void Stream_Decompression::process(secure_vector<byte>& buf, size_t offset, u32bit flags)
{
BOTAN_ASSERT(m_stream, "Initialized");
BOTAN_ASSERT(buf.size() >= offset, "Offset is sane");
if(m_buffer.size() < buf.size() + offset)
m_buffer.resize(buf.size() + offset);
m_stream->next_in(buf.data() + offset, buf.size() - offset);
m_stream->next_out(m_buffer.data() + offset, m_buffer.size() - offset);
while(true)
{
const bool stream_end = m_stream->run(flags);
if(stream_end)
{
if(m_stream->avail_in() == 0) // all data consumed?
{
m_buffer.resize(m_buffer.size() - m_stream->avail_out());
clear();
break;
}
// More data follows: try to process as a following stream
const size_t read = (buf.size() - offset) - m_stream->avail_in();
start();
m_stream->next_in(buf.data() + offset + read, buf.size() - offset - read);
}
if(m_stream->avail_out() == 0)
{
const size_t added = 8 + m_buffer.size();
m_buffer.resize(m_buffer.size() + added);
m_stream->next_out(m_buffer.data() + m_buffer.size() - added, added);
}
else if(m_stream->avail_in() == 0)
{
m_buffer.resize(m_buffer.size() - m_stream->avail_out());
break;
}
}
copy_mem(m_buffer.data(), buf.data(), offset);
buf.swap(m_buffer);
}
void Stream_Compression::process(secure_vector<byte>& buf, size_t offset, u32bit flags)
{
BOTAN_ASSERT(m_stream, "Initialized");
BOTAN_ASSERT(buf.size() >= offset, "Offset is sane");
if(m_buffer.size() < buf.size() + offset)
m_buffer.resize(buf.size() + offset);
// If the output buffer has zero length, .data() might return nullptr. This would
// make some compression algorithms (notably those provided by zlib) fail.
// Any small positive value works fine, but we choose 32 as it is the smallest power
// of two that is large enough to hold all the headers and trailers of the common
// formats, preventing further resizings to make room for output data.
if(m_buffer.size() == 0)
m_buffer.resize(32);
m_stream->next_in(buf.data() + offset, buf.size() - offset);
m_stream->next_out(m_buffer.data() + offset, m_buffer.size() - offset);
while(true)
{
m_stream->run(flags);
if(m_stream->avail_out() == 0)
{
const size_t added = 8 + m_buffer.size();
m_buffer.resize(m_buffer.size() + added);
m_stream->next_out(m_buffer.data() + m_buffer.size() - added, added);
}
else if(m_stream->avail_in() == 0)
{
m_buffer.resize(m_buffer.size() - m_stream->avail_out());
break;
}
}
copy_mem(m_buffer.data(), buf.data(), offset);
buf.swap(m_buffer);
}
