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 #include "apr_file_io.h"
19 #include <errno.h>
20 #include <string.h>
21
setptr(apr_file_t * thefile,apr_off_t pos)22 static apr_status_t setptr(apr_file_t *thefile, apr_off_t pos )
23 {
24 apr_off_t newbufpos;
25 apr_status_t rv;
26 DWORD rc;
27
28 if (thefile->direction == 1) {
29 /* XXX: flush here is not mutex protected */
30 rv = apr_file_flush(thefile);
31 if (rv != APR_SUCCESS)
32 return rv;
33 thefile->bufpos = thefile->dataRead = 0;
34 thefile->direction = 0;
35 }
36
37 /* We may be truncating to size here.
38 * XXX: testing an 'unsigned' as >= 0 below indicates a bug
39 */
40 newbufpos = pos - (thefile->filePtr - thefile->dataRead);
41
42 if (newbufpos >= 0 && newbufpos <= (apr_off_t)thefile->dataRead) {
43 thefile->bufpos = (apr_size_t)newbufpos;
44 rv = APR_SUCCESS;
45 } else {
46 DWORD offlo = (DWORD)pos;
47 LONG offhi = (LONG)(pos >> 32);
48 rc = SetFilePointer(thefile->filehand, offlo, &offhi, FILE_BEGIN);
49
50 if (rc == (DWORD)-1)
51 /* A legal value, perhaps? MSDN implies prior SetLastError isn't
52 * needed, googling for SetLastError SetFilePointer seems
53 * to confirm this. INVALID_SET_FILE_POINTER is too recently
54 * added for us to rely on it as a constant.
55 */
56 rv = apr_get_os_error();
57 else
58 rv = APR_SUCCESS;
59
60 if (rv == APR_SUCCESS) {
61 rv = APR_SUCCESS;
62 thefile->eof_hit = 0;
63 thefile->bufpos = thefile->dataRead = 0;
64 thefile->filePtr = pos;
65 }
66 }
67
68 return rv;
69 }
70
71
apr_file_seek(apr_file_t * thefile,apr_seek_where_t where,apr_off_t * offset)72 APR_DECLARE(apr_status_t) apr_file_seek(apr_file_t *thefile, apr_seek_where_t where, apr_off_t *offset)
73 {
74 apr_finfo_t finfo;
75 apr_status_t rc = APR_SUCCESS;
76
77 thefile->eof_hit = 0;
78
79 if (thefile->buffered) {
80 switch (where) {
81 case APR_SET:
82 rc = setptr(thefile, *offset);
83 break;
84
85 case APR_CUR:
86 rc = setptr(thefile, thefile->filePtr - thefile->dataRead
87 + thefile->bufpos + *offset);
88 break;
89
90 case APR_END:
91 rc = apr_file_info_get(&finfo, APR_FINFO_SIZE, thefile);
92 if (rc == APR_SUCCESS)
93 rc = setptr(thefile, finfo.size + *offset);
94 break;
95
96 default:
97 return APR_EINVAL;
98 }
99
100 *offset = thefile->filePtr - thefile->dataRead + thefile->bufpos;
101 return rc;
102 }
103 /* A file opened with APR_FOPEN_XTHREAD has been opened for overlapped i/o.
104 * APR must explicitly track the file pointer in this case.
105 */
106 else if (thefile->pOverlapped || thefile->flags & APR_FOPEN_XTHREAD) {
107 switch(where) {
108 case APR_SET:
109 thefile->filePtr = *offset;
110 break;
111
112 case APR_CUR:
113 thefile->filePtr += *offset;
114 break;
115
116 case APR_END:
117 rc = apr_file_info_get(&finfo, APR_FINFO_SIZE, thefile);
118 if (rc == APR_SUCCESS && finfo.size + *offset >= 0)
119 thefile->filePtr = finfo.size + *offset;
120 break;
121
122 default:
123 return APR_EINVAL;
124 }
125 *offset = thefile->filePtr;
126 return rc;
127 }
128 else {
129 DWORD howmove;
130 DWORD offlo = (DWORD)*offset;
131 DWORD offhi = (DWORD)(*offset >> 32);
132
133 switch(where) {
134 case APR_SET:
135 howmove = FILE_BEGIN; break;
136 case APR_CUR:
137 howmove = FILE_CURRENT; break;
138 case APR_END:
139 howmove = FILE_END; break;
140 default:
141 return APR_EINVAL;
142 }
143 offlo = SetFilePointer(thefile->filehand, (LONG)offlo,
144 (LONG*)&offhi, howmove);
145 if (offlo == 0xFFFFFFFF)
146 rc = apr_get_os_error();
147 else
148 rc = APR_SUCCESS;
149 /* Since we can land at 0xffffffff we will measure our APR_SUCCESS */
150 if (rc == APR_SUCCESS)
151 *offset = ((apr_off_t)offhi << 32) | offlo;
152 return rc;
153 }
154 }
155
156
apr_file_trunc(apr_file_t * thefile,apr_off_t offset)157 APR_DECLARE(apr_status_t) apr_file_trunc(apr_file_t *thefile, apr_off_t offset)
158 {
159 apr_status_t rv;
160 DWORD offlo = (DWORD)offset;
161 LONG offhi = (LONG)(offset >> 32);
162 DWORD rc;
163
164 if (thefile->buffered) {
165 if (thefile->direction == 1) {
166 /* Figure out what needs to be flushed. Don't flush the part
167 * of the write buffer that will get truncated anyway.
168 */
169 if (offset < thefile->filePtr) {
170 thefile->bufpos = 0;
171 }
172 else if (offset < thefile->filePtr + (apr_off_t)thefile->bufpos) {
173 thefile->bufpos = offset - thefile->filePtr;
174 }
175
176 if (thefile->bufpos != 0) {
177 rv = apr_file_flush(thefile);
178 if (rv != APR_SUCCESS)
179 return rv;
180 }
181 }
182 else if (thefile->direction == 0) {
183 /* Discard the read buffer, as we are about to reposition
184 * ourselves to the end of file.
185 */
186 thefile->bufpos = 0;
187 thefile->dataRead = 0;
188 }
189 }
190
191 rc = SetFilePointer(thefile->filehand, offlo, &offhi, FILE_BEGIN);
192 if (rc == 0xFFFFFFFF)
193 if ((rv = apr_get_os_error()) != APR_SUCCESS)
194 return rv;
195 thefile->filePtr = offset;
196 /* Don't report EOF until the next read. */
197 thefile->eof_hit = 0;
198
199 if (!SetEndOfFile(thefile->filehand))
200 return apr_get_os_error();
201
202 return APR_SUCCESS;
203 }
204