func mergeDomains(engine storage.Engine, w origins.Writer, domains []string, since, asof time.Time) int {
var (
err error
count int
log *view.Log
)
iters := make([]origins.Iterator, len(domains))
// Merge and output facts across domains.
for i, d := range domains {
log, err = view.OpenLog(engine, d, "commit")
if err != nil {
logrus.Fatal(err)
}
iters[i] = log.View(since, asof)
}
if count, err = origins.Copy(view.Merge(iters...), w); err != nil {
logrus.Fatal(err)
}
return count
}
func TestMultiDomainLogIter(t *testing.T) {
domains := []string{"test", "another_test"}
// Number of transactions
n := 100
// Number of facts per transaction
m := 100
engine := randMultidomainStorage(domains, n, m)
// Open and merge the commit logs.
log0, err := view.OpenLog(engine, domains[0], "commit")
if err != nil {
t.Fatal(err)
}
log1, err := view.OpenLog(engine, domains[1], "commit")
if err != nil {
t.Fatal(err)
}
now := time.Now()
mergedStreams := view.Merge(log0.Asof(now), log1.Asof(now))
if err = mergedStreams.Err(); err != nil {
t.Fatal(err)
}
i := 0
var prevTrnId uint64 = 1<<64 - 1
for {
f := mergedStreams.Next()
if err = mergedStreams.Err(); err != nil {
t.Fatal(err)
}
if f == nil {
break
} else {
if prevTrnId < f.Transaction {
t.Errorf("Transactions are ordered incorrectly")
}
i++
}
}
if i != n*m {
t.Errorf("expected %d facts, got %d", n*m, i)
}
}
func benchmarkDomainMerge(b *testing.B, numTrn, factsPerTrn, numDomains int) {
var err error
domains := make([]string, numDomains)
iters := make([]origins.Iterator, len(domains))
logs := make([]*view.Log, len(domains))
for j := 0; j < numDomains; j++ {
domains[j] = "domain_" + strconv.Itoa(j+1)
}
engine := randMultidomainStorage(domains, numTrn, factsPerTrn)
for j := 0; j < len(domains); j++ {
logs[j], err = view.OpenLog(engine, domains[j], "commit")
if err != nil {
b.Fatal(err)
}
}
now := time.Now()
b.ResetTimer()
for i := 0; i < b.N; i++ {
for j := 0; j < len(domains); j++ {
iters[j] = logs[j].Asof(now)
}
iter := view.Merge(iters...)
if err := iter.Err(); err != nil {
b.Fatal(err)
}
// The Merge() operation is lazy, and most of the actual work happens during Next(),
// so to evaluate the true cost of merging we need to time how long it takes to step
// through the resulting iterator.
_, err = testNext(iter)
if err != nil {
b.Fatal(err)
}
}
}