#TILE DATABASE CORRUPT FIX HOW TO#

How To Corrupt An SQLite Database File).Д¬ould you redo the same test copying/deleting/pasting back both files? My assumption is that in your case the corruption might come from async cache.db and cache.db-journal (cf.

I like the idea of reusing the cache.db file too, and just did on Window (OK, I did nothing really interesting but I connected to the database and ran a select count(*) from Just tried what you tested but I couldn't reproduce the database corruption.

refreshDb() is designed exactly for your need - a clean db close decided by an admin.

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Is there anything slightly different you did in your own test? Maybe the differences come from an Android version file management discrepancy.

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And I didn't change anything to my code regarding closing the database.

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This worked as expected by me, except for Android dismissing the read-only file property.

looking for SQLiteReadOnlyDatabaseException in LogCat.

File sizes are 85Mb (bigger) and 200Kb (exactly the same size), which is acceptable Therefore not only I get my data back, but the db is writable, and I could travel a bit on the map on new geo places The read-only property is automatically unset for both files (for the record I cannot set this property for those files on my smartphone with Windows Explorer I could only do that for the files when on my laptop).

set the original files cache.db and cache.db-journal as read only on my laptop (windows), paste them back into osmdroid cache location, overwriting.

File sizes are 2Mb and 60Kb, which is acceptable Everything works as expected, from an empty writable db.

cut cache.db and cache.db-journal to my laptop.

It is ( /storage/emulated/0/osmdroid/tiles)

check if my cache db location is reachable from my laptop.

I need to try your 'delete/copy' database Indeed, a nExpensiveAdminTasksDuringSplashScreen() method could I tried to reproduce your SQLiteReadOnlyDatabaseException test but didn't manage to. Opening and closing a db takes resources, and we also have to deal with async downloads too. The refreshDb() action is supposed to be rather an admin task (something strange happened to the db, or we explicitly changed the db file path) than something to run each time the end-user tilts its screen.

ItвЂ™s totally OK to not close the DB connection explicitly in your code and you will not need to handle this An explicit drawback is that when Thread-1 calls getDb() it gets the db and plans to use it, but if Thread-2 just called onDetach() 1/10000th second later, the db referenced by Thread-1 is closed when it uses it. it is not possible for reads and writes to occur on the database at the same time I found an interesting article called Transactions and threads in SQLite on Android, which also pointed me to (): If it's a bug, version(s) of android this affects:ДЄll Version of osmdroid the issue relates to:

: Attempt to invoke virtual method 'long java.io.File.length()' on a null object referenceДЄt .nCleanupOperation(SqlTileWriter.java:114)ДЄt .SqlTileWriter$1.run(SqlTileWriter.java:69)ДЄt $1.run(GarbageCollector.java:31)

04-19 10:39:39.749 E/SQLiteDatabase: Error inserting expires=1334919638000 provider=Mapnik key=905965568ДЄ: database is locked (code 5)ДЄt .nativeExecuteForLastInsertedRowId(Native Method)ДЄt .executeForLastInsertedRowId(SQLiteConnection.java:783)ДЄt .executeForLastInsertedRowId(SQLiteSession.java:788)ДЄt .executeInsert(SQLiteStatement.java:86)ДЄt .insertWithOnConflict(SQLiteDatabase.java:1548)ДЄt .replace(SQLiteDatabase.java:1464)ДЄt .SqlTileWriter.saveFile(SqlTileWriter.java:150)ДЄt .MapTileDownloader$TileLoader.loadTile(MapTileDownloader.java:255)ДЄt .MapTileModuleProviderBase$n(MapTileModuleProviderBase.java:315)ДЄt .runWorker(ThreadPoolExecutor.java:1162)ДЄt $n(ThreadPoolExecutor.java:636)Д 4-19 10:39:42.265 E/SQLiteDatabase: Error inserting expires=1334880026000 provider=Mapnik key=905973758Д 4-19 10:39:42.578 E/AndroidRuntime: FATAL EXCEPTION: Thread-4

Tile database corrupt fix