81 lines
1.8 KiB
C++
81 lines
1.8 KiB
C++
/* -----------------------------------------------------------------------------
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GSFramework
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Copyright 2001-2013 Emmanuel Julien. All Rights Reserved.
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----------------------------------------------------------------------------- */
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#include "filesystem/io_handle_segment.h"
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using namespace GS::IO;
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//------------------------------------------------------------------------------
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size_t HandleSegment::GetSize()
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{ return size; }
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//------------------------------------------------------------------------------
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//------------------------------------------------------------------------------
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size_t HandleSegment::Tell()
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{ return cursor; }
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size_t HandleSegment::Seek(ptrdiff_t offset, Base::SeekRef ref)
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{
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switch (ref)
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{
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case Base::SeekStart:
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cursor = offset;
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break;
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case Base::SeekCurrent:
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cursor += offset;
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break;
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case Base::SeekEnd:
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cursor = size - offset;
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break;
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}
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if (cursor > size)
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{
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cursor = 0;
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return (size_t)-1;
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}
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return 0;
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}
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//------------------------------------------------------------------------------
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//------------------------------------------------------------------------------
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/*
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IO segment must always restore the original handle position and act as
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transparently as possible.
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*/
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size_t HandleSegment::Read(void *b, size_t s)
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{
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size_t o = 0;
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size_t t = handle->Tell();
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if (!handle->Seek(offset + cursor, Base::SeekStart))
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{
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if (s > (size - cursor))
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s = size - cursor;
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o = handle->Read(b, s);
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cursor += o;
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}
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handle->Seek(t, Base::SeekStart);
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return o;
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}
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size_t HandleSegment::Write(const void *b, size_t s)
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{
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size_t o = 0;
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size_t t = handle->Tell();
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if (!handle->Seek(offset + cursor, Base::SeekStart))
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{
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o = handle->Write(b, s);
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cursor += o;
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}
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handle->Seek(t, Base::SeekStart);
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return o;
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}
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//------------------------------------------------------------------------------
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