mirror of
https://github.com/RGBCube/serenity
synced 2025-10-31 15:12:45 +00:00
133 lines
3.9 KiB
C++
133 lines
3.9 KiB
C++
/*
|
|
* Copyright (c) 2020, Peter Elliott <pelliott@ualberta.ca>
|
|
* 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 THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 THE COPYRIGHT HOLDER 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 <AK/LogStream.h>
|
|
#include <LibTar/TarStream.h>
|
|
|
|
namespace Tar {
|
|
TarFileStream::TarFileStream(TarStream& tar_stream)
|
|
: m_tar_stream(tar_stream)
|
|
, m_generation(tar_stream.m_generation)
|
|
{
|
|
}
|
|
|
|
size_t TarFileStream::read(Bytes bytes)
|
|
{
|
|
// verify that the stream has not advanced
|
|
ASSERT(m_tar_stream.m_generation == m_generation);
|
|
|
|
if (has_any_error())
|
|
return 0;
|
|
|
|
auto to_read = min(bytes.size(), m_tar_stream.header().size() - m_tar_stream.m_file_offset);
|
|
|
|
auto nread = m_tar_stream.m_stream.read(bytes.trim(to_read));
|
|
m_tar_stream.m_file_offset += nread;
|
|
return nread;
|
|
}
|
|
|
|
bool TarFileStream::unreliable_eof() const
|
|
{
|
|
// verify that the stream has not advanced
|
|
ASSERT(m_tar_stream.m_generation == m_generation);
|
|
|
|
return m_tar_stream.m_stream.unreliable_eof()
|
|
|| m_tar_stream.m_file_offset >= m_tar_stream.header().size();
|
|
}
|
|
|
|
bool TarFileStream::read_or_error(Bytes bytes)
|
|
{
|
|
// verify that the stream has not advanced
|
|
ASSERT(m_tar_stream.m_generation == m_generation);
|
|
|
|
if (read(bytes) < bytes.size()) {
|
|
set_fatal_error();
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
bool TarFileStream::discard_or_error(size_t count)
|
|
{
|
|
// verify that the stream has not advanced
|
|
ASSERT(m_tar_stream.m_generation == m_generation);
|
|
|
|
if (count > m_tar_stream.header().size() - m_tar_stream.m_file_offset) {
|
|
return false;
|
|
}
|
|
m_tar_stream.m_file_offset += count;
|
|
return m_tar_stream.m_stream.discard_or_error(count);
|
|
}
|
|
|
|
TarStream::TarStream(InputStream& stream)
|
|
: m_stream(stream)
|
|
{
|
|
if (!m_stream.read_or_error(Bytes(&m_header, sizeof(m_header)))) {
|
|
m_finished = true;
|
|
return;
|
|
}
|
|
ASSERT(m_stream.discard_or_error(block_size - sizeof(Header)));
|
|
}
|
|
|
|
static constexpr unsigned long block_ceiling(unsigned long offset)
|
|
{
|
|
return block_size * (1 + ((offset - 1) / block_size));
|
|
}
|
|
|
|
void TarStream::advance()
|
|
{
|
|
if (m_finished)
|
|
return;
|
|
|
|
m_generation++;
|
|
ASSERT(m_stream.discard_or_error(block_ceiling(m_header.size()) - m_file_offset));
|
|
m_file_offset = 0;
|
|
|
|
if (!m_stream.read_or_error(Bytes(&m_header, sizeof(m_header)))) {
|
|
m_finished = true;
|
|
return;
|
|
}
|
|
if (!valid()) {
|
|
m_finished = true;
|
|
return;
|
|
}
|
|
|
|
ASSERT(m_stream.discard_or_error(block_size - sizeof(Header)));
|
|
}
|
|
|
|
bool TarStream::valid() const
|
|
{
|
|
return header().magic() == ustar_magic;
|
|
}
|
|
|
|
TarFileStream TarStream::file_contents()
|
|
{
|
|
ASSERT(!m_finished);
|
|
return TarFileStream(*this);
|
|
}
|
|
|
|
}
|