arsetbit.c

roots--一个轻量级的内存数据库系统。基于Hash Map的table设计。快速轻巧。

/*
Copyright (c) 2003, Dan Kranz and Arnold Rom
All rights reserved.

Redistribution and use in source and binary forms, with or
without modification, are permitted provided that the following
conditions are met:

    * Redistributions of source code must retain the above
      copyright notice, this list of conditions and the following
      disclaimer.

    * Redistributions in binary form must reproduce the above
      copyright notice, this list of conditions and the following
      disclaimer in the documentation and/or other materials
      provided with the distribution.

    * The names of its contributors may not be used to endorse or
      promote products derived from this software without specific
      prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

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

/* ############################################################################# */
/* #                        SETBIT(FIRST,LNEXTL,STRING)                        # */
/* #  -----------------------------------------------------------------------  # */
/* #  Purpose                                                                  # */
/* #  -------                                                                  # */
/* #  Use SETBIT to store the line numbers of a linked list in a bit vector.   # */
/* #                                                                           # */
/* #  Input  FIRST,LNEXTL  represent  a set of line numbers associated with a  # */
/* #  rectangular ROOTS BLOCK.                                                 # */
/* #                                                                           # */
/* #  The  output bit vector is represented by the STRING argument.  The left  # */
/* #  to  right  bit  positions  of  STRING  represent LINE numbers 1 through  # */
/* #  NLINE; the latter correspond to the physical lines of a BLOCK.           # */
/* #                                                                           # */
/* #  Note:  we  do  not  need  to  look  at  BLOCK  to  perform  the current  # */
/* #  operation.                                                               # */
/* #                                                                           # */
/* #  SETBIT sets STRING(LINE) to "1" for all LINES found in FIRST,LNEXTL.     # */
/* #                                                                           # */
/* #  Important: SETBIT   does   not   clear  STRING.   This  chore  is  your  # */
/* #             responsibility!  This is done so that you can form the union  # */
/* #             of several sublists by multiple calls to SETBIT.              # */
/* #                                                                           # */
/* #  The  output  string(s)  constructed with SETBIT are typically processed  # */
/* #  with the ROOTS set operation routines; e.g.  LGAND, LGOR etc.            # */
/* #                                                                           # */
/* #  To prune for a generated set use ROOTS operation SETPRN.                 # */
/* #                                                                           # */
/* #  The call arguments to the current routine are as follows:                # */
/* #  ---------------------------------------------------------                # */
/* #  FIRST,LNEXTL - define the input sub-list members (conventional ROOTS)    # */
/* #                                                                           # */
/* #  STRING       - is a byte array whose length is large enough to hold the  # */
/* #                 largest LINE number contained in FIRST,LNEXTL; i.e.  let  # */
/* #                 NLINE  be  the  maximum  line  referred  to by the input  # */
/* #                 sub-list,  then STRING  should  be  at least (NLINE/8)+1  # */
/* #                 bytes  long.   N.B.  if NLINE is a multiple of 8 you can  # */
/* #                 get away with (NLINE/8)!                                  # */
/* ############################################################################# */


/* small internal routines */

static void sos(void) {RootsSOS("setbit sos exit\n"); abort();}


void setbit(
                      long *first,
                      unsigned short *lnextl,
                      BYTE *string
                      )
/* --------------------------------------------------------- */
{       /* setbit START */
/* --------------------------------------------------------- */

/*      local data */

        long guard=MAXLIN;
        long q;

        BYTE tbits[8]= {0x80,0x40,0x20,0x10,0x08,0x04,0x02,01};

        ScanLinkedList(*first,lnextl,q)
        {
        if(!guard--)sos();
        *(string+((q-1)>>3))|=tbits[(q-1)&0x7];
        }
        return;
/* --------------------------------------------------------- */
}       /* setbit END */
/* --------------------------------------------------------- */