Print.cpp

/*
 Print.cpp - Base class that provides print() and println()
 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

 Modified 23 November 2006 by David A. Mellis
 Modified December 2014 by Ivan Grokhotkov
 Modified May 2015 by Michael C. Miller - ESP31B progmem support
 */

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include "Arduino.h"

#include "Print.h"
extern "C" {
    #include "time.h"
}

// Public Methods //////////////////////////////////////////////////////////////

/* default implementation: may be overridden */
size_t Print::write(const uint8_t *buffer, size_t size)
{
    size_t n = 0;
    while(size--) {
        n += write(*buffer++);
    }
    return n;
}

size_t Print::printf(const char *format, ...)
{
    char loc_buf[64];
    char * temp = loc_buf;
    va_list arg;
    va_list copy;
    va_start(arg, format);
    va_copy(copy, arg);
    size_t len = vsnprintf(NULL, 0, format, arg);
    va_end(copy);
    if(len >= sizeof(loc_buf)){
        temp = new char[len+1];
        if(temp == NULL) {
            return 0;
        }
    }
    len = vsnprintf(temp, len+1, format, arg);
    write((uint8_t*)temp, len);
    va_end(arg);
    if(len > 64){
        delete[] temp;
    }
    return len;
}

size_t Print::print(const __FlashStringHelper *ifsh)
{
    return print(reinterpret_cast<const char *>(ifsh));
}

size_t Print::print(const String &s)
{
    return write(s.c_str(), s.length());
}

size_t Print::print(const char str[])
{
    return write(str);
}

size_t Print::print(char c)
{
    return write(c);
}

size_t Print::print(unsigned char b, int base)
{
    return print((unsigned long) b, base);
}

size_t Print::print(int n, int base)
{
    return print((long) n, base);
}

size_t Print::print(unsigned int n, int base)
{
    return print((unsigned long) n, base);
}

size_t Print::print(long n, int base)
{
    if(base == 0) {
        return write(n);
    } else if(base == 10) {
        if(n < 0) {
            int t = print('-');
            n = -n;
            return printNumber(n, 10) + t;
        }
        return printNumber(n, 10);
    } else {
        return printNumber(n, base);
    }
}

size_t Print::print(unsigned long n, int base)
{
    if(base == 0) {
        return write(n);
    } else {
        return printNumber(n, base);
    }
}

size_t Print::print(double n, int digits)
{
    return printFloat(n, digits);
}

size_t Print::println(const __FlashStringHelper *ifsh)
{
    size_t n = print(ifsh);
    n += println();
    return n;
}

size_t Print::print(const Printable& x)
{
    return x.printTo(*this);
}

size_t Print::print(struct tm * timeinfo, const char * format)
{
    const char * f = format;
    if(!f){
        f = "%c";
    }
    char buf[64];
    size_t written = strftime(buf, 64, f, timeinfo);
    print(buf);
    return written;
}

size_t Print::println(void)
{
    return print("\r\n");
}

size_t Print::println(const String &s)
{
    size_t n = print(s);
    n += println();
    return n;
}

size_t Print::println(const char c[])
{
    size_t n = print(c);
    n += println();
    return n;
}

size_t Print::println(char c)
{
    size_t n = print(c);
    n += println();
    return n;
}

size_t Print::println(unsigned char b, int base)
{
    size_t n = print(b, base);
    n += println();
    return n;
}

size_t Print::println(int num, int base)
{
    size_t n = print(num, base);
    n += println();
    return n;
}

size_t Print::println(unsigned int num, int base)
{
    size_t n = print(num, base);
    n += println();
    return n;
}

size_t Print::println(long num, int base)
{
    size_t n = print(num, base);
    n += println();
    return n;
}

size_t Print::println(unsigned long num, int base)
{
    size_t n = print(num, base);
    n += println();
    return n;
}

size_t Print::println(double num, int digits)
{
    size_t n = print(num, digits);
    n += println();
    return n;
}

size_t Print::println(const Printable& x)
{
    size_t n = print(x);
    n += println();
    return n;
}

size_t Print::println(struct tm * timeinfo, const char * format)
{
    size_t n = print(timeinfo, format);
    n += println();
    return n;
}

// Private Methods /////////////////////////////////////////////////////////////

size_t Print::printNumber(unsigned long n, uint8_t base)
{
    char buf[8 * sizeof(long) + 1]; // Assumes 8-bit chars plus zero byte.
    char *str = &buf[sizeof(buf) - 1];

    *str = '\0';

    // prevent crash if called with base == 1
    if(base < 2) {
        base = 10;
    }

    do {
        unsigned long m = n;
        n /= base;
        char c = m - base * n;
        *--str = c < 10 ? c + '0' : c + 'A' - 10;
    } while(n);

    return write(str);
}

size_t Print::printFloat(double number, uint8_t digits)
{
    size_t n = 0;

    if(isnan(number)) {
        return print("nan");
    }
    if(isinf(number)) {
        return print("inf");
    }
    if(number > 4294967040.0) {
        return print("ovf");    // constant determined empirically
    }
    if(number < -4294967040.0) {
        return print("ovf");    // constant determined empirically
    }

    // Handle negative numbers
    if(number < 0.0) {
        n += print('-');
        number = -number;
    }

    // Round correctly so that print(1.999, 2) prints as "2.00"
    double rounding = 0.5;
    for(uint8_t i = 0; i < digits; ++i) {
        rounding /= 10.0;
    }

    number += rounding;

    // Extract the integer part of the number and print it
    unsigned long int_part = (unsigned long) number;
    double remainder = number - (double) int_part;
    n += print(int_part);

    // Print the decimal point, but only if there are digits beyond
    if(digits > 0) {
        n += print(".");
    }

    // Extract digits from the remainder one at a time
    while(digits-- > 0) {
        remainder *= 10.0;
        int toPrint = int(remainder);
        n += print(toPrint);
        remainder -= toPrint;
    }

    return n;
}