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// Package storetest provides a helper for testing throttled stores.
package storetest // import "github.com/throttled/throttled/store/storetest"
import (
"math/rand"
"strconv"
"sync/atomic"
"testing"
"time"
"github.com/throttled/throttled"
)
// TestGCRAStore tests the behavior of a GCRAStore implementation for
// compliance with the throttled API. It does not require support
// for TTLs.
func TestGCRAStore(t *testing.T, st throttled.GCRAStore) {
// GetWithTime a missing key
if have, _, err := st.GetWithTime("foo"); err != nil {
t.Fatal(err)
} else if have != -1 {
t.Errorf("expected GetWithTime to return -1 for a missing key but got %d", have)
}
// SetIfNotExists on a new key
want := int64(1)
if set, err := st.SetIfNotExistsWithTTL("foo", want, 0); err != nil {
t.Fatal(err)
} else if !set {
t.Errorf("expected SetIfNotExists on an empty key to succeed")
}
before := time.Now()
if have, now, err := st.GetWithTime("foo"); err != nil {
t.Fatal(err)
} else if have != want {
t.Errorf("expected GetWithTime to return %d but got %d", want, have)
} else if now.UnixNano() <= 0 {
t.Errorf("expected GetWithTime to return a time representable representable as a positive int64 of nanoseconds since the epoch")
} else if now.Before(before) || now.After(time.Now()) {
// Note that we make the assumption here that the store is running on
// the same machine as this test and thus shares a clock. This can be a
// little tricky in the case of Redis, which could be running
// elsewhere. The test assumes that it's running either locally on on
// Travis (where currently the Redis is available on localhost). If new
// test environments are procured, this may need to be revisited.
t.Errorf("expected GetWithTime to return a time between the time before the call and the time after the call")
}
// SetIfNotExists on an existing key
if set, err := st.SetIfNotExistsWithTTL("foo", 123, 0); err != nil {
t.Fatal(err)
} else if set {
t.Errorf("expected SetIfNotExists on an existing key to fail")
}
if have, _, err := st.GetWithTime("foo"); err != nil {
t.Fatal(err)
} else if have != want {
t.Errorf("expected GetWithTime to return %d but got %d", want, have)
}
// SetIfNotExists on a different key
if set, err := st.SetIfNotExistsWithTTL("bar", 456, 0); err != nil {
t.Fatal(err)
} else if !set {
t.Errorf("expected SetIfNotExists on an empty key to succeed")
}
// Returns the false on a missing key
if swapped, err := st.CompareAndSwapWithTTL("baz", 1, 2, 0); err != nil {
t.Fatal(err)
} else if swapped {
t.Errorf("expected CompareAndSwap to fail on a missing key")
}
// Test a successful CAS
want = int64(2)
if swapped, err := st.CompareAndSwapWithTTL("foo", 1, want, 0); err != nil {
t.Fatal(err)
} else if !swapped {
t.Errorf("expected CompareAndSwap to succeed")
}
if have, _, err := st.GetWithTime("foo"); err != nil {
t.Fatal(err)
} else if have != want {
t.Errorf("expected GetWithTime to return %d but got %d", want, have)
}
// Test an unsuccessful CAS
if swapped, err := st.CompareAndSwapWithTTL("foo", 1, 2, 0); err != nil {
t.Fatal(err)
} else if swapped {
t.Errorf("expected CompareAndSwap to fail")
}
if have, _, err := st.GetWithTime("foo"); err != nil {
t.Fatal(err)
} else if have != want {
t.Errorf("expected GetWithTime to return %d but got %d", want, have)
}
}
// TestGCRAStoreTTL tests the behavior of TTLs in a GCRAStore implementation.
func TestGCRAStoreTTL(t *testing.T, st throttled.GCRAStore) {
ttl := time.Second
want := int64(1)
key := "ttl"
if _, err := st.SetIfNotExistsWithTTL(key, want, ttl); err != nil {
t.Fatal(err)
}
if have, _, err := st.GetWithTime(key); err != nil {
t.Fatal(err)
} else if have != want {
t.Errorf("expected GetWithTime to return %d, got %d", want, have)
}
// I can't think of a generic way to test expiration without a sleep
time.Sleep(ttl + time.Millisecond)
if have, _, err := st.GetWithTime(key); err != nil {
t.Fatal(err)
} else if have != -1 {
t.Errorf("expected GetWithTime to fail on an expired key but got %d", have)
}
}
// BenchmarkGCRAStore runs parallel benchmarks against a GCRAStore implementation.
// Aside from being useful for performance testing, this is useful for finding
// race conditions with the Go race detector.
func BenchmarkGCRAStore(b *testing.B, st throttled.GCRAStore) {
seed := int64(42)
var attempts, updates int64
b.RunParallel(func(pb *testing.PB) {
// We need atomic behavior around the RNG or go detects a race in the test
delta := int64(1)
seedValue := atomic.AddInt64(&seed, delta) - delta
gen := rand.New(rand.NewSource(seedValue))
for pb.Next() {
key := strconv.FormatInt(gen.Int63n(50), 10)
var v int64
var updated bool
v, _, err := st.GetWithTime(key)
if v == -1 {
updated, err = st.SetIfNotExistsWithTTL(key, gen.Int63(), 0)
if err != nil {
b.Error(err)
}
} else if err != nil {
b.Error(err)
} else {
updated, err = st.CompareAndSwapWithTTL(key, v, gen.Int63(), 0)
if err != nil {
b.Error(err)
}
}
atomic.AddInt64(&attempts, 1)
if updated {
atomic.AddInt64(&updates, 1)
}
}
})
b.Logf("%d/%d update operations succeeed", updates, attempts)
}
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