Stream.h

/*
  Stream.h - base class for character-based streams.
  Copyright (c) 2010 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

  parsing functions based on TextFinder library by Michael Margolis
*/

#pragma once

#include <inttypes.h>
#include "Print.h"

// compatibility macros for testing
/*
#define   getInt()            parseInt()
#define   getInt(ignore)      parseInt(ignore)
#define   getFloat()          parseFloat()
#define   getFloat(ignore)    parseFloat(ignore)
#define   getString( pre_string, post_string, buffer, length)
readBytesBetween( pre_string, terminator, buffer, length)
*/

// This enumeration provides the lookahead options for parseInt(), parseFloat()
// The rules set out here are used until either the first valid character is found
// or a time out occurs due to lack of input.
enum LookaheadMode {
  SKIP_ALL,        // All invalid characters are ignored.
  SKIP_NONE,       // Nothing is skipped, and the stream is not touched unless the first waiting character is valid.
  SKIP_WHITESPACE  // Only tabs, spaces, line feeds & carriage returns are skipped.
};

#define NO_IGNORE_CHAR '\x01'  // a char not found in a valid ASCII numeric field

class Stream : public Print {
protected:
  unsigned long _timeout;                                          // number of milliseconds to wait for the next char before aborting timed read
  unsigned long _startMillis;                                      // used for timeout measurement
  int timedRead();                                                 // private method to read stream with timeout
  int timedPeek();                                                 // private method to peek stream with timeout
  int peekNextDigit(LookaheadMode lookahead, bool detectDecimal);  // returns the next numeric digit in the stream or -1 if timeout

public:
  virtual int available() = 0;
  virtual int read() = 0;
  virtual int peek() = 0;

  Stream() {
    _timeout = 1000;
  }

  // parsing methods

  void setTimeout(unsigned long timeout);  // sets maximum milliseconds to wait for stream data, default is 1 second
  unsigned long getTimeout(void) {
    return _timeout;
  }

  bool find(const char *target);  // reads data from the stream until the target string is found
  bool find(const uint8_t *target) {
    return find((const char *)target);
  }
  // returns true if target string is found, false if timed out (see setTimeout)

  bool find(const char *target, size_t length);  // reads data from the stream until the target string of given length is found
  bool find(const uint8_t *target, size_t length) {
    return find((const char *)target, length);
  }
  // returns true if target string is found, false if timed out

  bool find(char target) {
    return find(&target, 1);
  }

  bool findUntil(const char *target, const char *terminator);  // as find but search ends if the terminator string is found
  bool findUntil(const uint8_t *target, const char *terminator) {
    return findUntil((const char *)target, terminator);
  }

  bool findUntil(const char *target, size_t targetLen, const char *terminate, size_t termLen);  // as above but search ends if the terminate string is found
  bool findUntil(const uint8_t *target, size_t targetLen, const char *terminate, size_t termLen) {
    return findUntil((const char *)target, targetLen, terminate, termLen);
  }

  long parseInt(LookaheadMode lookahead = SKIP_ALL, char ignore = NO_IGNORE_CHAR);
  // 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.

  float parseFloat(LookaheadMode lookahead = SKIP_ALL, char ignore = NO_IGNORE_CHAR);
  // float version of parseInt

  virtual size_t readBytes(char *buffer, size_t length);  // read chars from stream into buffer
  virtual size_t readBytes(uint8_t *buffer, size_t length) {
    return readBytes((char *)buffer, length);
  }
  // terminates if length characters have been read or timeout (see setTimeout)
  // returns the number of characters placed in the buffer (0 means no valid data found)

  size_t readBytesUntil(char terminator, char *buffer, size_t length);  // as readBytes with terminator character
  size_t readBytesUntil(char terminator, uint8_t *buffer, size_t length) {
    return readBytesUntil(terminator, (char *)buffer, length);
  }
  // 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)

  // Arduino String functions to be added here
  virtual String readString();
  String readStringUntil(char terminator);

protected:
  long parseInt(char ignore) {
    return parseInt(SKIP_ALL, ignore);
  }
  float parseFloat(char ignore) {
    return parseFloat(SKIP_ALL, ignore);
  }
  // These overload exists for compatibility with any class that has derived
  // Stream and used parseFloat/Int with a custom ignore character. To keep
  // the public API simple, these overload remains protected.

  struct MultiTarget {
    const char *str;  // string you're searching for
    size_t len;       // length of string you're searching for
    size_t index;     // index used by the search routine.
  };

  // This allows you to search for an arbitrary number of strings.
  // Returns index of the target that is found first or -1 if timeout occurs.
  int findMulti(struct MultiTarget *targets, int tCount);
};

#undef NO_IGNORE_CHAR