summaryrefslogtreecommitdiffstats
path: root/include/utils/Tokenizer.h
blob: bb25f374cb343c5cc80b9d400e2ab9f59eca813f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
/*
 * Copyright (C) 2010 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef _UTILS_TOKENIZER_H
#define _UTILS_TOKENIZER_H

#include <assert.h>
#include <utils/Errors.h>
#include <utils/FileMap.h>
#include <utils/String8.h>

namespace android {

/**
 * A simple tokenizer for loading and parsing ASCII text files line by line.
 */
class Tokenizer {
    Tokenizer(const String8& filename, FileMap* fileMap, char* buffer,
            bool ownBuffer, size_t length);

public:
    ~Tokenizer();

    /**
     * Opens a file and maps it into memory.
     *
     * Returns NO_ERROR and a tokenizer for the file, if successful.
     * Otherwise returns an error and sets outTokenizer to NULL.
     */
    static status_t open(const String8& filename, Tokenizer** outTokenizer);

    /**
     * Prepares to tokenize the contents of a string.
     *
     * Returns NO_ERROR and a tokenizer for the string, if successful.
     * Otherwise returns an error and sets outTokenizer to NULL.
     */
    static status_t fromContents(const String8& filename,
            const char* contents, Tokenizer** outTokenizer);

    /**
     * Returns true if at the end of the file.
     */
    inline bool isEof() const { return mCurrent == getEnd(); }

    /**
     * Returns true if at the end of the line or end of the file.
     */
    inline bool isEol() const { return isEof() || *mCurrent == '\n'; }

    /**
     * Gets the name of the file.
     */
    inline String8 getFilename() const { return mFilename; }

    /**
     * Gets a 1-based line number index for the current position.
     */
    inline int32_t getLineNumber() const { return mLineNumber; }

    /**
     * Formats a location string consisting of the filename and current line number.
     * Returns a string like "MyFile.txt:33".
     */
    String8 getLocation() const;

    /**
     * Gets the character at the current position.
     * Returns null at end of file.
     */
    inline char peekChar() const { return isEof() ? '\0' : *mCurrent; }

    /**
     * Gets the remainder of the current line as a string, excluding the newline character.
     */
    String8 peekRemainderOfLine() const;

    /**
     * Gets the character at the current position and advances past it.
     * Returns null at end of file.
     */
    inline char nextChar() { return isEof() ? '\0' : *(mCurrent++); }

    /**
     * Gets the next token on this line stopping at the specified delimiters
     * or the end of the line whichever comes first and advances past it.
     * Also stops at embedded nulls.
     * Returns the token or an empty string if the current character is a delimiter
     * or is at the end of the line.
     */
    String8 nextToken(const char* delimiters);

    /**
     * Advances to the next line.
     * Does nothing if already at the end of the file.
     */
    void nextLine();

    /**
     * Skips over the specified delimiters in the line.
     * Also skips embedded nulls.
     */
    void skipDelimiters(const char* delimiters);

private:
    Tokenizer(const Tokenizer& other); // not copyable

    String8 mFilename;
    FileMap* mFileMap;
    char* mBuffer;
    bool mOwnBuffer;
    size_t mLength;

    const char* mCurrent;
    int32_t mLineNumber;

    inline const char* getEnd() const { return mBuffer + mLength; }

};

} // namespace android

#endif // _UTILS_TOKENIZER_H