DwString::DwString(const DwString &aStr, size_t aPos, size_t aLen)
{
assert(aPos <= aStr.mLength);
if(sEmptyRep == 0)
{
sEmptyBuffer[0] = 0;
sEmptyRep = new DwStringRep(sEmptyBuffer, kEmptyBufferSize);
assert(sEmptyRep != 0);
}
DBG_STMT(aStr.CheckInvariants())
size_t pos = DW_MIN(aPos, aStr.mLength);
size_t len = DW_MIN(aLen, aStr.mLength - pos);
if(len > 0)
{
mRep = new_rep_reference(aStr.mRep);
mStart = aStr.mStart + pos;
mLength = len;
}
else /* if (len == 0) */
{
mRep = new_rep_reference(sEmptyRep);
mStart = 0;
mLength = 0;
}
}
DwString::DwString(char *aBuf, size_t aSize, size_t aStart, size_t aLen)
{
assert(aBuf != 0);
assert(aSize > 0);
assert(aLen < aSize);
assert(aStart < aSize - aLen);
if(sEmptyRep == 0)
{
sEmptyBuffer[0] = 0;
sEmptyRep = new DwStringRep(sEmptyBuffer, kEmptyBufferSize);
assert(sEmptyRep != 0);
}
DBG_STMT(sEmptyRep->CheckInvariants())
// Set valid values, in case an exception is thrown
mRep = new_rep_reference(sEmptyRep);
mStart = 0;
mLength = 0;
DwStringRep *rep = new DwStringRep(aBuf, aSize);
assert(rep != 0);
if(rep != 0)
{
mRep = rep;
mStart = aStart;
mLength = aLen;
}
else /* if (rep == 0) */
{
delete [] aBuf;
}
}
void DwString::ReleaseBuffer(char** aBuf, size_t* aSize, size_t* aStart,
size_t* aLen)
{
assert(aBuf != 0);
assert(aSize != 0);
assert(aStart != 0);
assert(aLen != 0);
if (mRep->mRefCount == 1) {
*aBuf = mRep->mBuffer;
*aSize = mRep->mSize;
}
else {
size_t size = mRep->mSize;
char* buf = new char [size];
assert(buf != 0);
if (buf != 0) {
mem_copy(mRep->mBuffer, size, buf);
*aBuf = buf;
*aSize = size;
}
else {
// If not throwing an exception, recover as best we can
*aBuf = 0;
*aSize = 0;
*aStart = mStart = 0;
*aLen = mLength = 0;
return;
}
}
*aStart = mStart;
*aLen = mLength;
mRep = new_rep_reference(sEmptyRep);
mStart = 0;
mLength = 0;
}
DwString::DwString()
{
if (sEmptyRep == 0) {
sEmptyBuffer[0] = 0;
sEmptyRep = new DwStringRep(sEmptyBuffer, kEmptyBufferSize);
assert(sEmptyRep != 0);
}
DBG_STMT(sEmptyRep->CheckInvariants())
mRep = new_rep_reference(sEmptyRep);
mStart = 0;
mLength = 0;
}
DwString::DwString(size_t aLen, char aChar)
{
assert(aLen != (size_t)-1);
if (sEmptyRep == 0) {
sEmptyBuffer[0] = 0;
sEmptyRep = new DwStringRep(sEmptyBuffer, kEmptyBufferSize);
assert(sEmptyRep != 0);
}
DBG_STMT(sEmptyRep->CheckInvariants())
// Set valid values, in case an exception is thrown
mRep = new_rep_reference(sEmptyRep);
mStart = 0;
mLength = 0;
_replace(0, mLength, aLen, aChar);
}
DwString& DwString::assign(const DwString& aStr, size_t aPos, size_t aLen)
{
assert(aPos <= aStr.mLength);
size_t pos = DW_MIN(aPos, aStr.mLength);
size_t len = DW_MIN(aLen, aStr.mLength - pos);
if (mRep == aStr.mRep) {
mStart = aStr.mStart + pos;
mLength = len;
}
else {
delete_rep_safely(mRep);
mRep = new_rep_reference(aStr.mRep);
mStart = aStr.mStart + pos;
mLength = len;
}
return *this;
}
DwString::DwString(const char* aCstr)
{
if (sEmptyRep == 0) {
sEmptyBuffer[0] = 0;
sEmptyRep = new DwStringRep(sEmptyBuffer, kEmptyBufferSize);
assert(sEmptyRep != 0);
}
DBG_STMT(sEmptyRep->CheckInvariants())
// Set valid values, in case an exception is thrown
mRep = new_rep_reference(sEmptyRep);
mStart = 0;
mLength = 0;
if ( aCstr ) {
size_t len = strlen(aCstr);
_replace(0, mLength, aCstr, len);
}
}
void DwString::_replace(size_t aPos1, size_t aLen1, size_t aLen2, char aChar)
{
assert(aPos1 <= mLength);
size_t pos1 = DW_MIN(aPos1, mLength);
size_t len1 = DW_MIN(aLen1, mLength - pos1);
assert(mStart + mLength - len1 < ((size_t) - 1) - aLen2);
size_t len2 = DW_MIN(aLen2, ((size_t) - 1) - (mStart + mLength - len1));
size_t i;
char *to;
const char *from;
size_t newLen = mLength - len1 + len2;
// Is new string empty?
if(newLen == 0)
{
if(mRep != sEmptyRep)
{
delete_rep_safely(mRep);
mRep = new_rep_reference(sEmptyRep);
mStart = 0;
mLength = 0;
}
}
// Is buffer shared? Is buffer too small?
else if(mRep->mRefCount > 1 || newLen >= mRep->mSize)
{
size_t size = newLen + 1;
char *newBuf = mem_alloc(&size);
assert(newBuf != 0);
if(newBuf != 0)
{
to = newBuf;
from = mRep->mBuffer + mStart;
for(i = 0; i < pos1; ++i) *to++ = *from++;
for(i = 0; i < len2; ++i) *to++ = aChar;
from = mRep->mBuffer + mStart + pos1 + len1;
for(i = 0; i < mLength - pos1 - len1; ++i) *to++ = *from++;
*to = 0;
DwStringRep *rep = new DwStringRep(newBuf, size);
assert(rep != 0);
if(rep != 0)
{
delete_rep_safely(mRep);
mRep = rep;
mStart = 0;
mLength = newLen;
}
}
}
// Is the replacement smaller than the replaced?
else if(len2 < len1)
{
to = mRep->mBuffer + mStart + pos1;
for(i = 0; i < len2; ++i) *to++ = aChar;
from = mRep->mBuffer + mStart + pos1 + len1;
for(i = 0; i < mLength - pos1 - len1; ++i) *to++ = *from++;
*to = 0;
mLength = newLen;
}
// Is there enough room at end of buffer?
else if(mStart + newLen < mRep->mSize)
{
to = mRep->mBuffer + mStart + newLen;
from = mRep->mBuffer + mStart + mLength - 1;
*to-- = 0;
for(i = 0; i < mLength - pos1 - len1; ++i) *to-- = *from--;
for(i = 0; i < len2; ++i) *to-- = aChar;
mLength = newLen;
}
// Is there enough room at beginning of buffer?
else if(len2 - len1 <= mStart)
{
to = mRep->mBuffer + mStart - (len2 - len1);
from = mRep->mBuffer + mStart;
for(i = 0; i < pos1; ++i) *to++ = *from++;
for(i = 0; i < len2; ++i) *to++ = aChar;
mStart -= len2 - len1;
mLength = newLen;
}
// There's enough room, but we must move characters.
else
{
to = mRep->mBuffer + newLen;
from = mRep->mBuffer + mStart + mLength - 1;
*to-- = 0;
for(i = 0; i < mLength - pos1 - len1; ++i) *to-- = *from--;
to = mRep->mBuffer;
from = mRep->mBuffer + mStart;
for(i = 0; i < pos1; ++i) *to++ = *from++;
for(i = 0; i < len2; ++i) *to++ = aChar;
mStart = 0;
mLength = newLen;
}
}
