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/* Machine-word-sized masks used in svn_eol__find_eol_start. 34 */ 35char * 36svn_eol__find_eol_start(char *buf, apr_size_t len) 37{ 38#if !SVN_UNALIGNED_ACCESS_IS_OK 39 40 /* On some systems, we need to make sure that buf is properly aligned 41 * for chunky data access. This overhead is still justified because 42 * only lines tend to be tens of chars long. 43 */ 44 for (; (len > 0) && ((apr_uintptr_t)buf) & (sizeof(apr_uintptr_t)-1) 45 ; ++buf, --len) 46 { 47 if (*buf == '\n' || *buf == '\r') 48 return buf; 49 } 50 51#endif 52 53 /* Scan the input one machine word at a time. */ 54 for (; len > sizeof(apr_uintptr_t) 55 ; buf += sizeof(apr_uintptr_t), len -= sizeof(apr_uintptr_t)) 56 { 57 /* This is a variant of the well-known strlen test: */ 58 apr_uintptr_t chunk = *(const apr_uintptr_t *)buf; 59 60 /* A byte in SVN__R_TEST is \0, iff it was \r in *BUF. 61 * Similarly, SVN__N_TEST is an indicator for \n. */ 62 apr_uintptr_t r_test = chunk ^ SVN__R_MASK; 63 apr_uintptr_t n_test = chunk ^ SVN__N_MASK; 64 65 /* A byte in SVN__R_TEST can by < 0x80, iff it has been \0 before 66 * (i.e. \r in *BUF). Dito for SVN__N_TEST. */ 67 r_test |= (r_test & SVN__LOWER_7BITS_SET) + SVN__LOWER_7BITS_SET; 68 n_test |= (n_test & SVN__LOWER_7BITS_SET) + SVN__LOWER_7BITS_SET; 69 70 /* Check whether at least one of the words contains a byte <0x80 71 * (if one is detected, there was a \r or \n in CHUNK). */ 72 if ((r_test & n_test & SVN__BIT_7_SET) != SVN__BIT_7_SET) 73 break; 74 } 75 76 /* The remaining odd bytes will be examined the naive way: */ 77 for (; len > 0; ++buf, --len) 78 { 79 if (*buf == '\n' || *buf == '\r') 80 return buf; 81 } 82 83 return NULL; 84} 85 86const char * 87svn_eol__detect_eol(char *buf, apr_size_t len, char **eolp) 88{ 89 char *eol; 90 91 eol = svn_eol__find_eol_start(buf, len); 92 if (eol) 93 { 94 if (eolp) 95 *eolp = eol; 96 97 if (*eol == '\n') 98 return "\n"; 99 100 /* We found a CR. */ 101 ++eol; 102 if (eol == buf + len || *eol != '\n') 103 return "\r"; 104 return "\r\n"; 105 } 106 107 return NULL; 108} 109