tmk_core/protocol/usb_hid/arduino-1.0.1/cores/arduino/Stream.cpp

   1 /*
   2  Stream.cpp - adds parsing methods to Stream class
   3  Copyright (c) 2008 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  Created July 2011
  20  parsing functions based on TextFinder library by Michael Margolis
  21  */
  22
  23 #include "Arduino.h"
  24 #include "Stream.h"
  25
  26 #define PARSE_TIMEOUT 1000  // default number of milli-seconds to wait
  27 #define NO_SKIP_CHAR  1  // a magic char not found in a valid ASCII numeric field
  28
  29 // private method to read stream with timeout
  30 int Stream::timedRead()
  31 {
  32   int c;
  33   _startMillis = millis();
  34   do {
  35     c = read();
  36     if (c >= 0) return c;
  37   } while(millis() - _startMillis < _timeout);
  38   return -1;     // -1 indicates timeout
  39 }
  40
  41 // private method to peek stream with timeout
  42 int Stream::timedPeek()
  43 {
  44   int c;
  45   _startMillis = millis();
  46   do {
  47     c = peek();
  48     if (c >= 0) return c;
  49   } while(millis() - _startMillis < _timeout);
  50   return -1;     // -1 indicates timeout
  51 }
  52
  53 // returns peek of the next digit in the stream or -1 if timeout
  54 // discards non-numeric characters
  55 int Stream::peekNextDigit()
  56 {
  57   int c;
  58   while (1) {
  59     c = timedPeek();
  60     if (c < 0) return c;  // timeout
  61     if (c == '-') return c;
  62     if (c >= '0' && c <= '9') return c;
  63     read();  // discard non-numeric
  64   }
  65 }
  66
  67 // Public Methods
  68 //////////////////////////////////////////////////////////////
  69
  70 void Stream::setTimeout(unsigned long timeout)  // sets the maximum number of milliseconds to wait
  71 {
  72   _timeout = timeout;
  73 }
  74
  75  // find returns true if the target string is found
  76 bool  Stream::find(char *target)
  77 {
  78   return findUntil(target, NULL);
  79 }
  80
  81 // reads data from the stream until the target string of given length is found
  82 // returns true if target string is found, false if timed out
  83 bool Stream::find(char *target, size_t length)
  84 {
  85   return findUntil(target, length, NULL, 0);
  86 }
  87
  88 // as find but search ends if the terminator string is found
  89 bool  Stream::findUntil(char *target, char *terminator)
  90 {
  91   return findUntil(target, strlen(target), terminator, strlen(terminator));
  92 }
  93
  94 // reads data from the stream until the target string of the given length is found
  95 // search terminated if the terminator string is found
  96 // returns true if target string is found, false if terminated or timed out
  97 bool Stream::findUntil(char *target, size_t targetLen, char *terminator, size_t termLen)
  98 {
  99   size_t index = 0;  // maximum target string length is 64k bytes!
 100   size_t termIndex = 0;
 101   int c;
 102
 103   if( *target == 0)
 104     return true;   // return true if target is a null string
 105   while( (c = timedRead()) > 0){
 106
 107     if(c != target[index])
 108       index = 0; // reset index if any char does not match
 109
 110     if( c == target[index]){
 111       //////Serial.print("found "); Serial.write(c); Serial.print("index now"); Serial.println(index+1);
 112       if(++index >= targetLen){ // return true if all chars in the target match
 113         return true;
 114       }
 115     }
 116
 117     if(termLen > 0 && c == terminator[termIndex]){
 118       if(++termIndex >= termLen)
 119         return false;       // return false if terminate string found before target string
 120     }
 121     else
 122       termIndex = 0;
 123   }
 124   return false;
 125 }
 126
 127
 128 // returns the first valid (long) integer value from the current position.
 129 // initial characters that are not digits (or the minus sign) are skipped
 130 // function is terminated by the first character that is not a digit.
 131 long Stream::parseInt()
 132 {
 133   return parseInt(NO_SKIP_CHAR); // terminate on first non-digit character (or timeout)
 134 }
 135
 136 // as above but a given skipChar is ignored
 137 // this allows format characters (typically commas) in values to be ignored
 138 long Stream::parseInt(char skipChar)
 139 {
 140   boolean isNegative = false;
 141   long value = 0;
 142   int c;
 143
 144   c = peekNextDigit();
 145   // ignore non numeric leading characters
 146   if(c < 0)
 147     return 0; // zero returned if timeout
 148
 149   do{
 150     if(c == skipChar)
 151       ; // ignore this charactor
 152     else if(c == '-')
 153       isNegative = true;
 154     else if(c >= '0' && c <= '9')        // is c a digit?
 155       value = value * 10 + c - '0';
 156     read();  // consume the character we got with peek
 157     c = timedPeek();
 158   }
 159   while( (c >= '0' && c <= '9') || c == skipChar );
 160
 161   if(isNegative)
 162     value = -value;
 163   return value;
 164 }
 165
 166
 167 // as parseInt but returns a floating point value
 168 float Stream::parseFloat()
 169 {
 170   return parseFloat(NO_SKIP_CHAR);
 171 }
 172
 173 // as above but the given skipChar is ignored
 174 // this allows format characters (typically commas) in values to be ignored
 175 float Stream::parseFloat(char skipChar){
 176   boolean isNegative = false;
 177   boolean isFraction = false;
 178   long value = 0;
 179   char c;
 180   float fraction = 1.0;
 181
 182   c = peekNextDigit();
 183     // ignore non numeric leading characters
 184   if(c < 0)
 185     return 0; // zero returned if timeout
 186
 187   do{
 188     if(c == skipChar)
 189       ; // ignore
 190     else if(c == '-')
 191       isNegative = true;
 192     else if (c == '.')
 193       isFraction = true;
 194     else if(c >= '0' && c <= '9')  {      // is c a digit?
 195       value = value * 10 + c - '0';
 196       if(isFraction)
 197          fraction *= 0.1;
 198     }
 199     read();  // consume the character we got with peek
 200     c = timedPeek();
 201   }
 202   while( (c >= '0' && c <= '9')  || c == '.' || c == skipChar );
 203
 204   if(isNegative)
 205     value = -value;
 206   if(isFraction)
 207     return value * fraction;
 208   else
 209     return value;
 210 }
 211
 212 // read characters from stream into buffer
 213 // terminates if length characters have been read, or timeout (see setTimeout)
 214 // returns the number of characters placed in the buffer
 215 // the buffer is NOT null terminated.
 216 //
 217 size_t Stream::readBytes(char *buffer, size_t length)
 218 {
 219   size_t count = 0;
 220   while (count < length) {
 221     int c = timedRead();
 222     if (c < 0) break;
 223     *buffer++ = (char)c;
 224     count++;
 225   }
 226   return count;
 227 }
 228
 229
 230 // as readBytes with terminator character
 231 // terminates if length characters have been read, timeout, or if the terminator character  detected
 232 // returns the number of characters placed in the buffer (0 means no valid data found)
 233
 234 size_t Stream::readBytesUntil(char terminator, char *buffer, size_t length)
 235 {
 236   if (length < 1) return 0;
 237   size_t index = 0;
 238   while (index < length) {
 239     int c = timedRead();
 240     if (c < 0 || c == terminator) break;
 241     *buffer++ = (char)c;
 242     index++;
 243   }
 244   return index; // return number of characters, not including null terminator
 245 }
 246
 247 String Stream::readString()
 248 {
 249   String ret;
 250   int c = timedRead();
 251   while (c >= 0)
 252   {
 253     ret += (char)c;
 254     c = timedRead();
 255   }
 256   return ret;
 257 }
 258
 259 String Stream::readStringUntil(char terminator)
 260 {
 261   String ret;
 262   int c = timedRead();
 263   while (c >= 0 && c != terminator)
 264   {
 265     ret += (char)c;
 266     c = timedRead();
 267   }
 268   return ret;
 269 }
 270