mrtest

Documentation

Overview

Package mrtest is a test package tightly tied to the mr package, separated out to avoid import cycles when other tests want to use it.

Index

• func MRCheck(ctx context.Context, eq *entroq.EntroQ, numDocs, numMappers, numReducers int) bool

Functions

func MRCheck

func MRCheck(ctx context.Context, eq *entroq.EntroQ, numDocs, numMappers, numReducers int) bool

MRCheck is a check function that runs a mapreduce using the specified number of mappers and reducers.

Creates a bunch of documents, filled with numeric strings (words are all numbers, makes things easy). We start with a known histogram, then we assemble documents by randomly drawing without replacement until the distribution is empty. That way we know our outputs from the beginning, and we get a random starting point.

When using with quick.Check, the first two arguments should usually be fixed, but the remainder can be "checked". Thus, it often makes sense to use it in a closure, thus:

config := &quick.Config{
	MaxCount: 5,
	Values: func(values []reflect.Value, rand *rand.Rand) {
		values[0] = reflect.ValueOf(rand.Intn(2000) + 1000)
		values[1] = reflect.ValueOf(rand.Intn(100) + 1)
		values[2] = reflect.ValueOf(rand.Intn(20) + 1)
	},
}
check := func(nm, nr int) bool {
	return MRCheck(ctx, client, nm, nr)
}
if err := quick.Check(check, config); err != nil {
	t.Fatal(err)
}