1 /*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * 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 #define LOG_TAG "Tokenizer"
18
19 #include <stdlib.h>
20 #include <unistd.h>
21 #include <fcntl.h>
22 #include <errno.h>
23 #include <sys/types.h>
24 #include <sys/stat.h>
25 #include <utils/Log.h>
26 #include <utils/Tokenizer.h>
27
28 // Enables debug output for the tokenizer.
29 #define DEBUG_TOKENIZER 0
30
31
32 namespace android {
33
isDelimiter(char ch,const char * delimiters)34 static inline bool isDelimiter(char ch, const char* delimiters) {
35 return strchr(delimiters, ch) != NULL;
36 }
37
Tokenizer(const String8 & filename,FileMap * fileMap,char * buffer,size_t length)38 Tokenizer::Tokenizer(const String8& filename, FileMap* fileMap, char* buffer, size_t length) :
39 mFilename(filename), mFileMap(fileMap),
40 mBuffer(buffer), mLength(length), mCurrent(buffer), mLineNumber(1) {
41 }
42
~Tokenizer()43 Tokenizer::~Tokenizer() {
44 if (mFileMap) {
45 mFileMap->release();
46 } else {
47 delete[] mBuffer;
48 }
49 }
50
open(const String8 & filename,Tokenizer ** outTokenizer)51 status_t Tokenizer::open(const String8& filename, Tokenizer** outTokenizer) {
52 *outTokenizer = NULL;
53
54 int result = NO_ERROR;
55 int fd = ::open(filename.string(), O_RDONLY);
56 if (fd < 0) {
57 result = -errno;
58 LOGE("Error opening file '%s', %s.", filename.string(), strerror(errno));
59 } else {
60 struct stat stat;
61 if (fstat(fd, &stat)) {
62 result = -errno;
63 LOGE("Error getting size of file '%s', %s.", filename.string(), strerror(errno));
64 } else {
65 size_t length = size_t(stat.st_size);
66
67 FileMap* fileMap = new FileMap();
68 char* buffer;
69 if (fileMap->create(NULL, fd, 0, length, true)) {
70 fileMap->advise(FileMap::SEQUENTIAL);
71 buffer = static_cast<char*>(fileMap->getDataPtr());
72 } else {
73 fileMap->release();
74 fileMap = NULL;
75
76 // Fall back to reading into a buffer since we can't mmap files in sysfs.
77 // The length we obtained from stat is wrong too (it will always be 4096)
78 // so we must trust that read will read the entire file.
79 buffer = new char[length];
80 ssize_t nrd = read(fd, buffer, length);
81 if (nrd < 0) {
82 result = -errno;
83 LOGE("Error reading file '%s', %s.", filename.string(), strerror(errno));
84 delete[] buffer;
85 buffer = NULL;
86 } else {
87 length = size_t(nrd);
88 }
89 }
90
91 if (!result) {
92 *outTokenizer = new Tokenizer(filename, fileMap, buffer, length);
93 }
94 }
95 close(fd);
96 }
97 return result;
98 }
99
getLocation() const100 String8 Tokenizer::getLocation() const {
101 String8 result;
102 result.appendFormat("%s:%d", mFilename.string(), mLineNumber);
103 return result;
104 }
105
peekRemainderOfLine() const106 String8 Tokenizer::peekRemainderOfLine() const {
107 const char* end = getEnd();
108 const char* eol = mCurrent;
109 while (eol != end) {
110 char ch = *eol;
111 if (ch == '\n') {
112 break;
113 }
114 eol += 1;
115 }
116 return String8(mCurrent, eol - mCurrent);
117 }
118
nextToken(const char * delimiters)119 String8 Tokenizer::nextToken(const char* delimiters) {
120 #if DEBUG_TOKENIZER
121 LOGD("nextToken");
122 #endif
123 const char* end = getEnd();
124 const char* tokenStart = mCurrent;
125 while (mCurrent != end) {
126 char ch = *mCurrent;
127 if (ch == '\n' || isDelimiter(ch, delimiters)) {
128 break;
129 }
130 mCurrent += 1;
131 }
132 return String8(tokenStart, mCurrent - tokenStart);
133 }
134
nextLine()135 void Tokenizer::nextLine() {
136 #if DEBUG_TOKENIZER
137 LOGD("nextLine");
138 #endif
139 const char* end = getEnd();
140 while (mCurrent != end) {
141 char ch = *(mCurrent++);
142 if (ch == '\n') {
143 mLineNumber += 1;
144 break;
145 }
146 }
147 }
148
skipDelimiters(const char * delimiters)149 void Tokenizer::skipDelimiters(const char* delimiters) {
150 #if DEBUG_TOKENIZER
151 LOGD("skipDelimiters");
152 #endif
153 const char* end = getEnd();
154 while (mCurrent != end) {
155 char ch = *mCurrent;
156 if (ch == '\n' || !isDelimiter(ch, delimiters)) {
157 break;
158 }
159 mCurrent += 1;
160 }
161 }
162
163 } // namespace android
164