Package github.com/qedus/nds is a datastore API for the Google App Engine (GAE) Go Runtime Environment that uses memcache to cache all datastore requests. It is compatible with both Classic and Managed VM products. This package guarantees strong cache consistency when using nds.Get* and nds.Put*, meaning you will never get data from a stale cache.

Exposed parts of this API are the same as the official one distributed by Google (google.golang.org/appengine/datastore). However, underneath github.com/qedus/nds uses a caching stategy similar to the GAE Python NDB API. In fact the caching strategy used here even fixes one or two of the Python NDB caching consistency bugs.

You can find the API documentation at http://godoc.org/github.com/qedus/nds.

One other benefit is that the standard datastore.GetMulti function only allows you to retrieve a maximum of 1000 entities at a time. The GetMulti in this package allows you to get as many as you need (within timeout limits) by concurrently calling the datastore until your entity request is fulfilled.

You can use this package in exactly the same way you would use google.golang.org/appengine/datastore. However, it is important that you use nds.Get*, nds.Put*, nds.Delete* and nds.RunInTransaction entirely within your code. Do not mix use of those functions with the google.golang.org/appengine/datastore equivalents as you will be liable to get stale datastore entities from github.com/qedus/nds.

Ultimately all you need to do is find/replace the following in your codebase:

• datastore.Get -> nds.Get
• datastore.Put -> nds.Put
• datastore.Delete -> nds.Delete
• datastore.RunInTransaction -> nds.RunInTransaction

This package has recently been converted to use context.Context instead of appengine.Context. The classic branch has an old version that uses appengine.Context.