path: root/hwc2/common/utils/SysTokenizer.h (plain)
blob: af16f34c6b71dd1c6b57036d47f2efccfa37b34e

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	#ifndef _SYS_TOKENIZER_H
23	#define _SYS_TOKENIZER_H
24
25	#include <assert.h>
26
27	#define MAX_STR_LEN 4096
28
29	/**
30	* A simple tokenizer for loading and parsing ASCII text files line by line.
31	*/
32	class SysTokenizer {
33	public:
34	SysTokenizer(const char*filename, char* buffer,
35	bool ownBuffer, size_t length);
36
37	~SysTokenizer();
38
39	/**
40	* Opens a file and maps it into memory.
41	*
42	* Returns NO_ERROR and a tokenizer for the file, if successful.
43	* Otherwise returns an error and sets outTokenizer to NULL.
44	*/
45	static int open(const char*filename, SysTokenizer** outTokenizer);
46
47	/**
48	* Prepares to tokenize the contents of a string.
49	*
50	* Returns NO_ERROR and a tokenizer for the string, if successful.
51	* Otherwise returns an error and sets outTokenizer to NULL.
52	*/
53	static int fromContents(const char*filename,
54	const char* contents, SysTokenizer** outTokenizer);
55
56	/**
57	* Returns true if at the end of the file.
58	*/
59	inline bool isEof() const { return mCurrent == getEnd(); }
60
61	/**
62	* Returns true if at the end of the line or end of the file.
63	*/
64	inline bool isEol() const { return isEof() || *mCurrent == '\n'; }
65
66	/**
67	* Gets the name of the file.
68	*/
69	inline char* getFilename() const { return const_cast<char*>(mFilename); }
70
71	/**
72	* Gets a 1-based line number index for the current position.
73	*/
74	inline int32_t getLineNumber() const { return mLineNumber; }
75
76	/**
77	* Formats a location string consisting of the filename and current line number.
78	* Returns a string like "MyFile.txt:33".
79	*/
80	char* getLocation() const;
81
82	/**
83	* Gets the character at the current position.
84	* Returns null at end of file.
85	*/
86	inline char peekChar() const { return isEof() ? '\0' : *mCurrent; }
87
88	/**
89	* Gets the remainder of the current line as a string, excluding the newline character.
90	*/
91	char* peekRemainderOfLine() const;
92
93	/**
94	* Gets the character at the current position and advances past it.
95	* Returns null at end of file.
96	*/
97	inline char nextChar() { return isEof() ? '\0' : *(mCurrent++); }
98
99	/**
100	* Gets the next token on this line stopping at the specified delimiters
101	* or the end of the line whichever comes first and advances past it.
102	* Also stops at embedded nulls.
103	* Returns the token or an empty string if the current character is a delimiter
104	* or is at the end of the line.
105	*/
106	char* nextToken(const char* delimiters);
107
108	/**
109	* Advances to the next line.
110	* Does nothing if already at the end of the file.
111	*/
112	void nextLine();
113
114	/**
115	* Skips over the specified delimiters in the line.
116	* Also skips embedded nulls.
117	*/
118	void skipDelimiters(const char* delimiters);
119
120	private:
121	const char* mFilename;
122	char* mBuffer;
123	bool mOwnBuffer;
124	size_t mLength;
125
126	const char* mCurrent;
127	int32_t mLineNumber;
128
129	char mStrs[MAX_STR_LEN];
130	char mLine[MAX_STR_LEN];
131	inline const char* getEnd() const { return mBuffer + mLength; }
132
133	};
134
135	#endif // _SYS_TOKENIZER_H
136