For EXT-2325: Should purge inventory cache moving from 1.23 to 2.0.

Added a version field at the beginning of inventory cache files.  If version field is not found or does not match expectected value, then the cache is discarded.  In 1.23, the version line triggers a warning but is otherwise ignored.

Reviewed by Seraph.

indra/newview/llinventorymodel.cpp

@@ -81,6 +81,10 @@ BOOL LLInventoryModel::sTimelyFetchPending = FALSE;
 LLFrameTimer LLInventoryModel::sFetchTimer;
 S16 LLInventoryModel::sBulkFetchCount = 0;
 
+// Increment this if the inventory contents change in a non-backwards-compatible way.
+// For viewer 2, the addition of link items makes a pre-viewer-2 cache incorrect.
+const S32 LLInventoryModel::sCurrentInvCacheVersion = 2;
+
 // RN: for some reason, using std::queue in the header file confuses the compiler which things it's an xmlrpc_queue
 static std::deque<LLUUID> sFetchQueue;
 
@@ -2101,7 +2105,8 @@ bool LLInventoryModel::loadSkeleton(
 				llinfos << "Unable to gunzip " << gzip_filename << llendl;
 			}
 		}
-		if(loadFromFile(inventory_filename, categories, items))
+		bool is_cache_obsolete = false;
+		if(loadFromFile(inventory_filename, categories, items, is_cache_obsolete))
 		{
 			// We were able to find a cache of files. So, use what we
 			// found to generate a set of categories we should add. We
@@ -2236,6 +2241,12 @@ bool LLInventoryModel::loadSkeleton(
 			// clean up the gunzipped file.
 			LLFile::remove(inventory_filename);
 		}
+		if(is_cache_obsolete)
+		{
+			// If out of date, remove the gzipped file too.
+			llwarns << "Inv cache out of date, removing" << llendl;
+			LLFile::remove(gzip_filename);
+		}
 		categories.clear(); // will unref and delete entries
 	}
 
@@ -2634,7 +2645,8 @@ bool LLUUIDAndName::operator>(const LLUUIDAndName& rhs) const
 // static
 bool LLInventoryModel::loadFromFile(const std::string& filename,
 									LLInventoryModel::cat_array_t& categories,
-									LLInventoryModel::item_array_t& items)
+									LLInventoryModel::item_array_t& items,
+									bool &is_cache_obsolete)
 {
 	if(filename.empty())
 	{
@@ -2651,11 +2663,32 @@ bool LLInventoryModel::loadFromFile(const std::string& filename,
 	// *NOTE: This buffer size is hard coded into scanf() below.
 	char buffer[MAX_STRING];		/*Flawfinder: ignore*/
 	char keyword[MAX_STRING];		/*Flawfinder: ignore*/
+	char value[MAX_STRING];			/*Flawfinder: ignore*/
+	is_cache_obsolete = true;  		// Obsolete until proven current
 	while(!feof(file) && fgets(buffer, MAX_STRING, file)) 
 	{
-		sscanf(buffer, " %254s", keyword);	/* Flawfinder: ignore */
-		if(0 == strcmp("inv_category", keyword))
+		sscanf(buffer, " %126s %126s", keyword, value);	/* Flawfinder: ignore */
+		if(0 == strcmp("inv_cache_version", keyword))
 		{
+			S32 version;
+			int succ = sscanf(value,"%d",&version);
+			if ((1 == succ) && (version == sCurrentInvCacheVersion))
+			{
+				// Cache is up to date
+				is_cache_obsolete = false;
+				continue;
+			}
+			else
+			{
+				// Cache is out of date
+				break;
+			}
+		}
+		else if(0 == strcmp("inv_category", keyword))
+		{
+			if (is_cache_obsolete)
+				break;
+			
 			LLPointer<LLViewerInventoryCategory> inv_cat = new LLViewerInventoryCategory(LLUUID::null);
 			if(inv_cat->importFileLocal(file))
 			{
@@ -2669,6 +2702,9 @@ bool LLInventoryModel::loadFromFile(const std::string& filename,
 		}
 		else if(0 == strcmp("inv_item", keyword))
 		{
+			if (is_cache_obsolete)
+				break;
+
 			LLPointer<LLViewerInventoryItem> inv_item = new LLViewerInventoryItem;
 			if( inv_item->importFileLocal(file) )
 			{
@@ -2700,6 +2736,8 @@ bool LLInventoryModel::loadFromFile(const std::string& filename,
 		}
 	}
 	fclose(file);
+	if (is_cache_obsolete)
+		return false;
 	return true;
 }
 
@@ -2721,6 +2759,7 @@ bool LLInventoryModel::saveToFile(const std::string& filename,
 		return false;
 	}
 
+	fprintf(file, "\tinv_cache_version\t%d\n",sCurrentInvCacheVersion);
 	S32 count = categories.count();
 	S32 i;
 	for(i = 0; i < count; ++i)

indra/newview/llinventorymodel.h

@@ -446,7 +446,8 @@ class LLInventoryModel
 	// file import/export.
 	static bool loadFromFile(const std::string& filename,
 							 cat_array_t& categories,
-							 item_array_t& items); 
+							 item_array_t& items,
+							 bool& is_cache_obsolete); 
 	static bool saveToFile(const std::string& filename,
 						   const cat_array_t& categories,
 						   const item_array_t& items); 
@@ -518,6 +519,9 @@ class LLInventoryModel
 	static F32 sMaxTimeBetweenFetches;
 	static S16 sBulkFetchCount;
 
+	// Expected inventory cache version
+	const static S32 sCurrentInvCacheVersion;
+	
 	// This flag is used to handle an invalid inventory state.
 	bool mIsAgentInvUsable;