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Diffstat (limited to 'cores/arduino/Stream.cpp')
| -rw-r--r-- | cores/arduino/Stream.cpp | 243 |
1 files changed, 243 insertions, 0 deletions
diff --git a/cores/arduino/Stream.cpp b/cores/arduino/Stream.cpp new file mode 100644 index 0000000..a7d9d38 --- /dev/null +++ b/cores/arduino/Stream.cpp @@ -0,0 +1,243 @@ +/* + Stream.cpp - adds parsing methods to Stream class + Copyright (c) 2008 David A. Mellis. All right reserved. + + This library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + This library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with this library; if not, write to the Free Software + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + + Created July 2011 + parsing functions based on TextFinder library by Michael Margolis + */ + +#include "Arduino.h" +#include "Stream.h" + +#define PARSE_TIMEOUT 1000 // default number of milli-seconds to wait +#define NO_SKIP_CHAR 1 // a magic char not found in a valid ASCII numeric field + +// private method to read stream with timeout +int Stream::timedRead() +{ + int c; + _startMillis = millis(); + do { + c = read(); + if (c >= 0) return c; + } while(millis() - _startMillis < _timeout); + return -1; // -1 indicates timeout +} + +// private method to peek stream with timeout +int Stream::timedPeek() +{ + int c; + _startMillis = millis(); + do { + c = peek(); + if (c >= 0) return c; + } while(millis() - _startMillis < _timeout); + return -1; // -1 indicates timeout +} + +// returns peek of the next digit in the stream or -1 if timeout +// discards non-numeric characters +int Stream::peekNextDigit() +{ + int c; + while (1) { + c = timedPeek(); + if (c < 0) return c; // timeout + if (c == '-') return c; + if (c >= '0' && c <= '9') return c; + read(); // discard non-numeric + } +} + +// Public Methods +////////////////////////////////////////////////////////////// + +void Stream::setTimeout(unsigned long timeout) // sets the maximum number of milliseconds to wait +{ + _timeout = timeout; +} + + // find returns true if the target string is found +bool Stream::find(char *target) +{ + return findUntil(target, NULL); +} + +// reads data from the stream until the target string of given length is found +// returns true if target string is found, false if timed out +bool Stream::find(char *target, size_t length) +{ + return findUntil(target, length, NULL, 0); +} + +// as find but search ends if the terminator string is found +bool Stream::findUntil(char *target, char *terminator) +{ + return findUntil(target, strlen(target), terminator, strlen(terminator)); +} + +// reads data from the stream until the target string of the given length is found +// search terminated if the terminator string is found +// returns true if target string is found, false if terminated or timed out +bool Stream::findUntil(char *target, size_t targetLen, char *terminator, size_t termLen) +{ + size_t index = 0; // maximum target string length is 64k bytes! + size_t termIndex = 0; + int c; + + if( *target == 0) + return true; // return true if target is a null string + while( (c = timedRead()) > 0){ + if( c == target[index]){ + //////Serial.print("found "); Serial.write(c); Serial.print("index now"); Serial.println(index+1); + if(++index >= targetLen){ // return true if all chars in the target match + return true; + } + } + else{ + index = 0; // reset index if any char does not match + } + if(termLen > 0 && c == terminator[termIndex]){ + if(++termIndex >= termLen) + return false; // return false if terminate string found before target string + } + else + termIndex = 0; + } + return false; +} + + +// returns the first valid (long) integer value from the current position. +// initial characters that are not digits (or the minus sign) are skipped +// function is terminated by the first character that is not a digit. +long Stream::parseInt() +{ + return parseInt(NO_SKIP_CHAR); // terminate on first non-digit character (or timeout) +} + +// as above but a given skipChar is ignored +// this allows format characters (typically commas) in values to be ignored +long Stream::parseInt(char skipChar) +{ + boolean isNegative = false; + long value = 0; + int c; + + c = peekNextDigit(); + // ignore non numeric leading characters + if(c < 0) + return 0; // zero returned if timeout + + do{ + if(c == skipChar) + ; // ignore this charactor + else if(c == '-') + isNegative = true; + else if(c >= '0' && c <= '9') // is c a digit? + value = value * 10 + c - '0'; + read(); // consume the character we got with peek + c = timedPeek(); + } + while( (c >= '0' && c <= '9') || c == skipChar ); + + if(isNegative) + value = -value; + return value; +} + + +// as parseInt but returns a floating point value +float Stream::parseFloat() +{ + return parseFloat(NO_SKIP_CHAR); +} + +// as above but the given skipChar is ignored +// this allows format characters (typically commas) in values to be ignored +float Stream::parseFloat(char skipChar){ + boolean isNegative = false; + boolean isFraction = false; + long value = 0; + char c; + float fraction = 1.0; + + c = peekNextDigit(); + // ignore non numeric leading characters + if(c < 0) + return 0; // zero returned if timeout + + do{ + if(c == skipChar) + ; // ignore + else if(c == '-') + isNegative = true; + else if (c == '.') + isFraction = true; + else if(c >= '0' && c <= '9') { // is c a digit? + value = value * 10 + c - '0'; + if(isFraction) + fraction *= 0.1; + } + read(); // consume the character we got with peek + c = timedPeek(); + } + while( (c >= '0' && c <= '9') || c == '.' || c == skipChar ); + + if(isNegative) + value = -value; + if(isFraction) + return value * fraction; + else + return value; +} + +// read characters from stream into buffer +// terminates if length characters have been read, null is detected or timeout (see setTimeout) +// returns the number of characters placed in the buffer (0 means no valid data found) +int Stream::readBytes( char *buffer, size_t length) +{ + return readBytesUntil( 0, buffer, length); +} + + +// as readBytes with terminator character +// terminates if length characters have been read, timeout, or if the terminator character detected +// returns the number of characters placed in the buffer (0 means no valid data found) + +int Stream::readBytesUntil( char terminator, char *buffer, size_t length) +{ + unsigned int index = 0; + *buffer = 0; + while(index < length-1 ){ + int c = timedRead(); + if( c <= 0 ){ + return 0; // timeout returns 0 ! + } + else if( c == terminator){ + buffer[index] = 0; // terminate the string + return index; // data got successfully + } + else{ + buffer[index++] = (char)c; + } + } + buffer[index] = 0; + return index; // here if buffer is full before detecting the terminator +} + |