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108 lines
3.5 KiB
C++
108 lines
3.5 KiB
C++
/* ScummVM - Graphic Adventure Engine
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*
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* ScummVM is the legal property of its developers, whose names
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* are too numerous to list here. Please refer to the COPYRIGHT
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* file distributed with this source distribution.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
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*
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* $URL$
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* $Id$
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*
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*/
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#ifndef COMMON_SUBSTREAM_H
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#define COMMON_SUBSTREAM_H
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#include "common/stream.h"
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namespace Common {
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/**
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* SubReadStream provides access to a ReadStream restricted to the range
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* [currentPosition, currentPosition+end).
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*
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* Manipulating the parent stream directly /will/ mess up a substream.
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* Likewise, manipulating two substreams of a parent stream will cause them to
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* step on each others toes.
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*/
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class SubReadStream : virtual public ReadStream {
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protected:
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ReadStream *_parentStream;
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DisposeAfterUse::Flag _disposeParentStream;
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uint32 _pos;
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uint32 _end;
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bool _eos;
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public:
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SubReadStream(ReadStream *parentStream, uint32 end, DisposeAfterUse::Flag disposeParentStream = DisposeAfterUse::NO)
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: _parentStream(parentStream),
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_disposeParentStream(disposeParentStream),
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_pos(0),
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_end(end),
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_eos(false) {
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assert(parentStream);
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}
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~SubReadStream() {
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if (_disposeParentStream)
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delete _parentStream;
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}
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virtual bool eos() const { return _eos; }
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virtual bool err() const { return _parentStream->err(); }
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virtual void clearErr() { _eos = false; _parentStream->clearErr(); }
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virtual uint32 read(void *dataPtr, uint32 dataSize);
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};
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/*
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* SeekableSubReadStream provides access to a SeekableReadStream restricted to
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* the range [begin, end).
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* The same caveats apply to SeekableSubReadStream as do to SeekableReadStream.
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*
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* Manipulating the parent stream directly /will/ mess up a substream.
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* @see SubReadStream
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*/
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class SeekableSubReadStream : public SubReadStream, public SeekableReadStream {
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protected:
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SeekableReadStream *_parentStream;
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uint32 _begin;
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public:
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SeekableSubReadStream(SeekableReadStream *parentStream, uint32 begin, uint32 end, DisposeAfterUse::Flag disposeParentStream = DisposeAfterUse::NO);
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virtual int32 pos() const { return _pos - _begin; }
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virtual int32 size() const { return _end - _begin; }
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virtual bool seek(int32 offset, int whence = SEEK_SET);
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};
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/**
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* This is a SeekableSubReadStream subclass which adds non-endian
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* read methods whose endianness is set on the stream creation.
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*
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* Manipulating the parent stream directly /will/ mess up a substream.
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* @see SubReadStream
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*/
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class SeekableSubReadStreamEndian : public SeekableSubReadStream, public ReadStreamEndian {
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public:
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SeekableSubReadStreamEndian(SeekableReadStream *parentStream, uint32 begin, uint32 end, bool bigEndian, DisposeAfterUse::Flag disposeParentStream = DisposeAfterUse::NO)
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: SeekableSubReadStream(parentStream, begin, end, disposeParentStream),
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ReadStreamEndian(bigEndian) {
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}
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};
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} // End of namespace Common
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#endif
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