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| 1 | +/* |
| 2 | + IStream.h - base class for character-based input streams. |
| 3 | + Copyright (c) 2010 David A. Mellis. All right reserved. |
| 4 | + |
| 5 | + This library is free software; you can redistribute it and/or |
| 6 | + modify it under the terms of the GNU Lesser General Public |
| 7 | + License as published by the Free Software Foundation; either |
| 8 | + version 2.1 of the License, or (at your option) any later version. |
| 9 | + |
| 10 | + This library is distributed in the hope that it will be useful, |
| 11 | + but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | + Lesser General Public License for more details. |
| 14 | + |
| 15 | + You should have received a copy of the GNU Lesser General Public |
| 16 | + License along with this library; if not, write to the Free Software |
| 17 | + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA |
| 18 | + |
| 19 | + parsing functions based on TextFinder library by Michael Margolis |
| 20 | +*/ |
| 21 | + |
| 22 | +#ifndef IStream_h |
| 23 | +#define IStream_h |
| 24 | + |
| 25 | +#include <inttypes.h> |
| 26 | + |
| 27 | +// compatability macros for testing |
| 28 | +/* |
| 29 | +#define getInt() parseInt() |
| 30 | +#define getInt(ignore) parseInt(ignore) |
| 31 | +#define getFloat() parseFloat() |
| 32 | +#define getFloat(ignore) parseFloat(ignore) |
| 33 | +#define getString( pre_string, post_string, buffer, length) |
| 34 | +readBytesBetween( pre_string, terminator, buffer, length) |
| 35 | +*/ |
| 36 | + |
| 37 | +// This enumeration provides the lookahead options for parseInt(), parseFloat() |
| 38 | +// The rules set out here are used until either the first valid character is found |
| 39 | +// or a time out occurs due to lack of input. |
| 40 | +enum LookaheadMode{ |
| 41 | + SKIP_ALL, // All invalid characters are ignored. |
| 42 | + SKIP_NONE, // Nothing is skipped, and the stream is not touched unless the first waiting character is valid. |
| 43 | + SKIP_WHITESPACE // Only tabs, spaces, line feeds & carriage returns are skipped. |
| 44 | +}; |
| 45 | + |
| 46 | +#define NO_IGNORE_CHAR '\x01' // a char not found in a valid ASCII numeric field |
| 47 | + |
| 48 | +class IStream |
| 49 | +{ |
| 50 | + protected: |
| 51 | + unsigned long _timeout; // number of milliseconds to wait for the next char before aborting timed read |
| 52 | + unsigned long _startMillis; // used for timeout measurement |
| 53 | + int timedRead(); // private method to read stream with timeout |
| 54 | + int timedPeek(); // private method to peek stream with timeout |
| 55 | + int peekNextDigit(LookaheadMode lookahead, bool detectDecimal); // returns the next numeric digit in the stream or -1 if timeout |
| 56 | + |
| 57 | + public: |
| 58 | + virtual int available() = 0; |
| 59 | + virtual int read() = 0; |
| 60 | + virtual int peek() = 0; |
| 61 | + |
| 62 | + IStream() {_timeout=1000;} |
| 63 | + |
| 64 | +// parsing methods |
| 65 | + |
| 66 | + void setTimeout(unsigned long timeout); // sets maximum milliseconds to wait for stream data, default is 1 second |
| 67 | + unsigned long getTimeout(void) { return _timeout; } |
| 68 | + |
| 69 | + bool find(char *target); // reads data from the stream until the target string is found |
| 70 | + bool find(uint8_t *target) { return find ((char *)target); } |
| 71 | + // returns true if target string is found, false if timed out (see setTimeout) |
| 72 | + |
| 73 | + bool find(char *target, size_t length); // reads data from the stream until the target string of given length is found |
| 74 | + bool find(uint8_t *target, size_t length) { return find ((char *)target, length); } |
| 75 | + // returns true if target string is found, false if timed out |
| 76 | + |
| 77 | + bool find(char target) { return find (&target, 1); } |
| 78 | + |
| 79 | + bool findUntil(char *target, char *terminator); // as find but search ends if the terminator string is found |
| 80 | + bool findUntil(uint8_t *target, char *terminator) { return findUntil((char *)target, terminator); } |
| 81 | + |
| 82 | + bool findUntil(char *target, size_t targetLen, char *terminate, size_t termLen); // as above but search ends if the terminate string is found |
| 83 | + bool findUntil(uint8_t *target, size_t targetLen, char *terminate, size_t termLen) {return findUntil((char *)target, targetLen, terminate, termLen); } |
| 84 | + |
| 85 | + long parseInt(LookaheadMode lookahead = SKIP_ALL, char ignore = NO_IGNORE_CHAR); |
| 86 | + // returns the first valid (long) integer value from the current position. |
| 87 | + // lookahead determines how parseInt looks ahead in the stream. |
| 88 | + // See LookaheadMode enumeration at the top of the file. |
| 89 | + // Lookahead is terminated by the first character that is not a valid part of an integer. |
| 90 | + // Once parsing commences, 'ignore' will be skipped in the stream. |
| 91 | + |
| 92 | + float parseFloat(LookaheadMode lookahead = SKIP_ALL, char ignore = NO_IGNORE_CHAR); |
| 93 | + // float version of parseInt |
| 94 | + |
| 95 | + size_t readBytes( char *buffer, size_t length); // read chars from stream into buffer |
| 96 | + size_t readBytes( uint8_t *buffer, size_t length) { return readBytes((char *)buffer, length); } |
| 97 | + // terminates if length characters have been read or timeout (see setTimeout) |
| 98 | + // returns the number of characters placed in the buffer (0 means no valid data found) |
| 99 | + |
| 100 | + size_t readBytesUntil( char terminator, char *buffer, size_t length); // as readBytes with terminator character |
| 101 | + size_t readBytesUntil( char terminator, uint8_t *buffer, size_t length) { return readBytesUntil(terminator, (char *)buffer, length); } |
| 102 | + // terminates if length characters have been read, timeout, or if the terminator character detected |
| 103 | + // returns the number of characters placed in the buffer (0 means no valid data found) |
| 104 | + |
| 105 | + // Arduino String functions to be added here |
| 106 | + String readString(); |
| 107 | + String readStringUntil(char terminator); |
| 108 | + |
| 109 | + protected: |
| 110 | + long parseInt(char ignore) { return parseInt(SKIP_ALL, ignore); } |
| 111 | + float parseFloat(char ignore) { return parseFloat(SKIP_ALL, ignore); } |
| 112 | + // These overload exists for compatibility with any class that has derived |
| 113 | + // IStream and used parseFloat/Int with a custom ignore character. To keep |
| 114 | + // the public API simple, these overload remains protected. |
| 115 | + |
| 116 | + struct MultiTarget { |
| 117 | + const char *str; // string you're searching for |
| 118 | + size_t len; // length of string you're searching for |
| 119 | + size_t index; // index used by the search routine. |
| 120 | + }; |
| 121 | + |
| 122 | + // This allows you to search for an arbitrary number of strings. |
| 123 | + // Returns index of the target that is found first or -1 if timeout occurs. |
| 124 | + int findMulti(struct MultiTarget *targets, int tCount); |
| 125 | +}; |
| 126 | + |
| 127 | +#undef NO_IGNORE_CHAR |
| 128 | +#endif |
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