WString.cpp

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/*
  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

  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"

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

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

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

String::String(const __FlashStringHelper *pstr)
{
        init();
        *this = pstr;
}

#if __cplusplus >= 201103L || defined(__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()
{
        free(buffer);
}

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

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

void String::invalidate(void)
{
        if (buffer) free(buffer);
        buffer = NULL;
        capacity = len = 0;
}

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)
{
        char *newbuffer = (char *)realloc(buffer, maxStrLen + 1);
        if (newbuffer) {
                buffer = newbuffer;
                capacity = maxStrLen;
                return 1;
        }
        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)
{
        if (!reserve(length)) {
                invalidate();
                return *this;
        }
        len = length;
        strcpy_P(buffer, (PGM_P)pstr);
        return *this;
}

#if __cplusplus >= 201103L || defined(__GXX_EXPERIMENTAL_CXX0X__)
void String::move(String &rhs)
{
        if (buffer) {
                if (rhs && 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;
}

#if __cplusplus >= 201103L || defined(__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)
{
        if (!str) return 0;
        int length = strlen_P((const char *) str);
        if (length == 0) return 1;
        unsigned int newlen = len + length;
        if (!reserve(newlen)) return 0;
        strcpy_P(buffer + len, (const char *) str);
        len = newlen;
        return 1;
}

/*********************************************/
/*  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
{
        return float(toDouble());
}

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