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forked from 0ad/0ad
0ad/source/lib/file/io/write_buffer.cpp
janwas 1861448e6c needed to split lib into separate headers and source files, which requires lots of drudgery to specify paths for each include filename (no longer relying on same-directory lookups)
also rename wchar -> utf8 to avoid conflict with <wchar.h> (requires
rebuild of workspace)
(unfortunately copying history fails to "502 bad gateway"; had to delete
old + add new independently)

This was SVN commit r7340.
2010-03-01 14:52:58 +00:00

126 lines
3.5 KiB
C++

/* Copyright (c) 2010 Wildfire Games
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include "precompiled.h"
#include "lib/file/io/write_buffer.h"
#include "lib/bits.h" // IsAligned
#include "lib/sysdep/cpu.h"
#include "lib/file/io/io.h"
#include "lib/file/io/io_align.h"
WriteBuffer::WriteBuffer()
: m_capacity(4096), m_data(io_Allocate(m_capacity)), m_size(0)
{
}
void WriteBuffer::Append(const void* data, size_t size)
{
if(m_size + size > m_capacity)
{
m_capacity = round_up_to_pow2(m_size + size);
shared_ptr<u8> newData = io_Allocate(m_capacity);
cpu_memcpy(newData.get(), m_data.get(), m_size);
m_data = newData;
}
cpu_memcpy(m_data.get() + m_size, data, size);
m_size += size;
}
void WriteBuffer::Overwrite(const void* data, size_t size, size_t offset)
{
debug_assert(offset+size < m_size);
cpu_memcpy(m_data.get()+offset, data, size);
}
//-----------------------------------------------------------------------------
// UnalignedWriter
//-----------------------------------------------------------------------------
UnalignedWriter::UnalignedWriter(const PFile& file, off_t ofs)
: m_file(file), m_alignedBuf(io_Allocate(BLOCK_SIZE))
{
m_alignedOfs = AlignedOffset(ofs);
const size_t misalignment = (size_t)(ofs - m_alignedOfs);
if(misalignment)
io_ReadAligned(m_file, m_alignedOfs, m_alignedBuf.get(), BLOCK_SIZE);
m_bytesUsed = misalignment;
}
UnalignedWriter::~UnalignedWriter()
{
Flush();
}
LibError UnalignedWriter::Append(const u8* data, size_t size) const
{
while(size != 0)
{
// optimization: write directly from the input buffer, if possible
const size_t alignedSize = (size / BLOCK_SIZE) * BLOCK_SIZE;
if(m_bytesUsed == 0 && IsAligned(data, SECTOR_SIZE) && alignedSize != 0)
{
RETURN_ERR(io_WriteAligned(m_file, m_alignedOfs, data, alignedSize));
m_alignedOfs += (off_t)alignedSize;
data += alignedSize;
size -= alignedSize;
}
const size_t chunkSize = std::min(size, BLOCK_SIZE-m_bytesUsed);
cpu_memcpy(m_alignedBuf.get()+m_bytesUsed, data, chunkSize);
m_bytesUsed += chunkSize;
data += chunkSize;
size -= chunkSize;
if(m_bytesUsed == BLOCK_SIZE)
RETURN_ERR(WriteBlock());
}
return INFO::OK;
}
void UnalignedWriter::Flush() const
{
if(m_bytesUsed)
{
memset(m_alignedBuf.get()+m_bytesUsed, 0, BLOCK_SIZE-m_bytesUsed);
(void)WriteBlock();
}
}
LibError UnalignedWriter::WriteBlock() const
{
RETURN_ERR(io_WriteAligned(m_file, m_alignedOfs, m_alignedBuf.get(), BLOCK_SIZE));
m_alignedOfs += BLOCK_SIZE;
m_bytesUsed = 0;
return INFO::OK;
}