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authoramcewen <amcewen@bcs.org.uk>2011-08-27 23:53:42 +0100
committeramcewen <amcewen@bcs.org.uk>2011-08-27 23:53:42 +0100
commitf9d50a793010db3a2968262f35d34edaf048a650 (patch)
tree5b66626e02248e4e0f9a3d61a0989c1b07e30ab0 /cores/arduino/Stream.cpp
parent58aaa903f8aaaf7735ca2df803ec028b420a754b (diff)
parent5130a1329462aa36d5f18e31851d3d9d5086e411 (diff)
Merge branch 'new-extension' of https://github.com/arduino/Arduino
Diffstat (limited to 'cores/arduino/Stream.cpp')
-rw-r--r--cores/arduino/Stream.cpp233
1 files changed, 233 insertions, 0 deletions
diff --git a/cores/arduino/Stream.cpp b/cores/arduino/Stream.cpp
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+/*
+ 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()
+{
+ //Serial.println(_timeout);
+ this->_startMillis = millis();
+ while(millis() - this->_startMillis < this->_timeout)
+ {
+ if (this->available() > 0) {
+ return this->read();
+ }
+ }
+ return -1; // -1 indicates timeout
+}
+
+// returns the next digit in the stream or -1 if timeout
+// discards non-numeric characters
+int Stream::getNextDigit()
+{
+ int c;
+ do{
+ c = timedRead();
+ if( c < 0)
+ return c; // timeout
+ }
+ while( c != '-' && (c < '0' || c > '9') ) ;
+
+return c;
+}
+
+// Public Methods
+//////////////////////////////////////////////////////////////
+
+void Stream::setTimeout( long timeout) // sets the maximum number of milliseconds to wait
+{
+ this->_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 = getNextDigit();
+ // 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';
+ c = timedRead();
+ }
+ while( (c >= '0' && c <= '9') || c == skipChar );
+
+ if(isNegative)
+ value = -value;
+ return value;
+}
+
+
+// as parseInt but returns a floating point value
+float Stream::parseFloat()
+{
+ 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;
+ float fValue;
+ char c;
+ float fraction = 1.0;
+
+ c = getNextDigit();
+ // 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;
+ }
+ c = timedRead();
+ }
+ 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)
+{
+ 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
+}
+