#include "config.h"
#include "StringBuilder.h"
#include "WTFString.h"
namespace WTF {
void StringBuilder::reifyString()
{
if (!m_string.isNull()) {
ASSERT(m_string.length() == m_length);
return;
}
if (!m_length) {
m_string = StringImpl::empty();
return;
}
ASSERT(m_buffer && m_length <= m_buffer->length());
m_string = (m_length == m_buffer->length())
? m_buffer.get()
: StringImpl::create(m_buffer, 0, m_length);
}
void StringBuilder::resize(unsigned newSize)
{
ASSERT(newSize <= m_length);
if (newSize == m_length)
return;
ASSERT(m_length);
if (m_buffer) {
if (!m_buffer->hasOneRef())
allocateBuffer(m_buffer->characters(), m_buffer->length());
m_length = newSize;
m_string = String();
return;
}
ASSERT(!m_string.isEmpty());
ASSERT(m_length == m_string.length());
ASSERT(newSize < m_string.length());
m_length = newSize;
m_string = StringImpl::create(m_string.impl(), 0, newSize);
}
void StringBuilder::reserveCapacity(unsigned newCapacity)
{
if (m_buffer) {
if (newCapacity > m_buffer->length())
allocateBuffer(m_buffer->characters(), newCapacity);
} else {
if (newCapacity > m_length)
allocateBuffer(m_string.characters(), newCapacity);
}
}
void StringBuilder::allocateBuffer(const UChar* currentCharacters, unsigned requiredLength)
{
RefPtr<StringImpl> buffer = StringImpl::createUninitialized(requiredLength, m_bufferCharacters);
memcpy(m_bufferCharacters, currentCharacters, static_cast<size_t>(m_length) * sizeof(UChar));
m_buffer = buffer.release();
m_string = String();
}
UChar* StringBuilder::appendUninitialized(unsigned length)
{
ASSERT(length);
unsigned requiredLength = length + m_length;
if (requiredLength < length)
CRASH();
if (m_buffer) {
ASSERT(m_buffer->length() >= m_length);
if (requiredLength <= m_buffer->length()) {
unsigned currentLength = m_length;
m_string = String();
m_length = requiredLength;
return m_bufferCharacters + currentLength;
}
allocateBuffer(m_buffer->characters(), std::max(requiredLength, m_buffer->length() * 2));
} else {
ASSERT(m_string.length() == m_length);
allocateBuffer(m_string.characters(), std::max(requiredLength, requiredLength * 2));
}
UChar* result = m_bufferCharacters + m_length;
m_length = requiredLength;
return result;
}
void StringBuilder::append(const UChar* characters, unsigned length)
{
if (!length)
return;
ASSERT(characters);
memcpy(appendUninitialized(length), characters, static_cast<size_t>(length) * 2);
}
void StringBuilder::append(const char* characters, unsigned length)
{
if (!length)
return;
ASSERT(characters);
UChar* dest = appendUninitialized(length);
const char* end = characters + length;
while (characters < end)
*(dest++) = *(const unsigned char*)(characters++);
}
void StringBuilder::shrinkToFit()
{
if (m_buffer && m_buffer->length() > (m_length + (m_length >> 2))) {
UChar* result;
m_string = StringImpl::createUninitialized(m_length, result);
memcpy(result, m_buffer->characters(), static_cast<size_t>(m_length) * 2); m_buffer = 0;
}
}
}