diff options
Diffstat (limited to 'cores/xinput/Stream.cpp')
-rw-r--r-- | cores/xinput/Stream.cpp | 318 |
1 files changed, 318 insertions, 0 deletions
diff --git a/cores/xinput/Stream.cpp b/cores/xinput/Stream.cpp new file mode 100644 index 0000000..9eff663 --- /dev/null +++ b/cores/xinput/Stream.cpp @@ -0,0 +1,318 @@ +/* + 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 + + findMulti/findUntil routines written by Jim Leonard/Xuth + */ + +#include "Arduino.h" +#include "Stream.h" + +#define PARSE_TIMEOUT 1000 // default number of milli-seconds to wait + +// protected 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 +} + +// protected 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(LookaheadMode lookahead, bool detectDecimal) +{ + int c; + while (1) { + c = timedPeek(); + + if( c < 0 || + c == '-' || + (c >= '0' && c <= '9') || + (detectDecimal && c == '.')) return c; + + switch( lookahead ){ + case SKIP_NONE: return -1; // Fail code. + case SKIP_WHITESPACE: + switch( c ){ + case ' ': + case '\t': + case '\r': + case '\n': break; + default: return -1; // Fail code. + } + case SKIP_ALL: + break; + } + 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, strlen(target), NULL, 0); +} + +// 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) +{ + if (terminator == NULL) { + MultiTarget t[1] = {{target, targetLen, 0}}; + return findMulti(t, 1) == 0 ? true : false; + } else { + MultiTarget t[2] = {{target, targetLen, 0}, {terminator, termLen, 0}}; + return findMulti(t, 2) == 0 ? true : false; + } +} + +// returns the first valid (long) integer value from the current position. +// lookahead determines how parseInt looks ahead in the stream. +// See LookaheadMode enumeration at the top of the file. +// Lookahead is terminated by the first character that is not a valid part of an integer. +// Once parsing commences, 'ignore' will be skipped in the stream. +long Stream::parseInt(LookaheadMode lookahead, char ignore) +{ + bool isNegative = false; + long value = 0; + int c; + + c = peekNextDigit(lookahead, false); + // ignore non numeric leading characters + if(c < 0) + return 0; // zero returned if timeout + + do{ + if(c == ignore) + ; // ignore this character + 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 == ignore ); + + if(isNegative) + value = -value; + return value; +} + +// as parseInt but returns a floating point value +float Stream::parseFloat(LookaheadMode lookahead, char ignore) +{ + bool isNegative = false; + bool isFraction = false; + long value = 0; + int c; + float fraction = 1.0; + + c = peekNextDigit(lookahead, true); + // ignore non numeric leading characters + if(c < 0) + return 0; // zero returned if timeout + + do{ + if(c == ignore) + ; // 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 == '.' && !isFraction) || c == ignore ); + + 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) 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) +{ + size_t index = 0; + while (index < length) { + int c = timedRead(); + if (c < 0 || c == terminator) break; + *buffer++ = (char)c; + index++; + } + return index; // return number of characters, not including null terminator +} + +String Stream::readString() +{ + String ret; + int c = timedRead(); + while (c >= 0) + { + ret += (char)c; + c = timedRead(); + } + return ret; +} + +String Stream::readStringUntil(char terminator) +{ + String ret; + int c = timedRead(); + while (c >= 0 && c != terminator) + { + ret += (char)c; + c = timedRead(); + } + return ret; +} + +int Stream::findMulti( struct Stream::MultiTarget *targets, int tCount) { + // any zero length target string automatically matches and would make + // a mess of the rest of the algorithm. + for (struct MultiTarget *t = targets; t < targets+tCount; ++t) { + if (t->len <= 0) + return t - targets; + } + + while (1) { + int c = timedRead(); + if (c < 0) + return -1; + + for (struct MultiTarget *t = targets; t < targets+tCount; ++t) { + // the simple case is if we match, deal with that first. + if (c == t->str[t->index]) { + if (++t->index == t->len) + return t - targets; + else + continue; + } + + // if not we need to walk back and see if we could have matched further + // down the stream (ie '1112' doesn't match the first position in '11112' + // but it will match the second position so we can't just reset the current + // index to 0 when we find a mismatch. + if (t->index == 0) + continue; + + int origIndex = t->index; + do { + --t->index; + // first check if current char works against the new current index + if (c != t->str[t->index]) + continue; + + // if it's the only char then we're good, nothing more to check + if (t->index == 0) { + t->index++; + break; + } + + // otherwise we need to check the rest of the found string + int diff = origIndex - t->index; + size_t i; + for (i = 0; i < t->index; ++i) { + if (t->str[i] != t->str[i + diff]) + break; + } + + // if we successfully got through the previous loop then our current + // index is good. + if (i == t->index) { + t->index++; + break; + } + + // otherwise we just try the next index + } while (t->index); + } + } + // unreachable + return -1; +} |