Update README.md

README.md

@@ -58,7 +58,8 @@ issued before load is finished is buffered and will be executed when
 load is done.
 * `onload` (optional): if you use autoloading, this is the handler called after the `loadDatabase`. It takes one `error` argument. If you use autoloading without specifying this handler, and an error happens during load, an error will be thrown.
 * `afterSerialization` (optional): hook you can use to transform data after it was serialized and before it is written to disk. Can be used for example to encrypt data before writing database to disk. This function takes a string as parameter (one line of an NeDB data file) and outputs the transformed string, **which must absolutely not contain a `\n` character** (or data will be lost)
-* `beforeDeserialization` (optional): reverse of `afterSerialization`. Make sure to include both and not just one or you risk data loss. For the same reason, make sure both functions are inverses of one another. **Warning: there are currently no failsafe mechanisms if the serialization hooks are not well formed or if they are not inverse. This may be done in the future but for now use with caution**
+* `beforeDeserialization` (optional): reverse of `afterSerialization`. Make sure to include both and not just one or you risk data loss. For the same reason, make sure both functions are inverses of one another. Some failsafe mechanisms are in place to prevent data loss if you misuse the serialization hooks: NeDB checks that never one is declared without the other, and checks that they are reverse of one another by testing on random strings of various lengths. In addition, if too much data is detected as corrupt, NeDB will refuse to start as it could mean you're not using the deserialization hook corresponding to the serialization hook used before (see below)
+* `corruptAlertThreshold` (optional): between 0 and 1, defaults to 10%. NeDB will refuse to start if more than this percentage of the datafile is corrupt. 0 means you don't tolerate any corruption, 1 means you don't care 
 * `nodeWebkitAppName` (optional, **DEPRECATED**): if you are using NeDB from whithin a Node Webkit app, specify its name (the same one you use in the `package.json`) in this field and the `filename` will be relative to the directory Node Webkit uses to store the rest of the application's data (local storage etc.). It works on Linux, OS X and Windows. Now that you can use `require('nw.gui').App.dataPath` in Node Webkit to get the path to the data directory for your application, you should not use this option anymore and it will be removed.
 
 If you use a persistent datastore without the `autoload` option, you need to call `loadDatabase` manually.