeout && ( elapsed >= timeout ) ) {
                        monojob_rc = ( ongoing_rc ? ongoing_rc : -ETIMEDOUT );
                        break;
                }

                /* Display progress, if applicable */
                elapsed = ( now - last_display );
                if ( string && ( elapsed >= TICKS_PER_SEC ) ) {
                        monojob_clear ( clear_len );
                        /* Normalise progress figures to avoid overflow */
                        scaled_completed = ( progress.completed / 128 );
                        scaled_total = ( progress.total / 128 );
                        if ( scaled_total ) {
                                percentage = ( ( 100 * scaled_completed ) /
                                               scaled_total );
                                clear_len = printf ( "%3d%%", percentage );
                        } else {
                                printf ( "." );
                                clear_len = 0;
                        }
                        if ( progress.message[0] ) {
                                clear_len += printf ( " [%s]",
                                                      progress.message );
                        }
                        last_display = now;
                }
        }
        rc = monojob_rc;
        monojob_close ( &monojob, rc );

        monojob_clear ( clear_len );
        if ( string ) {
                if ( rc ) {
                        printf ( " %s\n", strerror ( rc ) );
                } else {
                        printf ( " ok\n" );
                }
        }

        return rc;
}