tree db3375293347972756394168b99dc5a2f7371998
parent 4b0dfa08a9af6f3bcc5ec3df2f322ce1cd71bce7
author Ken Ashcraft <kash@google.com> 1406328781 -0700
committer Ken Ashcraft <kash@google.com> 1406328783 -0700

veyron/services/store/memstore/query: Add sample() function.

The sample() function randomly samples the stream of results using reservoir
sampling.  sample() takes a single integer argument specifying the number
of samples to return.

I plan to use this function in the Store codelab to randomly select
a fortune.

Change-Id: I574a0fef77cff4fe602c1b300c80c5be33318fef