Update the vendoring of bmizerany/perks/quantile.

This is still from my own fork as there are still critical PRs that
bmizerany hasn't responded to yet.

Change-Id: Ib46e68ec9ecbae9423b1bfe1311569426dfc7ba0

_vendor/perks/MANIFEST

@@ -1 +1 @@
-Imported at da3e0acc8525a74a0ac8651ac5e7a68891291fdf from https://github.com/u-c-l/perks/tree/opt/pool-for-sample .
+Imported at 5d903d2c5dc7f55829e36c62ae6c5f5f6d75e70a from https://github.com/u-c-l/perks .

_vendor/perks/quantile/bench_test.go

@@ -5,6 +5,8 @@ import (
 )
 
 func BenchmarkInsertTargeted(b *testing.B) {
+	b.ReportAllocs()
+
 	s := NewTargeted(0.01, 0.5, 0.9, 0.99)
 	b.ResetTimer()
 	for i := float64(0); i < float64(b.N); i++ {

_vendor/perks/quantile/pool.go

@@ -1,28 +0,0 @@
-//+build !go1.3
-
-package quantile
-
-type samplePool struct {
-	pool chan *Sample
-}
-
-func newSamplePool(capacity int) *samplePool {
-	return &samplePool{pool: make(chan *Sample, capacity)}
-}
-
-func (sp *samplePool) Get(value, width, delta float64) *Sample {
-	select {
-	case sample := <-sp.pool:
-		sample.Value, sample.Width, sample.Delta = value, width, delta
-		return sample
-	default:
-		return &Sample{value, width, delta}
-	}
-}
-
-func (sp *samplePool) Put(sample *Sample) {
-	select {
-	case sp.pool <- sample:
-	default:
-	}
-}

_vendor/perks/quantile/pool_1_3.go

@@ -1,26 +0,0 @@
-//+build go1.3
-
-package quantile
-
-import "sync"
-
-// With the Go1.3 sync Pool, there is no max capacity, and a globally shared
-// pool is more efficient.
-var globalSamplePool = sync.Pool{New: func() interface{} { return &Sample{} }}
-
-type samplePool struct{}
-
-func newSamplePool(capacity int) *samplePool {
-	// capacity ignored for Go1.3 sync.Pool.
-	return &samplePool{}
-}
-
-func (_ samplePool) Get(value, width, delta float64) *Sample {
-	sample := globalSamplePool.Get().(*Sample)
-	sample.Value, sample.Width, sample.Delta = value, width, delta
-	return sample
-}
-
-func (_ samplePool) Put(sample *Sample) {
-	globalSamplePool.Put(sample)
-}

_vendor/perks/quantile/stream.go

@@ -80,11 +80,7 @@ type Stream struct {
 
 func newStream(ƒ invariant) *Stream {
 	const defaultEpsilon = 0.01
-	x := &stream{
+	x := &stream{epsilon: defaultEpsilon, ƒ: ƒ}
-		epsilon: defaultEpsilon,
-		ƒ:       ƒ,
-		pool:    newSamplePool(1024),
-	}
 	return &Stream{x, make(Samples, 0, 500), true}
 }
 
@@ -173,9 +169,8 @@ func (s *Stream) flushed() bool {
 type stream struct {
 	epsilon float64
 	n       float64
-	l       []*Sample
+	l       []Sample
 	ƒ       invariant
-	pool    *samplePool
 }
 
 // SetEpsilon sets the error epsilon for the Stream. The default epsilon is
@@ -187,9 +182,6 @@ func (s *stream) SetEpsilon(epsilon float64) {
 }
 
 func (s *stream) reset() {
-	for _, sample := range s.l {
-		s.pool.Put(sample)
-	}
 	s.l = s.l[:0]
 	s.n = 0
 }
@@ -206,15 +198,15 @@ func (s *stream) merge(samples Samples) {
 			c := s.l[i]
 			if c.Value > sample.Value {
 				// Insert at position i.
-				s.l = append(s.l, nil)
+				s.l = append(s.l, Sample{})
 				copy(s.l[i+1:], s.l[i:])
-				s.l[i] = s.pool.Get(sample.Value, sample.Width, math.Floor(s.ƒ(s, r))-1)
+				s.l[i] = Sample{sample.Value, sample.Width, math.Floor(s.ƒ(s, r)) - 1}
 				i++
 				goto inserted
 			}
 			r += c.Width
 		}
-		s.l = append(s.l, s.pool.Get(sample.Value, sample.Width, 0))
+		s.l = append(s.l, Sample{sample.Value, sample.Width, 0})
 		i++
 	inserted:
 		s.n += sample.Width
@@ -245,19 +237,21 @@ func (s *stream) compress() {
 		return
 	}
 	x := s.l[len(s.l)-1]
+	xi := len(s.l) - 1
 	r := s.n - 1 - x.Width
 
 	for i := len(s.l) - 2; i >= 0; i-- {
 		c := s.l[i]
 		if c.Width+x.Width+x.Delta <= s.ƒ(s, r) {
 			x.Width += c.Width
+			s.l[xi] = x
 			// Remove element at i.
 			copy(s.l[i:], s.l[i+1:])
-			s.l[len(s.l)-1] = nil
 			s.l = s.l[:len(s.l)-1]
-			s.pool.Put(c)
+			xi -= 1
 		} else {
 			x = c
+			xi = i
 		}
 		r -= c.Width
 	}
@@ -265,8 +259,6 @@ func (s *stream) compress() {
 
 func (s *stream) samples() Samples {
 	samples := make(Samples, len(s.l))
-	for i, c := range s.l {
+	copy(samples, s.l)
-		samples[i] = *c
-	}
 	return samples
 }

_vendor/perks/quantile/stream_test.go

@@ -1,7 +1,6 @@
 package quantile
 
 import (
-	"math"
 	"math/rand"
 	"sort"
 	"testing"
@@ -12,26 +11,23 @@ func TestQuantRandQuery(t *testing.T) {
 	a := make([]float64, 0, 1e5)
 	rand.Seed(42)
 	for i := 0; i < cap(a); i++ {
-		v := float64(rand.Int63())
+		v := rand.NormFloat64()
 		s.Insert(v)
 		a = append(a, v)
 	}
 	t.Logf("len: %d", s.Count())
 	sort.Float64s(a)
-	w := getPerc(a, 0.50)
+	w, min, max := getPerc(a, 0.50)
-	if g := s.Query(0.50); math.Abs(w-g)/w > 0.03 {
+	if g := s.Query(0.50); g < min || g > max {
-		t.Errorf("perc50: want %v, got %v", w, g)
+		t.Errorf("perc50: want %v [%f,%f], got %v", w, min, max, g)
-		t.Logf("e: %f", math.Abs(w-g)/w)
 	}
-	w = getPerc(a, 0.90)
+	w, min, max = getPerc(a, 0.90)
-	if g := s.Query(0.90); math.Abs(w-g)/w > 0.03 {
+	if g := s.Query(0.90); g < min || g > max {
-		t.Errorf("perc90: want %v, got %v", w, g)
+		t.Errorf("perc90: want %v [%f,%f], got %v", w, min, max, g)
-		t.Logf("e: %f", math.Abs(w-g)/w)
 	}
-	w = getPerc(a, 0.99)
+	w, min, max = getPerc(a, 0.99)
-	if g := s.Query(0.99); math.Abs(w-g)/w > 0.03 {
+	if g := s.Query(0.99); g < min || g > max {
-		t.Errorf("perc99: want %v, got %v", w, g)
+		t.Errorf("perc99: want %v [%f,%f], got %v", w, min, max, g)
-		t.Logf("e: %f", math.Abs(w-g)/w)
 	}
 }
 
@@ -51,7 +47,7 @@ func TestQuantRandMergeQuery(t *testing.T) {
 	rand.Seed(42)
 	a := make([]float64, 0, 1e6)
 	for i := 0; i < cap(a); i++ {
-		v := float64(rand.Int63())
+		v := rand.NormFloat64()
 		a = append(a, v)
 		ch <- v
 	}
@@ -63,20 +59,17 @@ func TestQuantRandMergeQuery(t *testing.T) {
 
 	t.Logf("len: %d", s.Count())
 	sort.Float64s(a)
-	w := getPerc(a, 0.50)
+	w, min, max := getPerc(a, 0.50)
-	if g := s.Query(0.50); math.Abs(w-g)/w > 0.03 {
+	if g := s.Query(0.50); g < min || g > max {
-		t.Errorf("perc50: want %v, got %v", w, g)
+		t.Errorf("perc50: want %v [%f,%f], got %v", w, min, max, g)
-		t.Logf("e: %f", math.Abs(w-g)/w)
 	}
-	w = getPerc(a, 0.90)
+	w, min, max = getPerc(a, 0.90)
-	if g := s.Query(0.90); math.Abs(w-g)/w > 0.03 {
+	if g := s.Query(0.90); g < min || g > max {
-		t.Errorf("perc90: want %v, got %v", w, g)
+		t.Errorf("perc90: want %v [%f,%f], got %v", w, min, max, g)
-		t.Logf("e: %f", math.Abs(w-g)/w)
 	}
-	w = getPerc(a, 0.99)
+	w, min, max = getPerc(a, 0.99)
-	if g := s.Query(0.99); math.Abs(w-g)/w > 0.03 {
+	if g := s.Query(0.99); g < min || g > max {
-		t.Errorf("perc99: want %v, got %v", w, g)
+		t.Errorf("perc99: want %v [%f,%f], got %v", w, min, max, g)
-		t.Logf("e: %f", math.Abs(w-g)/w)
 	}
 }
 
@@ -122,7 +115,15 @@ func TestDefaults(t *testing.T) {
 	}
 }
 
-func getPerc(x []float64, p float64) float64 {
+func getPerc(x []float64, p float64) (want, min, max float64) {
 	k := int(float64(len(x)) * p)
-	return x[k]
+	lower := int(float64(len(x)) * (p - 0.04))
+	if lower < 0 {
+		lower = 0
+	}
+	upper := int(float64(len(x))*(p+0.04)) + 1
+	if upper >= len(x) {
+		upper = len(x) - 1
+	}
+	return x[k], x[lower], x[upper]
 }