/* Device.c V2.1  Module to remember and find devices...*/

/*
        This is part of ODS2 written by Paul Nankervis,
        email address:  Paulnank@au1.ibm.com

        ODS2 is distributed freely for all members of the
        VMS community to use. However all derived works
        must maintain comments in their source to acknowledge
        the contibution of the original author.
*/

/* Should have mechanism to return actual device name... */

/*  This module is simple enough - it just keeps track of
    device names and initialization... */

#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "access.h"
#include "cache.h"
#include "device.h"
#include "ssdef.h"

static void *device_create( unsigned devsiz, void *keyval, unsigned *retsts );
static int device_compare( unsigned keylen, void *keyval, void *node );

static struct DEV *dev_root = NULL;


/************************************************************ device_create() */

/* device_create() creates a device object... */

static void *device_create( unsigned devsiz, void *keyval, unsigned *retsts ) {

    register struct DEV *dev;

    dev = (struct DEV *) malloc( sizeof( struct DEV ) + devsiz + 1 );
    if ( dev == NULL ) {
        *retsts = SS$_INSFMEM;
        return NULL;
    }
    dev->cache.objmanager = NULL;
    dev->cache.objtype = OBJTYPE_DEV;
    dev->vcb = NULL;
    dev->access = 0;
    memcpy( dev->devnam, keyval, devsiz );
    memcpy( dev->devnam + devsiz, ":", 2 );
    *retsts = SS$_NORMAL;
    return dev;
}

/*********************************************************** device_compare() */

/* device_compare() compares a device name to that of a device object... */

static int device_compare( unsigned keylen, void *keyval, void *node ) {

    register int cmp;
    register const char *keynam = (const char *) keyval;
    register const char *devnam = ((const struct DEV *) node)->devnam;

    cmp = 0;
    while ( keylen-- > 0 ) {
        cmp = toupper( *keynam++ ) - toupper( *devnam++ );
        if ( cmp != 0 ) {
            break;
        }
    }
    if ( cmp == 0 && *devnam != '\0' && *devnam != ':' ) {
        cmp = -1;
    }
    return cmp;
}

/************************************************************ device_lookup() */

/* device_lookup() is to to find devices... */

unsigned device_lookup( unsigned devlen, char *devnam, int create,
                        struct DEV **retdev ) {

    unsigned sts, devsiz;
    register struct DEV *dev;

    for ( devsiz = 0; devsiz < devlen; devsiz++ ) {
        if ( devnam[devsiz] == ':' ) {
            break;
        }
    }
    dev = (struct DEV *) cache_find( (void *) &dev_root, devsiz, devnam, &sts,
                                     device_compare,
                                     create ? device_create : NULL );
    if ( dev == NULL ) {
        if ( sts == SS$_ITEMNOTFOUND ) {
            sts = SS$_NOSUCHDEV;
        }
    } else {
        *retdev = dev;
        sts = SS$_NORMAL;
    }
    return sts;
}