+++ /dev/null
-/*
- * Copyright (C) 2010 Apple Inc. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
- * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
- * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
- * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- */
-
-#include "config.h"
-#include "StringBuilder.h"
-
-#include "WTFString.h"
-
-namespace WTF {
-
-void StringBuilder::reifyString()
-{
- // Check if the string already exists.
- if (!m_string.isNull()) {
- ASSERT(m_string.length() == m_length);
- return;
- }
-
- // Check for empty.
- if (!m_length) {
- m_string = StringImpl::empty();
- return;
- }
-
- // Must be valid in the buffer, take a substring (unless string fills the buffer).
- 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)
-{
- // Check newSize < m_length, hence m_length > 0.
- ASSERT(newSize <= m_length);
- if (newSize == m_length)
- return;
- ASSERT(m_length);
-
- // If there is a buffer, we only need to duplicate it if it has more than one ref.
- if (m_buffer) {
- if (!m_buffer->hasOneRef())
- allocateBuffer(m_buffer->characters(), m_buffer->length());
- m_length = newSize;
- m_string = String();
- return;
- }
-
- // Since m_length && !m_buffer, the string must be valid in m_string, and m_string.length() > 0.
- 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 there is already a buffer, then grow if necessary.
- if (newCapacity > m_buffer->length())
- allocateBuffer(m_buffer->characters(), newCapacity);
- } else {
- // Grow the string, if necessary.
- if (newCapacity > m_length)
- allocateBuffer(m_string.characters(), newCapacity);
- }
-}
-
-// Allocate a new buffer, copying in currentCharacters (these may come from either m_string
-// or m_buffer, neither will be reassigned until the copy has completed).
-void StringBuilder::allocateBuffer(const UChar* currentCharacters, unsigned requiredLength)
-{
- // Copy the existing data into a new buffer, set result to point to the end of the existing data.
- RefPtr<StringImpl> buffer = StringImpl::createUninitialized(requiredLength, m_bufferCharacters);
- memcpy(m_bufferCharacters, currentCharacters, static_cast<size_t>(m_length) * sizeof(UChar)); // This can't overflow.
-
- // Update the builder state.
- m_buffer = buffer.release();
- m_string = String();
-}
-
-// Make 'length' additional capacity be available in m_buffer, update m_string & m_length,
-// return a pointer to the newly allocated storage.
-UChar* StringBuilder::appendUninitialized(unsigned length)
-{
- ASSERT(length);
-
- // Calcuate the new size of the builder after appending.
- unsigned requiredLength = length + m_length;
- if (requiredLength < length)
- CRASH();
-
- if (m_buffer) {
- // If the buffer is valid it must be at least as long as the current builder contents!
- ASSERT(m_buffer->length() >= m_length);
-
- // Check if the buffer already has sufficient capacity.
- if (requiredLength <= m_buffer->length()) {
- unsigned currentLength = m_length;
- m_string = String();
- m_length = requiredLength;
- return m_bufferCharacters + currentLength;
- }
-
- // We need to realloc the buffer.
- 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 the buffer is at least 80% full, don't bother copying. Need to tune this heuristic!
- 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); // This can't overflow.
- m_buffer = 0;
- }
-}
-
-} // namespace WTF
projects / apple / javascriptcore.git / blobdiff