summaryrefslogtreecommitdiff
path: root/indra/newview/llinventoryobserver.cpp
blob: 86147d65e6b4f86c5e96dd5adf48fe124d3e26f5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
/** 
 * @file llinventoryobserver.cpp
 * @brief Implementation of the inventory observers used to track agent inventory.
 *
 * $LicenseInfo:firstyear=2002&license=viewergpl$
 * 
 * Copyright (c) 2002-2009, Linden Research, Inc.
 * 
 * Second Life Viewer Source Code
 * The source code in this file ("Source Code") is provided by Linden Lab
 * to you under the terms of the GNU General Public License, version 2.0
 * ("GPL"), unless you have obtained a separate licensing agreement
 * ("Other License"), formally executed by you and Linden Lab.  Terms of
 * the GPL can be found in doc/GPL-license.txt in this distribution, or
 * online at http://secondlifegrid.net/programs/open_source/licensing/gplv2
 * 
 * There are special exceptions to the terms and conditions of the GPL as
 * it is applied to this Source Code. View the full text of the exception
 * in the file doc/FLOSS-exception.txt in this software distribution, or
 * online at
 * http://secondlifegrid.net/programs/open_source/licensing/flossexception
 * 
 * By copying, modifying or distributing this software, you acknowledge
 * that you have read and understood your obligations described above,
 * and agree to abide by those obligations.
 * 
 * ALL LINDEN LAB SOURCE CODE IS PROVIDED "AS IS." LINDEN LAB MAKES NO
 * WARRANTIES, EXPRESS, IMPLIED OR OTHERWISE, REGARDING ITS ACCURACY,
 * COMPLETENESS OR PERFORMANCE.
 * $/LicenseInfo$
 */

#include "llviewerprecompiledheaders.h"

#include "llinventoryobserver.h"

#include "llassetstorage.h"
#include "llcrc.h"
#include "lldir.h"
#include "llsys.h"
#include "llxfermanager.h"
#include "message.h"

#include "llagent.h"
#include "llagentwearables.h"
#include "llfloater.h"
#include "llfocusmgr.h"
#include "llinventorybridge.h"
#include "llinventoryfunctions.h"
#include "llinventorymodel.h"
#include "llviewermessage.h"
#include "llviewerwindow.h"
#include "llviewerregion.h"
#include "llappviewer.h"
#include "lldbstrings.h"
#include "llviewerstats.h"
#include "llnotificationsutil.h"
#include "llcallbacklist.h"
#include "llpreview.h"
#include "llviewercontrol.h"
#include "llvoavatarself.h"
#include "llsdutil.h"
#include <deque>

// If the viewer gets a notification, your observer assumes
// that that notification is for itself and then tries to process
// the results.  The notification could be for something else (e.g.
// you're fetching an item and a notification gets triggered because
// you renamed some other item).  This counter is to specify how many
// notification to wait for before giving up.
static const U32 MAX_NUM_NOTIFICATIONS_TO_PROCESS = 20;

LLInventoryObserver::LLInventoryObserver()
{
}

// virtual
LLInventoryObserver::~LLInventoryObserver()
{
}

LLInventoryFetchObserver::LLInventoryFetchObserver(const LLUUID& id)
{
	mIDs.clear();
	if (id != LLUUID::null)
	{
		setFetchID(id);
	}
}

LLInventoryFetchObserver::LLInventoryFetchObserver(const uuid_vec_t& ids)
{
	setFetchIDs(ids);
}

BOOL LLInventoryFetchObserver::isFinished() const
{
	return mIncomplete.empty();
}

void LLInventoryFetchObserver::setFetchIDs(const uuid_vec_t& ids)
{
	mIDs = ids;
}
void LLInventoryFetchObserver::setFetchID(const LLUUID& id)
{
	mIDs.clear();
	mIDs.push_back(id);
}


void LLInventoryCompletionObserver::changed(U32 mask)
{
	// scan through the incomplete items and move or erase them as
	// appropriate.
	if (!mIncomplete.empty())
	{
		for (uuid_vec_t::iterator it = mIncomplete.begin(); it < mIncomplete.end(); )
		{
			const LLViewerInventoryItem* item = gInventory.getItem(*it);
			if (!item)
			{
				it = mIncomplete.erase(it);
				continue;
			}
			if (item->isFinished())
			{
				mComplete.push_back(*it);
				it = mIncomplete.erase(it);
				continue;
			}
			++it;
		}
		if (mIncomplete.empty())
		{
			done();
		}
	}
}

void LLInventoryCompletionObserver::watchItem(const LLUUID& id)
{
	if (id.notNull())
	{
		mIncomplete.push_back(id);
	}
}

LLInventoryFetchItemsObserver::LLInventoryFetchItemsObserver(const LLUUID& item_id) :
	LLInventoryFetchObserver(item_id),

	mNumTries(MAX_NUM_NOTIFICATIONS_TO_PROCESS)
{
	mIDs.clear();
	mIDs.push_back(item_id);
}

LLInventoryFetchItemsObserver::LLInventoryFetchItemsObserver(const uuid_vec_t& item_ids) :
	LLInventoryFetchObserver(item_ids),

	mNumTries(MAX_NUM_NOTIFICATIONS_TO_PROCESS)
{
}

void LLInventoryFetchItemsObserver::changed(U32 mask)
{
	BOOL any_items_missing = FALSE;

	// scan through the incomplete items and move or erase them as
	// appropriate.
	if (!mIncomplete.empty())
	{
		for (uuid_vec_t::iterator it = mIncomplete.begin(); it < mIncomplete.end(); )
		{
			const LLUUID& item_id = (*it);
			LLViewerInventoryItem* item = gInventory.getItem(item_id);
			if (!item)
			{
				any_items_missing = TRUE;
				if (mNumTries > 0)
				{
					// Keep trying.
					++it;
				}
				else
				{
					// Just concede that this item hasn't arrived in reasonable time and continue on.
					llwarns << "Fetcher timed out when fetching inventory item assetID:" << item_id << llendl;
					it = mIncomplete.erase(it);
				}
				continue;
			}
			if (item->isFinished())
			{
				mComplete.push_back(item_id);
				it = mIncomplete.erase(it);
				continue;
			}
			++it;
		}
		if (any_items_missing)
		{
			mNumTries--;
		}

		if (mIncomplete.empty())
		{
			mNumTries = MAX_NUM_NOTIFICATIONS_TO_PROCESS;
			done();
		}
	}
	//llinfos << "LLInventoryFetchItemsObserver::changed() mComplete size " << mComplete.size() << llendl;
	//llinfos << "LLInventoryFetchItemsObserver::changed() mIncomplete size " << mIncomplete.size() << llendl;
}

void fetch_items_from_llsd(const LLSD& items_llsd)
{
	if (!items_llsd.size() || gDisconnected) return;
	LLSD body;
	body[0]["cap_name"] = "FetchInventory";
	body[1]["cap_name"] = "FetchLib";
	for (S32 i=0; i<items_llsd.size();i++)
	{
		if (items_llsd[i]["owner_id"].asString() == gAgent.getID().asString())
		{
			body[0]["items"].append(items_llsd[i]);
			continue;
		}
		if (items_llsd[i]["owner_id"].asString() == ALEXANDRIA_LINDEN_ID.asString())
		{
			body[1]["items"].append(items_llsd[i]);
			continue;
		}
	}
		
	for (S32 i=0; i<body.size(); i++)
	{
		if(!gAgent.getRegion())
		{
			llwarns<<"Agent's region is null"<<llendl;
			break;
		}
		if (0 >= body[i].size()) continue;
		std::string url = gAgent.getRegion()->getCapability(body[i]["cap_name"].asString());

		if (!url.empty())
		{
			body[i]["agent_id"]	= gAgent.getID();
			LLHTTPClient::post(url, body[i], new LLInventoryModel::fetchInventoryResponder(body[i]));
			break;
		}

		LLMessageSystem* msg = gMessageSystem;
		BOOL start_new_message = TRUE;
		for (S32 j=0; j<body[i]["items"].size(); j++)
		{
			LLSD item_entry = body[i]["items"][j];
			if (start_new_message)
			{
				start_new_message = FALSE;
				msg->newMessageFast(_PREHASH_FetchInventory);
				msg->nextBlockFast(_PREHASH_AgentData);
				msg->addUUIDFast(_PREHASH_AgentID, gAgent.getID());
				msg->addUUIDFast(_PREHASH_SessionID, gAgent.getSessionID());
			}
			msg->nextBlockFast(_PREHASH_InventoryData);
			msg->addUUIDFast(_PREHASH_OwnerID, item_entry["owner_id"].asUUID());
			msg->addUUIDFast(_PREHASH_ItemID, item_entry["item_id"].asUUID());
			if (msg->isSendFull(NULL))
			{
				start_new_message = TRUE;
				gAgent.sendReliableMessage();
			}
		}
		if (!start_new_message)
		{
			gAgent.sendReliableMessage();
		}
	}
}

void LLInventoryFetchItemsObserver::startFetch()
{
	LLUUID owner_id;
	LLSD items_llsd;
	for (uuid_vec_t::const_iterator it = mIDs.begin(); it < mIDs.end(); ++it)
	{
		LLViewerInventoryItem* item = gInventory.getItem(*it);
		if (item)
		{
			if (item->isFinished())
			{
				// It's complete, so put it on the complete container.
				mComplete.push_back(*it);
				continue;
			}
			else
			{
				owner_id = item->getPermissions().getOwner();
			}
		}
		else
		{
			// assume it's agent inventory.
			owner_id = gAgent.getID();
		}
		
		// It's incomplete, so put it on the incomplete container, and
		// pack this on the message.
		mIncomplete.push_back(*it);
		
		// Prepare the data to fetch
		LLSD item_entry;
		item_entry["owner_id"] = owner_id;
		item_entry["item_id"] = (*it);
		items_llsd.append(item_entry);
	}
	fetch_items_from_llsd(items_llsd);
}

LLInventoryFetchDescendentsObserver::LLInventoryFetchDescendentsObserver(const LLUUID& cat_id) :
	LLInventoryFetchObserver(cat_id)
{
}

LLInventoryFetchDescendentsObserver::LLInventoryFetchDescendentsObserver(const uuid_vec_t& cat_ids) :
	LLInventoryFetchObserver(cat_ids)
{
}

// virtual
void LLInventoryFetchDescendentsObserver::changed(U32 mask)
{
	for (uuid_vec_t::iterator it = mIncomplete.begin(); it < mIncomplete.end();)
	{
		const LLViewerInventoryCategory* cat = gInventory.getCategory(*it);
		if (!cat)
		{
			it = mIncomplete.erase(it);
			continue;
		}
		if (isCategoryComplete(cat))
		{
			mComplete.push_back(*it);
			it = mIncomplete.erase(it);
			continue;
		}
		++it;
	}
	if (mIncomplete.empty())
	{
		done();
	}
}

void LLInventoryFetchDescendentsObserver::startFetch()
{
	for (uuid_vec_t::const_iterator it = mIDs.begin(); it != mIDs.end(); ++it)
	{
		LLViewerInventoryCategory* cat = gInventory.getCategory(*it);
		if (!cat) continue;
		if (!isCategoryComplete(cat))
		{
			cat->fetch();		//blindly fetch it without seeing if anything else is fetching it.
			mIncomplete.push_back(*it);	//Add to list of things being downloaded for this observer.
		}
		else
		{
			mComplete.push_back(*it);
		}
	}
}

BOOL LLInventoryFetchDescendentsObserver::isCategoryComplete(const LLViewerInventoryCategory* cat) const
{
	const S32 version = cat->getVersion();
	const S32 expected_num_descendents = cat->getDescendentCount();
	if ((version == LLViewerInventoryCategory::VERSION_UNKNOWN) ||
		(expected_num_descendents == LLViewerInventoryCategory::DESCENDENT_COUNT_UNKNOWN))
	{
		return FALSE;
	}
	// it might be complete - check known descendents against
	// currently available.
	LLInventoryModel::cat_array_t* cats;
	LLInventoryModel::item_array_t* items;
	gInventory.getDirectDescendentsOf(cat->getUUID(), cats, items);
	if (!cats || !items)
	{
		llwarns << "Category '" << cat->getName() << "' descendents corrupted, fetch failed." << llendl;
		// NULL means the call failed -- cats/items map doesn't exist (note: this does NOT mean
		// that the cat just doesn't have any items or subfolders).
		// Unrecoverable, so just return done so that this observer can be cleared
		// from memory.
		return TRUE;
	}
	const S32 current_num_known_descendents = cats->count() + items->count();
	
	// Got the number of descendents that we were expecting, so we're done.
	if (current_num_known_descendents == expected_num_descendents)
	{
		return TRUE;
	}

	// Error condition, but recoverable.  This happens if something was added to the
	// category before it was initialized, so accountForUpdate didn't update descendent
	// count and thus the category thinks it has fewer descendents than it actually has.
	if (current_num_known_descendents >= expected_num_descendents)
	{
		llwarns << "Category '" << cat->getName() << "' expected descendentcount:" << expected_num_descendents << " descendents but got descendentcount:" << current_num_known_descendents << llendl;
		const_cast<LLViewerInventoryCategory *>(cat)->setDescendentCount(current_num_known_descendents);
		return TRUE;
	}
	return FALSE;
}

LLInventoryFetchComboObserver::LLInventoryFetchComboObserver(const uuid_vec_t& folder_ids,
															 const uuid_vec_t& item_ids)
{
	mFetchDescendents = new LLInventoryFetchDescendentsObserver(folder_ids);

	uuid_vec_t pruned_item_ids;
	for (uuid_vec_t::const_iterator item_iter = item_ids.begin();
		 item_iter != item_ids.end();
		 ++item_iter)
	{
		const LLUUID& item_id = (*item_iter);
		const LLViewerInventoryItem* item = gInventory.getItem(item_id);
		if (item && std::find(folder_ids.begin(), folder_ids.end(), item->getParentUUID()) == folder_ids.end())
		{
			continue;
		}
		pruned_item_ids.push_back(item_id);
	}

	mFetchItems = new LLInventoryFetchItemsObserver(pruned_item_ids);
	mFetchDescendents = new LLInventoryFetchDescendentsObserver(folder_ids);
}

LLInventoryFetchComboObserver::~LLInventoryFetchComboObserver()
{
	mFetchItems->done();
	mFetchDescendents->done();
	delete mFetchItems;
	delete mFetchDescendents;
}

void LLInventoryFetchComboObserver::changed(U32 mask)
{
	mFetchItems->changed(mask);
	mFetchDescendents->changed(mask);
	if (mFetchItems->isFinished() && mFetchDescendents->isFinished())
	{
		done();
	}
}

void LLInventoryFetchComboObserver::startFetch()
{
	mFetchItems->startFetch();
	mFetchDescendents->startFetch();
}

void LLInventoryExistenceObserver::watchItem(const LLUUID& id)
{
	if (id.notNull())
	{
		mMIA.push_back(id);
	}
}

void LLInventoryExistenceObserver::changed(U32 mask)
{
	// scan through the incomplete items and move or erase them as
	// appropriate.
	if (!mMIA.empty())
	{
		for (uuid_vec_t::iterator it = mMIA.begin(); it < mMIA.end(); )
		{
			LLViewerInventoryItem* item = gInventory.getItem(*it);
			if (!item)
			{
				++it;
				continue;
			}
			mExist.push_back(*it);
			it = mMIA.erase(it);
		}
		if (mMIA.empty())
		{
			done();
		}
	}
}

void LLInventoryMoveFromWorldObserver::changed(U32 mask)
{
	if(!(mask & LLInventoryObserver::ADD))
	{
		return;
	}

	// nothing is watched
	if (mWatchedAssets.size() == 0)
	{
		return;
	}

	LLPointer<LLViewerInventoryItem> item = new LLViewerInventoryItem;
	LLMessageSystem* msg = gMessageSystem;
	S32 num_blocks = msg->getNumberOfBlocksFast(_PREHASH_InventoryData);
	for(S32 i = 0; i < num_blocks; ++i)
	{
		item->unpackMessage(msg, _PREHASH_InventoryData, i);
		const LLUUID& asset_uuid = item->getAssetUUID();
		if (item->getUUID().notNull() && asset_uuid.notNull())
		{
			if (isAssetWatched(asset_uuid))
			{
				LL_DEBUGS("Inventory_Move") << "Found asset UUID: " << asset_uuid << LL_ENDL;
				mAddedItems.push_back(item->getUUID());
			}
		}
	}

	if (mAddedItems.size() == mWatchedAssets.size())
	{
		done();
		LL_DEBUGS("Inventory_Move") << "All watched items are added & processed." << LL_ENDL;
		mAddedItems.clear();

		// Unable to clean watched items here due to somebody can require to check them in current frame.
		// set dirty state to clean them while next watch cycle.
		mIsDirty = true;
	}
}

void LLInventoryMoveFromWorldObserver::watchAsset(const LLUUID& asset_id)
{
	if(asset_id.notNull())
	{
		if (mIsDirty)
		{
			LL_DEBUGS("Inventory_Move") << "Watched items are dirty. Clean them." << LL_ENDL;
			mWatchedAssets.clear();
			mIsDirty = false;
		}

		mWatchedAssets.push_back(asset_id);
		onAssetAdded(asset_id);
	}
}

bool LLInventoryMoveFromWorldObserver::isAssetWatched( const LLUUID& asset_id )
{
	return std::find(mWatchedAssets.begin(), mWatchedAssets.end(), asset_id) != mWatchedAssets.end();
}

void LLInventoryAddedObserver::changed(U32 mask)
{
	if (!(mask & LLInventoryObserver::ADD))
	{
		return;
	}

	// *HACK: If this was in response to a packet off
	// the network, figure out which item was updated.
	LLMessageSystem* msg = gMessageSystem;

	std::string msg_name;
	if (mMessageName.empty())
	{
		msg_name = msg->getMessageName();
	}
	else
	{
		msg_name = mMessageName;
	}

	if (msg_name.empty())
	{
		return;
	}
	
	// We only want newly created inventory items. JC
	if ( msg_name != "UpdateCreateInventoryItem")
	{
		return;
	}

	LLPointer<LLViewerInventoryItem> titem = new LLViewerInventoryItem;
	S32 num_blocks = msg->getNumberOfBlocksFast(_PREHASH_InventoryData);
	for (S32 i = 0; i < num_blocks; ++i)
	{
		titem->unpackMessage(msg, _PREHASH_InventoryData, i);
		if (!(titem->getUUID().isNull()))
		{
			//we don't do anything with null keys
			mAdded.push_back(titem->getUUID());
		}
	}
	if (!mAdded.empty())
	{
		done();
	}
}

LLInventoryTransactionObserver::LLInventoryTransactionObserver(const LLTransactionID& transaction_id) :
	mTransactionID(transaction_id)
{
}

void LLInventoryTransactionObserver::changed(U32 mask)
{
	if (mask & LLInventoryObserver::ADD)
	{
		// This could be it - see if we are processing a bulk update
		LLMessageSystem* msg = gMessageSystem;
		if (msg->getMessageName()
		   && (0 == strcmp(msg->getMessageName(), "BulkUpdateInventory")))
		{
			// we have a match for the message - now check the
			// transaction id.
			LLUUID id;
			msg->getUUIDFast(_PREHASH_AgentData, _PREHASH_TransactionID, id);
			if (id == mTransactionID)
			{
				// woo hoo, we found it
				uuid_vec_t folders;
				uuid_vec_t items;
				S32 count;
				count = msg->getNumberOfBlocksFast(_PREHASH_FolderData);
				S32 i;
				for (i = 0; i < count; ++i)
				{
					msg->getUUIDFast(_PREHASH_FolderData, _PREHASH_FolderID, id, i);
					if (id.notNull())
					{
						folders.push_back(id);
					}
				}
				count = msg->getNumberOfBlocksFast(_PREHASH_ItemData);
				for (i = 0; i < count; ++i)
				{
					msg->getUUIDFast(_PREHASH_ItemData, _PREHASH_ItemID, id, i);
					if (id.notNull())
					{
						items.push_back(id);
					}
				}

				// call the derived class the implements this method.
				done(folders, items);
			}
		}
	}
}

void LLInventoryCategoriesObserver::changed(U32 mask)
{
	if (!mCategoryMap.size())
		return;

	for (category_map_t::iterator iter = mCategoryMap.begin();
		 iter != mCategoryMap.end();
		 ++iter)
	{
		LLViewerInventoryCategory* category = gInventory.getCategory((*iter).first);
		if (!category)
			continue;

		const S32 version = category->getVersion();
		const S32 expected_num_descendents = category->getDescendentCount();
		if ((version == LLViewerInventoryCategory::VERSION_UNKNOWN) ||
			(expected_num_descendents == LLViewerInventoryCategory::DESCENDENT_COUNT_UNKNOWN))
		{
			continue;
		}

		// Check number of known descendents to find out whether it has changed.
		LLInventoryModel::cat_array_t* cats;
		LLInventoryModel::item_array_t* items;
		gInventory.getDirectDescendentsOf((*iter).first, cats, items);
		if (!cats || !items)
		{
			llwarns << "Category '" << category->getName() << "' descendents corrupted, fetch failed." << llendl;
			// NULL means the call failed -- cats/items map doesn't exist (note: this does NOT mean
			// that the cat just doesn't have any items or subfolders).
			// Unrecoverable, so just skip this category.

			llassert(cats != NULL && items != NULL);
		}
		const S32 current_num_known_descendents = cats->count() + items->count();

		LLCategoryData cat_data = (*iter).second;

		// If category version or descendents count has changed
		// update category data in mCategoryMap and fire a callback.
		if (version != cat_data.mVersion || current_num_known_descendents != cat_data.mDescendentsCount)
		{
			cat_data.mVersion = version;
			cat_data.mDescendentsCount = current_num_known_descendents;

			cat_data.mCallback();
		}
	}
}

bool LLInventoryCategoriesObserver::addCategory(const LLUUID& cat_id, callback_t cb)
{
	S32 version;
	S32 current_num_known_descendents;
	bool can_be_added = true;

	LLViewerInventoryCategory* category = gInventory.getCategory(cat_id);
	if (category)
	{
		// Inventory category version is used to find out if some changes
		// to a category have been made.
		version = category->getVersion();

		LLInventoryModel::cat_array_t* cats;
		LLInventoryModel::item_array_t* items;
		gInventory.getDirectDescendentsOf(cat_id, cats, items);
		if (!cats || !items)
		{
			llwarns << "Category '" << category->getName() << "' descendents corrupted, fetch failed." << llendl;
			// NULL means the call failed -- cats/items map doesn't exist (note: this does NOT mean
			// that the cat just doesn't have any items or subfolders).
			// Unrecoverable, so just return "false" meaning that the category can't be observed.
			can_be_added = false;

			llassert(cats != NULL && items != NULL);
		}
		current_num_known_descendents = cats->count() + items->count();
	}
	else
	{
		// If category could not be retrieved it might mean that
		// inventory is unusable at the moment so the category is
		// stored with VERSION_UNKNOWN and DESCENDENT_COUNT_UNKNOWN,
		// it may be updated later.
		version = LLViewerInventoryCategory::VERSION_UNKNOWN;
		current_num_known_descendents = LLViewerInventoryCategory::DESCENDENT_COUNT_UNKNOWN;
	}

	if (can_be_added)
	{
		mCategoryMap.insert(category_map_value_t(cat_id, LLCategoryData(cb, version, current_num_known_descendents)));
	}

	return can_be_added;
}

void LLInventoryCategoriesObserver::removeCategory(const LLUUID& cat_id)
{
	mCategoryMap.erase(cat_id);
}