Low-probability data loss risk issues

[brodycj]

I discovered and resolved some low-probability data loss risk issues on cordova-sqlite-storage:

• litehelpers/Cordova-sqlite-storage#666 - Transaction problem after page change, WITH POSSIBLE DATA LOSS, resolved with workaround solution to issue close database request before opening in JavaScript (see https://github.com/litehelpers/Cordova-sqlite-storage/blob/storage-master/SQLitePlugin.coffee.md#L253-L262 for the solution in CoffeeScript, https://github.com/litehelpers/Cordova-sqlite-storage/blob/storage-master/www/SQLitePlugin.js#L204-L214 for the solution in JavaScript)
• litehelpers/Cordova-sqlite-storage#716 - possible iOS threading issue, resolved by using PSPDFThreadSafeMutableDictionary from https://gist.github.com/steipete/5928916

A couple other items to watch for:

• It is recommended to build the iOS platform version with -DSQLITE_THREADSAFE=2 since the database may actually be accessed from multiple threads (though not concurrently). I think this is the default.
• EXTRA DURABLE build setting is recommended to avoid possible corruption, as discussed in http://sqlite.1065341.n5.nabble.com/Is-WAL-mode-more-robust-against-corruption-td99624.html and litehelpers/Cordova-sqlite-storage#736

Recommended solution: merging the changes from https://github.com/brodybits/cordova-sqlite-legacy-build-support would include the solutions for litehelpers/Cordova-sqlite-storage#666 and litehelpers/Cordova-sqlite-storage#716.

I would be happy to answer any questions. I would be happy to recommend this project for SpatiaLite support if we can include the solutions for litehelpers/Cordova-sqlite-storage#666 and litehelpers/Cordova-sqlite-storage#716 in this plugin version.

[Cultrarius]

Thank you, that is very helpful!

This has at the moment not the highest priority for us, but we will merge these fixes as soon as we can.