WString.cpp

/*
 WString.cpp - String library for Wiring & Arduino
 ...mostly rewritten by Paul Stoffregen...
 Copyright (c) 2009-10 Hernando Barragan.  All rights reserved.
 Copyright 2011, Paul Stoffregen, paul@pjrc.com
 Modified by Ivan Grokhotkov, 2014 - ESP31B support
 Modified by Michael C. Miller, 2015 - ESP31B progmem support

 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
 */

#include "WString.h"
#include "stdlib_noniso.h"
#include "esp32-hal-log.h"
//extern "C" {
//#include "esp_common.h"
//}

/*********************************************/
/*  Constructors                             */
/*********************************************/

String::String(const char *cstr)
{
    init();
    if(cstr) {
        copy(cstr, strlen(cstr));
    }
}

String::String(const String &value)
{
    init();
    *this = value;
}

#ifdef __GXX_EXPERIMENTAL_CXX0X__
String::String(String &&rval)
{
    init();
    move(rval);
}

String::String(StringSumHelper &&rval)
{
    init();
    move(rval);
}
#endif

String::String(char c)
{
    init();
    char buf[2];
    buf[0] = c;
    buf[1] = 0;
    *this = buf;
}

String::String(unsigned char value, unsigned char base)
{
    init();
    char buf[1 + 8 * sizeof(unsigned char)];
    utoa(value, buf, base);
    *this = buf;
}

String::String(int value, unsigned char base)
{
    init();
    char buf[2 + 8 * sizeof(int)];
    itoa(value, buf, base);
    *this = buf;
}

String::String(unsigned int value, unsigned char base)
{
    init();
    char buf[1 + 8 * sizeof(unsigned int)];
    utoa(value, buf, base);
    *this = buf;
}

String::String(long value, unsigned char base)
{
    init();
    char buf[2 + 8 * sizeof(long)];
    ltoa(value, buf, base);
    *this = buf;
}

String::String(unsigned long value, unsigned char base)
{
    init();
    char buf[1 + 8 * sizeof(unsigned long)];
    ultoa(value, buf, base);
    *this = buf;
}

String::String(float value, unsigned char decimalPlaces)
{
    init();
    char buf[33];
    *this = dtostrf(value, (decimalPlaces + 2), decimalPlaces, buf);
}

String::String(double value, unsigned char decimalPlaces)
{
    init();
    char buf[33];
    *this = dtostrf(value, (decimalPlaces + 2), decimalPlaces, buf);
}

String::~String()
{
    if(buffer) {
        free(buffer);
    }
    init();
}

// /*********************************************/
// /*  Memory Management                        */
// /*********************************************/

inline void String::init(void)
{
    buffer = NULL;
    capacity = 0;
    len = 0;
}

void String::invalidate(void)
{
    if(buffer) {
        free(buffer);
    }
    init();
}

unsigned char String::reserve(unsigned int size)
{
    if(buffer && capacity >= size) {
        return 1;
    }
    if(changeBuffer(size)) {
        if(len == 0) {
            buffer[0] = 0;
        }
        return 1;
    }
    return 0;
}

unsigned char String::changeBuffer(unsigned int maxStrLen)
{
    size_t newSize = ((maxStrLen + 16) & (~0xf)) - 1;
    char *newbuffer = (char *) realloc(buffer, newSize+1);
    if(newbuffer) {
        if(newSize > len){
            if(newSize > capacity){
                memset(newbuffer+capacity, 0, newSize-capacity);
            }
        } else {
            //new buffer can not fit the old len
            newbuffer[newSize] = 0;
            len = newSize;
        }
        capacity = newSize;
        buffer = newbuffer;
        return 1;
    }
    log_e("realloc failed! Buffer unchanged");
    return 0;
}

// /*********************************************/
// /*  Copy and Move                            */
// /*********************************************/

String & String::copy(const char *cstr, unsigned int length)
{
    if(!reserve(length)) {
        invalidate();
        return *this;
    }
    len = length;
    strcpy(buffer, cstr);
    return *this;
}

String & String::copy(const __FlashStringHelper *pstr, unsigned int length)
{
    return copy(reinterpret_cast<const char *>(pstr), length);
}

#ifdef __GXX_EXPERIMENTAL_CXX0X__
void String::move(String &rhs)
{
    if(buffer) {
        if(capacity >= rhs.len) {
            strcpy(buffer, rhs.buffer);
            len = rhs.len;
            rhs.len = 0;
            return;
        } else {
            free(buffer);
        }
    }
    buffer = rhs.buffer;
    capacity = rhs.capacity;
    len = rhs.len;
    rhs.buffer = NULL;
    rhs.capacity = 0;
    rhs.len = 0;
}
#endif

String & String::operator =(const String &rhs)
{
    if(this == &rhs) {
        return *this;
    }

    if(rhs.buffer) {
        copy(rhs.buffer, rhs.len);
    } else {
        invalidate();
    }

    return *this;
}

#ifdef __GXX_EXPERIMENTAL_CXX0X__
String & String::operator =(String &&rval)
{
    if(this != &rval) {
        move(rval);
    }
    return *this;
}

String & String::operator =(StringSumHelper &&rval)
{
    if(this != &rval) {
        move(rval);
    }
    return *this;
}
#endif

String & String::operator =(const char *cstr)
{
    if(cstr) {
        copy(cstr, strlen(cstr));
    } else {
        invalidate();
    }

    return *this;
}

String & String::operator = (const __FlashStringHelper *pstr)
{
    if (pstr) copy(pstr, strlen_P((PGM_P)pstr));
    else invalidate();

    return *this;
}

// /*********************************************/
// /*  concat                                   */
// /*********************************************/

unsigned char String::concat(const String &s)
{
    return concat(s.buffer, s.len);
}

unsigned char String::concat(const char *cstr, unsigned int length)
{
    unsigned int newlen = len + length;
    if(!cstr) {
        return 0;
    }
    if(length == 0) {
        return 1;
    }
    if(!reserve(newlen)) {
        return 0;
    }
    strcpy(buffer + len, cstr);
    len = newlen;
    return 1;
}

unsigned char String::concat(const char *cstr)
{
    if(!cstr) {
        return 0;
    }
    return concat(cstr, strlen(cstr));
}

unsigned char String::concat(char c)
{
    char buf[2];
    buf[0] = c;
    buf[1] = 0;
    return concat(buf, 1);
}

unsigned char String::concat(unsigned char num)
{
    char buf[1 + 3 * sizeof(unsigned char)];
    itoa(num, buf, 10);
    return concat(buf, strlen(buf));
}

unsigned char String::concat(int num)
{
    char buf[2 + 3 * sizeof(int)];
    itoa(num, buf, 10);
    return concat(buf, strlen(buf));
}

unsigned char String::concat(unsigned int num)
{
    char buf[1 + 3 * sizeof(unsigned int)];
    utoa(num, buf, 10);
    return concat(buf, strlen(buf));
}

unsigned char String::concat(long num)
{
    char buf[2 + 3 * sizeof(long)];
    ltoa(num, buf, 10);
    return concat(buf, strlen(buf));
}

unsigned char String::concat(unsigned long num)
{
    char buf[1 + 3 * sizeof(unsigned long)];
    ultoa(num, buf, 10);
    return concat(buf, strlen(buf));
}

unsigned char String::concat(float num)
{
    char buf[20];
    char* string = dtostrf(num, 4, 2, buf);
    return concat(string, strlen(string));
}

unsigned char String::concat(double num)
{
    char buf[20];
    char* string = dtostrf(num, 4, 2, buf);
    return concat(string, strlen(string));
}

unsigned char String::concat(const __FlashStringHelper * str)
{
    return concat(reinterpret_cast<const char *>(str));
}

/*********************************************/
/*  Concatenate                              */
/*********************************************/

StringSumHelper & operator +(const StringSumHelper &lhs, const String &rhs)
{
    StringSumHelper &a = const_cast<StringSumHelper&>(lhs);
    if(!a.concat(rhs.buffer, rhs.len)) {
        a.invalidate();
    }
    return a;
}

StringSumHelper & operator +(const StringSumHelper &lhs, const char *cstr)
{
    StringSumHelper &a = const_cast<StringSumHelper&>(lhs);
    if(!cstr || !a.concat(cstr, strlen(cstr))) {
        a.invalidate();
    }
    return a;
}

StringSumHelper & operator +(const StringSumHelper &lhs, char c)
{
    StringSumHelper &a = const_cast<StringSumHelper&>(lhs);
    if(!a.concat(c)) {
        a.invalidate();
    }
    return a;
}

StringSumHelper & operator +(const StringSumHelper &lhs, unsigned char num)
{
    StringSumHelper &a = const_cast<StringSumHelper&>(lhs);
    if(!a.concat(num)) {
        a.invalidate();
    }
    return a;
}

StringSumHelper & operator +(const StringSumHelper &lhs, int num)
{
    StringSumHelper &a = const_cast<StringSumHelper&>(lhs);
    if(!a.concat(num)) {
        a.invalidate();
    }
    return a;
}

StringSumHelper & operator +(const StringSumHelper &lhs, unsigned int num)
{
    StringSumHelper &a = const_cast<StringSumHelper&>(lhs);
    if(!a.concat(num)) {
        a.invalidate();
    }
    return a;
}

StringSumHelper & operator +(const StringSumHelper &lhs, long num)
{
    StringSumHelper &a = const_cast<StringSumHelper&>(lhs);
    if(!a.concat(num)) {
        a.invalidate();
    }
    return a;
}

StringSumHelper & operator +(const StringSumHelper &lhs, unsigned long num)
{
    StringSumHelper &a = const_cast<StringSumHelper&>(lhs);
    if(!a.concat(num)) {
        a.invalidate();
    }
    return a;
}

StringSumHelper & operator +(const StringSumHelper &lhs, float num)
{
    StringSumHelper &a = const_cast<StringSumHelper&>(lhs);
    if(!a.concat(num)) {
        a.invalidate();
    }
    return a;
}

StringSumHelper & operator +(const StringSumHelper &lhs, double num)
{
    StringSumHelper &a = const_cast<StringSumHelper&>(lhs);
    if(!a.concat(num)) {
        a.invalidate();
    }
    return a;
}

StringSumHelper & operator + (const StringSumHelper &lhs, const __FlashStringHelper *rhs)
{
    StringSumHelper &a = const_cast<StringSumHelper&>(lhs);
    if (!a.concat(rhs))	a.invalidate();
    return a;
}

// /*********************************************/
// /*  Comparison                               */
// /*********************************************/

int String::compareTo(const String &s) const
{
    if(!buffer || !s.buffer) {
        if(s.buffer && s.len > 0) {
            return 0 - *(unsigned char *) s.buffer;
        }
        if(buffer && len > 0) {
            return *(unsigned char *) buffer;
        }
        return 0;
    }
    return strcmp(buffer, s.buffer);
}

unsigned char String::equals(const String &s2) const
{
    return (len == s2.len && compareTo(s2) == 0);
}

unsigned char String::equals(const char *cstr) const
{
    if(len == 0) {
        return (cstr == NULL || *cstr == 0);
    }
    if(cstr == NULL) {
        return buffer[0] == 0;
    }
    return strcmp(buffer, cstr) == 0;
}

unsigned char String::operator<(const String &rhs) const
{
    return compareTo(rhs) < 0;
}

unsigned char String::operator>(const String &rhs) const
{
    return compareTo(rhs) > 0;
}

unsigned char String::operator<=(const String &rhs) const
{
    return compareTo(rhs) <= 0;
}

unsigned char String::operator>=(const String &rhs) const
{
    return compareTo(rhs) >= 0;
}

unsigned char String::equalsIgnoreCase(const String &s2) const
{
    if(this == &s2) {
        return 1;
    }
    if(len != s2.len) {
        return 0;
    }
    if(len == 0) {
        return 1;
    }
    const char *p1 = buffer;
    const char *p2 = s2.buffer;
    while(*p1) {
        if(tolower(*p1++) != tolower(*p2++)) {
            return 0;
        }
    }
    return 1;
}

unsigned char String::startsWith(const String &s2) const
{
    if(len < s2.len) {
        return 0;
    }
    return startsWith(s2, 0);
}

unsigned char String::startsWith(const String &s2, unsigned int offset) const
{
    if(offset > len - s2.len || !buffer || !s2.buffer) {
        return 0;
    }
    return strncmp(&buffer[offset], s2.buffer, s2.len) == 0;
}

unsigned char String::endsWith(const String &s2) const
{
    if(len < s2.len || !buffer || !s2.buffer) {
        return 0;
    }
    return strcmp(&buffer[len - s2.len], s2.buffer) == 0;
}

// /*********************************************/
// /*  Character Access                         */
// /*********************************************/

char String::charAt(unsigned int loc) const
{
    return operator[](loc);
}

void String::setCharAt(unsigned int loc, char c)
{
    if(loc < len) {
        buffer[loc] = c;
    }
}

char & String::operator[](unsigned int index)
{
    static char dummy_writable_char;
    if(index >= len || !buffer) {
        dummy_writable_char = 0;
        return dummy_writable_char;
    }
    return buffer[index];
}

char String::operator[](unsigned int index) const
{
    if(index >= len || !buffer) {
        return 0;
    }
    return buffer[index];
}

void String::getBytes(unsigned char *buf, unsigned int bufsize, unsigned int index) const
{
    if(!bufsize || !buf) {
        return;
    }
    if(index >= len) {
        buf[0] = 0;
        return;
    }
    unsigned int n = bufsize - 1;
    if(n > len - index) {
        n = len - index;
    }
    strncpy((char *) buf, buffer + index, n);
    buf[n] = 0;
}

// /*********************************************/
// /*  Search                                   */
// /*********************************************/

int String::indexOf(char c) const
{
    return indexOf(c, 0);
}

int String::indexOf(char ch, unsigned int fromIndex) const
{
    if(fromIndex >= len) {
        return -1;
    }
    const char* temp = strchr(buffer + fromIndex, ch);
    if(temp == NULL) {
        return -1;
    }
    return temp - buffer;
}

int String::indexOf(const String &s2) const
{
    return indexOf(s2, 0);
}

int String::indexOf(const String &s2, unsigned int fromIndex) const
{
    if(fromIndex >= len) {
        return -1;
    }
    const char *found = strstr(buffer + fromIndex, s2.buffer);
    if(found == NULL) {
        return -1;
    }
    return found - buffer;
}

int String::lastIndexOf(char theChar) const
{
    return lastIndexOf(theChar, len - 1);
}

int String::lastIndexOf(char ch, unsigned int fromIndex) const
{
    if(fromIndex >= len) {
        return -1;
    }
    char tempchar = buffer[fromIndex + 1];
    buffer[fromIndex + 1] = '\0';
    char* temp = strrchr(buffer, ch);
    buffer[fromIndex + 1] = tempchar;
    if(temp == NULL) {
        return -1;
    }
    return temp - buffer;
}

int String::lastIndexOf(const String &s2) const
{
    return lastIndexOf(s2, len - s2.len);
}

int String::lastIndexOf(const String &s2, unsigned int fromIndex) const
{
    if(s2.len == 0 || len == 0 || s2.len > len) {
        return -1;
    }
    if(fromIndex >= len) {
        fromIndex = len - 1;
    }
    int found = -1;
    for(char *p = buffer; p <= buffer + fromIndex; p++) {
        p = strstr(p, s2.buffer);
        if(!p) {
            break;
        }
        if((unsigned int) (p - buffer) <= fromIndex) {
            found = p - buffer;
        }
    }
    return found;
}

String String::substring(unsigned int left, unsigned int right) const
{
    if(left > right) {
        unsigned int temp = right;
        right = left;
        left = temp;
    }
    String out;
    if(left >= len) {
        return out;
    }
    if(right > len) {
        right = len;
    }
    char temp = buffer[right];  // save the replaced character
    buffer[right] = '\0';
    out = buffer + left;  // pointer arithmetic
    buffer[right] = temp;  //restore character
    return out;
}

// /*********************************************/
// /*  Modification                             */
// /*********************************************/

void String::replace(char find, char replace)
{
    if(!buffer) {
        return;
    }
    for(char *p = buffer; *p; p++) {
        if(*p == find) {
            *p = replace;
        }
    }
}

void String::replace(const String& find, const String& replace)
{
    if(len == 0 || find.len == 0) {
        return;
    }
    int diff = replace.len - find.len;
    char *readFrom = buffer;
    char *foundAt;
    if(diff == 0) {
        while((foundAt = strstr(readFrom, find.buffer)) != NULL) {
            memcpy(foundAt, replace.buffer, replace.len);
            readFrom = foundAt + replace.len;
        }
    } else if(diff < 0) {
        char *writeTo = buffer;
        while((foundAt = strstr(readFrom, find.buffer)) != NULL) {
            unsigned int n = foundAt - readFrom;
            memcpy(writeTo, readFrom, n);
            writeTo += n;
            memcpy(writeTo, replace.buffer, replace.len);
            writeTo += replace.len;
            readFrom = foundAt + find.len;
            len += diff;
        }
        strcpy(writeTo, readFrom);
    } else {
        unsigned int size = len; // compute size needed for result
        while((foundAt = strstr(readFrom, find.buffer)) != NULL) {
            readFrom = foundAt + find.len;
            size += diff;
        }
        if(size == len) {
            return;
        }
        if(size > capacity && !changeBuffer(size)) {
            return;    // XXX: tell user!
        }
        int index = len - 1;
        while(index >= 0 && (index = lastIndexOf(find, index)) >= 0) {
            readFrom = buffer + index + find.len;
            memmove(readFrom + diff, readFrom, len - (readFrom - buffer));
            len += diff;
            buffer[len] = 0;
            memcpy(buffer + index, replace.buffer, replace.len);
            index--;
        }
    }
}

void String::remove(unsigned int index)
{
    // Pass the biggest integer as the count. The remove method
    // below will take care of truncating it at the end of the
    // string.
    remove(index, (unsigned int) -1);
}

void String::remove(unsigned int index, unsigned int count)
{
    if(index >= len) {
        return;
    }
    if(count <= 0) {
        return;
    }
    if(count > len - index) {
        count = len - index;
    }
    char *writeTo = buffer + index;
    len = len - count;
    strncpy(writeTo, buffer + index + count, len - index);
    buffer[len] = 0;
}

void String::toLowerCase(void)
{
    if(!buffer) {
        return;
    }
    for(char *p = buffer; *p; p++) {
        *p = tolower(*p);
    }
}

void String::toUpperCase(void)
{
    if(!buffer) {
        return;
    }
    for(char *p = buffer; *p; p++) {
        *p = toupper(*p);
    }
}

void String::trim(void)
{
    if(!buffer || len == 0) {
        return;
    }
    char *begin = buffer;
    while(isspace(*begin)) {
        begin++;
    }
    char *end = buffer + len - 1;
    while(isspace(*end) && end >= begin) {
        end--;
    }
    len = end + 1 - begin;
    if(begin > buffer) {
        memcpy(buffer, begin, len);
    }
    buffer[len] = 0;
}

// /*********************************************/
// /*  Parsing / Conversion                     */
// /*********************************************/

long String::toInt(void) const
{
    if(buffer) {
        return atol(buffer);
    }
    return 0;
}

float String::toFloat(void) const
{
    if(buffer) {
        return atof(buffer);
    }
    return 0;
}

double String::toDouble(void) const {
    if (buffer) {
        return atof(buffer);    
    }
    return 0;
}

unsigned char String::equalsConstantTime(const String &s2) const {
    // To avoid possible time-based attacks present function
    // compares given strings in a constant time.
    if(len != s2.len)
        return 0;
    //at this point lengths are the same
    if(len == 0)
        return 1;
    //at this point lenghts are the same and non-zero
    const char *p1 = buffer;
    const char *p2 = s2.buffer;
    unsigned int equalchars = 0;
    unsigned int diffchars = 0;
    while(*p1) {
        if(*p1 == *p2)
            ++equalchars;
        else
            ++diffchars;
        ++p1;
        ++p2;
    }
    //the following should force a constant time eval of the condition without a compiler "logical shortcut"
    unsigned char equalcond = (equalchars == len);
    unsigned char diffcond = (diffchars == 0);
    return (equalcond & diffcond); //bitwise AND
}