rpn.c

VLC Player Source Code

/*****************************************************************************
 * rpn.c : RPN evaluator for the HTTP Interface
 *****************************************************************************
 * Copyright (C) 2001-2006 the VideoLAN team
 * $Id: 712b145d7b8af8c486b249de0be152442221eca1 $
 *
 * Authors: Gildas Bazin <[e-mail]>
 *          Laurent Aimar <[e-mail]>
 *          Christophe Massiot <[e-mail]>
 *
 * 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
 * (at your option) 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.
 *****************************************************************************/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif

#include "http.h"
#include "vlc_url.h"
#include "vlc_meta.h"
#include "vlc_strings.h"

static vlc_object_t *GetVLCObject( intf_thread_t *p_intf,
                                   const char *psz_object,
                                   bool *pb_need_release )
{
    intf_sys_t    *p_sys = p_intf->p_sys;
    int i_object_type = 0;
    vlc_object_t *p_object = NULL;
    *pb_need_release = false;

    if( !strcmp( psz_object, "VLC_OBJECT_LIBVLC" ) )
        p_object = VLC_OBJECT(p_intf->p_libvlc);
    else if( !strcmp( psz_object, "VLC_OBJECT_INTF" ) )
        p_object = VLC_OBJECT(p_intf);
    else if( !strcmp( psz_object, "VLC_OBJECT_PLAYLIST" ) )
        p_object = VLC_OBJECT(p_sys->p_playlist);
    else if( !strcmp( psz_object, "VLC_OBJECT_INPUT" ) )
        p_object = VLC_OBJECT(p_sys->p_input);
    else if( !strcmp( psz_object, "VLC_OBJECT_VOUT" ) )
        i_object_type = VLC_OBJECT_VOUT;
    else if( !strcmp( psz_object, "VLC_OBJECT_AOUT" ) )
        i_object_type = VLC_OBJECT_AOUT;
    else
        msg_Warn( p_intf, "unknown object type (%s)", psz_object );

    if( p_object == NULL && i_object_type )
    {
        *pb_need_release = true;
        p_object = vlc_object_find( p_intf, i_object_type, FIND_ANYWHERE );
    }

    return p_object;
}

void SSInit( rpn_stack_t *st )
{
    st->i_stack = 0;
}

void SSClean( rpn_stack_t *st )
{
    while( st->i_stack > 0 )
    {
        free( st->stack[--st->i_stack] );
    }
}

void SSPush( rpn_stack_t *st, const char *s )
{
    if( st->i_stack < STACK_MAX )
    {
        st->stack[st->i_stack++] = strdup( s );
    }
}

char *SSPop( rpn_stack_t *st )
{
    if( st->i_stack <= 0 )
    {
        return strdup( "" );
    }
    else
    {
        return st->stack[--st->i_stack];
    }
}

int SSPopN( rpn_stack_t *st, mvar_t  *vars )
{
    char *name;
    char *value;

    char *end;
    int  i;

    name = SSPop( st );
    i = strtol( name, &end, 0 );
    if( end == name )
    {
        value = mvar_GetValue( vars, name );
        i = atoi( value );
    }
    free( name );

    return( i );
}

void SSPushN( rpn_stack_t *st, int i )
{
    char v[12];

    snprintf( v, sizeof (v), "%d", i );
    SSPush( st, v );
}

void EvaluateRPN( intf_thread_t *p_intf, mvar_t  *vars,
                      rpn_stack_t *st, char *exp )
{
    intf_sys_t    *p_sys = p_intf->p_sys;

    while( exp != NULL && *exp != '\0' )
    {
        char *p, *s;

        /* skip space */
        while( *exp == ' ' )
        {
            exp++;
        }

        if( *exp == '\'' )
        {
            /* extract string */
            p = FirstWord( exp, exp );
            SSPush( st, exp );
            exp = p;
            continue;
        }

        /* extract token */
        p = FirstWord( exp, exp );
        s = exp;
        if( p == NULL )
        {
            exp += strlen( exp );
        }
        else
        {
            exp = p;
        }

        if( *s == '\0' )
        {
            break;
        }

        /* 1. Integer function */
        if( !strcmp( s, "!" ) )
        {
            SSPushN( st, ~SSPopN( st, vars ) );
        }
        else if( !strcmp( s, "^" ) )
        {
            SSPushN( st, SSPopN( st, vars ) ^ SSPopN( st, vars ) );
        }
        else if( !strcmp( s, "&" ) )
        {
            SSPushN( st, SSPopN( st, vars ) & SSPopN( st, vars ) );
        }
        else if( !strcmp( s, "|" ) )
        {
            SSPushN( st, SSPopN( st, vars ) | SSPopN( st, vars ) );
        }
        else if( !strcmp( s, "+" ) )
        {
            SSPushN( st, SSPopN( st, vars ) + SSPopN( st, vars ) );
        }
        else if( !strcmp( s, "-" ) )
        {
            int j = SSPopN( st, vars );
            int i = SSPopN( st, vars );
            SSPushN( st, i - j );
        }
        else if( !strcmp( s, "*" ) )
        {
            SSPushN( st, SSPopN( st, vars ) * SSPopN( st, vars ) );
        }
        else if( !strcmp( s, "/" ) )
        {
            int i, j;

            j = SSPopN( st, vars );
            i = SSPopN( st, vars );

            SSPushN( st, j != 0 ? i / j : 0 );
        }
        else if( !strcmp( s, "%" ) )
        {
            int i, j;

            j = SSPopN( st, vars );
            i = SSPopN( st, vars );

            SSPushN( st, j != 0 ? i % j : 0 );
        }
        /* 2. integer tests */
        else if( !strcmp( s, "=" ) )
        {
            SSPushN( st, SSPopN( st, vars ) == SSPopN( st, vars ) ? -1 : 0 );
        }
        else if( !strcmp( s, "!=" ) )
        {
            SSPushN( st, SSPopN( st, vars ) != SSPopN( st, vars ) ? -1 : 0 );
        }
        else if( !strcmp( s, "<" ) )
        {
            int j = SSPopN( st, vars );
            int i = SSPopN( st, vars );

            SSPushN( st, i < j ? -1 : 0 );
        }
        else if( !strcmp( s, ">" ) )
        {
            int j = SSPopN( st, vars );
            int i = SSPopN( st, vars );

            SSPushN( st, i > j ? -1 : 0 );
        }
        else if( !strcmp( s, "<=" ) )
        {
            int j = SSPopN( st, vars );
            int i = SSPopN( st, vars );

            SSPushN( st, i <= j ? -1 : 0 );
        }
        else if( !strcmp( s, ">=" ) )
        {
            int j = SSPopN( st, vars );
            int i = SSPopN( st, vars );

            SSPushN( st, i >= j ? -1 : 0 );
        }
        /* 3. string functions */
        else if( !strcmp( s, "strcat" ) )
        {
            char *s2 = SSPop( st );
            char *s1 = SSPop( st );
            char *str = malloc( strlen( s1 ) + strlen( s2 ) + 1 );

            strcpy( str, s1 );
            strcat( str, s2 );

            SSPush( st, str );
            free( s1 );
            free( s2 );
            free( str );
        }
        else if( !strcmp( s, "strcmp" ) )
        {
            char *s2 = SSPop( st );
            char *s1 = SSPop( st );

            SSPushN( st, strcmp( s1, s2 ) );
            free( s1 );
            free( s2 );
        }
        else if( !strcmp( s, "strncmp" ) )
        {
            int n = SSPopN( st, vars );
            char *s2 = SSPop( st );
            char *s1 = SSPop( st );

            SSPushN( st, strncmp( s1, s2 , n ) );
            free( s1 );
            free( s2 );
        }
        else if( !strcmp( s, "strsub" ) )
        {
            int n = SSPopN( st, vars );
            int m = SSPopN( st, vars );
            int i_len;
            char *s = SSPop( st );
            char *str;

            if( n >= m )
            {
                i_len = n - m + 1;
            }
            else
            {
                i_len = 0;
            }

            str = malloc( i_len + 1 );

            memcpy( str, s + m - 1, i_len );
            str[ i_len ] = '\0';

            SSPush( st, str );
            free( s );
            free( str );
        }
        else if( !strcmp( s, "strlen" ) )
        {
            char *str = SSPop( st );

            SSPushN( st, strlen( str ) );
            free( str );
        }
        else if( !strcmp( s, "str_replace" ) )
        {
            char *psz_to = SSPop( st );
            char *psz_from = SSPop( st );
            char *psz_in = SSPop( st );
            char *psz_in_current = psz_in;
            char *psz_out = malloc( strlen(psz_in) * strlen(psz_to) + 1 );
            char *psz_out_current = psz_out;

            while( (p = strstr( psz_in_current, psz_from )) != NULL )
            {
                memcpy( psz_out_current, psz_in_current, p - psz_in_current );
                psz_out_current += p - psz_in_current;
                strcpy( psz_out_current, psz_to );
                psz_out_current += strlen(psz_to);
                psz_in_current = p + strlen(psz_from);
            }
            strcpy( psz_out_current, psz_in_current );
            psz_out_current += strlen(psz_in_current);
            *psz_out_current = '\0';

            SSPush( st, psz_out );
            free( psz_to );
            free( psz_from );
            free( psz_in );
            free( psz_out );
        }
        else if( !strcmp( s, "url_extract" ) )
        {
            char *url = mvar_GetValue( vars, "url_value" );
            char *name = SSPop( st );
            char *value = ExtractURIString( url, name );
            if( value != NULL )
            {
                decode_URI( value );
                SSPush( st, value );
                free( value );
            }
            else
                SSPush( st, "" );

            free( name );
        }
        else if( !strcmp( s, "url_encode" ) )