197 lines
3.7 KiB
C++
197 lines
3.7 KiB
C++
// File: crn_buffer_stream.h
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// See Copyright Notice and license at the end of inc/crnlib.h
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#pragma once
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#include "crn_data_stream.h"
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namespace crnlib
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{
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class buffer_stream : public data_stream
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{
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public:
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buffer_stream() :
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data_stream(),
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m_pBuf(NULL),
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m_size(0),
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m_ofs(0)
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{
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}
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buffer_stream(void* p, uint size) :
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data_stream(),
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m_pBuf(NULL),
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m_size(0),
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m_ofs(0)
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{
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open(p, size);
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}
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buffer_stream(const void* p, uint size) :
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data_stream(),
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m_pBuf(NULL),
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m_size(0),
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m_ofs(0)
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{
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open(p, size);
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}
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virtual ~buffer_stream()
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{
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}
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bool open(const void* p, uint size)
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{
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CRNLIB_ASSERT(p);
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close();
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if ((!p) || (!size))
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return false;
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m_opened = true;
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m_pBuf = (uint8*)(p);
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m_size = size;
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m_ofs = 0;
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m_attribs = cDataStreamSeekable | cDataStreamReadable;
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return true;
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}
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bool open(void* p, uint size)
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{
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CRNLIB_ASSERT(p);
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close();
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if ((!p) || (!size))
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return false;
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m_opened = true;
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m_pBuf = static_cast<uint8*>(p);
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m_size = size;
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m_ofs = 0;
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m_attribs = cDataStreamSeekable | cDataStreamWritable | cDataStreamReadable;
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return true;
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}
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virtual bool close()
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{
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if (m_opened)
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{
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m_opened = false;
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m_pBuf = NULL;
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m_size = 0;
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m_ofs = 0;
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return true;
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}
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return false;
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}
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const void* get_buf() const { return m_pBuf; }
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void* get_buf() { return m_pBuf; }
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virtual const void* get_ptr() const { return m_pBuf; }
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virtual uint read(void* pBuf, uint len)
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{
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CRNLIB_ASSERT(pBuf && (len <= 0x7FFFFFFF));
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if ((!m_opened) || (!is_readable()) || (!len))
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return 0;
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CRNLIB_ASSERT(m_ofs <= m_size);
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uint bytes_left = m_size - m_ofs;
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len = math::minimum<uint>(len, bytes_left);
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if (len)
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memcpy(pBuf, &m_pBuf[m_ofs], len);
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m_ofs += len;
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return len;
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}
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virtual uint write(const void* pBuf, uint len)
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{
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CRNLIB_ASSERT(pBuf && (len <= 0x7FFFFFFF));
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if ((!m_opened) || (!is_writable()) || (!len))
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return 0;
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CRNLIB_ASSERT(m_ofs <= m_size);
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uint bytes_left = m_size - m_ofs;
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len = math::minimum<uint>(len, bytes_left);
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if (len)
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memcpy(&m_pBuf[m_ofs], pBuf, len);
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m_ofs += len;
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return len;
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}
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virtual bool flush()
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{
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if (!m_opened)
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return false;
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return true;
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}
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virtual uint64 get_size()
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{
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if (!m_opened)
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return 0;
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return m_size;
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}
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virtual uint64 get_remaining()
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{
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if (!m_opened)
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return 0;
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CRNLIB_ASSERT(m_ofs <= m_size);
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return m_size - m_ofs;
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}
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virtual uint64 get_ofs()
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{
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if (!m_opened)
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return 0;
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return m_ofs;
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}
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virtual bool seek(int64 ofs, bool relative)
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{
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if ((!m_opened) || (!is_seekable()))
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return false;
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int64 new_ofs = relative ? (m_ofs + ofs) : ofs;
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if (new_ofs < 0)
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return false;
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else if (new_ofs > m_size)
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return false;
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m_ofs = static_cast<uint>(new_ofs);
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post_seek();
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return true;
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}
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private:
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uint8* m_pBuf;
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uint m_size;
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uint m_ofs;
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};
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} // namespace crnlib
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