hre_api.c

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

/* 
 *  hre_api.c:        Implementation of HRE API
 *  Author:           James &
 *  Created On:       Wed Dec  9 13:49:14 1992
 *  Last Modified By: James Kempf
 *  Last Modified On: Fri Sep 23 13:49:04 1994
 *  Update Count:     137
 *  Copyright (c) 1994 by Sun Microsystems Computer Company
 *  All rights reserved.
 *  
 *  Use and copying of this software and preparation of 
 *  derivative works based upon this software are permitted.
 *  Any distribution of this software or derivative works
 *  must comply with all applicable United States export control
 *  laws.
 *
 *  This software is made available as is, and Sun Microsystems
 *  Computer Company makes no warranty about the software, its
 *  performance, or its conformity to any specification
 */

#include <u.h>
#include <libc.h>
#include <draw.h>
#include <scribble.h>

#include "scribbleimpl.h"
#include "hre_internal.h"

/* ari -- prototype for rii function */
recognizer __recognizer_internal_initialize(rec_info* ri);

/*Version number of API.*/

char* REC_VERSION = "2.0";

/*Domain name for internationalized text.*/

#define INTL_DOMAIN "recognition_manager"

/* XXX -- Intl Hack -- Jay & Ari */
#define	dgettext(domain, msg)	(msg)
#define	bindtextdomain(dirname,	domain)

/*
 * These magic numbers are used to ensure the integrity of the
 * recognizer structure.
*/


#define REC_MAGIC       0xfeed
#define REC_END_MAGIC   0xbeef

/*Check the recognizer for validity*/

#define RI_CHECK_MAGIC(rec) \
  ( (rec != nil) && \
    (((recognizer)rec)->recognizer_magic == REC_MAGIC) && \
   (((recognizer)rec)->recognizer_end_magic == REC_END_MAGIC) &&\
   (((recognizer)rec)->recognizer_version == REC_VERSION) )

/*The name of the initialization & finalization functions.*/

/* static char rii_name[] = "__recognizer_internal_initialize";
static char rif_name[] = "__recognizer_internal_finalize";  */

/*User home directory for recognizer info.*/
/* ari -- changed USERRECHOME from ".recognizers" */
#define HOME "HOME"
#define USERRECHOME ".classifiers"

/*Local functions*/

static char* shared_library_name(char* directory,char* locale,char* name);
static rec_info* make_rec_info(char* directory,char* name,char** subset);
static void delete_rec_info(rec_info* ri);
static int check_for_user_home(void);
static void intl_initialize(void);

static void cleanup_rec_element(rec_element* re,bool delete_points_p);

/*The last error.*/

static char* the_last_error = nil;

static char *safe_malloc (int nbytes)
{
  char *res = malloc(nbytes);
  if (res == nil) {
    sysfatal("malloc failure");
  }
  return (res);
}


/*
 * Implementation of API functions
*/

/*
 * recognizer_load - Load the recognizer matching the rec_info struct.
 * If name is not null, then load the recognizer having that name. Returns
 * the recognizer object, or null if it can't load the recognizer, and
 * sets errno to indicate why.
*/

recognizer 
recognizer_load(char* directory, char* name, char** subset)
{
    recognizer	rec;				/*the recognizer*/
    rec_info*	rinf;				/*rec_info for recognizer information*/
    static bool	intl_init = false;	/*true if recog. manager initted.*/

    if( intl_init == false ) {
      intl_init = true;
      intl_initialize();
    }

    /*The name takes precedence.*/
    rinf = make_rec_info(directory, name, subset);
    if (rinf == nil) {
	the_last_error = 
	  dgettext(INTL_DOMAIN,
		   "Ran out of memory during prelinking initialization.");
	return((recognizer)nil);
    } 
/* fprint(2, "Got past make_rec_info.\n"); */

    /*Let recognition code create recognizer and initialize*/
    rec = __recognizer_internal_initialize(rinf);
    if (rec == nil) {
	return((recognizer)nil);
    }
/* fprint(2, "Did rii.\n"); */
    /*Check whether it's been correctly initialized*/

    if( rec->recognizer_load_state == nil ||
        rec->recognizer_save_state == nil ||
        rec->recognizer_load_dictionary == nil ||
        rec->recognizer_save_dictionary == nil ||
        rec->recognizer_free_dictionary == nil ||
        rec->recognizer_add_to_dictionary == nil ||
        rec->recognizer_delete_from_dictionary == nil ||
        rec->recognizer_error == nil ||
        rec->recognizer_set_context == nil ||
        rec->recognizer_get_context == nil ||
        rec->recognizer_clear == nil ||
        rec->recognizer_get_buffer == nil ||
        rec->recognizer_set_buffer == nil ||
        rec->recognizer_translate == nil ||
        rec->recognizer_get_extension_functions == nil ||
        rec->recognizer_get_gesture_names == nil ||
        rec->recognizer_set_gesture_action == nil
       ) {

	recognizer_unload(rec);
/* fprint(2, "Unloading b/c null function pointer.\n"); */
	the_last_error = 
	  dgettext(INTL_DOMAIN,
		   "One or more recognizer function pointers is nil.");
	return((recognizer)nil);
    }


    /*Set the rec_info structure.*/

    rec->recognizer_info = rinf;

    /*Check whether home directory is there for recognizer info.*/

/*
 *  ari -- don't bother.  We're not going to load from each user's
 *  home directory at this point.  Instead, we'll use a stupid
 *  little a-b-c file because it loads FAST.
 *
 *    if( check_for_user_home() < 0 ) {
 *	recognizer_unload(rec);
 *	return((recognizer)nil);
 *   }
 */
    /*We got it!*/
/* fprint(2, "Done.\n"); */

    return(rec);
}

/*
 * recognizer_unload - Unload the recognizer.
*/

int
recognizer_unload(recognizer rec)
{
    /*Make sure magic numbers right.*/
    
	if( !RI_CHECK_MAGIC(rec) ) {
		the_last_error = dgettext(INTL_DOMAIN,"Bad recognizer object.");
		return(-1);
	}
    
	return __recognizer_internal_finalize(rec);
}

/*
 * recognizer_load_state-Get any recognizer state associated with name
 * in dir. Note that name may not be simple file name, since
 * there may be more than one file involved. Return 0 if successful,
 * -1 if not.
*/

int recognizer_load_state(recognizer rec, char* dir, char* name)
{
    /*Make sure magic numbers right.*/

    if( !RI_CHECK_MAGIC(rec) ) {
		the_last_error = dgettext(INTL_DOMAIN,"Bad recognizer object.");
		return(-1);
    }

    /*Do the function.*/

    return(rec->recognizer_load_state(rec, dir, name));
}

/*
 * recognizer_save_state-Save any recognizer state to name
 * in dir. Note that name may not be a simple file name, since
 * there may be more than one file involved. Return 0 if successful,
 * -1 if not.
*/

int recognizer_save_state(recognizer rec,char* dir,char* name)
{
    /*Make sure magic numbers right.*/

    if( !RI_CHECK_MAGIC(rec) ) {
	the_last_error = dgettext(INTL_DOMAIN,"Bad recognizer object.");
	return(-1);
    }

    /*Do the function.*/

    return(rec->recognizer_save_state(rec,dir,name));
}

/*
 * recognizer_load_dictionary-Load dictionary, return pointer
 * to it, or nil if error.
*/

wordset recognizer_load_dictionary(recognizer rec,char* dir,char* name)
{
    /*Make sure magic numbers right.*/

    if( !RI_CHECK_MAGIC(rec) ) {
	the_last_error = dgettext(INTL_DOMAIN,"Bad recognizer object.");
	return(nil);
    }

    /*Do the function.*/

    return(rec->recognizer_load_dictionary(rec,dir,name));
}

/*
 * recognizer_save_dictionary-Save the  dictionary to the file, return 0 if
 * OK, -1 if error.
*/

int recognizer_save_dictionary(recognizer rec,char* dir,char* name,wordset dict)
{
    /*Make sure magic numbers right.*/

    if( !RI_CHECK_MAGIC(rec) ) {
	the_last_error = dgettext(INTL_DOMAIN,"Bad recognizer object.");
	return(-1);
    }

    /*Do the function.*/

    return(rec->recognizer_save_dictionary(rec,dir,name,dict));
}

/*
 * recognizer_free_dictionary-Free the dictionary, return 0 if
 * OK, -1 if error.
*/

int recognizer_free_dictionary(recognizer rec,wordset dict)
{
    /*Make sure magic numbers right.*/

    if( !RI_CHECK_MAGIC(rec) ) {
	the_last_error = dgettext(INTL_DOMAIN,"Bad recognizer object.");
	return(-1);
    }

    /*Do the function.*/

    return(rec->recognizer_free_dictionary(rec,dict));
}

/*
 * recognizer_add_to_dictionary-Add word to the dictionary,
 * return 0 if OK, -1 if error.
*/


int recognizer_add_to_dictionary(recognizer rec,letterset* word,wordset dict)
{
    /*Make sure magic numbers right.*/

    if( !RI_CHECK_MAGIC(rec) ) {
	the_last_error = dgettext(INTL_DOMAIN,"Bad recognizer object.");
	return(-1);
    }

    /*Do the function.*/

    return(rec->recognizer_add_to_dictionary(rec,word,dict));
}

/*
 * recognizer_delete_from_dictionary-Delete word from the dictionary,
 * return 0 if OK, -1 if error.
*/

int 
recognizer_delete_from_dictionary(recognizer rec,letterset* word,wordset dict)
{
    /*Make sure magic numbers right.*/

    if( !RI_CHECK_MAGIC(rec) ) {
	the_last_error = dgettext(INTL_DOMAIN,"Bad recognizer object.");
	return(-1);
    }

    /*Do the function.*/

    return(rec->recognizer_delete_from_dictionary(rec,word,dict));
}

/*
 * recognizer_get_info-Get a pointers to the rec_info
 * giving the locales and subsets supported by the recognizer
 * and the shared library pathname.
*/

const rec_info*
recognizer_get_info(recognizer rec)
{
    /*Make sure magic numbers right.*/

    if( !RI_CHECK_MAGIC(rec) ) {
	the_last_error = dgettext(INTL_DOMAIN,"Bad recognizer object.");
	return((rec_info*)nil);
    }

    /*Return the rec_info object.*/

    return(rec->recognizer_info);
}

/*
 * recognizer_manager_version-Return the version number string of the
 * recognition manager.
*/

const char* recognizer_manager_version(recognizer rec)
{
    /*Make sure magic numbers right.*/

    if( !RI_CHECK_MAGIC(rec) ) {
	the_last_error = dgettext(INTL_DOMAIN,"Bad recognizer object.");
	return(nil);
    }

    return(rec->recognizer_version);
  
}
/*
 * recognizer_error-Return the last error message, or nil if none.
*/

char* recognizer_error(recognizer rec)
{
    
    /*Make sure magic numbers right and function there.*/

    if( !RI_CHECK_MAGIC(rec) && the_last_error == nil ) {
      return(dgettext(INTL_DOMAIN,"Bad recognizer object."));

    } else if( the_last_error != nil ) {
      char* error = the_last_error;

      the_last_error = nil;
      return(error);
    }

    /*Do the function.*/

    return(rec->recognizer_error(rec));
}

/*
 * recognizer_set_context-Set the recognition context for translation.
 * Return 0 if successful, -1 if error.
*/

int recognizer_set_context(recognizer rec,rc* rec_xt)
{

    /*Make sure magic numbers right.*/

    if( !RI_CHECK_MAGIC(rec) ) {
	the_last_error = dgettext(INTL_DOMAIN,"Bad recognizer object.");
	return(-1);
    }

    /*Do the function.*/

    return(rec->recognizer_set_context(rec,rec_xt));
}

/* 
 * recognzier_get_context-Get the recognition context for translation.
 * If none or error, return nil.
*/

rc* recognizer_get_context(recognizer rec)
{

    /*Make sure magic numbers right.*/

    if( !RI_CHECK_MAGIC(rec) ) {
	the_last_error = dgettext(INTL_DOMAIN,"Bad recognizer object.");
	return(nil);
    }

    /*Do the function.*/

    return(rec->recognizer_get_context(rec));
}

/*
 * recognizer_clear-Clear buffer and recognition context.
 * Return 0 if success, else -1.
*/

int recognizer_clear(recognizer rec,bool delete_points_p)
{

    /*Make sure magic numbers right.*/

    if( !RI_CHECK_MAGIC(rec) ) {
	the_last_error = dgettext(INTL_DOMAIN,"Bad recognizer object.");
	return(-1);
    }

    /*Do the function.*/

    return(rec->recognizer_clear(rec,delete_points_p));
}

/*recognizer_get_buffer-Get stroke buffer. Return 0 if success, else -1.*/


int recognizer_get_buffer(recognizer rec, uint* nstrokes,Stroke** strokes)
{

    /*Make sure magic numbers right.*/

    if( !RI_CHECK_MAGIC(rec) ) {
	the_last_error = dgettext(INTL_DOMAIN,"Bad recognizer object.");
	return(-1);
    }

    /*Do the function.*/

    return(rec->recognizer_get_buffer(rec,nstrokes,strokes));

}

/*
 * recognizer_set_buffer-Set stroke buffer to arg. Return 0 if success, else 
 * return -1.
*/

int recognizer_set_buffer(recognizer rec,uint nstrokes,Stroke* strokes)
{

    /*Make sure magic numbers right.*/

    if( !RI_CHECK_MAGIC(rec) ) {
	the_last_error = dgettext(INTL_DOMAIN,"Bad recognizer object.");
	return(-1);
    }

    /*Do the function.*/

    return(rec->recognizer_set_buffer(rec,nstrokes,strokes));

}

/*
 * recognizer_translate-Translate the strokes in the current context, including
 * buffered strokes. If nstrokes == 0 or strokes == nil, return 
 * translation of stroke buffer.
*/

int recognizer_translate(recognizer rec,
			 uint nstrokes,
			 Stroke* strokes,
			 bool correlate_p,
			 int* nret,
			 rec_alternative** ret)
{
    int retval;
    char msg[80];
    /*Make sure magic numbers right.*/

    if( !RI_CHECK_MAGIC(rec) ) {
	the_last_error = dgettext(INTL_DOMAIN, msg);
	return(-1);
    }

/* ari */
/*    {
 *      uint i;
 *      Stroke ari_pstr;
 *      pen_point* ari_pts;
 *      int ari;
 *      for (i = 0; i < nstrokes; i++) {
 *	ari_pstr = strokes[i];
 *	ari_pts = ari_pstr.ps_pts;
 *	fprint(2, "\nrecognizer_translate: ari_pts = %ld, sizeof(Time) = %d, sizeof(ari_pts[0] = %d, %d points are...\n", ari_pts, sizeof(Time), sizeof(ari_pts[0]), ari_pstr.ps_npts);
 *	for (ari = 0; ari < ari_pstr.ps_npts; ari++)
 *	   fprint(2, "%ld -- (%d, %d)  ", ari_pts[ari], ari_pts[ari].x, ari_pts[ari].y);
 *      }
 *    }     
*/
    /*Do the function.*/
/* ari -- this is calling cmu_recognizer_translate */
    retval = rec->recognizer_translate(rec,
				     nstrokes,
				     strokes,
				     correlate_p,
				     nret,
				     ret);
    return (retval);
}


/*
 * recognizer_get_extension_functions-Return a null terminated array
 * of functions providing extended functionality. Their interfaces
 * will change depending on the recognizer.
*/

rec_fn* recognizer_get_extension_functions(recognizer rec)
{
    /*Make sure magic numbers right.*/

    if( !RI_CHECK_MAGIC(rec) ) {
	the_last_error = dgettext(INTL_DOMAIN,"Bad recognizer object.");
	return((rec_fn*)nil);
    }

    /*Do the function.*/

    return(rec->recognizer_get_extension_functions(rec));
}


/*
 * recognizer_get_gesture_names - Return a null terminated array of
 * gesture name strings.
*/

char**
recognizer_get_gesture_names(recognizer rec)
{
    /*Make sure magic numbers right.*/

    if( !RI_CHECK_MAGIC(rec) ) {
	the_last_error = dgettext(INTL_DOMAIN,"Bad recognizer object.");
	return(nil);
    }

    /*Do the function.*/

    return(rec->recognizer_get_gesture_names(rec));
}

/*
 * recognizer_set_gesture_action-Set the action function for the gesture.
*/

xgesture 
recognizer_train_gestures(recognizer rec,char* name,xgesture fn,void* wsinfo)
{
    /*Make sure magic numbers right.*/

    if( !RI_CHECK_MAGIC(rec) ) {
	the_last_error = dgettext(INTL_DOMAIN,"Bad recognizer object.");
	return((xgesture)-1);
    }

    /*Do the function.*/

    return(rec->recognizer_set_gesture_action(rec,name,fn,wsinfo));
}

/*
 * Local functions.
*/

/*
 * shared_library_name-Get the full pathname to the shared library,
 *    based on the recognizer name and the environment.
*/


static char* shared_library_name(char* directory,char* locale,char* name)
{
    char* ret;
    int len = strlen(name);

    /*If directory is there, it takes precedence.*/

    if( directory != nil ) {
		ret = (char*)safe_malloc(strlen(directory) + len + 2);
		strcpy(ret,directory);
		strcat(ret,"/");
		strcat(ret,name);
    } else {
		char* dir;
	
		/*First try the environment variable.*/
	
		if( (dir = getenv(RECHOME)) == nil ) {
		    dir = "REC_DEFAULT_HOME_DIR";
	
		  }
	
		ret = (char*)safe_malloc(strlen(dir) + strlen(locale) + len + 3);
		/*Form the pathname.*/
		strcpy(ret,dir);
		strcat(ret,"/");
		strcat(ret,locale);
		strcat(ret,"/");