darling-WTF/wtf/StringPrintStream.cpp
2023-04-24 20:14:26 -07:00

138 lines
4.4 KiB
C++

/*
* Copyright (C) 2012 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 <wtf/StringPrintStream.h>
#include <stdarg.h>
#include <stdio.h>
#include <wtf/FastMalloc.h>
namespace WTF {
StringPrintStream::StringPrintStream()
: m_buffer(m_inlineBuffer)
, m_next(0)
, m_size(sizeof(m_inlineBuffer))
{
m_buffer[0] = 0; // Make sure that we always have a null terminator.
}
StringPrintStream::~StringPrintStream()
{
if (m_buffer == m_inlineBuffer)
return;
fastFree(m_buffer);
}
void StringPrintStream::vprintf(const char* format, va_list argList)
{
ASSERT_WITH_SECURITY_IMPLICATION(m_next < m_size);
ASSERT(!m_buffer[m_next]);
va_list firstPassArgList;
va_copy(firstPassArgList, argList);
int numberOfBytesNotIncludingTerminatorThatWouldHaveBeenWritten =
vsnprintf(m_buffer + m_next, m_size - m_next, format, firstPassArgList);
va_end(firstPassArgList);
int numberOfBytesThatWouldHaveBeenWritten =
numberOfBytesNotIncludingTerminatorThatWouldHaveBeenWritten + 1;
if (m_next + numberOfBytesThatWouldHaveBeenWritten <= m_size) {
m_next += numberOfBytesNotIncludingTerminatorThatWouldHaveBeenWritten;
return; // This means that vsnprintf() succeeded.
}
increaseSize(m_next + numberOfBytesThatWouldHaveBeenWritten);
int numberOfBytesNotIncludingTerminatorThatWereWritten =
vsnprintf(m_buffer + m_next, m_size - m_next, format, argList);
int numberOfBytesThatWereWritten = numberOfBytesNotIncludingTerminatorThatWereWritten + 1;
ASSERT_UNUSED(numberOfBytesThatWereWritten, m_next + numberOfBytesThatWereWritten <= m_size);
m_next += numberOfBytesNotIncludingTerminatorThatWereWritten;
ASSERT_WITH_SECURITY_IMPLICATION(m_next < m_size);
ASSERT(!m_buffer[m_next]);
}
CString StringPrintStream::toCString()
{
ASSERT(m_next == strlen(m_buffer));
return CString(m_buffer, m_next);
}
void StringPrintStream::reset()
{
m_next = 0;
m_buffer[0] = 0;
}
Expected<String, UTF8ConversionError> StringPrintStream::tryToString()
{
ASSERT(m_next == strlen(m_buffer));
if (m_next > String::MaxLength)
return makeUnexpected(UTF8ConversionError::OutOfMemory);
return String::fromUTF8(m_buffer, m_next);
}
String StringPrintStream::toString()
{
ASSERT(m_next == strlen(m_buffer));
return String::fromUTF8(m_buffer, m_next);
}
String StringPrintStream::toStringWithLatin1Fallback()
{
ASSERT(m_next == strlen(m_buffer));
return String::fromUTF8WithLatin1Fallback(m_buffer, m_next);
}
void StringPrintStream::increaseSize(size_t newSize)
{
ASSERT_WITH_SECURITY_IMPLICATION(newSize > m_size);
ASSERT(newSize > sizeof(m_inlineBuffer));
// Use exponential resizing to reduce thrashing.
m_size = newSize << 1;
// Use fastMalloc instead of fastRealloc because we know that for the sizes we're using,
// fastRealloc will just do malloc+free anyway. Also, this simplifies the code since
// we can't realloc the inline buffer.
char* newBuffer = static_cast<char*>(fastMalloc(m_size));
memcpy(newBuffer, m_buffer, m_next + 1);
if (m_buffer != m_inlineBuffer)
fastFree(m_buffer);
m_buffer = newBuffer;
}
} // namespace WTF