1/*
2 * The copyright in this software is being made available under the 2-clauses
3 * BSD License, included below. This software may be subject to other third
4 * party and contributor rights, including patent rights, and no such rights
5 * are granted under this license.
6 *
7 * Copyright (c) 2002-2014, Universite catholique de Louvain (UCL), Belgium
8 * Copyright (c) 2002-2014, Professor Benoit Macq
9 * Copyright (c) 2001-2003, David Janssens
10 * Copyright (c) 2002-2003, Yannick Verschueren
11 * Copyright (c) 2003-2007, Francois-Olivier Devaux
12 * Copyright (c) 2003-2014, Antonin Descampe
13 * Copyright (c) 2005, Herve Drolon, FreeImage Team
14 * Copyright (c) 2008, 2011-2012, Centre National d'Etudes Spatiales (CNES), FR
15 * Copyright (c) 2012, CS Systemes d'Information, France
16 * All rights reserved.
17 *
18 * Redistribution and use in source and binary forms, with or without
19 * modification, are permitted provided that the following conditions
20 * are met:
21 * 1. Redistributions of source code must retain the above copyright
22 *    notice, this list of conditions and the following disclaimer.
23 * 2. Redistributions in binary form must reproduce the above copyright
24 *    notice, this list of conditions and the following disclaimer in the
25 *    documentation and/or other materials provided with the distribution.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS `AS IS'
28 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
29 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
30 * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
31 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37 * POSSIBILITY OF SUCH DAMAGE.
38 */
39
40#include "opj_includes.h"
41
42/* ----------------------------------------------------------------------- */
43
44
45/* ----------------------------------------------------------------------- */
46
47void opj_write_bytes_BE (OPJ_BYTE * p_buffer, OPJ_UINT32 p_value, OPJ_UINT32 p_nb_bytes)
48{
49	const OPJ_BYTE * l_data_ptr = ((const OPJ_BYTE *) &p_value)+sizeof(OPJ_UINT32)-p_nb_bytes;
50
51	assert(p_nb_bytes > 0 && p_nb_bytes <=  sizeof(OPJ_UINT32));
52
53	memcpy(p_buffer,l_data_ptr,p_nb_bytes);
54}
55
56void opj_write_bytes_LE (OPJ_BYTE * p_buffer, OPJ_UINT32 p_value, OPJ_UINT32 p_nb_bytes)
57{
58	const OPJ_BYTE * l_data_ptr = ((const OPJ_BYTE *) &p_value) + p_nb_bytes - 1;
59	OPJ_UINT32 i;
60
61	assert(p_nb_bytes > 0 && p_nb_bytes <= sizeof(OPJ_UINT32));
62
63	for	(i=0;i<p_nb_bytes;++i) {
64		*(p_buffer++) = *(l_data_ptr--);
65	}
66}
67
68void opj_read_bytes_BE(const OPJ_BYTE * p_buffer, OPJ_UINT32 * p_value, OPJ_UINT32 p_nb_bytes)
69{
70	OPJ_BYTE * l_data_ptr = ((OPJ_BYTE *) p_value);
71
72	assert(p_nb_bytes > 0 && p_nb_bytes <= sizeof(OPJ_UINT32));
73
74	*p_value = 0;
75	memcpy(l_data_ptr+sizeof(OPJ_UINT32)-p_nb_bytes,p_buffer,p_nb_bytes);
76}
77
78void opj_read_bytes_LE(const OPJ_BYTE * p_buffer, OPJ_UINT32 * p_value, OPJ_UINT32 p_nb_bytes)
79{
80	OPJ_BYTE * l_data_ptr = ((OPJ_BYTE *) p_value) + p_nb_bytes-1;
81	OPJ_UINT32 i;
82
83	assert(p_nb_bytes > 0 && p_nb_bytes <= sizeof(OPJ_UINT32));
84
85	*p_value = 0;
86	for (i=0;i<p_nb_bytes;++i) {
87		*(l_data_ptr--) = *(p_buffer++);
88	}
89}
90
91void opj_write_double_BE(OPJ_BYTE * p_buffer, OPJ_FLOAT64 p_value)
92{
93	const OPJ_BYTE * l_data_ptr = ((const OPJ_BYTE *) &p_value);
94	memcpy(p_buffer,l_data_ptr,sizeof(OPJ_FLOAT64));
95}
96
97void opj_write_double_LE(OPJ_BYTE * p_buffer, OPJ_FLOAT64 p_value)
98{
99	const OPJ_BYTE * l_data_ptr = ((const OPJ_BYTE *) &p_value) + sizeof(OPJ_FLOAT64) - 1;
100	OPJ_UINT32 i;
101	for	(i=0;i<sizeof(OPJ_FLOAT64);++i) {
102		*(p_buffer++) = *(l_data_ptr--);
103	}
104}
105
106void opj_read_double_BE(const OPJ_BYTE * p_buffer, OPJ_FLOAT64 * p_value)
107{
108	OPJ_BYTE * l_data_ptr = ((OPJ_BYTE *) p_value);
109	memcpy(l_data_ptr,p_buffer,sizeof(OPJ_FLOAT64));
110}
111
112void opj_read_double_LE(const OPJ_BYTE * p_buffer, OPJ_FLOAT64 * p_value)
113{
114	OPJ_BYTE * l_data_ptr = ((OPJ_BYTE *) p_value) + sizeof(OPJ_FLOAT64)-1;
115	OPJ_UINT32 i;
116	for (i=0;i<sizeof(OPJ_FLOAT64);++i) {
117		*(l_data_ptr--) = *(p_buffer++);
118	}
119}
120
121void opj_write_float_BE(OPJ_BYTE * p_buffer, OPJ_FLOAT32 p_value)
122{
123	const OPJ_BYTE * l_data_ptr = ((const OPJ_BYTE *) &p_value);
124	memcpy(p_buffer,l_data_ptr,sizeof(OPJ_FLOAT32));
125}
126
127void opj_write_float_LE(OPJ_BYTE * p_buffer, OPJ_FLOAT32 p_value)
128{
129	const OPJ_BYTE * l_data_ptr = ((const OPJ_BYTE *) &p_value) + sizeof(OPJ_FLOAT32) - 1;
130	OPJ_UINT32 i;
131	for	(i=0;i<sizeof(OPJ_FLOAT32);++i) {
132		*(p_buffer++) = *(l_data_ptr--);
133	}
134}
135
136void opj_read_float_BE(const OPJ_BYTE * p_buffer, OPJ_FLOAT32 * p_value)
137{
138	OPJ_BYTE * l_data_ptr = ((OPJ_BYTE *) p_value);
139	memcpy(l_data_ptr,p_buffer,sizeof(OPJ_FLOAT32));
140}
141
142void opj_read_float_LE(const OPJ_BYTE * p_buffer, OPJ_FLOAT32 * p_value)
143{
144	OPJ_BYTE * l_data_ptr = ((OPJ_BYTE *) p_value) + sizeof(OPJ_FLOAT32)-1;
145	OPJ_UINT32 i;
146	for	(i=0;i<sizeof(OPJ_FLOAT32);++i) {
147		*(l_data_ptr--) = *(p_buffer++);
148	}
149}
150
151opj_stream_t* OPJ_CALLCONV opj_stream_create(OPJ_SIZE_T p_buffer_size,OPJ_BOOL l_is_input)
152{
153	opj_stream_private_t * l_stream = 00;
154	l_stream = (opj_stream_private_t*) opj_calloc(1,sizeof(opj_stream_private_t));
155	if (! l_stream) {
156		return 00;
157	}
158
159	l_stream->m_buffer_size = p_buffer_size;
160	l_stream->m_stored_data = (OPJ_BYTE *) opj_malloc(p_buffer_size);
161	if (! l_stream->m_stored_data) {
162		opj_free(l_stream);
163		return 00;
164	}
165
166	l_stream->m_current_data = l_stream->m_stored_data;
167
168	if (l_is_input) {
169		l_stream->m_status |= opj_stream_e_input;
170		l_stream->m_opj_skip = opj_stream_read_skip;
171		l_stream->m_opj_seek = opj_stream_read_seek;
172	}
173	else {
174		l_stream->m_status |= opj_stream_e_output;
175		l_stream->m_opj_skip = opj_stream_write_skip;
176		l_stream->m_opj_seek = opj_stream_write_seek;
177	}
178
179	l_stream->m_read_fn = opj_stream_default_read;
180	l_stream->m_write_fn = opj_stream_default_write;
181	l_stream->m_skip_fn = opj_stream_default_skip;
182	l_stream->m_seek_fn = opj_stream_default_seek;
183
184	return (opj_stream_t *) l_stream;
185}
186
187opj_stream_t* OPJ_CALLCONV opj_stream_default_create(OPJ_BOOL l_is_input)
188{
189	return opj_stream_create(OPJ_J2K_STREAM_CHUNK_SIZE,l_is_input);
190}
191
192void OPJ_CALLCONV opj_stream_destroy(opj_stream_t* p_stream)
193{
194	opj_stream_private_t* l_stream = (opj_stream_private_t*) p_stream;
195
196	if (l_stream) {
197		if (l_stream->m_free_user_data_fn) {
198			l_stream->m_free_user_data_fn(l_stream->m_user_data);
199		}
200		opj_free(l_stream->m_stored_data);
201		l_stream->m_stored_data = 00;
202		opj_free(l_stream);
203	}
204}
205
206void OPJ_CALLCONV opj_stream_set_read_function(opj_stream_t* p_stream, opj_stream_read_fn p_function)
207{
208	opj_stream_private_t* l_stream = (opj_stream_private_t*) p_stream;
209
210	if ((!l_stream) || (! (l_stream->m_status & opj_stream_e_input))) {
211		return;
212	}
213
214	l_stream->m_read_fn = p_function;
215}
216
217void OPJ_CALLCONV opj_stream_set_seek_function(opj_stream_t* p_stream, opj_stream_seek_fn p_function)
218{
219	opj_stream_private_t* l_stream = (opj_stream_private_t*) p_stream;
220
221	if (!l_stream) {
222		return;
223	}
224	l_stream->m_seek_fn = p_function;
225}
226
227void OPJ_CALLCONV opj_stream_set_write_function(opj_stream_t* p_stream, opj_stream_write_fn p_function)
228{
229	opj_stream_private_t* l_stream = (opj_stream_private_t*) p_stream;
230
231	if ((!l_stream )|| (! (l_stream->m_status & opj_stream_e_output))) {
232		return;
233	}
234
235	l_stream->m_write_fn = p_function;
236}
237
238void OPJ_CALLCONV opj_stream_set_skip_function(opj_stream_t* p_stream, opj_stream_skip_fn p_function)
239{
240	opj_stream_private_t* l_stream = (opj_stream_private_t*) p_stream;
241
242	if (! l_stream) {
243		return;
244	}
245
246	l_stream->m_skip_fn = p_function;
247}
248
249void OPJ_CALLCONV opj_stream_set_user_data(opj_stream_t* p_stream, void * p_data, opj_stream_free_user_data_fn p_function)
250{
251	opj_stream_private_t* l_stream = (opj_stream_private_t*) p_stream;
252	if (!l_stream)
253		return;
254	l_stream->m_user_data = p_data;
255  l_stream->m_free_user_data_fn = p_function;
256}
257
258void OPJ_CALLCONV opj_stream_set_user_data_length(opj_stream_t* p_stream, OPJ_UINT64 data_length)
259{
260	opj_stream_private_t* l_stream = (opj_stream_private_t*) p_stream;
261	if (!l_stream)
262		return;
263	l_stream->m_user_data_length = data_length;
264}
265
266OPJ_SIZE_T opj_stream_read_data (opj_stream_private_t * p_stream,OPJ_BYTE * p_buffer, OPJ_SIZE_T p_size, opj_event_mgr_t * p_event_mgr)
267{
268	OPJ_SIZE_T l_read_nb_bytes = 0;
269	if (p_stream->m_bytes_in_buffer >= p_size) {
270		memcpy(p_buffer,p_stream->m_current_data,p_size);
271		p_stream->m_current_data += p_size;
272		p_stream->m_bytes_in_buffer -= p_size;
273		l_read_nb_bytes += p_size;
274		p_stream->m_byte_offset += (OPJ_OFF_T)p_size;
275		return l_read_nb_bytes;
276	}
277
278	/* we are now in the case when the remaining data if not sufficient */
279	if (p_stream->m_status & opj_stream_e_end) {
280		l_read_nb_bytes += p_stream->m_bytes_in_buffer;
281		memcpy(p_buffer,p_stream->m_current_data,p_stream->m_bytes_in_buffer);
282		p_stream->m_current_data += p_stream->m_bytes_in_buffer;
283		p_stream->m_byte_offset += (OPJ_OFF_T)p_stream->m_bytes_in_buffer;
284		p_stream->m_bytes_in_buffer = 0;
285		return l_read_nb_bytes ? l_read_nb_bytes : (OPJ_SIZE_T)-1;
286	}
287
288	/* the flag is not set, we copy data and then do an actual read on the stream */
289	if (p_stream->m_bytes_in_buffer) {
290		l_read_nb_bytes += p_stream->m_bytes_in_buffer;
291		memcpy(p_buffer,p_stream->m_current_data,p_stream->m_bytes_in_buffer);
292		p_stream->m_current_data = p_stream->m_stored_data;
293		p_buffer += p_stream->m_bytes_in_buffer;
294		p_size -= p_stream->m_bytes_in_buffer;
295		p_stream->m_byte_offset += (OPJ_OFF_T)p_stream->m_bytes_in_buffer;
296		p_stream->m_bytes_in_buffer = 0;
297	}
298	else {
299    /* case where we are already at the end of the buffer
300       so reset the m_current_data to point to the start of the
301       stored buffer to get ready to read from disk*/
302		p_stream->m_current_data = p_stream->m_stored_data;
303	}
304
305	for (;;) {
306		/* we should read less than a chunk -> read a chunk */
307		if (p_size < p_stream->m_buffer_size) {
308			/* we should do an actual read on the media */
309			p_stream->m_bytes_in_buffer = p_stream->m_read_fn(p_stream->m_stored_data,p_stream->m_buffer_size,p_stream->m_user_data);
310
311			if (p_stream->m_bytes_in_buffer == (OPJ_SIZE_T)-1) {
312				/* end of stream */
313				opj_event_msg(p_event_mgr, EVT_INFO, "Stream reached its end !\n");
314
315				p_stream->m_bytes_in_buffer = 0;
316				p_stream->m_status |= opj_stream_e_end;
317				/* end of stream */
318				return l_read_nb_bytes ? l_read_nb_bytes : (OPJ_SIZE_T)-1;
319			}
320			else if	(p_stream->m_bytes_in_buffer < p_size) {
321				/* not enough data */
322				l_read_nb_bytes += p_stream->m_bytes_in_buffer;
323				memcpy(p_buffer,p_stream->m_current_data,p_stream->m_bytes_in_buffer);
324				p_stream->m_current_data = p_stream->m_stored_data;
325				p_buffer += p_stream->m_bytes_in_buffer;
326				p_size -= p_stream->m_bytes_in_buffer;
327				p_stream->m_byte_offset += (OPJ_OFF_T)p_stream->m_bytes_in_buffer;
328				p_stream->m_bytes_in_buffer = 0;
329			}
330			else {
331				l_read_nb_bytes += p_size;
332				memcpy(p_buffer,p_stream->m_current_data,p_size);
333				p_stream->m_current_data += p_size;
334				p_stream->m_bytes_in_buffer -= p_size;
335				p_stream->m_byte_offset += (OPJ_OFF_T)p_size;
336				return l_read_nb_bytes;
337			}
338		}
339		else {
340			/* direct read on the dest buffer */
341			p_stream->m_bytes_in_buffer = p_stream->m_read_fn(p_buffer,p_size,p_stream->m_user_data);
342
343			if (p_stream->m_bytes_in_buffer == (OPJ_SIZE_T)-1) {
344				/*  end of stream */
345				opj_event_msg(p_event_mgr, EVT_INFO, "Stream reached its end !\n");
346
347				p_stream->m_bytes_in_buffer = 0;
348				p_stream->m_status |= opj_stream_e_end;
349				/* end of stream */
350				return l_read_nb_bytes ? l_read_nb_bytes : (OPJ_SIZE_T)-1;
351			}
352			else if (p_stream->m_bytes_in_buffer < p_size) {
353				/* not enough data */
354				l_read_nb_bytes += p_stream->m_bytes_in_buffer;
355				p_stream->m_current_data = p_stream->m_stored_data;
356				p_buffer += p_stream->m_bytes_in_buffer;
357				p_size -= p_stream->m_bytes_in_buffer;
358				p_stream->m_byte_offset += (OPJ_OFF_T)p_stream->m_bytes_in_buffer;
359				p_stream->m_bytes_in_buffer = 0;
360			}
361			else {
362				/* we have read the exact size */
363				l_read_nb_bytes += p_stream->m_bytes_in_buffer;
364				p_stream->m_byte_offset += (OPJ_OFF_T)p_stream->m_bytes_in_buffer;
365				p_stream->m_current_data = p_stream->m_stored_data;
366				p_stream->m_bytes_in_buffer = 0;
367				return l_read_nb_bytes;
368			}
369		}
370	}
371}
372
373OPJ_SIZE_T opj_stream_write_data (opj_stream_private_t * p_stream,
374								  const OPJ_BYTE * p_buffer,
375								  OPJ_SIZE_T p_size,
376								  opj_event_mgr_t * p_event_mgr)
377{
378	OPJ_SIZE_T l_remaining_bytes = 0;
379	OPJ_SIZE_T l_write_nb_bytes = 0;
380
381	if (p_stream->m_status & opj_stream_e_error) {
382		return (OPJ_SIZE_T)-1;
383	}
384
385	for (;;) {
386		l_remaining_bytes = p_stream->m_buffer_size - p_stream->m_bytes_in_buffer;
387
388		/* we have more memory than required */
389		if (l_remaining_bytes >= p_size) {
390			memcpy(p_stream->m_current_data, p_buffer, p_size);
391
392			p_stream->m_current_data += p_size;
393			p_stream->m_bytes_in_buffer += p_size;
394			l_write_nb_bytes += p_size;
395			p_stream->m_byte_offset += (OPJ_OFF_T)p_size;
396
397			return l_write_nb_bytes;
398		}
399
400		/* we copy data and then do an actual read on the stream */
401		if (l_remaining_bytes) {
402			l_write_nb_bytes += l_remaining_bytes;
403
404			memcpy(p_stream->m_current_data,p_buffer,l_remaining_bytes);
405
406			p_stream->m_current_data = p_stream->m_stored_data;
407
408			p_buffer += l_remaining_bytes;
409			p_size -= l_remaining_bytes;
410			p_stream->m_bytes_in_buffer += l_remaining_bytes;
411			p_stream->m_byte_offset += (OPJ_OFF_T)l_remaining_bytes;
412		}
413
414		if (! opj_stream_flush(p_stream, p_event_mgr)) {
415			return (OPJ_SIZE_T)-1;
416		}
417	}
418
419}
420
421OPJ_BOOL opj_stream_flush (opj_stream_private_t * p_stream, opj_event_mgr_t * p_event_mgr)
422{
423	/* the number of bytes written on the media. */
424	OPJ_SIZE_T l_current_write_nb_bytes = 0;
425
426	p_stream->m_current_data = p_stream->m_stored_data;
427
428	while (p_stream->m_bytes_in_buffer) {
429		/* we should do an actual write on the media */
430		l_current_write_nb_bytes = p_stream->m_write_fn(p_stream->m_current_data,
431														p_stream->m_bytes_in_buffer,
432														p_stream->m_user_data);
433
434		if (l_current_write_nb_bytes == (OPJ_SIZE_T)-1) {
435			p_stream->m_status |= opj_stream_e_error;
436			opj_event_msg(p_event_mgr, EVT_INFO, "Error on writing stream!\n");
437
438			return OPJ_FALSE;
439		}
440
441		p_stream->m_current_data += l_current_write_nb_bytes;
442		p_stream->m_bytes_in_buffer -= l_current_write_nb_bytes;
443	}
444
445	p_stream->m_current_data = p_stream->m_stored_data;
446
447	return OPJ_TRUE;
448}
449
450OPJ_OFF_T opj_stream_read_skip (opj_stream_private_t * p_stream, OPJ_OFF_T p_size, opj_event_mgr_t * p_event_mgr)
451{
452	OPJ_OFF_T l_skip_nb_bytes = 0;
453	OPJ_OFF_T l_current_skip_nb_bytes = 0;
454
455	assert( p_size >= 0 );
456
457	if (p_stream->m_bytes_in_buffer >= (OPJ_SIZE_T)p_size) {
458		p_stream->m_current_data += p_size;
459		/* it is safe to cast p_size to OPJ_SIZE_T since it is <= m_bytes_in_buffer
460		which is of type OPJ_SIZE_T */
461		p_stream->m_bytes_in_buffer -= (OPJ_SIZE_T)p_size;
462		l_skip_nb_bytes += p_size;
463		p_stream->m_byte_offset += l_skip_nb_bytes;
464		return l_skip_nb_bytes;
465	}
466
467	/* we are now in the case when the remaining data if not sufficient */
468	if (p_stream->m_status & opj_stream_e_end) {
469		l_skip_nb_bytes += (OPJ_OFF_T)p_stream->m_bytes_in_buffer;
470		p_stream->m_current_data += p_stream->m_bytes_in_buffer;
471		p_stream->m_bytes_in_buffer = 0;
472		p_stream->m_byte_offset += l_skip_nb_bytes;
473		return l_skip_nb_bytes ? l_skip_nb_bytes : (OPJ_OFF_T) -1;
474	}
475
476	/* the flag is not set, we copy data and then do an actual skip on the stream */
477	if (p_stream->m_bytes_in_buffer) {
478		l_skip_nb_bytes += (OPJ_OFF_T)p_stream->m_bytes_in_buffer;
479		p_stream->m_current_data = p_stream->m_stored_data;
480		p_size -= (OPJ_OFF_T)p_stream->m_bytes_in_buffer;
481		p_stream->m_bytes_in_buffer = 0;
482	}
483
484	while (p_size > 0) {
485		/* we should do an actual skip on the media */
486		l_current_skip_nb_bytes = p_stream->m_skip_fn(p_size, p_stream->m_user_data);
487		if (l_current_skip_nb_bytes == (OPJ_OFF_T) -1) {
488			opj_event_msg(p_event_mgr, EVT_INFO, "Stream reached its end !\n");
489
490			p_stream->m_status |= opj_stream_e_end;
491			p_stream->m_byte_offset += l_skip_nb_bytes;
492			/* end if stream */
493			return l_skip_nb_bytes ? l_skip_nb_bytes : (OPJ_OFF_T) -1;
494		}
495		p_size -= l_current_skip_nb_bytes;
496		l_skip_nb_bytes += l_current_skip_nb_bytes;
497	}
498
499	p_stream->m_byte_offset += l_skip_nb_bytes;
500
501	return l_skip_nb_bytes;
502}
503
504OPJ_OFF_T opj_stream_write_skip (opj_stream_private_t * p_stream, OPJ_OFF_T p_size, opj_event_mgr_t * p_event_mgr)
505{
506	OPJ_BOOL l_is_written = 0;
507	OPJ_OFF_T l_current_skip_nb_bytes = 0;
508	OPJ_OFF_T l_skip_nb_bytes = 0;
509
510	if (p_stream->m_status & opj_stream_e_error) {
511		return (OPJ_OFF_T) -1;
512	}
513
514	/* we should flush data */
515	l_is_written = opj_stream_flush (p_stream, p_event_mgr);
516	if (! l_is_written) {
517		p_stream->m_status |= opj_stream_e_error;
518		p_stream->m_bytes_in_buffer = 0;
519		return (OPJ_OFF_T) -1;
520	}
521	/* then skip */
522
523	while (p_size > 0) {
524		/* we should do an actual skip on the media */
525		l_current_skip_nb_bytes = p_stream->m_skip_fn(p_size, p_stream->m_user_data);
526
527		if (l_current_skip_nb_bytes == (OPJ_OFF_T)-1) {
528			opj_event_msg(p_event_mgr, EVT_INFO, "Stream error!\n");
529
530			p_stream->m_status |= opj_stream_e_error;
531			p_stream->m_byte_offset += l_skip_nb_bytes;
532			/* end if stream */
533			return l_skip_nb_bytes ? l_skip_nb_bytes : (OPJ_OFF_T)-1;
534		}
535		p_size -= l_current_skip_nb_bytes;
536		l_skip_nb_bytes += l_current_skip_nb_bytes;
537	}
538
539	p_stream->m_byte_offset += l_skip_nb_bytes;
540
541	return l_skip_nb_bytes;
542}
543
544OPJ_OFF_T opj_stream_tell (const opj_stream_private_t * p_stream)
545{
546	return p_stream->m_byte_offset;
547}
548
549OPJ_OFF_T opj_stream_get_number_byte_left (const opj_stream_private_t * p_stream)
550{
551  assert( p_stream->m_byte_offset >= 0 );
552  assert( p_stream->m_user_data_length >= (OPJ_UINT64)p_stream->m_byte_offset);
553  return p_stream->m_user_data_length ?
554				(OPJ_OFF_T)(p_stream->m_user_data_length) - p_stream->m_byte_offset :
555				0;
556}
557
558OPJ_OFF_T opj_stream_skip (opj_stream_private_t * p_stream, OPJ_OFF_T p_size, opj_event_mgr_t * p_event_mgr)
559{
560	assert(p_size >= 0);
561	return p_stream->m_opj_skip(p_stream,p_size,p_event_mgr);
562}
563
564OPJ_BOOL opj_stream_read_seek (opj_stream_private_t * p_stream, OPJ_OFF_T p_size, opj_event_mgr_t * p_event_mgr)
565{
566	OPJ_ARG_NOT_USED(p_event_mgr);
567	p_stream->m_current_data = p_stream->m_stored_data;
568	p_stream->m_bytes_in_buffer = 0;
569
570	if( !(p_stream->m_seek_fn(p_size,p_stream->m_user_data)) ) {
571		p_stream->m_status |= opj_stream_e_end;
572		return OPJ_FALSE;
573	}
574	else {
575		/* reset stream status */
576		p_stream->m_status &= (~opj_stream_e_end);
577		p_stream->m_byte_offset = p_size;
578
579	}
580
581	return OPJ_TRUE;
582}
583
584OPJ_BOOL opj_stream_write_seek (opj_stream_private_t * p_stream, OPJ_OFF_T p_size, opj_event_mgr_t * p_event_mgr)
585{
586	if (! opj_stream_flush(p_stream,p_event_mgr)) {
587		p_stream->m_status |= opj_stream_e_error;
588		return OPJ_FALSE;
589	}
590
591	p_stream->m_current_data = p_stream->m_stored_data;
592	p_stream->m_bytes_in_buffer = 0;
593
594	if (! p_stream->m_seek_fn(p_size,p_stream->m_user_data)) {
595		p_stream->m_status |= opj_stream_e_error;
596		return OPJ_FALSE;
597	}
598	else {
599		p_stream->m_byte_offset = p_size;
600	}
601
602	return OPJ_TRUE;
603}
604
605OPJ_BOOL opj_stream_seek (opj_stream_private_t * p_stream, OPJ_OFF_T p_size, struct opj_event_mgr * p_event_mgr)
606{
607	assert(p_size >= 0);
608	return p_stream->m_opj_seek(p_stream,p_size,p_event_mgr);
609}
610
611OPJ_BOOL opj_stream_has_seek (const opj_stream_private_t * p_stream)
612{
613	return p_stream->m_seek_fn != opj_stream_default_seek;
614}
615
616OPJ_SIZE_T opj_stream_default_read (void * p_buffer, OPJ_SIZE_T p_nb_bytes, void * p_user_data)
617{
618	OPJ_ARG_NOT_USED(p_buffer);
619	OPJ_ARG_NOT_USED(p_nb_bytes);
620	OPJ_ARG_NOT_USED(p_user_data);
621	return (OPJ_SIZE_T) -1;
622}
623
624OPJ_SIZE_T opj_stream_default_write (void * p_buffer, OPJ_SIZE_T p_nb_bytes, void * p_user_data)
625{
626	OPJ_ARG_NOT_USED(p_buffer);
627	OPJ_ARG_NOT_USED(p_nb_bytes);
628	OPJ_ARG_NOT_USED(p_user_data);
629	return (OPJ_SIZE_T) -1;
630}
631
632OPJ_OFF_T opj_stream_default_skip (OPJ_OFF_T p_nb_bytes, void * p_user_data)
633{
634	OPJ_ARG_NOT_USED(p_nb_bytes);
635	OPJ_ARG_NOT_USED(p_user_data);
636	return (OPJ_OFF_T) -1;
637}
638
639OPJ_BOOL opj_stream_default_seek (OPJ_OFF_T p_nb_bytes, void * p_user_data)
640{
641	OPJ_ARG_NOT_USED(p_nb_bytes);
642	OPJ_ARG_NOT_USED(p_user_data);
643	return OPJ_FALSE;
644}
645