Hi Rowan, My apologies. My sample app does use NSDocument. But my production app doesn't. And they both exhibit the same problem.
On Tue, Apr 18, 2017 at 12:29 AM, Rowan Worth <row...@dug.com> wrote: > Hey Brendan, > > I'm no OSX expert, but from what I've read this afternoon about NSDocument > and friends combined with what I know about sqlite I have to say you are > completely mad to continue passing sqlite databases to NSDocument, > *especially* as you don't define your own sub-class to do any of the file > management. > > Relying on some NSDocument sub-class builtin to the system and then also > opening the DB with CouchbaseLite may well violate section 2.2.1 of "how to > corrupt an sqlite database" (multiple copies of sqlite linked into the same > application). Even if not, it sounds like NSDocument has a tendency to copy > files around for eg. auto-save purposes. > > I'd be very *very* surprised if there's an sqlite bug here. I'd take the > advice given to you on bountysource and watch your application's file > system operations to begin to understand what is going on behind the > scenes. > > -Rowan > > > > On 18 April 2017 at 13:01, Brendan Duddridge <brend...@gmail.com> wrote: > > > Thanks Richard for your reply. > > > > Sorry about the COLLATE problem. That's a Couchbase Lite thing. > > > > I find it weird that a different WAL file is getting in there somehow > when > > a power failure occurs. I'm a bit stumped at how it can even write to the > > file system the moment the power shuts down so I don't even understand > how > > the database file can get corrupted. Unless the corruption happens when > > the database file is opened up next and tries to use this improper WAL > > file. > > > > In my main project I'm using SQLCipher as my SQLite layer. But in the > demo > > project I posted, I'm just using the built-in macOS Sierra SQLite > library. > > In both cases though I can cause SQLite file corruption by cutting the > > power on my MacBook Pro. > > > > I'm going to do further investigations to see if there's any misuse of > > SQLite that I can find. Although the developers of Couchbase Lite are far > > smarter than I and I'm sure they're doing things by the book. > > > > Perhaps the only think I can think of that I'm doing that may be > unorthodox > > is by storing the SQLite files inside a macOS package. But at the unix > > layer that's really just a directory, so I don't know how that could > cause > > a problem. Unless macOS treats the package in a way differently than a > > normal folder and is causing things to get moved around or written when a > > power failure occurs. > > > > This problem has been plaguing me for quite a long time actually. I hope > > that I can find a solution somehow. > > > > Thanks, > > > > Brendan > > > > > I worked around the "COLLATE JSON" problem (by writing my own JSON > > > collation). That allows me to analyze your database and WAL file. > > > > > > It appears that the WAL file is not the correct WAL file for that > > > database. It is as if someone has taken an unrelated WAL file and > > > renamed it to have the same base name as your database. Or the other > > > way around - someone has renamed your database to have the same base > > > name as the WAL file. > > > > > > Your demonstration application does not call SQLite directly. Instead > > > it appears to use two libraries that in turn call SQLite: > > > libsqlcrypt.a and the CouchbaseLite.framework. You do not provide > > > sources to these other libraries, so I am unable to deduce what they > > > are doing. > > > > > > So, in the absence of further evidence, I am going to diagnose this as > > > a misuse of SQLite by one of the two libraries that you are linking - > > > probably a misuse in the form of trying to rename or unlink or > > > otherwise modify the database file using ordinary operating system > > > calls while a connection to the database is open. > > _______________________________________________ > > sqlite-users mailing list > > sqlite-users@mailinglists.sqlite.org > > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > > > _______________________________________________ > sqlite-users mailing list > sqlite-users@mailinglists.sqlite.org > http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users > _______________________________________________ sqlite-users mailing list sqlite-users@mailinglists.sqlite.org http://mailinglists.sqlite.org/cgi-bin/mailman/listinfo/sqlite-users
