Context Navigation

source: GTP/trunk/App/Demos/Geom/include/OgreDataStream.h @ 1030

Revision 1030, 15.4 KB checked in by gumbau, 18 years ago (diff)
Ogre Stuff initial import

Line
1	/*
2	-----------------------------------------------------------------------------
3	This source file is part of OGRE
4	(Object-oriented Graphics Rendering Engine)
5	For the latest info, see http://www.ogre3d.org/
6
7	Copyright (c) 2000-2005 The OGRE Team
8	Also see acknowledgements in Readme.html
9
10	This program is free software; you can redistribute it and/or modify it under
11	the terms of the GNU Lesser General Public License as published by the Free Software
12	Foundation; either version 2 of the License, or (at your option) any later
13	version.
14
15	This program is distributed in the hope that it will be useful, but WITHOUT
16	ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
17	FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.
18
19	You should have received a copy of the GNU Lesser General Public License along with
20	this program; if not, write to the Free Software Foundation, Inc., 59 Temple
21	Place - Suite 330, Boston, MA 02111-1307, USA, or go to
22	http://www.gnu.org/copyleft/lesser.txt.
23	-----------------------------------------------------------------------------
24	*/
25	#ifndef __DataStream_H__
26	#define __DataStream_H__
27
28	#include "OgrePrerequisites.h"
29	#include "OgreString.h"
30	#include "OgreSharedPtr.h"
31	#include <istream>
32
33	namespace Ogre {
34
35	/** General purpose class used for encapsulating the reading of data.
36	@remarks
37	This class performs basically the same tasks as std::basic_istream,
38	except that it does not have any formatting capabilities, and is
39	designed to be subclassed to receive data from multiple sources,
40	including libraries which have no compatiblity with the STL's
41	stream interfaces. As such, this is an abstraction of a set of
42	wrapper classes which pretend to be standard stream classes but
43	can actually be implemented quite differently.
44	@par
45	Generally, if a plugin or application provides an ArchiveFactory,
46	it should also provide a DataStream subclass which will be used
47	to stream data out of that Archive implementation, unless it can
48	use one of the common implementations included.
49	@note
50	Ogre makes no guarantees about thread safety, for performance reasons.
51	If you wish to access stream data asynchronously then you should
52	organise your own mutexes to avoid race conditions.
53	*/
54	class _OgreExport DataStream
55	{
56	protected:
57	/// The name (e.g. resource name) that can be used to identify the source fot his data (optional)
58	String mName;
59	/// Size of the data in the stream (may be 0 if size cannot be determined)
60	size_t mSize;
61	#define OGRE_STREAM_TEMP_SIZE 128
62	/// Temporary buffer area used for formatted read
63	char mTmpArea[OGRE_STREAM_TEMP_SIZE];
64	public:
65	/// Constructor for creating unnamed streams
66	DataStream() : mSize(0) {}
67	/// Constructor for creating named streams
68	DataStream(const String& name) : mName(name), mSize(0) {}
69	/// Returns the name of the stream, if it has one.
70	const String& getName(void) { return mName; }
71	virtual ~DataStream() {}
72	// Streaming operators
73	template<typename T> DataStream& operator>>(T& val);
74	/** Read the requisite number of bytes from the stream,
75	stopping at the end of the file.
76	@param buf Reference to a buffer pointer
77	@param count Number of bytes to read
78	@returns The number of bytes read
79	*/
80	virtual size_t read(void* buf, size_t count) = 0;
81	/** Get a single line from the stream.
82	@remarks
83	The delimiter character is not included in the data
84	returned, and it is skipped over so the next read will occur
85	after it. The buffer contents will include a
86	terminating character.
87	@param buf Reference to a buffer pointer
88	@param maxCount The maximum length of data to be read, excluding the terminating character
89	@param delim The delimiter to stop at
90	@returns The number of bytes read, excluding the terminating character
91	*/
92	virtual size_t readLine(char* buf, size_t maxCount, const String& delim = "\n") = 0;
93
94	/** Returns a String containing the next line of data, optionally
95	trimmed for whitespace.
96	@remarks
97	This is a convenience method for text streams only, allowing you to
98	retrieve a String object containing the next line of data. The data
99	is read up to the next newline character and the result trimmed if
100	required.
101	@param
102	trimAfter If true, the line is trimmed for whitespace (as in
103	String.trim(true,true))
104	*/
105	virtual String getLine( bool trimAfter = true );
106
107	/** Returns a String containing the entire stream.
108	@remarks
109	This is a convenience method for text streams only, allowing you to
110	retrieve a String object containing all the data in the stream.
111	*/
112	virtual String getAsString(void);
113
114	/** Skip a single line from the stream.
115	@param delim The delimiter(s) to stop at
116	@returns The number of bytes skipped
117	*/
118	virtual size_t skipLine(const String& delim = "\n") = 0;
119
120	/** Skip a defined number of bytes. This can also be a negative value, in which case
121	the file pointer rewinds a defined number of bytes. */
122	virtual void skip(long count) = 0;
123
124	/** Repositions the read point to a specified byte.
125	*/
126	virtual void seek( size_t pos ) = 0;
127
128	/** Returns the current byte offset from beginning */
129	virtual size_t tell(void) const = 0;
130
131	/** Returns true if the stream has reached the end.
132	*/
133	virtual bool eof(void) const = 0;
134
135	/** Returns the total size of the data to be read from the stream,
136	or 0 if this is indeterminate for this stream.
137	*/
138	size_t size(void) const { return mSize; }
139
140	/** Close the stream; this makes further operations invalid. */
141	virtual void close(void) = 0;
142
143
144	};
145
146	/** Shared pointer to allow data streams to be passed around without
147	worrying about deallocation
148	*/
149	typedef SharedPtr<DataStream> DataStreamPtr;
150
151	/// List of DataStream items
152	typedef std::list<DataStreamPtr> DataStreamList;
153	/// Shared pointer to list of DataStream items
154	typedef SharedPtr<DataStreamList> DataStreamListPtr;
155
156	/** Common subclass of DataStream for handling data from chunks of memory.
157	*/
158	class _OgreExport MemoryDataStream : public DataStream
159	{
160	protected:
161	/// Pointer to the start of the data area
162	uchar* mData;
163	/// Pointer to the current position in the memory
164	uchar* mPos;
165	/// Pointer to the end of the memory
166	uchar* mEnd;
167	/// Do we delete the memory on close
168	bool mFreeOnClose;
169	public:
170
171	/** Wrap an existing memory chunk in a stream.
172	@param pMem Pointer to the exising memory
173	@param size The size of the memory chunk in bytes
174	@param freeOnClose If true, the memory associated will be destroyed
175	when the stream is destroyed.
176	*/
177	MemoryDataStream(void* pMem, size_t size, bool freeOnClose = false);
178
179	/** Wrap an existing memory chunk in a named stream.
180	@param name The name to give the stream
181	@param pMem Pointer to the exising memory
182	@param size The size of the memory chunk in bytes
183	@param freeOnClose If true, the memory associated will be destroyed
184	when the stream is destroyed.
185	*/
186	MemoryDataStream(const String& name, void* pMem, size_t size,
187	bool freeOnClose = false);
188
189	/** Create a stream which pre-buffers the contents of another stream.
190	@remarks
191	This constructor can be used to intentionally read in the entire
192	contents of another stream, copying them to the internal buffer
193	and thus making them available in memory as a single unit.
194	@param sourceStream Another DataStream which will provide the source
195	of data
196	@param freeOnClose If true, the memory associated will be destroyed
197	when the stream is destroyed.
198	*/
199	MemoryDataStream(DataStream& sourceStream,
200	bool freeOnClose = true);
201
202	/** Create a stream which pre-buffers the contents of another stream.
203	@remarks
204	This constructor can be used to intentionally read in the entire
205	contents of another stream, copying them to the internal buffer
206	and thus making them available in memory as a single unit.
207	@param sourceStream Weak reference to another DataStream which will provide the source
208	of data
209	@param freeOnClose If true, the memory associated will be destroyed
210	when the stream is destroyed.
211	*/
212	MemoryDataStream(DataStreamPtr& sourceStream,
213	bool freeOnClose = true);
214
215	/** Create a named stream which pre-buffers the contents of
216	another stream.
217	@remarks
218	This constructor can be used to intentionally read in the entire
219	contents of another stream, copying them to the internal buffer
220	and thus making them available in memory as a single unit.
221	@param name The name to give the stream
222	@param sourceStream Another DataStream which will provide the source
223	of data
224	@param freeOnClose If true, the memory associated will be destroyed
225	when the stream is destroyed.
226	*/
227	MemoryDataStream(const String& name, DataStream& sourceStream,
228	bool freeOnClose = true);
229
230	/** Create a named stream which pre-buffers the contents of
231	another stream.
232	@remarks
233	This constructor can be used to intentionally read in the entire
234	contents of another stream, copying them to the internal buffer
235	and thus making them available in memory as a single unit.
236	@param name The name to give the stream
237	@param sourceStream Another DataStream which will provide the source
238	of data
239	@param freeOnClose If true, the memory associated will be destroyed
240	when the stream is destroyed.
241	*/
242	MemoryDataStream(const String& name, const DataStreamPtr& sourceStream,
243	bool freeOnClose = true);
244
245	/** Create a stream with a brand new empty memory chunk.
246	@param size The size of the memory chunk to create in bytes
247	@param freeOnClose If true, the memory associated will be destroyed
248	when the stream is destroyed.
249	*/
250	MemoryDataStream(size_t size, bool freeOnClose = true);
251	/** Create a named stream with a brand new empty memory chunk.
252	@param name The name to give the stream
253	@param size The size of the memory chunk to create in bytes
254	@param freeOnClose If true, the memory associated will be destroyed
255	when the stream is destroyed.
256	*/
257	MemoryDataStream(const String& name, size_t size,
258	bool freeOnClose = true);
259
260	~MemoryDataStream();
261
262	/** Get a pointer to the start of the memory block this stream holds. */
263	uchar* getPtr(void) { return mData; }
264
265	/** Get a pointer to the current position in the memory block this stream holds. */
266	uchar* getCurrentPtr(void) { return mPos; }
267
268	/** @copydoc DataStream::read
269	*/
270	size_t read(void* buf, size_t count);
271	/** @copydoc DataStream::readLine
272	*/
273	size_t readLine(char* buf, size_t maxCount, const String& delim = "\n");
274
275	/** @copydoc DataStream::skipLine
276	*/
277	size_t skipLine(const String& delim = "\n");
278
279	/** @copydoc DataStream::skip
280	*/
281	void skip(long count);
282
283	/** @copydoc DataStream::seek
284	*/
285	void seek( size_t pos );
286
287	/** @copydoc DataStream::tell
288	*/
289	size_t tell(void) const;
290
291	/** @copydoc DataStream::eof
292	*/
293	bool eof(void) const;
294
295	/** @copydoc DataStream::close
296	*/
297	void close(void);
298
299	/** Sets whether or not to free the encapsulated memory on close. */
300	void setFreeOnClose(bool free) { mFreeOnClose = free; }
301	};
302
303	/** Shared pointer to allow memory data streams to be passed around without
304	worrying about deallocation
305	*/
306	typedef SharedPtr<MemoryDataStream> MemoryDataStreamPtr;
307
308	/** Common subclass of DataStream for handling data from
309	std::basic_istream.
310	*/
311	class _OgreExport FileStreamDataStream : public DataStream
312	{
313	protected:
314	/// Reference to source stream
315	std::ifstream* mpStream;
316	bool mFreeOnClose;
317	public:
318	/** Construct stream from an STL stream
319	@param s Pointer to source stream
320	@param freeOnClose Whether to delete the underlying stream on
321	destruction of this class
322	*/
323	FileStreamDataStream(std::ifstream* s,
324	bool freeOnClose = true);
325	/** Construct named stream from an STL stream
326	@param name The name to give this stream
327	@param s Pointer to source stream
328	@param freeOnClose Whether to delete the underlying stream on
329	destruction of this class
330	*/
331	FileStreamDataStream(const String& name,
332	std::ifstream* s,
333	bool freeOnClose = true);
334
335	/** Construct named stream from an STL stream, and tell it the size
336	@remarks
337	This variant tells the class the size of the stream too, which
338	means this class does not need to seek to the end of the stream
339	to determine the size up-front. This can be beneficial if you have
340	metadata about the contents of the stream already.
341	@param name The name to give this stream
342	@param s Pointer to source stream
343	@param size Size of the stream contents in bytes
344	@param freeOnClose Whether to delete the underlying stream on
345	destruction of this class
346	*/
347	FileStreamDataStream(const String& name,
348	std::ifstream* s,
349	size_t size,
350	bool freeOnClose = true);
351
352	~FileStreamDataStream();
353
354	/** @copydoc DataStream::read
355	*/
356	size_t read(void* buf, size_t count);
357	/** @copydoc DataStream::readLine
358	*/
359	size_t readLine(char* buf, size_t maxCount, const String& delim = "\n");
360
361	/** @copydoc DataStream::skipLine
362	*/
363	size_t skipLine(const String& delim = "\n");
364
365	/** @copydoc DataStream::skip
366	*/
367	void skip(long count);
368
369	/** @copydoc DataStream::seek
370	*/
371	void seek( size_t pos );
372
373	/** @copydoc DataStream::tell
374	*/
375	size_t tell(void) const;
376
377	/** @copydoc DataStream::eof
378	*/
379	bool eof(void) const;
380
381	/** @copydoc DataStream::close
382	*/
383	void close(void);
384
385
386	};
387
388	/** Common subclass of DataStream for handling data from C-style file
389	handles.
390	@remarks
391	Use of this class is generally discouraged; if you want to wrap file
392	access in a DataStream, you should definitely be using the C++ friendly
393	FileStreamDataStream. However, since there are quite a few applications
394	and libraries still wedded to the old FILE handle access, this stream
395	wrapper provides some backwards compatibility.
396	*/
397	class _OgreExport FileHandleDataStream : public DataStream
398	{
399	protected:
400	FILE* mFileHandle;
401	public:
402	/// Create stream from a C file handle
403	FileHandleDataStream(FILE* handle);
404	/// Create named stream from a C file handle
405	FileHandleDataStream(const String& name, FILE* handle);
406	~FileHandleDataStream();
407
408	/** @copydoc DataStream::read
409	*/
410	size_t read(void* buf, size_t count);
411	/** @copydoc DataStream::readLine
412	*/
413	size_t readLine(char* buf, size_t maxCount, const String& delim = "\n");
414
415	/** @copydoc DataStream::skipLine
416	*/
417	size_t skipLine(const String& delim = "\n");
418
419	/** @copydoc DataStream::skip
420	*/
421	void skip(long count);
422
423	/** @copydoc DataStream::seek
424	*/
425	void seek( size_t pos );
426
427	/** @copydoc DataStream::tell
428	*/
429	size_t tell(void) const;
430
431	/** @copydoc DataStream::eof
432	*/
433	bool eof(void) const;
434
435	/** @copydoc DataStream::close
436	*/
437	void close(void);
438
439	};
440	}
441	#endif
442

Note: See TracBrowser for help on using the repository browser.

Download in other formats: