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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>
-
- #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;
- unsigned long startMillis = millis();
- do {
- c = read();
- if (c >= 0) return c;
- yield();
- } while(millis() - startMillis < _timeout);
- return -1; // -1 indicates timeout
- }
-
- // private method to peek stream with timeout
- int Stream::timedPeek()
- {
- int c;
- unsigned long startMillis = millis();
- do {
- c = peek();
- if (c >= 0) return c;
- yield();
- } 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(const 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(const 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(const char *target, const char *terminator)
- {
- if(target == NULL) return true;
- size_t tlen = (terminator==NULL)?0:strlen(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(const char *target, size_t targetLen, const char *terminator, size_t termLen)
- {
- size_t index = 0; // maximum target string length is 64k bytes!
- size_t termIndex = 0;
- int c;
- if( target == NULL) return true;
- if( *target == 0) return true; // return true if target is a null string
- if (terminator == NULL) termLen = 0;
-
- 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;
- int 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, or timeout (see setTimeout)
- // returns the number of characters placed in the buffer
- // the buffer is NOT null terminated.
- //
- size_t Stream::readBytes(char *buffer, size_t length)
- {
- size_t count = 0;
- while (count < length) {
- int c = timedRead();
- if (c < 0) {
- setReadError();
- break;
- }
- *buffer++ = (char)c;
- count++;
- }
- return count;
- }
-
-
- // 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)
-
- size_t Stream::readBytesUntil(char terminator, char *buffer, size_t length)
- {
- if (length < 1) return 0;
- length--;
- size_t index = 0;
- while (index < length) {
- int c = timedRead();
- if (c == terminator) break;
- if (c < 0) {
- setReadError();
- break;
- }
- *buffer++ = (char)c;
- index++;
- }
- *buffer = 0;
- return index; // return number of characters, not including null terminator
- }
-
- String Stream::readString(size_t max)
- {
- String str;
- size_t length = 0;
- while (length < max) {
- int c = timedRead();
- if (c < 0) {
- setReadError();
- break; // timeout
- }
- if (c == 0) break;
- str += (char)c;
- length++;
- }
- return str;
- }
-
- String Stream::readStringUntil(char terminator, size_t max)
- {
- String str;
- size_t length = 0;
- while (length < max) {
- int c = timedRead();
- if (c < 0) {
- setReadError();
- break; // timeout
- }
- if (c == 0 || c == terminator) break;
- str += (char)c;
- length++;
- }
- return str;
- }
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