path: root/hwc2/common/utils/SysTokenizer.cpp (plain)
blob: 2855e27e19415442b0f0b8d50fdba60d333ba844

1	/*
2	* Copyright (C) 2011 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	* @author Tellen Yu
16	* @version 1.0
17	* @date 2014/11/04
18	* @par function description:
19	* - 1 parse file use tokenizer
20	*/
21
22	#define LOG_TAG "hwcomposer"
23	//#define LOG_NDEBUG 0
24
25	#include <stdio.h>
26	#include <string.h>
27	#include <stdlib.h>
28	#include <unistd.h>
29	#include <fcntl.h>
30	#include <errno.h>
31	#include <sys/types.h>
32	#include <sys/stat.h>
33	#include <HwcTrace.h>
34
35	#include "SysTokenizer.h"
36
37	// Enables debug output for the tokenizer.
38	#define DEBUG_TOKENIZER 1
39
40	static inline bool isDelimiter(char ch, const char* delimiters) {
41	return strchr(delimiters, ch) != NULL;
42	}
43
44	SysTokenizer::SysTokenizer(const char*filename, char* buffer,
45	bool ownBuffer, size_t length) :
46	mFilename(filename),
47	mBuffer(buffer), mOwnBuffer(ownBuffer), mLength(length),
48	mCurrent(buffer), mLineNumber(1) {
49	}
50
51	SysTokenizer::~SysTokenizer() {
52	if (mOwnBuffer) {
53	delete[] mBuffer;
54	}
55	}
56
57	int SysTokenizer::open(const char*filename, SysTokenizer** outTokenizer) {
58	*outTokenizer = NULL;
59
60	int result = 0;
61	int fd = ::open(filename, O_RDONLY);
62	if (fd < 0) {
63	result = -errno;
64	ETRACE("Error opening file '%s', %s.", filename, strerror(errno));
65	} else {
66	struct stat stat;
67	if (fstat(fd, &stat)) {
68	result = -errno;
69	ETRACE("Error getting size of file '%s', %s.", filename, strerror(errno));
70	} else {
71	size_t length = size_t(stat.st_size);
72	bool ownBuffer = false;
73	char* buffer;
74
75	// Fall back to reading into a buffer since we can't mmap files in sysfs.
76	// The length we obtained from stat is wrong too (it will always be 4096)
77	// so we must trust that read will read the entire file.
78	buffer = new char[length];
79	ownBuffer = true;
80	ssize_t nrd = read(fd, buffer, length);
81	if (nrd < 0) {
82	result = -errno;
83	ETRACE("Error reading file '%s', %s.", filename, strerror(errno));
84	delete[] buffer;
85	buffer = NULL;
86	} else {
87	length = size_t(nrd);
88	}
89
90	if (!result) {
91	*outTokenizer = new SysTokenizer(filename, buffer, ownBuffer, length);
92	}
93	}
94	close(fd);
95	}
96	return result;
97	}
98
99	int SysTokenizer::fromContents(const char*filename,
100	const char* contents, SysTokenizer** outTokenizer) {
101	*outTokenizer = new SysTokenizer(filename,
102	const_cast<char*>(contents), false, strlen(contents));
103	return 0;
104	}
105
106	char* SysTokenizer::getLocation() const {
107	memset((void*)mStrs, 0 , MAX_STR_LEN);
108	sprintf((char *)mStrs, "%s:%d", mFilename, mLineNumber);
109	return (char *)mStrs;
110	}
111
112	char* SysTokenizer::peekRemainderOfLine() const {
113	const char* end = getEnd();
114	const char* eol = mCurrent;
115	while (eol != end) {
116	char ch = *eol;
117	if (ch == '\n') {
118	break;
119	}
120	eol += 1;
121	}
122
123	memset((void*)mLine, 0 , MAX_STR_LEN);
124	strncpy((char *)mLine, mCurrent, eol - mCurrent);
125	return (char *)mLine;
126	}
127
128	char* SysTokenizer::nextToken(const char* delimiters) {
129	const char* end = getEnd();
130	const char* tokenStart = mCurrent;
131
132	#if DEBUG_TOKENIZER
133	ITRACE("nextToken mCurrent:%s, delimiters:%s\n", mCurrent, delimiters);
134	#endif
135
136	while (mCurrent != end) {
137	char ch = *mCurrent;
138	if (ch == '\n' || isDelimiter(ch, delimiters)) {
139	break;
140	}
141	mCurrent += 1;
142	}
143
144	memset((void*)mStrs, 0 , MAX_STR_LEN);
145	strncpy((char *)mStrs, tokenStart, mCurrent - tokenStart);
146
147	#if DEBUG_TOKENIZER
148	ITRACE("nextToken parse end str:%s, num:%d \n", mStrs, mCurrent - tokenStart);
149	#endif
150	return (char *)mStrs;
151	}
152
153	void SysTokenizer::nextLine() {
154	#if DEBUG_TOKENIZER
155	VTRACE("nextLine");
156	#endif
157	const char* end = getEnd();
158	while (mCurrent != end) {
159	char ch = *(mCurrent++);
160	if (ch == '\n') {
161	mLineNumber += 1;
162	break;
163	}
164	}
165	}
166
167	void SysTokenizer::skipDelimiters(const char* delimiters) {
168	#if DEBUG_TOKENIZER
169	VTRACE("skipDelimiters");
170	#endif
171	const char* end = getEnd();
172	while (mCurrent != end) {
173	char ch = *mCurrent;
174	if (ch == '\n' || !isDelimiter(ch, delimiters)) {
175	break;
176	}
177	mCurrent += 1;
178	}
179	}
180
181