usr/src/sys.386bsd/nfs/nfscompress.h

/*
 * Copyright (c) 1989 The Regents of the University of California.
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Rick Macklem at The University of Guelph.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS 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 REGENTS 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.
 *
 *      @(#)nfscompress.h       7.2 (Berkeley) 10/2/90
 */

/*
 * Definitions for the compression algorithm
 */
#define NFSC_MAX        17
#define NFSCRL          0xe0
#define NFSCRLE(a)      (NFSCRL | ((a) - 2))

#define nfscput(c) \
                if (oleft == 0) { \
                        MGET(om, M_WAIT, MT_DATA); \
                        if (clget) \
                                MCLGET(om, M_WAIT); \
                        om->m_len = 0; \
                        oleft = M_TRAILINGSPACE(om) - 1; \
                        *mp = om; \
                        mp = &om->m_next; \
                        op = mtod(om, u_char *); \
                } else \
                        oleft--; \
                *op++ = (c); \
                om->m_len++; \
                olen++

#define nfscget(c) \
                if (ileft == 0) { \
                        do { \
                                m = m->m_next; \
                        } while (m && m->m_len == 0); \
                        if (m) { \
                                ileft = m->m_len - 1; \
                                ip = mtod(m, u_char *); \
                                (c) = *ip++; \
                        } else { \
                                (c) = '\0'; \
                                noteof = 0; \
                        } \
                } else { \
                        (c) = *ip++; \
                        ileft--; \
                }