1 /* $OpenBSD: mmfile.c,v 1.14 2011/07/17 12:17:10 aschrijver 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/param.h> 30 #include <sys/mman.h> 31 #include <sys/stat.h> 32 33 #include <err.h> 34 #include <fcntl.h> 35 #include <stdlib.h> 36 #include <unistd.h> 37 38 #include "grep.h" 39 40 #ifndef SMALL 41 42 #define MAX_MAP_LEN 1048576 43 44 mmf_t * 45 mmopen(const char *fn, const char *mode) 46 { 47 mmf_t *mmf; 48 struct stat st; 49 50 #ifndef __minix 51 /* XXX ignore mode for now */ 52 mode = mode; 53 #endif /* !__minix */ 54 55 mmf = grep_malloc(sizeof *mmf); 56 if ((mmf->fd = open(fn, O_RDONLY)) == -1) 57 goto ouch1; 58 if (fstat(mmf->fd, &st) == -1) 59 goto ouch2; 60 if (st.st_size > SIZE_T_MAX) /* too big to mmap */ 61 goto ouch2; 62 if (!S_ISREG(st.st_mode)) /* only mmap regular files */ 63 goto ouch2; 64 mmf->len = (size_t)st.st_size; 65 mmf->base = mmap(NULL, mmf->len, PROT_READ, MAP_PRIVATE, mmf->fd, (off_t)0); 66 if (mmf->base == MAP_FAILED) 67 goto ouch2; 68 mmf->ptr = mmf->base; 69 mmf->end = mmf->base + mmf->len; 70 #ifndef __minix 71 madvise(mmf->base, mmf->len, MADV_SEQUENTIAL); 72 #endif /* !__minix */ 73 return mmf; 74 75 ouch2: 76 close(mmf->fd); 77 ouch1: 78 free(mmf); 79 return NULL; 80 } 81 82 void 83 mmclose(mmf_t *mmf) 84 { 85 munmap(mmf->base, mmf->len); 86 close(mmf->fd); 87 free(mmf); 88 } 89 90 char * 91 mmfgetln(mmf_t *mmf, size_t *l) 92 { 93 static char *p; 94 95 if (mmf->ptr >= mmf->end) 96 return NULL; 97 for (p = mmf->ptr; mmf->ptr < mmf->end; ++mmf->ptr) 98 if (*mmf->ptr == '\n') 99 break; 100 101 *l = mmf->ptr - p; 102 ++mmf->ptr; 103 return p; 104 } 105 106 #endif 107