This repository has been archived on 2020-09-09. You can view files and clone it, but cannot push or open issues or pull requests.
arduino_universal_serial_ad.../Universal_Serial_Adapter/Libraries/SdFat/istream.cpp

412 lines
9.8 KiB
C++

/* Arduino SdFat Library
* Copyright (C) 2012 by William Greiman
*
* This file is part of the Arduino SdFat Library
*
* This Library is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with the Arduino SdFat Library. If not, see
* <http://www.gnu.org/licenses/>.
*/
#include <float.h>
#include <istream.h>
//------------------------------------------------------------------------------
/**
* Extract a character if one is available.
*
* \return The character or -1 if a failure occurs. A failure is indicated
* by the stream state.
*/
int istream::get() {
int c;
gcount_ = 0;
c = getch();
if (c < 0) {
setstate(failbit);
} else {
gcount_ = 1;
}
return c;
}
//------------------------------------------------------------------------------
/**
* Extract a character if one is available.
*
* \param[out] c location to receive the extracted character.
*
* \return always returns *this. A failure is indicated by the stream state.
*/
istream& istream::get(char& c) {
int tmp = get();
if (tmp >= 0) c = tmp;
return *this;
}
//------------------------------------------------------------------------------
/**
* Extract characters.
*
* \param[out] str Location to receive extracted characters.
* \param[in] n Size of str.
* \param[in] delim Delimiter
*
* Characters are extracted until extraction fails, n is less than 1,
* n-1 characters are extracted, or the next character equals
* \a delim (delim is not extracted). If no characters are extracted
* failbit is set. If end-of-file occurs the eofbit is set.
*
* \return always returns *this. A failure is indicated by the stream state.
*/
istream& istream::get(char *str, streamsize n, char delim) {
int c;
FatPos_t pos;
gcount_ = 0;
while ((gcount_ + 1) < n) {
c = getch(&pos);
if (c < 0) {
break;
}
if (c == delim) {
setpos(&pos);
break;
}
str[gcount_++] = c;
}
if (n > 0) str[gcount_] = '\0';
if (gcount_ == 0) setstate(failbit);
return *this;
}
//------------------------------------------------------------------------------
void istream::getBool(bool *b) {
if ((flags() & boolalpha) == 0) {
getNumber(b);
return;
}
PGM_P truePtr = PSTR("true");
PGM_P falsePtr = PSTR("false");
const uint8_t true_len = 4;
const uint8_t false_len = 5;
bool trueOk = true;
bool falseOk = true;
uint8_t i = 0;
int c = readSkip();
while (1) {
falseOk = falseOk && c == pgm_read_byte(falsePtr + i);
trueOk = trueOk && c == pgm_read_byte(truePtr + i);
if (trueOk == false && falseOk == false) break;
i++;
if (trueOk && i == true_len) {
*b = true;
return;
}
if (falseOk && i == false_len) {
*b = false;
return;
}
c = getch();
}
setstate(failbit);
}
//------------------------------------------------------------------------------
void istream::getChar(char* ch) {
int16_t c = readSkip();
if (c < 0) {
setstate(failbit);
} else {
*ch = c;
}
}
//------------------------------------------------------------------------------
//
// http://www.exploringbinary.com/category/numbers-in-computers/
//
int16_t const EXP_LIMIT = 100;
static const uint32_t uint32_max = (uint32_t)-1;
bool istream::getDouble(double* value) {
bool got_digit = false;
bool got_dot = false;
bool neg;
int16_t c;
bool expNeg = false;
int16_t exp = 0;
int16_t fracExp = 0;
uint32_t frac = 0;
FatPos_t endPos;
double pow10;
double v;
getpos(&endPos);
c = readSkip();
neg = c == '-';
if (c == '-' || c == '+') {
c = getch();
}
while (1) {
if (isdigit(c)) {
got_digit = true;
if (frac < uint32_max/10) {
frac = frac * 10 + (c - '0');
if (got_dot) fracExp--;
} else {
if (!got_dot) fracExp++;
}
} else if (!got_dot && c == '.') {
got_dot = true;
} else {
break;
}
if (fracExp < -EXP_LIMIT || fracExp > EXP_LIMIT) goto fail;
c = getch(&endPos);
}
if (!got_digit) goto fail;
if (c == 'e' || c == 'E') {
c = getch();
expNeg = c == '-';
if (c == '-' || c == '+') {
c = getch();
}
while (isdigit(c)) {
if (exp > EXP_LIMIT) goto fail;
exp = exp * 10 + (c - '0');
c = getch(&endPos);
}
}
v = static_cast<double>(frac);
exp = expNeg ? fracExp - exp : fracExp + exp;
expNeg = exp < 0;
if (expNeg) exp = -exp;
pow10 = 10.0;
while (exp) {
if (exp & 1) {
if (expNeg) {
// check for underflow
if (v < FLT_MIN * pow10 && frac != 0) goto fail;
v /= pow10;
} else {
// check for overflow
if (v > FLT_MAX / pow10) goto fail;
v *= pow10;
}
}
pow10 *= pow10;
exp >>= 1;
}
setpos(&endPos);
*value = neg ? -v : v;
return true;
fail:
// error restore position to last good place
setpos(&endPos);
setstate(failbit);
return false;
}
//------------------------------------------------------------------------------
/**
* Extract characters
*
* \param[out] str Location to receive extracted characters.
* \param[in] n Size of str.
* \param[in] delim Delimiter
*
* Characters are extracted until extraction fails,
* the next character equals \a delim (delim is extracted), or n-1
* characters are extracted.
*
* The failbit is set if no characters are extracted or n-1 characters
* are extracted. If end-of-file occurs the eofbit is set.
*
* \return always returns *this. A failure is indicated by the stream state.
*/
istream& istream::getline(char *str, streamsize n, char delim) {
FatPos_t pos;
int c;
gcount_ = 0;
if (n > 0) str[0] = '\0';
while (1) {
c = getch(&pos);
if (c < 0) {
break;
}
if (c == delim) {
gcount_++;
break;
}
if ((gcount_ + 1) >= n) {
setpos(&pos);
setstate(failbit);
break;
}
str[gcount_++] = c;
str[gcount_] = '\0';
}
if (gcount_ == 0) setstate(failbit);
return *this;
}
//------------------------------------------------------------------------------
bool istream::getNumber(uint32_t posMax, uint32_t negMax, uint32_t* num) {
int16_t c;
int8_t any = 0;
int8_t have_zero = 0;
uint8_t neg;
uint32_t val = 0;
uint32_t cutoff;
uint8_t cutlim;
FatPos_t endPos;
uint8_t f = flags() & basefield;
uint8_t base = f == oct ? 8 : f != hex ? 10 : 16;
getpos(&endPos);
c = readSkip();
neg = c == '-' ? 1 : 0;
if (c == '-' || c == '+') {
c = getch();
}
if (base == 16 && c == '0') { // TESTSUITE
c = getch(&endPos);
if (c == 'X' || c == 'x') {
c = getch();
// remember zero in case no hex digits follow x/X
have_zero = 1;
} else {
any = 1;
}
}
// set values for overflow test
cutoff = neg ? negMax : posMax;
cutlim = cutoff % base;
cutoff /= base;
while (1) {
if (isdigit(c)) {
c -= '0';
} else if (isalpha(c)) {
c -= isupper(c) ? 'A' - 10 : 'a' - 10;
} else {
break;
}
if (c >= base) {
break;
}
if (val > cutoff || (val == cutoff && c > cutlim)) {
// indicate overflow error
any = -1;
break;
}
val = val * base + c;
c = getch(&endPos);
any = 1;
}
setpos(&endPos);
if (any > 0 || (have_zero && any >= 0)) {
*num = neg ? -val : val;
return true;
}
setstate(failbit);
return false;
}
//------------------------------------------------------------------------------
/**
*
*/
void istream::getStr(char *str) {
FatPos_t pos;
uint16_t i = 0;
uint16_t m = width() ? width() - 1 : 0XFFFE;
if (m != 0) {
getpos(&pos);
int c = readSkip();
while (i < m) {
if (c < 0) {
break;
}
if (isspace(c)) {
setpos(&pos);
break;
}
str[i++] = c;
c = getch(&pos);
}
}
str[i] = '\0';
if (i == 0) setstate(failbit);
width(0);
}
//------------------------------------------------------------------------------
/**
* Extract characters and discard them.
*
* \param[in] n maximum number of characters to ignore.
* \param[in] delim Delimiter.
*
* Characters are extracted until extraction fails, \a n characters
* are extracted, or the next input character equals \a delim
* (the delimiter is extracted). If end-of-file occurs the eofbit is set.
*
* Failures are indicated by the state of the stream.
*
* \return *this
*
*/
istream& istream::ignore(streamsize n, int delim) {
int c;
gcount_ = 0;
while (gcount_ < n) {
c = getch();
if (c < 0) {
break;
}
gcount_++;
if (c == delim) break;
}
return *this;
}
//------------------------------------------------------------------------------
/**
* Return the next available character without consuming it.
*
* \return The character if the stream state is good else -1;
*
*/
int istream::peek() {
int16_t c;
FatPos_t pos;
gcount_ = 0;
getpos(&pos);
c = getch();
if (c < 0) {
if (!bad()) setstate(eofbit);
} else {
setpos(&pos);
}
return c;
}
//------------------------------------------------------------------------------
int16_t istream::readSkip() {
int16_t c;
do {
c = getch();
} while (isspace(c) && (flags() & skipws));
return c;
}
//------------------------------------------------------------------------------
/** used to implement ws() */
void istream::skipWhite() {
int c;
FatPos_t pos;
do {
c = getch(&pos);
} while (isspace(c));
setpos(&pos);
}