1 /* $OpenBSD: mmfile.c,v 1.19 2019/01/27 14:43:09 deraadt Exp $ */
2
3 /*-
4 * Copyright (c) 1999 James Howard and Dag-Erling Co�dan Sm�rgrav
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26 * SUCH DAMAGE.
27 */
28
29 #include <sys/mman.h>
30 #include <sys/stat.h>
31
32 #include <err.h>
33 #include <fcntl.h>
34 #include <stdlib.h>
35 #include <unistd.h>
36
37 #include "grep.h"
38
39 #ifndef SMALL
40
41 #define MAX_MAP_LEN 1048576
42
43 mmf_t *
mmopen(int fd,struct stat * st)44 mmopen(int fd, struct stat *st)
45 {
46 mmf_t *mmf;
47
48 mmf = grep_malloc(sizeof *mmf);
49 if (st->st_size > SIZE_MAX) /* too big to mmap */
50 goto ouch;
51 mmf->len = (size_t)st->st_size;
52 mmf->fd = fd;
53 mmf->base = mmap(NULL, mmf->len, PROT_READ, MAP_PRIVATE, mmf->fd, (off_t)0);
54 if (mmf->base == MAP_FAILED)
55 goto ouch;
56 mmf->ptr = mmf->base;
57 mmf->end = mmf->base + mmf->len;
58 madvise(mmf->base, mmf->len, MADV_SEQUENTIAL);
59 return mmf;
60
61 ouch:
62 free(mmf);
63 return NULL;
64 }
65
66 void
mmclose(mmf_t * mmf)67 mmclose(mmf_t *mmf)
68 {
69 munmap(mmf->base, mmf->len);
70 close(mmf->fd);
71 free(mmf);
72 }
73
74 char *
mmfgetln(mmf_t * mmf,size_t * l)75 mmfgetln(mmf_t *mmf, size_t *l)
76 {
77 static char *p;
78
79 if (mmf->ptr >= mmf->end)
80 return NULL;
81 for (p = mmf->ptr; mmf->ptr < mmf->end; ++mmf->ptr)
82 if (*mmf->ptr == '\n')
83 break;
84
85 *l = mmf->ptr - p;
86 ++mmf->ptr;
87 return p;
88 }
89
90 #endif
91