1/* 2 * Copyright (c) 1983, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE.
| 1/* 2 * Copyright (c) 1983, 1993 3 * The Regents of the University of California. All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. All advertising materials mentioning features or use of this software 14 * must display the following acknowledgement: 15 * This product includes software developed by the University of 16 * California, Berkeley and its contributors. 17 * 4. Neither the name of the University nor the names of its contributors 18 * may be used to endorse or promote products derived from this software 19 * without specific prior written permission. 20 * 21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31 * SUCH DAMAGE.
|
| 32 * 33 * $FreeBSD: head/lib/libc/gen/telldir.c 69656 2000-12-06 03:15:49Z deischen $
|
32 */ 33 34#if defined(LIBC_SCCS) && !defined(lint) 35static char sccsid[] = "@(#)telldir.c 8.1 (Berkeley) 6/4/93"; 36#endif /* LIBC_SCCS and not lint */ 37 38#include <sys/param.h> 39#include <dirent.h> 40#include <stdlib.h> 41#include <unistd.h> 42 43/* 44 * The option SINGLEUSE may be defined to say that a telldir 45 * cookie may be used only once before it is freed. This option 46 * is used to avoid having memory usage grow without bound. 47 */ 48#define SINGLEUSE 49 50/* 51 * One of these structures is malloced to describe the current directory 52 * position each time telldir is called. It records the current magic 53 * cookie returned by getdirentries and the offset within the buffer 54 * associated with that return value. 55 */
| 34 */ 35 36#if defined(LIBC_SCCS) && !defined(lint) 37static char sccsid[] = "@(#)telldir.c 8.1 (Berkeley) 6/4/93"; 38#endif /* LIBC_SCCS and not lint */ 39 40#include <sys/param.h> 41#include <dirent.h> 42#include <stdlib.h> 43#include <unistd.h> 44 45/* 46 * The option SINGLEUSE may be defined to say that a telldir 47 * cookie may be used only once before it is freed. This option 48 * is used to avoid having memory usage grow without bound. 49 */ 50#define SINGLEUSE 51 52/* 53 * One of these structures is malloced to describe the current directory 54 * position each time telldir is called. It records the current magic 55 * cookie returned by getdirentries and the offset within the buffer 56 * associated with that return value. 57 */
|
56struct ddloc { 57 struct ddloc *loc_next;/* next structure in list */
| 58struct _ddloc { 59 LIST_ENTRY(_ddloc) loc_lqe; /* entry in list */
|
58 long loc_index; /* key associated with structure */ 59 long loc_seek; /* magic cookie returned by getdirentries */ 60 long loc_loc; /* offset of entry in buffer */
| 60 long loc_index; /* key associated with structure */ 61 long loc_seek; /* magic cookie returned by getdirentries */ 62 long loc_loc; /* offset of entry in buffer */
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61 const DIR* loc_dirp; /* directory which used this entry */
| |
62}; 63
| 63}; 64
|
64#define NDIRHASH 32 /* Num of hash lists, must be a power of 2 */ 65#define LOCHASH(i) ((i)&(NDIRHASH-1)) 66 67static long dd_loccnt; /* Index of entry for sequential readdir's */ 68static struct ddloc *dd_hash[NDIRHASH]; /* Hash list heads for ddlocs */ 69
| |
70/* 71 * return a pointer into a directory 72 */ 73long 74telldir(dirp)
| 65/* 66 * return a pointer into a directory 67 */ 68long 69telldir(dirp)
|
75 const DIR *dirp;
| 70 DIR *dirp;
|
76{
| 71{
|
77 register int index; 78 register struct ddloc *lp;
| 72 struct _ddloc *lp;
|
79
| 73
|
80 if ((lp = (struct ddloc *)malloc(sizeof(struct ddloc))) == NULL)
| 74 if ((lp = (struct _ddloc *)malloc(sizeof(struct _ddloc))) == NULL)
|
81 return (-1);
| 75 return (-1);
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82 index = dd_loccnt++; 83 lp->loc_index = index;
| 76 lp->loc_index = dirp->dd_loccnt++;
|
84 lp->loc_seek = dirp->dd_seek; 85 lp->loc_loc = dirp->dd_loc;
| 77 lp->loc_seek = dirp->dd_seek; 78 lp->loc_loc = dirp->dd_loc;
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86 lp->loc_dirp = dirp; 87 lp->loc_next = dd_hash[LOCHASH(index)]; 88 dd_hash[LOCHASH(index)] = lp; 89 return (index);
| 79 LIST_INSERT_HEAD(&dirp->dd_locq, lp, loc_lqe); 80 return (lp->loc_index);
|
90} 91 92/* 93 * seek to an entry in a directory. 94 * Only values returned by "telldir" should be passed to seekdir. 95 */ 96void 97_seekdir(dirp, loc)
| 81} 82 83/* 84 * seek to an entry in a directory. 85 * Only values returned by "telldir" should be passed to seekdir. 86 */ 87void 88_seekdir(dirp, loc)
|
98 register DIR *dirp;
| 89 DIR *dirp;
|
99 long loc; 100{
| 90 long loc; 91{
|
101 register struct ddloc *lp; 102 register struct ddloc **prevlp;
| 92 struct _ddloc *lp;
|
103 struct dirent *dp; 104
| 93 struct dirent *dp; 94
|
105 prevlp = &dd_hash[LOCHASH(loc)]; 106 lp = *prevlp; 107 while (lp != NULL) {
| 95 LIST_FOREACH(lp, &dirp->dd_locq, loc_lqe) {
|
108 if (lp->loc_index == loc) 109 break;
| 96 if (lp->loc_index == loc) 97 break;
|
110 prevlp = &lp->loc_next; 111 lp = lp->loc_next;
| |
112 } 113 if (lp == NULL) 114 return; 115 if (lp->loc_loc == dirp->dd_loc && lp->loc_seek == dirp->dd_seek) 116 goto found; 117 (void) lseek(dirp->dd_fd, (off_t)lp->loc_seek, SEEK_SET); 118 dirp->dd_seek = lp->loc_seek; 119 dirp->dd_loc = 0; 120 while (dirp->dd_loc < lp->loc_loc) { 121 dp = readdir(dirp); 122 if (dp == NULL) 123 break; 124 } 125found: 126#ifdef SINGLEUSE
| 98 } 99 if (lp == NULL) 100 return; 101 if (lp->loc_loc == dirp->dd_loc && lp->loc_seek == dirp->dd_seek) 102 goto found; 103 (void) lseek(dirp->dd_fd, (off_t)lp->loc_seek, SEEK_SET); 104 dirp->dd_seek = lp->loc_seek; 105 dirp->dd_loc = 0; 106 while (dirp->dd_loc < lp->loc_loc) { 107 dp = readdir(dirp); 108 if (dp == NULL) 109 break; 110 } 111found: 112#ifdef SINGLEUSE
|
127 *prevlp = lp->loc_next;
| 113 LIST_REMOVE(lp, loc_lqe);
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128 free((caddr_t)lp); 129#endif 130} 131 132/* 133 * Reclaim memory for telldir cookies which weren't used. 134 */ 135void 136_reclaim_telldir(dirp)
| 114 free((caddr_t)lp); 115#endif 116} 117 118/* 119 * Reclaim memory for telldir cookies which weren't used. 120 */ 121void 122_reclaim_telldir(dirp)
|
137 register const DIR *dirp;
| 123 DIR *dirp;
|
138{
| 124{
|
139 register struct ddloc *lp; 140 register struct ddloc **prevlp; 141 int i;
| 125 struct _ddloc *lp; 126 struct _ddloc *templp;
|
142
| 127
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143 for (i = 0; i < NDIRHASH; i++) { 144 prevlp = &dd_hash[i]; 145 lp = *prevlp; 146 while (lp != NULL) { 147 if (lp->loc_dirp == dirp) { 148 *prevlp = lp->loc_next; 149 free((caddr_t)lp); 150 lp = *prevlp; 151 continue; 152 } 153 prevlp = &lp->loc_next; 154 lp = lp->loc_next; 155 }
| 128 lp = LIST_FIRST(&dirp->dd_locq); 129 while (lp != NULL) { 130 templp = lp; 131 lp = LIST_NEXT(lp, loc_lqe); 132 free(templp);
|
156 }
| 133 }
|
| 134 LIST_INIT(&dirp->dd_locq);
|
157}
| 135}
|