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File: [local] / src / usr.bin / compress / nullopen.c (download)
Revision 1.6, Sat Sep 3 11:41:10 2016 UTC (7 years, 9 months ago) by tedu
start pulling apart some function pointers that take too many parameters because of excessive code sharing. compression and decompression are not entirely similar, they should share less. ok joerg millert |
/* $OpenBSD: nullopen.c,v 1.6 2016/09/03 11:41:10 tedu Exp $ */ /* * Copyright (c) 2003 Can Erkin Acar * Copyright (c) 1997 Michael Shalayeff * All rights reserved. * * 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. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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. * */ #include <sys/types.h> #include <stdio.h> #include <stdlib.h> #include <errno.h> #include <unistd.h> #include "compress.h" typedef struct { off_t total_in; off_t total_out; int fd; int gotmagic; char mode; } null_stream; char null_magic[2]; void * null_ropen(int fd, char *name, int gotmagic) { null_stream *s; if (fd < 0) return NULL; if ((s = calloc(1, sizeof(null_stream))) == NULL) return NULL; s->fd = fd; s->gotmagic = gotmagic; s->total_in = s->total_out = 0; s->mode = 'r'; return s; } void * null_wopen(int fd, char *name, int bits, u_int32_t mtime) { null_stream *s; if (fd < 0) return NULL; if ((s = calloc(1, sizeof(null_stream))) == NULL) return NULL; s->fd = fd; s->gotmagic = 0; s->total_in = s->total_out = 0; s->mode = 'w'; return s; } int null_close(void *cookie, struct z_info *info, const char *name, struct stat *sb) { null_stream *s = (null_stream*) cookie; int err = 0; if (s == NULL) return -1; if (info != NULL) { info->mtime = 0; info->crc = (u_int32_t)-1; info->hlen = 0; info->total_in = (off_t) s->total_in; info->total_out = (off_t) s->total_out; } setfile(name, s->fd, sb); err = close(s->fd); free(s); return err; } int null_flush(void *cookie, int flush) { null_stream *s = (null_stream*)cookie; if (s == NULL || s->mode != 'w') { errno = EBADF; return (-1); } return 0; } int null_read(void *cookie, char *buf, int len) { null_stream *s = (null_stream*)cookie; if (s == NULL) { errno = EBADF; return (-1); } if (s->gotmagic) { if (len < 2) { errno = EBADF; return (-1); } buf[0] = null_magic[0]; buf[1] = null_magic[1]; s->gotmagic = 0; return (2); } return read(s->fd, buf, len); } int null_write(void *cookie, const char *buf, int len) { null_stream *s = (null_stream*)cookie; if (s == NULL) { errno = EBADF; return (-1); } return write(s->fd, buf, len); }