thirdparty/scummvm
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COMMON: Make implementation of Buffered*Stream classes internal

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svn-id: r54326
This commit is contained in:
Max Horn 2010-11-18 17:02:51 +00:00
parent b8f0026739
commit 152e52d015
6 changed files with 176 additions and 93 deletions
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154
common/stream.cpp
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@ -89,6 +89,33 @@ bool MemoryReadStream::seek(int32 offs, int whence) {
return true; // FIXME: STREAM REWRITE
}
bool MemoryWriteStreamDynamic::seek(int32 offs, int whence) {
// Pre-Condition
assert(_pos <= _size);
switch (whence) {
case SEEK_END:
// SEEK_END works just like SEEK_SET, only 'reversed',
// i.e. from the end.
offs = _size + offs;
// Fall through
case SEEK_SET:
_ptr = _data + offs;
_pos = offs;
break;
case SEEK_CUR:
_ptr += offs;
_pos += offs;
break;
}
// Post-Condition
assert(_pos <= _size);
return true; // FIXME: STREAM REWRITE
}
#pragma mark -
enum {
LF = 0x0A,
CR = 0x0D
@ -222,6 +249,37 @@ bool SeekableSubReadStream::seek(int32 offset, int whence) {
return ret;
}
#pragma mark -
namespace {
/**
* Wrapper class which adds buffering to any given ReadStream.
* Users can specify how big the buffer should be, and whether the
* wrapped stream should be disposed when the wrapper is disposed.
*/
class BufferedReadStream : virtual public ReadStream {
protected:
ReadStream *_parentStream;
DisposeAfterUse::Flag _disposeParentStream;
byte *_buf;
uint32 _pos;
bool _eos; // end of stream
uint32 _bufSize;
uint32 _realBufSize;
public:
BufferedReadStream(ReadStream *parentStream, uint32 bufSize, DisposeAfterUse::Flag disposeParentStream);
virtual ~BufferedReadStream();
virtual bool eos() const { return _eos; }
virtual bool err() const { return _parentStream->err(); }
virtual void clearErr() { _eos = false; _parentStream->clearErr(); }
virtual uint32 read(void *dataPtr, uint32 dataSize);
};
BufferedReadStream::BufferedReadStream(ReadStream *parentStream, uint32 bufSize, DisposeAfterUse::Flag disposeParentStream)
: _parentStream(parentStream),
_disposeParentStream(disposeParentStream),
@ -290,6 +348,35 @@ uint32 BufferedReadStream::read(void *dataPtr, uint32 dataSize) {
return alreadyRead + dataSize;
}
} // End of nameless namespace
ReadStream *wrapBufferedReadStream(ReadStream *parentStream, uint32 bufSize, DisposeAfterUse::Flag disposeParentStream) {
if (parentStream)
return new BufferedReadStream(parentStream, bufSize, disposeParentStream);
return 0;
}
#pragma mark -
namespace {
/**
* Wrapper class which adds buffering to any given SeekableReadStream.
* @see BufferedReadStream
*/
class BufferedSeekableReadStream : public BufferedReadStream, public SeekableReadStream {
protected:
SeekableReadStream *_parentStream;
public:
BufferedSeekableReadStream(SeekableReadStream *parentStream, uint32 bufSize, DisposeAfterUse::Flag disposeParentStream = DisposeAfterUse::NO);
virtual int32 pos() const { return _parentStream->pos() - (_bufSize - _pos); }
virtual int32 size() const { return _parentStream->size(); }
virtual bool seek(int32 offset, int whence = SEEK_SET);
};
BufferedSeekableReadStream::BufferedSeekableReadStream(SeekableReadStream *parentStream, uint32 bufSize, DisposeAfterUse::Flag disposeParentStream)
: BufferedReadStream(parentStream, bufSize, disposeParentStream),
_parentStream(parentStream) {
@ -319,6 +406,46 @@ bool BufferedSeekableReadStream::seek(int32 offset, int whence) {
return true;
}
} // End of nameless namespace
SeekableReadStream *wrapBufferedSeekableReadStream(SeekableReadStream *parentStream, uint32 bufSize, DisposeAfterUse::Flag disposeParentStream) {
if (parentStream)
return new BufferedSeekableReadStream(parentStream, bufSize, disposeParentStream);
return 0;
}
#pragma mark -
namespace {
/**
* Wrapper class which adds buffering to any WriteStream.
*/
class BufferedWriteStream : public WriteStream {
protected:
WriteStream *_parentStream;
DisposeAfterUse::Flag _disposeParentStream;
byte *_buf;
uint32 _pos;
const uint32 _bufSize;
/**
* Write out the data in the buffer.
*
* @note This method is identical to flush() (which actually is
* implemented by calling this method), except that it is not
* virtual, hence there is less overhead calling it.
*/
bool flushBuffer();
public:
BufferedWriteStream(WriteStream *parentStream, uint32 bufSize, DisposeAfterUse::Flag disposeParentStream = DisposeAfterUse::NO);
virtual ~BufferedWriteStream();
virtual uint32 write(const void *dataPtr, uint32 dataSize);
virtual bool flush() { return flushBuffer(); }
};
BufferedWriteStream::BufferedWriteStream(WriteStream *parentStream, uint32 bufSize, DisposeAfterUse::Flag disposeParentStream)
: _parentStream(parentStream),
_disposeParentStream(disposeParentStream),
@ -369,29 +496,12 @@ bool BufferedWriteStream::flushBuffer() {
return true;
}
bool MemoryWriteStreamDynamic::seek(int32 offs, int whence) {
// Pre-Condition
assert(_pos <= _size);
switch (whence) {
case SEEK_END:
// SEEK_END works just like SEEK_SET, only 'reversed',
// i.e. from the end.
offs = _size + offs;
// Fall through
case SEEK_SET:
_ptr = _data + offs;
_pos = offs;
break;
} // End of nameless namespace
case SEEK_CUR:
_ptr += offs;
_pos += offs;
break;
}
// Post-Condition
assert(_pos <= _size);
return true; // FIXME: STREAM REWRITE
WriteStream *wrapBufferedWriteStream(WriteStream *parentStream, uint32 bufSize, DisposeAfterUse::Flag disposeParentStream) {
if (parentStream)
return new BufferedWriteStream(parentStream, bufSize, disposeParentStream);
return 0;
}
} // End of namespace Common