Question

I have a C++ map based structure that I’d like to save onto an ext3 based flash disk running Android. The structure looks like this:

class kvBucket {
   ...
   map<string, kvBucket*> buckets;
   map<string, string> keyPairs;
   ...
}
class kvTree {
   ...
   kvBucket base;
   ...
}

What’s a good way to save the ‘base’ object (which has about a few hundred entries)?

1. database (sqlite3) accessed through Android JNI
2. object serialization (boost)
3. save as XML or JSON file
4. something else

One consideration is that it needs to be crash proof, so if someone pulls the plug on the device while writing to disk, I need to recover gracefully.

Answer 1

Any of these solutions would be great.

If you want it to be crash-proof, do your writing to a temporary file, and only replace the original file after the write is complete. The worst scenario is that you have two valid files.