1 /* Licensed to the Apache Software Foundation (ASF) under one or more
2 * contributor license agreements. See the NOTICE file distributed with
3 * this work for additional information regarding copyright ownership.
4 * The ASF licenses this file to You under the Apache License, Version 2.0
5 * (the "License"); you may not use this file except in compliance with
6 * the License. You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "apr_arch_file_io.h"
18
setptr(apr_file_t * thefile,apr_off_t pos)19 static apr_status_t setptr(apr_file_t *thefile, apr_off_t pos )
20 {
21 apr_off_t newbufpos;
22 apr_status_t rv;
23
24 if (thefile->direction == 1) {
25 rv = apr_file_flush_locked(thefile);
26 if (rv) {
27 return rv;
28 }
29 thefile->bufpos = thefile->direction = thefile->dataRead = 0;
30 }
31
32 newbufpos = pos - (thefile->filePtr - thefile->dataRead);
33 if (newbufpos >= 0 && newbufpos <= thefile->dataRead) {
34 thefile->bufpos = newbufpos;
35 rv = APR_SUCCESS;
36 }
37 else {
38 if (lseek(thefile->filedes, pos, SEEK_SET) != -1) {
39 thefile->bufpos = thefile->dataRead = 0;
40 thefile->filePtr = pos;
41 rv = APR_SUCCESS;
42 }
43 else {
44 rv = errno;
45 }
46 }
47
48 return rv;
49 }
50
51
apr_file_seek(apr_file_t * thefile,apr_seek_where_t where,apr_off_t * offset)52 APR_DECLARE(apr_status_t) apr_file_seek(apr_file_t *thefile, apr_seek_where_t where, apr_off_t *offset)
53 {
54 apr_off_t rv;
55
56 thefile->eof_hit = 0;
57
58 if (thefile->buffered) {
59 int rc = EINVAL;
60 apr_finfo_t finfo;
61
62 file_lock(thefile);
63
64 switch (where) {
65 case APR_SET:
66 rc = setptr(thefile, *offset);
67 break;
68
69 case APR_CUR:
70 rc = setptr(thefile, thefile->filePtr - thefile->dataRead + thefile->bufpos + *offset);
71 break;
72
73 case APR_END:
74 rc = apr_file_info_get_locked(&finfo, APR_FINFO_SIZE, thefile);
75 if (rc == APR_SUCCESS)
76 rc = setptr(thefile, finfo.size + *offset);
77 break;
78 }
79
80 *offset = thefile->filePtr - thefile->dataRead + thefile->bufpos;
81
82 file_unlock(thefile);
83
84 return rc;
85 }
86 else {
87 rv = lseek(thefile->filedes, *offset, where);
88 if (rv == -1) {
89 *offset = -1;
90 return errno;
91 }
92 else {
93 *offset = rv;
94 return APR_SUCCESS;
95 }
96 }
97 }
98
apr_file_trunc(apr_file_t * fp,apr_off_t offset)99 apr_status_t apr_file_trunc(apr_file_t *fp, apr_off_t offset)
100 {
101 if (fp->buffered) {
102 int rc = 0;
103 file_lock(fp);
104 if (fp->direction == 1 && fp->bufpos != 0) {
105 apr_off_t len = fp->filePtr + fp->bufpos;
106 if (offset < len) {
107 /* New file end fall below our write buffer limit.
108 * Figure out if and what needs to be flushed.
109 */
110 apr_off_t off = len - offset;
111 if (off >= 0 && off <= fp->bufpos)
112 fp->bufpos = fp->bufpos - (size_t)off;
113 else
114 fp->bufpos = 0;
115 }
116 rc = apr_file_flush_locked(fp);
117 /* Reset buffer positions for write mode */
118 fp->bufpos = fp->direction = fp->dataRead = 0;
119 }
120 file_unlock(fp);
121 if (rc) {
122 return rc;
123 }
124 }
125 if (ftruncate(fp->filedes, offset) == -1) {
126 return errno;
127 }
128 return apr_file_seek(fp, APR_SET, &offset);
129 }
130