xhamster.c

数据挖掘中de一个算法 hamster的实例

  /* --- evaluate command --- */
  switch (cmd) {                /* evaluate command read */
    case '@':                   /* --- error in child process */
      stop((id) ? E_EXEC : E_POPEN);
      return;                   /* stop execution */

    case 'c':                   /* --- create hamster */
      if (hamster) {            /* if a hamster already exists */
        sprintf(hmscb[0].reply, "c -1\n");
        break;                  /* deny creation request and */
      }                         /* abort command evaluation */
      hmscb[0].sprite =         /* create a sprite */
        spr_create(w_maze, SPRITEWD, SPRITEWD, hms_bmap, red);
      if (!hmscb[0].sprite) { stop(E_NOMEM); return; }
      hmscb[0].hamster =        /* create a hamster */
      hamster = hms_create(maze, 0, HMS_EAST, hms_disp);
      if (!hamster) { stop(E_NOMEM); return; }
      hms_pos(hamster, &x, &y); /* get hamster position */
      sprintf(hmscb[0].reply, "c %d %d %d %d %d %d %d\n",
        hms_id(hamster), x, y, hms_dir(hamster), hms_look(hamster),
        hms_corn(hamster), hms_load(hamster));
      break;                    /* send hamster data */

    case 'd':                   /* --- delete hamster */
      fprintf(p_out, "d 0\n");  /* echo delete command, */
      fflush(p_out);            /* flush pipe buffer */
      stop(E_NONE); return;     /* and stop execution */

    case 'm':                   /* --- move hamster */
      hms_move(hamster);        /* move hamster forward */
      hms_pos(hamster, &x, &y); /* and get new position */
      sprintf(hmscb[id].reply, "m %d %d %d %d %d\n",
        hms_id(hamster), x, y, hms_look(hamster), hms_corn(hamster));
      break;                    /* reply with new hamster data */

    case 't':                   /* --- turn hamster */
      hms_turn(hamster, arg);   /* turn hamster around */
      sprintf(hmscb[id].reply, "t %d %d %d\n",
        hms_id(hamster), hms_dir(hamster), hms_look(hamster));
      break;                    /* reply with new hamster data */

    case 'l':                   /* --- take/drop corn */
      hms_take(hamster, arg);   /* take/drop some corn */
      sprintf(hmscb[id].reply, "l %d %d %d\n",
        hms_id(hamster), hms_corn(hamster), hms_load(hamster));
      break;                    /* send new hamster data */

    default:                    /* --- unknown command */
      stop(E_PREAD); return;    /* stop execution */
  }
  if (!spr_busy(hmscb[id].sprite)) /* if the sprite is not busy, */
    reply(NULL, NULL, NULL);       /* send reply directly */
}  /* icb_pipe() */

/*--------------------------------------------------------------------*/

static void start (void)
{                               /* --- start hamster */
  int p2c[2];                   /* pipe from parent to child */
  int c2p[2];                   /* pipe from child to parent */
  int fd_out, fd_in;            /* buffers for file descriptors */

  if (running) return;          /* if hamster is running, abort */
  mn_visible(menu, MN_ITEMS, 5);/* show/hide menu items */
  mn_enable (menu, MN_ITEMS, 4);/* enable/disable menu items */
  #ifdef DEMO                   /* for the demonstration version */
  { FILE *t;                    /* wait for a file `demo' */
    do { t = fopen("demo", "r");/* to be created, before */
    } while (!t); fclose(t); }  /* starting the hamster */
  #endif
  if ((pipe(p2c) != 0) || (pipe(c2p) != 0)) {
    error(E_POPEN); return; }   /* create pipes and */
  pid = fork();                 /* fork child process */
  if (pid == -1) { error(E_FORK); return; }

  /* --- child process --- */
  if (pid ==  0) {              /* if this is the child process */
    close(STDOUT_FILENO);       /* connect first  pipe to stdout */
    fd_out = dup2(c2p[1], STDOUT_FILENO);
    close(STDIN_FILENO);        /* connect second pipe to stdin */
    fd_in  = dup2(p2c[0], STDIN_FILENO);
    close(c2p[0]); close(c2p[1]);  /* close pipe handles */
    close(p2c[0]); close(p2c[1]);  /* and check for success */
    if ((fd_out != STDOUT_FILENO) || (fd_in != STDIN_FILENO)) {
      printf("@ 0\n"); fflush(stdout); _exit(-1); }
    execl(appdata.fn_hms, appdata.fn_hms, NULL);
    printf("@ 1\n"); fflush(stdout); _exit(-1);
  }                             /* execute child program */

  /* --- parent process --- */
  close(p2c[0]); close(c2p[1]); /* close child ends of pipes */
  p_in  = fdopen(c2p[0], "r");  /* if this is the parent process, */
  p_out = fdopen(p2c[1], "w");  /* open streams on both pipes */
  if (!p_in || !p_out) {        /* and check for success */
    close(p2c[1]); close(c2p[0]);
    kill(pid, SIGKILL); error(E_POPEN);
    return;                     /* if an error occurred, */
  }                             /* close pipes and terminate child */
  ip_pipe = XtAppAddInput(appctx, c2p[0], (XtPointer)XtInputReadMask,
              icb_pipe, NULL);  /* install pipe read procedure */
  running = 1;                  /* set running flag and resize window */
  resize(appdata.xext, appdata.yext);
}  /* start() */

/*----------------------------------------------------------------------
  Action Functions
----------------------------------------------------------------------*/

static void load (Widget w, XEvent *e, String *s, Cardinal *c)
{                               /* --- File > (Re)Load Maze... */
  CCHAR *t;                     /* buffer for dialog box title */

  if (running || (*c != 1))     /* if running or wrong number */
    return;                     /* of arguments, abort function */
  if (((*s)[0] == '0')          /* if to reload maze */
  &&  (strcmp(appdata.fn_maze, NONAME) != 0))
    dcb_load(NULL, (void*)1, appdata.fn_maze);
  else {                        /* if to load new maze */
    mn_enable(menu, MN_MENU, 0);/* disable menu bar */
    XtVaGetValues(XtNameToWidget(mn_menubar(menu), "*load"),
      XtNlabel, &t, NULL);      /* get menu item text */
    if (fselect(w_top, t, NULL, NULL, dcb_load) != 0) {
      error(E_DIALOG); mn_enable(menu, MN_MENU, 1); }
  }                             /* get maze file name */
}  /* load() */

/*--------------------------------------------------------------------*/

static void save (Widget w, XEvent *e, String *s, Cardinal *c)
{                               /* --- File > Save Maze... */
  CCHAR *t;                     /* buffer for dialog box title */

  if (running || (*c != 1))     /* if running or wrong number */
    return;                     /* of arguments, abort function */
  if (((*s)[0] == '0')          /* if to save maze */
  &&  (strcmp(appdata.fn_maze, NONAME) != 0))
    dcb_save(NULL, (void*)1, appdata.fn_maze);
  else {                        /* if to save under a new name */
    mn_enable(menu, MN_MENU, 0);/* disable menu bar */
    XtVaGetValues(XtNameToWidget(mn_menubar(menu), "*save"),
      XtNlabel, &t, NULL);      /* get menu item text */
    if (fselect(w_top, t, NULL, NULL, dcb_save) != 0) {
      error(E_DIALOG); mn_enable(menu, MN_MENU, 1); }
  }                             /* get maze file name */
}  /* save() */

/*--------------------------------------------------------------------*/

static void select (Widget w, XEvent *e, String *s, Cardinal *c)
{                               /* --- File > Select Hamster... */
  CCHAR *t;                     /* buffer for dialog box title */

  if (running) return;          /* get name of hamster file to load */ 
  mn_enable(menu, MN_MENU, 0);  /* disable menu bar */
  XtVaGetValues(XtNameToWidget(mn_menubar(menu), "*select"),
    XtNlabel, &t, NULL);        /* get menu item text */
  if (fselect(w_top, t, NULL, NULL, dcb_select) != 0) {
    error(E_DIALOG); mn_enable(menu, MN_MENU, 1); }
}  /* select() */

/*--------------------------------------------------------------------*/

static void quit (Widget w, XEvent *e, String *s, Cardinal *c)
{                               /* --- File > Quit */
  if (running) stop(E_NONE);    /* if hamster is running, stop it */
  if (w_top) XtDestroyApplicationContext(appctx);
  exit(0);                      /* terminate program */
}  /* quit() */

/*--------------------------------------------------------------------*/

static void redraw (Widget w, XEvent *e, String *s, Cardinal *c)
{                               /* --- Actions > Redraw */
  XRectangle rc;                /* clipping rectangle */
  int xext, yext;               /* maze extension */
  int x, y;                     /* loop variables */
  int t;                        /* result of spr_undraw */

  if (!gc) {                    /* if graphics context not created */
    gc = XCreateGC(display, window, 0, NULL);
    if (!gc) { error(E_GRAPH); return; }
  }                             /* create a graphics context */
  if (e && (e->type == Expose)){/* if called by Xt, */
    rc.x      = e->xexpose.x;   /* build and set */
    rc.y      = e->xexpose.y;   /* clipping rectangle */
    rc.width  = e->xexpose.width;
    rc.height = e->xexpose.height;
    XSetClipRectangles(display, gc, 0, 0, &rc, 1, Unsorted);
  }
  t = (hmscb[0].sprite)         /* undraw sprite */
    ? spr_undraw(hmscb[0].sprite) : 1;
  mz_exts(maze, &xext, &yext);  /* get maze extensions */
  for (x = xext; --x >= 0; )    /* traverse columns */
    for (y = yext; --y >= 0; )  /* traverse lines of column */
      draw_field(x, y);         /* and draw field */
  if (t == 0)                   /* if sprite was drawn, redraw it */
    spr_draw(hmscb[0].sprite, INT_MIN, INT_MIN);
  if (!running)                 /* if not running, */
    mn_info(menu, "");          /* clear the score */
  XFlush(display);              /* flush buffered drawing commands */
  XSetClipMask(display, gc, None);      /* and clear clipping mask */
}  /* redraw() */

/*--------------------------------------------------------------------*/

static void size (Widget w, XEvent *e, String *s, Cardinal *c)
{                               /* --- Actions > Set Maze Size... */
  static char buf[16];          /* buffer to format values */

  if (running) return;          /* if a hamster is running, abort */
  if (!psh_size) {              /* if dialog box is not created */
    psh_size = psh_create("sizeDlg", w_top, 1);
    if (!psh_size) return;      /* create a property sheet */
    if ((psh_addline(psh_size, "xExtLabel")         != 0)
    ||  (psh_additem(psh_size, "xExt", PSH_EDIT, 0) != 0)
    ||  (psh_addline(psh_size, "yExtLabel")         != 0)
    ||  (psh_additem(psh_size, "yExt", PSH_EDIT, 0) != 0)) {
      psh_delete(psh_size); error(E_WIDGET); }
  }                             /* set browse button callback */
  mn_enable(menu, MN_MENU, 0);  /* disable menu bar */
  sprintf(buf, "%d", appdata.xext); psh_setval(psh_size, "xExt", buf);
  sprintf(buf, "%d", appdata.yext); psh_setval(psh_size, "yExt", buf);
  psh_handle(psh_size, dcb_size);  /* set values and handle dialog */
}  /* size() */

/*--------------------------------------------------------------------*/

static void random (Widget w, XEvent *e, String *s, Cardinal *c)
{                               /* --- Actions > Randomize Maze... */
  static char buf[16];          /* buffer to format values */

  if (running) return;          /* if a hamster is running, abort */
  if (!psh_random) {            /* if dialog box is not created */
    psh_random = psh_create("randomDlg", w_top, 1);
    if (!psh_random) return;    /* create a property sheet */
    if ((psh_addline(psh_random, "wallProbLabel")         != 0)
    ||  (psh_additem(psh_random, "wallProb", PSH_EDIT, 0) != 0)
    ||  (psh_addline(psh_random, "totalLabel")            != 0)
    ||  (psh_additem(psh_random, "total",    PSH_EDIT, 0) != 0)
    ||  (psh_addline(psh_random, "maxHeapLabel")          != 0)
    ||  (psh_additem(psh_random, "maxHeap",  PSH_EDIT, 0) != 0)) {
      psh_delete(psh_random); error(E_WIDGET); }
  }                             /* set browse button callback */
  mn_enable(menu, MN_MENU, 0);  /* disable menu bar */
  sprintf(buf, "%d", (int)(appdata.wallprob *100 +0.5));
  psh_setval(psh_random, "wallProb", buf);
  sprintf(buf, "%d", appdata.total);
  psh_setval(psh_random, "total", buf);
  sprintf(buf, "%d", appdata.maxheap);
  psh_setval(psh_random, "maxHeap", buf);
  psh_handle(psh_random, dcb_random); /* set values and handle dialog */
}  /* random() */

/*--------------------------------------------------------------------*/

static void speed (Widget w, XEvent *e, String *s, Cardinal *c)
{                               /* --- Actions > Set Hamster Speed... */
  static char buf[16];          /* buffer to format values */

  if (!psh_speed) {             /* if dialog box is not created */
    psh_speed = psh_create("speedDlg", w_top, 1);
    if (!psh_speed) return;     /* create a property sheet */
    if ((psh_addline(psh_speed, "speedLabel")         != 0)