1 /*
2 * eol.c : generic eol/keyword routines
3 *
4 * ====================================================================
5 * Licensed to the Apache Software Foundation (ASF) under one
6 * or more contributor license agreements. See the NOTICE file
7 * distributed with this work for additional information
8 * regarding copyright ownership. The ASF licenses this file
9 * to you under the Apache License, Version 2.0 (the
10 * "License"); you may not use this file except in compliance
11 * with the License. You may obtain a copy of the License at
12 *
13 * http://www.apache.org/licenses/LICENSE-2.0
14 *
15 * Unless required by applicable law or agreed to in writing,
16 * software distributed under the License is distributed on an
17 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
18 * KIND, either express or implied. See the License for the
19 * specific language governing permissions and limitations
20 * under the License.
21 * ====================================================================
22 */
23
24
25
26 #define APR_WANT_STRFUNC
27
28 #include <apr_file_io.h>
29 #include "svn_io.h"
30 #include "private/svn_eol_private.h"
31 #include "private/svn_dep_compat.h"
32
33 char *
svn_eol__find_eol_start(char * buf,apr_size_t len)34 svn_eol__find_eol_start(char *buf, apr_size_t len)
35 {
36 #if SVN_UNALIGNED_ACCESS_IS_OK
37
38 /* Scan the input one machine word at a time. */
39 for (; len > sizeof(apr_uintptr_t)
40 ; buf += sizeof(apr_uintptr_t), len -= sizeof(apr_uintptr_t))
41 {
42 /* This is a variant of the well-known strlen test: */
43 apr_uintptr_t chunk = *(const apr_uintptr_t *)buf;
44
45 /* A byte in SVN__R_TEST is \0, iff it was \r in *BUF.
46 * Similarly, SVN__N_TEST is an indicator for \n. */
47 apr_uintptr_t r_test = chunk ^ SVN__R_MASK;
48 apr_uintptr_t n_test = chunk ^ SVN__N_MASK;
49
50 /* A byte in SVN__R_TEST can only be < 0x80, iff it has been \0 before
51 * (i.e. \r in *BUF). Ditto for SVN__N_TEST. */
52 r_test |= (r_test & SVN__LOWER_7BITS_SET) + SVN__LOWER_7BITS_SET;
53 n_test |= (n_test & SVN__LOWER_7BITS_SET) + SVN__LOWER_7BITS_SET;
54
55 /* Check whether at least one of the words contains a byte <0x80
56 * (if one is detected, there was a \r or \n in CHUNK). */
57 if ((r_test & n_test & SVN__BIT_7_SET) != SVN__BIT_7_SET)
58 break;
59 }
60
61 #endif
62
63 /* The remaining odd bytes will be examined the naive way: */
64 for (; len > 0; ++buf, --len)
65 {
66 if (*buf == '\n' || *buf == '\r')
67 return buf;
68 }
69
70 return NULL;
71 }
72
73 const char *
svn_eol__detect_eol(char * buf,apr_size_t len,char ** eolp)74 svn_eol__detect_eol(char *buf, apr_size_t len, char **eolp)
75 {
76 char *eol;
77
78 eol = svn_eol__find_eol_start(buf, len);
79 if (eol)
80 {
81 if (eolp)
82 *eolp = eol;
83
84 if (*eol == '\n')
85 return "\n";
86
87 /* We found a CR. */
88 ++eol;
89 if (eol == buf + len || *eol != '\n')
90 return "\r";
91 return "\r\n";
92 }
93
94 return NULL;
95 }
96