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various changes from sm4 and sm-ssc (svn); see updated changelog for the full information

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This commit is contained in:
AJ Kelly
2010-02-18 23:17:24 -06:00
parent f9bfc80fa9
commit 5c5ef54a48
26 changed files with 436 additions and 260 deletions
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src/RageFileDriverReadAhead.cpp
+25 -20
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@@ -65,7 +65,6 @@ RageFileDriverReadAhead::RageFileDriverReadAhead( RageFileBasic *pFile, int iCac
m_pFile = pFile;
m_iFilePos = pFile->Tell();
m_bFileOwned = false;
m_bReadAheadNeeded = true;
m_iPostBufferReadAhead = iPostBufferReadAhead;
FillBuffer( iCacheBytes );
@@ -79,7 +78,6 @@ RageFileDriverReadAhead::RageFileDriverReadAhead( const RageFileDriverReadAhead
m_iFilePos = cpy.m_iFilePos;
m_bFileOwned = true;
m_iPostBufferReadAhead = cpy.m_iPostBufferReadAhead;
m_bReadAheadNeeded = cpy.m_bReadAheadNeeded;
RageFileManagerReadAhead::CacheHintStreaming( m_pFile );
}
@@ -117,32 +115,39 @@ void RageFileDriverReadAhead::FillBuffer( int iBytes )
int RageFileDriverReadAhead::ReadInternal( void *pBuffer, size_t iBytes )
{
/* If we're in the buffered area, and we havn't already done read-ahead, start it. */
int iRet = -1;
if( m_bReadAheadNeeded && m_iFilePos < (int) m_sBuffer.size() )
{
RageFileManagerReadAhead::ReadAhead( m_pFile, m_iPostBufferReadAhead );
m_bReadAheadNeeded = false;
// If we can serve data out of the buffer, use it.
iRet = min( iBytes, m_sBuffer.size() - m_iFilePos );
memcpy( pBuffer, m_sBuffer.data() + m_iFilePos, iRet );
}
else if( !m_bReadAheadNeeded && m_iFilePos >= (int) m_sBuffer.size() )
else
{
/* Reset, so next time we rewind we'll read-ahead again. */
m_bReadAheadNeeded = true;
// Read out of the underlying file.
iRet = m_pFile->Read( pBuffer, iBytes );
}
/* If we can serve data out of the buffer, use it. */
if( m_iFilePos < (int) m_sBuffer.size() )
{
size_t iFromBuffer = min( iBytes, m_sBuffer.size() - m_iFilePos );
memcpy( pBuffer, m_sBuffer.data() + m_iFilePos, iFromBuffer );
m_iFilePos += iFromBuffer;
return iFromBuffer;
}
/* Read out of the underlying file. */
int iRet = m_pFile->Read( pBuffer, iBytes );
if( iRet != -1 )
m_iFilePos += iRet;
/*
* Hint the read-ahead. We only strictly need to do this when reading data from
* m_sBuffer, so the kernel knows to start reading data ahead of it. Always
* doing it is simpler, and reduces some skips when under I/O load.
*/
RageFileManagerReadAhead::ReadAhead( m_pFile, m_iPostBufferReadAhead );
/*
* We're streaming the file, so we don't need data that we've already read in cache.
* Hint the OS to discard it, so it doesn't push more useful data out of cache.
*
* Keep the previous 32k of data in cache. This prevents an issue in Linux: if we're at
* the end of the file, flush the cache, then try to read (resulting in 0 bytes), it'll
* hit the disk if we've flushed.
*/
RageFileManagerReadAhead::DiscardCache( m_pFile, -m_iPostBufferReadAhead - 1024*32, m_iPostBufferReadAhead );
return iRet;
}