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 #ifndef _UTILS_TOKENIZER_H 18 #define _UTILS_TOKENIZER_H 19 20 #include <assert.h> 21 #include <utils/Errors.h> 22 #include <utils/FileMap.h> 23 #include <utils/String8.h> 24 25 namespace android { 26 27 /** 28 * A simple tokenizer for loading and parsing ASCII text files line by line. 29 */ 30 class Tokenizer { 31 Tokenizer(const String8& filename, FileMap* fileMap, char* buffer, 32 bool ownBuffer, size_t length); 33 34 public: 35 ~Tokenizer(); 36 37 /** 38 * Opens a file and maps it into memory. 39 * 40 * Returns OK and a tokenizer for the file, if successful. 41 * Otherwise returns an error and sets outTokenizer to NULL. 42 */ 43 static status_t open(const String8& filename, Tokenizer** outTokenizer); 44 45 /** 46 * Prepares to tokenize the contents of a string. 47 * 48 * Returns OK and a tokenizer for the string, if successful. 49 * Otherwise returns an error and sets outTokenizer to NULL. 50 */ 51 static status_t fromContents(const String8& filename, 52 const char* contents, Tokenizer** outTokenizer); 53 54 /** 55 * Returns true if at the end of the file. 56 */ isEof()57 inline bool isEof() const { return mCurrent == getEnd(); } 58 59 /** 60 * Returns true if at the end of the line or end of the file. 61 */ isEol()62 inline bool isEol() const { return isEof() || *mCurrent == '\n'; } 63 64 /** 65 * Gets the name of the file. 66 */ getFilename()67 inline String8 getFilename() const { return mFilename; } 68 69 /** 70 * Gets a 1-based line number index for the current position. 71 */ getLineNumber()72 inline int32_t getLineNumber() const { return mLineNumber; } 73 74 /** 75 * Formats a location string consisting of the filename and current line number. 76 * Returns a string like "MyFile.txt:33". 77 */ 78 String8 getLocation() const; 79 80 /** 81 * Gets the character at the current position. 82 * Returns null at end of file. 83 */ peekChar()84 inline char peekChar() const { return isEof() ? '\0' : *mCurrent; } 85 86 /** 87 * Gets the remainder of the current line as a string, excluding the newline character. 88 */ 89 String8 peekRemainderOfLine() const; 90 91 /** 92 * Gets the character at the current position and advances past it. 93 * Returns null at end of file. 94 */ nextChar()95 inline char nextChar() { return isEof() ? '\0' : *(mCurrent++); } 96 97 /** 98 * Gets the next token on this line stopping at the specified delimiters 99 * or the end of the line whichever comes first and advances past it. 100 * Also stops at embedded nulls. 101 * Returns the token or an empty string if the current character is a delimiter 102 * or is at the end of the line. 103 */ 104 String8 nextToken(const char* delimiters); 105 106 /** 107 * Advances to the next line. 108 * Does nothing if already at the end of the file. 109 */ 110 void nextLine(); 111 112 /** 113 * Skips over the specified delimiters in the line. 114 * Also skips embedded nulls. 115 */ 116 void skipDelimiters(const char* delimiters); 117 118 private: 119 Tokenizer(const Tokenizer& other); // not copyable 120 121 String8 mFilename; 122 FileMap* mFileMap; 123 char* mBuffer; 124 bool mOwnBuffer; 125 size_t mLength; 126 127 const char* mCurrent; 128 int32_t mLineNumber; 129 getEnd()130 inline const char* getEnd() const { return mBuffer + mLength; } 131 132 }; 133 134 } // namespace android 135 136 #endif // _UTILS_TOKENIZER_H 137