Merge pull request #115 from oliver006/oh_couple_of_tweaks

A couple of tweaks

.gitignore

 redis_exporter
 coverage.out
+dist/
 pkg/
 src/
-vendor/
+.DS_Store
+.idea

Gopkg.lock

+# This file is autogenerated, do not edit; changes may be undone by the next 'dep ensure'.
+
+
+[[projects]]
+  branch = "master"
+  name = "github.com/beorn7/perks"
+  packages = ["quantile"]
+  revision = "4c0e84591b9aa9e6dcfdf3e020114cd81f89d5f9"
+
+[[projects]]
+  name = "github.com/cloudfoundry-community/go-cfenv"
+  packages = ["."]
+  revision = "f920e9562d5f951cbf11785728f67258c38a10d0"
+  version = "v1.17.0"
+
+[[projects]]
+  name = "github.com/garyburd/redigo"
+  packages = ["internal","redis"]
+  revision = "47dc60e71eed504e3ef8e77ee3c6fe720f3be57f"
+  version = "v1.3.0"
+
+[[projects]]
+  branch = "master"
+  name = "github.com/golang/protobuf"
+  packages = ["proto"]
+  revision = "1e59b77b52bf8e4b449a57e6f79f21226d571845"
+
+[[projects]]
+  name = "github.com/matttproud/golang_protobuf_extensions"
+  packages = ["pbutil"]
+  revision = "3247c84500bff8d9fb6d579d800f20b3e091582c"
+  version = "v1.0.0"
+
+[[projects]]
+  branch = "master"
+  name = "github.com/mitchellh/mapstructure"
+  packages = ["."]
+  revision = "06020f85339e21b2478f756a78e295255ffa4d6a"
+
+[[projects]]
+  name = "github.com/prometheus/client_golang"
+  packages = ["prometheus","prometheus/promhttp"]
+  revision = "c5b7fccd204277076155f10851dad72b76a49317"
+  version = "v0.8.0"
+
+[[projects]]
+  branch = "master"
+  name = "github.com/prometheus/client_model"
+  packages = ["go"]
+  revision = "6f3806018612930941127f2a7c6c453ba2c527d2"
+
+[[projects]]
+  branch = "master"
+  name = "github.com/prometheus/common"
+  packages = ["expfmt","internal/bitbucket.org/ww/goautoneg","model"]
+  revision = "e3fb1a1acd7605367a2b378bc2e2f893c05174b7"
+
+[[projects]]
+  branch = "master"
+  name = "github.com/prometheus/procfs"
+  packages = [".","xfs"]
+  revision = "a6e9df898b1336106c743392c48ee0b71f5c4efa"
+
+[[projects]]
+  name = "github.com/prometheus/prometheus"
+  packages = ["util/strutil"]
+  revision = "0a74f98628a0463dddc90528220c94de5032d1a0"
+  version = "v2.0.0"
+
+[[projects]]
+  name = "github.com/sirupsen/logrus"
+  packages = ["."]
+  revision = "f006c2ac4710855cf0f916dd6b77acf6b048dc6e"
+  version = "v1.0.3"
+
+[[projects]]
+  branch = "master"
+  name = "golang.org/x/crypto"
+  packages = ["ssh/terminal"]
+  revision = "9f005a07e0d31d45e6656d241bb5c0f2efd4bc94"
+
+[[projects]]
+  branch = "master"
+  name = "golang.org/x/sys"
+  packages = ["unix","windows"]
+  revision = "665f6529cca930e27b831a0d1dafffbe1c172924"
+
+[solve-meta]
+  analyzer-name = "dep"
+  analyzer-version = 1
+  inputs-digest = "2e013c0d4c7fe5e64f3b7e69e8aaabff0bb64b43d5acb6e2fddc383e2104dec3"
+  solver-name = "gps-cdcl"
+  solver-version = 1

Gopkg.toml

+
+# Gopkg.toml example
+#
+# Refer to https://github.com/golang/dep/blob/master/docs/Gopkg.toml.md
+# for detailed Gopkg.toml documentation.
+#
+# required = ["github.com/user/thing/cmd/thing"]
+# ignored = ["github.com/user/project/pkgX", "bitbucket.org/user/project/pkgA/pkgY"]
+#
+# [[constraint]]
+#   name = "github.com/user/project"
+#   version = "1.0.0"
+#
+# [[constraint]]
+#   name = "github.com/user/project2"
+#   branch = "dev"
+#   source = "github.com/myfork/project2"
+#
+# [[override]]
+#  name = "github.com/x/y"
+#  version = "2.4.0"
+
+
+[[constraint]]
+  name = "github.com/cloudfoundry-community/go-cfenv"
+  version = "1.17.0"
+
+[[constraint]]
+  name = "github.com/garyburd/redigo"
+  version = "1.3.0"
+
+[[constraint]]
+  name = "github.com/prometheus/client_golang"
+  version = "0.8.0"
+
+[[constraint]]
+  branch = "master"
+  name = "github.com/prometheus/client_model"
+
+[[constraint]]
+  name = "github.com/sirupsen/logrus"
+  version = "1.0.3"

circle.yml

@@ -9,7 +9,7 @@ machine:
     SRC_LOCATION:     "/home/ubuntu/.go_workspace/src/github.com/$CIRCLE_PROJECT_USERNAME/$CIRCLE_PROJECT_REPONAME"
     COVERAGE_PROFILE: "/home/ubuntu/coverage.out"
     GO_LDFLAGS:       '-extldflags "-static" -X main.VERSION=$CIRCLE_TAG -X main.COMMIT_SHA1=$CIRCLE_SHA1 -X main.BUILD_DATE=$(date +%F-%T)'
-    MY_GO_VERSION:    "1.8.3"
+    MY_GO_VERSION:    "1.9.2"
 dependencies:
   pre:
@@ -28,10 +28,6 @@ dependencies:
   cache_directories:
     - ~/redis-3.2.10
   override:
-    - sudo add-apt-repository ppa:masterminds/glide -y
-    - sudo apt-get update
-    - sudo apt-get install glide -y
-    - glide --version
     - mkdir -p "/home/ubuntu/.go_workspace/src/github.com/$CIRCLE_PROJECT_USERNAME"
     - ln -s $HOME/$CIRCLE_PROJECT_REPONAME $SRC_LOCATION
@@ -41,12 +37,11 @@ test:
     - go version
     - echo " ! gofmt -d main.go       2>&1 | read " | bash
     - echo " ! gofmt -d exporter/*.go 2>&1 | read " | bash
-    - go vet ./...
+    - go vet ./exporter/...
     - go get github.com/mattn/goveralls
     - go get golang.org/x/tools/cmd/cover
-    - cd $SRC_LOCATION && glide install
   override:
-    - cd $SRC_LOCATION && go test -v -cover -race -coverprofile=$COVERAGE_PROFILE ./exporter/...
+    - cd $SRC_LOCATION && go test -v -covermode=atomic -cover -race -coverprofile=$COVERAGE_PROFILE ./exporter/...
   post:
     - if [ -n "$COVERALLS_TOKEN" ]; then /home/ubuntu/.go_workspace/bin/goveralls -coverprofile=$COVERAGE_PROFILE -service=circle-ci -repotoken=$COVERALLS_TOKEN ;  fi

exporter/redis.go

@@ -11,6 +11,7 @@ import (
 	"github.com/garyburd/redigo/redis"
 	"github.com/prometheus/client_golang/prometheus"
+	prom_strutil "github.com/prometheus/prometheus/util/strutil"
 	log "github.com/sirupsen/logrus"
 )
@@ -280,19 +281,15 @@ func (e *Exporter) Collect(ch chan<- prometheus.Metric) {
 }
 func includeMetric(s string) bool {
-
 	if strings.HasPrefix(s, "db") || strings.HasPrefix(s, "cmdstat_") || strings.HasPrefix(s, "cluster_") {
 		return true
 	}
-
 	_, ok := metricMap[s]
-
 	return ok
 }
 func sanitizeMetricName(n string) string {
-	n = strings.Replace(n, "-", "_", -1)
-	return n
+	return prom_strutil.SanitizeLabelName(n)
 }
 func extractVal(s string) (val float64, err error) {
@@ -373,6 +370,29 @@ func parseConnectedSlaveString(slaveName string, slaveInfo string) (offset float
 	return
 }
+func extractConfigMetrics(config []string, addr string, alias string, scrapes chan<- scrapeResult) error {
+	if len(config)%2 != 0 {
+		return fmt.Errorf("invalid config: %#v", config)
+	}
+
+	for pos := 0; pos < len(config)/2; pos++ {
+		strKey := config[pos*2]
+		strVal := config[pos*2+1]
+
+		// todo: we can add more configs to this map if there's interest
+		if !map[string]bool{
+			"maxmemory": true,
+		}[strKey] {
+			continue
+		}
+
+		if val, err := strconv.ParseFloat(strVal, 64); err == nil {
+			scrapes <- scrapeResult{Name: fmt.Sprintf("config_%s", config[pos*2]), Addr: addr, Alias: alias, Value: val}
+		}
+	}
+	return nil
+}
+
 func (e *Exporter) extractInfoMetrics(info, addr string, alias string, scrapes chan<- scrapeResult) error {
 	cmdstats := false
 	lines := strings.Split(info, "\r\n")
@@ -432,6 +452,8 @@ func (e *Exporter) extractInfoMetrics(info, addr string, alias string, scrapes c
 		if cmdstats {
 			/*
+				Format:
+
 				cmdstat_get:calls=21,usec=175,usec_per_call=8.33
 				cmdstat_set:calls=61,usec=3139,usec_per_call=51.46
 				cmdstat_setex:calls=75,usec=1260,usec_per_call=16.80
@@ -557,18 +579,24 @@ func (e *Exporter) scrapeRedisHost(scrapes chan<- scrapeResult, addr string, idx
 	defer c.Close()
 	log.Debugf("connected to: %s", addr)
+	if config, err := redis.Strings(c.Do("CONFIG", "GET", "*")); err == nil {
+		extractConfigMetrics(config, addr, e.redis.Aliases[idx], scrapes)
+	} else {
+		log.Errorf("redis err: %s", err)
+	}
+
 	info, err := redis.String(c.Do("INFO", "ALL"))
 	if err == nil {
 		e.extractInfoMetrics(info, addr, e.redis.Aliases[idx], scrapes)
 	} else {
-		log.Printf("redis err: %s", err)
+		log.Errorf("redis err: %s", err)
 		return err
 	}
 	if strings.Index(info, "cluster_enabled:1") != -1 {
 		info, err = redis.String(c.Do("CLUSTER", "INFO"))
 		if err != nil {
-			log.Printf("redis err: %s", err)
+			log.Errorf("redis err: %s", err)
 		} else {
 			e.extractInfoMetrics(info, addr, e.redis.Aliases[idx], scrapes)
 		}
@@ -602,9 +630,11 @@ func (e *Exporter) scrapeRedisHost(scrapes chan<- scrapeResult, addr string, idx
 		}
 		for _, key := range obtainedKeys {
+			dbLabel := "db" + k.db
+			keyLabel := key
 			if tempVal, err := c.Do("GET", key); err == nil && tempVal != nil {
 				if val, err := strconv.ParseFloat(fmt.Sprintf("%s", tempVal), 64); err == nil {
-					e.keyValues.WithLabelValues(addr, e.redis.Aliases[idx], "db"+k.db, key).Set(val)
+					e.keyValues.WithLabelValues(addr, e.redis.Aliases[idx], dbLabel, keyLabel).Set(val)
 				}
 			}
@@ -617,7 +647,7 @@ func (e *Exporter) scrapeRedisHost(scrapes chan<- scrapeResult, addr string, idx
 				"STRLEN",
 			} {
 				if tempVal, err := c.Do(op, key); err == nil && tempVal != nil {
-					e.keySizes.WithLabelValues(addr, e.redis.Aliases[idx], "db"+k.db, key).Set(float64(tempVal.(int64)))
+					e.keySizes.WithLabelValues(addr, e.redis.Aliases[idx], dbLabel, keyLabel).Set(float64(tempVal.(int64)))
 					break
 				}
 			}

exporter/redis_test.go

@@ -322,6 +322,7 @@ func TestExporterMetrics(t *testing.T) {
 		"db_avg_ttl_seconds",
 		"used_cpu_sys",
 		"loading_dump_file", // testing renames
+		"config_maxmemory",  // testing config extraction
 	}
 	for _, k := range wantKeys {
@@ -781,7 +782,7 @@ func TestKeysReset(t *testing.T) {
 func init() {
 	for _, n := range []string{"john", "paul", "ringo", "george"} {
-		key := fmt.Sprintf("key:%s-%d", n, ts)
+		key := fmt.Sprintf("key_%s_%d", n, ts)
 		keys = append(keys, key)
 	}
@@ -789,7 +790,7 @@ func init() {
 	keys = append(keys, "wildcard", "wildbeast", "wildwoods")
 	for _, n := range []string{"A.J.", "Howie", "Nick", "Kevin", "Brian"} {
-		key := fmt.Sprintf("key:exp-%s-%d", n, ts)
+		key := fmt.Sprintf("key_exp_%s_%d", n, ts)
 		keysExpiring = append(keysExpiring, key)
 	}

glide.lock

-hash: a7c02256b12a590f5b43639325817155ea183b8196727e182c51cdb8e06145ea
-updated: 2017-10-16T19:10:37.60453427-04:00
-imports:
-- name: github.com/beorn7/perks
-  version: 4c0e84591b9aa9e6dcfdf3e020114cd81f89d5f9
-  subpackages:
-  - quantile
-- name: github.com/cloudfoundry-community/go-cfenv
-  version: f920e9562d5f951cbf11785728f67258c38a10d0
-- name: github.com/garyburd/redigo
-  version: 8873b2f1995f59d4bcdd2b0dc9858e2cb9bf0c13
-  subpackages:
-  - internal
-  - redis
-- name: github.com/golang/protobuf
-  version: 3852dcfda249c2097355a6aabb199a28d97b30df
-  subpackages:
-  - proto
-- name: github.com/matttproud/golang_protobuf_extensions
-  version: c12348ce28de40eed0136aa2b644d0ee0650e56c
-  subpackages:
-  - pbutil
-- name: github.com/mitchellh/mapstructure
-  version: 53818660ed4955e899c0bcafa97299a388bd7c8e
-- name: github.com/prometheus/client_golang
-  version: c5b7fccd204277076155f10851dad72b76a49317
-  subpackages:
-  - prometheus
-- name: github.com/prometheus/client_model
-  version: 6f3806018612930941127f2a7c6c453ba2c527d2
-  subpackages:
-  - go
-- name: github.com/prometheus/common
-  version: 9e0844febd9e2856f839c9cb974fbd676d1755a8
-  subpackages:
-  - expfmt
-  - internal/bitbucket.org/ww/goautoneg
-  - model
-- name: github.com/prometheus/procfs
-  version: 1878d9fbb537119d24b21ca07effd591627cd160
-- name: github.com/sirupsen/logrus
-  version: d26492970760ca5d33129d2d799e34be5c4782eb
-- name: golang.org/x/sys
-  version: d4feaf1a7e61e1d9e79e6c4e76c6349e9cab0a03
-  subpackages:
-  - unix
-testImports: []

main.go

@@ -49,7 +49,7 @@ func main() {
 	default:
 		log.SetFormatter(&log.TextFormatter{})
 	}
-	log.Printf("Redis Metrics Exporter %s    build date: %s    sha1: %s    Go: %s\n",
+	log.Printf("Redis Metrics Exporter %s    build date: %s    sha1: %s    Go: %s",
 		VERSION, BUILD_DATE, COMMIT_SHA1,
 		runtime.Version(),
 	)

vendor/github.com/beorn7/perks/.gitignore

+*.test
+*.prof

vendor/github.com/beorn7/perks/LICENSE

+Copyright (C) 2013 Blake Mizerany
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

vendor/github.com/beorn7/perks/README.md

+# Perks for Go (golang.org)
+
+Perks contains the Go package quantile that computes approximate quantiles over
+an unbounded data stream within low memory and CPU bounds.
+
+For more information and examples, see:
+http://godoc.org/github.com/bmizerany/perks
+
+A very special thank you and shout out to Graham Cormode (Rutgers University),
+Flip Korn (AT&T Labs–Research), S. Muthukrishnan (Rutgers University), and
+Divesh Srivastava (AT&T Labs–Research) for their research and publication of
+[Effective Computation of Biased Quantiles over Data Streams](http://www.cs.rutgers.edu/~muthu/bquant.pdf)
+
+Thank you, also:
+* Armon Dadgar (@armon)
+* Andrew Gerrand (@nf)
+* Brad Fitzpatrick (@bradfitz)
+* Keith Rarick (@kr)
+
+FAQ:
+
+Q: Why not move the quantile package into the project root?
+A: I want to add more packages to perks later.
+
+Copyright (C) 2013 Blake Mizerany
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

vendor/github.com/beorn7/perks/quantile/bench_test.go

+package quantile
+
+import (
+	"testing"
+)
+
+func BenchmarkInsertTargeted(b *testing.B) {
+	b.ReportAllocs()
+
+	s := NewTargeted(Targets)
+	b.ResetTimer()
+	for i := float64(0); i < float64(b.N); i++ {
+		s.Insert(i)
+	}
+}
+
+func BenchmarkInsertTargetedSmallEpsilon(b *testing.B) {
+	s := NewTargeted(TargetsSmallEpsilon)
+	b.ResetTimer()
+	for i := float64(0); i < float64(b.N); i++ {
+		s.Insert(i)
+	}
+}
+
+func BenchmarkInsertBiased(b *testing.B) {
+	s := NewLowBiased(0.01)
+	b.ResetTimer()
+	for i := float64(0); i < float64(b.N); i++ {
+		s.Insert(i)
+	}
+}
+
+func BenchmarkInsertBiasedSmallEpsilon(b *testing.B) {
+	s := NewLowBiased(0.0001)
+	b.ResetTimer()
+	for i := float64(0); i < float64(b.N); i++ {
+		s.Insert(i)
+	}
+}
+
+func BenchmarkQuery(b *testing.B) {
+	s := NewTargeted(Targets)
+	for i := float64(0); i < 1e6; i++ {
+		s.Insert(i)
+	}
+	b.ResetTimer()
+	n := float64(b.N)
+	for i := float64(0); i < n; i++ {
+		s.Query(i / n)
+	}
+}
+
+func BenchmarkQuerySmallEpsilon(b *testing.B) {
+	s := NewTargeted(TargetsSmallEpsilon)
+	for i := float64(0); i < 1e6; i++ {
+		s.Insert(i)
+	}
+	b.ResetTimer()
+	n := float64(b.N)
+	for i := float64(0); i < n; i++ {
+		s.Query(i / n)
+	}
+}

vendor/github.com/beorn7/perks/quantile/example_test.go

+// +build go1.1
+
+package quantile_test
+
+import (
+	"bufio"
+	"fmt"
+	"log"
+	"os"
+	"strconv"
+	"time"
+
+	"github.com/beorn7/perks/quantile"
+)
+
+func Example_simple() {
+	ch := make(chan float64)
+	go sendFloats(ch)
+
+	// Compute the 50th, 90th, and 99th percentile.
+	q := quantile.NewTargeted(map[float64]float64{
+		0.50: 0.005,
+		0.90: 0.001,
+		0.99: 0.0001,
+	})
+	for v := range ch {
+		q.Insert(v)
+	}
+
+	fmt.Println("perc50:", q.Query(0.50))
+	fmt.Println("perc90:", q.Query(0.90))
+	fmt.Println("perc99:", q.Query(0.99))
+	fmt.Println("count:", q.Count())
+	// Output:
+	// perc50: 5
+	// perc90: 16
+	// perc99: 223
+	// count: 2388
+}
+
+func Example_mergeMultipleStreams() {
+	// Scenario:
+	// We have multiple database shards. On each shard, there is a process
+	// collecting query response times from the database logs and inserting
+	// them into a Stream (created via NewTargeted(0.90)), much like the
+	// Simple example. These processes expose a network interface for us to
+	// ask them to serialize and send us the results of their
+	// Stream.Samples so we may Merge and Query them.
+	//
+	// NOTES:
+	// * These sample sets are small, allowing us to get them
+	// across the network much faster than sending the entire list of data
+	// points.
+	//
+	// * For this to work correctly, we must supply the same quantiles
+	// a priori the process collecting the samples supplied to NewTargeted,
+	// even if we do not plan to query them all here.
+	ch := make(chan quantile.Samples)
+	getDBQuerySamples(ch)
+	q := quantile.NewTargeted(map[float64]float64{0.90: 0.001})
+	for samples := range ch {
+		q.Merge(samples)
+	}
+	fmt.Println("perc90:", q.Query(0.90))
+}
+
+func Example_window() {
+	// Scenario: We want the 90th, 95th, and 99th percentiles for each
+	// minute.
+
+	ch := make(chan float64)
+	go sendStreamValues(ch)
+
+	tick := time.NewTicker(1 * time.Minute)
+	q := quantile.NewTargeted(map[float64]float64{
+		0.90: 0.001,
+		0.95: 0.0005,
+		0.99: 0.0001,
+	})
+	for {
+		select {
+		case t := <-tick.C:
+			flushToDB(t, q.Samples())
+			q.Reset()
+		case v := <-ch:
+			q.Insert(v)
+		}
+	}
+}
+
+func sendStreamValues(ch chan float64) {
+	// Use your imagination
+}
+
+func flushToDB(t time.Time, samples quantile.Samples) {
+	// Use your imagination
+}
+
+// This is a stub for the above example. In reality this would hit the remote
+// servers via http or something like it.
+func getDBQuerySamples(ch chan quantile.Samples) {}
+
+func sendFloats(ch chan<- float64) {
+	f, err := os.Open("exampledata.txt")
+	if err != nil {
+		log.Fatal(err)
+	}
+	sc := bufio.NewScanner(f)
+	for sc.Scan() {
+		b := sc.Bytes()
+		v, err := strconv.ParseFloat(string(b), 64)
+		if err != nil {
+			log.Fatal(err)
+		}
+		ch <- v
+	}
+	if sc.Err() != nil {
+		log.Fatal(sc.Err())
+	}
+	close(ch)
+}

vendor/github.com/beorn7/perks/quantile/exampledata.txt

+8
+5
+26
+12
+5
+235
+13
+6
+28
+30
+3
+3
+3
+3
+5
+2
+33
+7
+2
+4
+7
+12
+14
+5
+8
+3
+10
+4
+5
+3
+6
+6
+209
+20
+3
+10
+14
+3
+4
+6
+8
+5
+11
+7
+3
+2
+3
+3
+212
+5
+222
+4
+10
+10
+5
+6
+3
+8
+3
+10
+254
+220
+2
+3
+5
+24
+5
+4
+222
+7
+3
+3
+223
+8
+15
+12
+14
+14
+3
+2
+2
+3
+13
+3
+11
+4
+4
+6
+5
+7
+13
+5
+3
+5
+2
+5
+3
+5
+2
+7
+15
+17
+14
+3
+6
+6
+3
+17
+5
+4
+7
+6
+4
+4
+8
+6
+8
+3
+9
+3
+6
+3
+4
+5
+3
+3
+660
+4
+6
+10
+3
+6
+3
+2
+5
+13
+2
+4
+4
+10
+4
+8
+4
+3
+7
+9
+9
+3
+10
+37
+3
+13
+4
+12
+3
+6
+10
+8
+5
+21
+2
+3
+8
+3
+2
+3
+3
+4
+12
+2
+4
+8
+8
+4
+3
+2
+20
+1
+6
+32
+2
+11
+6
+18
+3
+8
+11
+3
+212
+3
+4
+2
+6
+7
+12
+11
+3
+2
+16
+10
+6
+4
+6
+3
+2
+7
+3
+2
+2
+2
+2
+5
+6
+4
+3
+10
+3
+4
+6
+5
+3
+4
+4
+5
+6
+4
+3
+4
+4
+5
+7
+5
+5
+3
+2
+7
+2
+4
+12
+4
+5
+6
+2
+4
+4
+8
+4
+15
+13
+7
+16
+5
+3
+23
+5
+5
+7
+3
+2
+9
+8
+7
+5
+8
+11
+4
+10
+76
+4
+47
+4
+3
+2
+7
+4
+2
+3
+37
+10
+4
+2
+20
+5
+4
+4
+10
+10
+4
+3
+7
+23
+240
+7
+13
+5
+5
+3
+3
+2
+5
+4
+2
+8
+7
+19
+2
+23
+8
+7
+2
+5
+3
+8
+3
+8
+13
+5
+5
+5
+2
+3
+23
+4
+9
+8
+4
+3
+3
+5
+220
+2
+3
+4
+6
+14
+3
+53
+6
+2
+5
+18
+6
+3
+219
+6
+5
+2
+5
+3
+6
+5
+15
+4
+3
+17
+3
+2
+4
+7
+2
+3
+3
+4
+4
+3
+2
+664
+6
+3
+23
+5
+5
+16
+5
+8
+2
+4
+2
+24
+12
+3
+2
+3
+5
+8
+3
+5
+4
+3
+14
+3
+5
+8
+2
+3
+7
+9
+4
+2
+3
+6
+8
+4
+3
+4
+6
+5
+3
+3
+6
+3
+19
+4
+4
+6
+3
+6
+3
+5
+22
+5
+4
+4
+3
+8
+11
+4
+9
+7
+6
+13
+4
+4
+4
+6
+17
+9
+3
+3
+3
+4
+3
+221
+5
+11
+3
+4
+2
+12
+6
+3
+5
+7
+5
+7
+4
+9
+7
+14
+37
+19
+217
+16
+3
+5
+2
+2
+7
+19
+7
+6
+7
+4
+24
+5
+11
+4
+7
+7
+9
+13
+3
+4
+3
+6
+28
+4
+4
+5
+5
+2
+5
+6
+4
+4
+6
+10
+5
+4
+3
+2
+3
+3
+6
+5
+5
+4
+3
+2
+3
+7
+4
+6
+18
+16
+8
+16
+4
+5
+8
+6
+9
+13
+1545
+6
+215
+6
+5
+6
+3
+45
+31
+5
+2
+2
+4
+3
+3
+2
+5
+4
+3
+5
+7
+7
+4
+5
+8
+5
+4
+749
+2
+31
+9
+11
+2
+11
+5
+4
+4
+7
+9
+11
+4
+5
+4
+7
+3
+4
+6
+2
+15
+3
+4
+3
+4
+3
+5
+2
+13
+5
+5
+3
+3
+23
+4
+4
+5
+7
+4
+13
+2
+4
+3
+4
+2
+6
+2
+7
+3
+5
+5
+3
+29
+5
+4
+4
+3
+10
+2
+3
+79
+16
+6
+6
+7
+7
+3
+5
+5
+7
+4
+3
+7
+9
+5
+6
+5
+9
+6
+3
+6
+4
+17
+2
+10
+9
+3
+6
+2
+3
+21
+22
+5
+11
+4
+2
+17
+2
+224
+2
+14
+3
+4
+4
+2
+4
+4
+4
+4
+5
+3
+4
+4
+10
+2
+6
+3
+3
+5
+7
+2
+7
+5
+6
+3
+218
+2
+2
+5
+2
+6
+3
+5
+222
+14
+6
+33
+3
+2
+5
+3
+3
+3
+9
+5
+3
+3
+2
+7
+4
+3
+4
+3
+5
+6
+5
+26
+4
+13
+9
+7
+3
+221
+3
+3
+4
+4
+4
+4
+2
+18
+5
+3
+7
+9
+6
+8
+3
+10
+3
+11
+9
+5
+4
+17
+5
+5
+6
+6
+3
+2
+4
+12
+17
+6
+7
+218
+4
+2
+4
+10
+3
+5
+15
+3
+9
+4
+3
+3
+6
+29
+3
+3
+4
+5
+5
+3
+8
+5
+6
+6
+7
+5
+3
+5
+3
+29
+2
+31
+5
+15
+24
+16
+5
+207
+4
+3
+3
+2
+15
+4
+4
+13
+5
+5
+4
+6
+10
+2
+7
+8
+4
+6
+20
+5
+3
+4
+3
+12
+12
+5
+17
+7
+3
+3
+3
+6
+10
+3
+5
+25
+80
+4
+9
+3
+2
+11
+3
+3
+2
+3
+8
+7
+5
+5
+19
+5
+3
+3
+12
+11
+2
+6
+5
+5
+5
+3
+3
+3
+4
+209
+14
+3
+2
+5
+19
+4
+4
+3
+4
+14
+5
+6
+4
+13
+9
+7
+4
+7
+10
+2
+9
+5
+7
+2
+8
+4
+6
+5
+5
+222
+8
+7
+12
+5
+216
+3
+4
+4
+6
+3
+14
+8
+7
+13
+4
+3
+3
+3
+3
+17
+5
+4
+3
+33
+6
+6
+33
+7
+5
+3
+8
+7
+5
+2
+9
+4
+2
+233
+24
+7
+4
+8
+10
+3
+4
+15
+2
+16
+3
+3
+13
+12
+7
+5
+4
+207
+4
+2
+4
+27
+15
+2
+5
+2
+25
+6
+5
+5
+6
+13
+6
+18
+6
+4
+12
+225
+10
+7
+5
+2
+2
+11
+4
+14
+21
+8
+10
+3
+5
+4
+232
+2
+5
+5
+3
+7
+17
+11
+6
+6
+23
+4
+6
+3
+5
+4
+2
+17
+3
+6
+5
+8
+3
+2
+2
+14
+9
+4
+4
+2
+5
+5
+3
+7
+6
+12
+6
+10
+3
+6
+2
+2
+19
+5
+4
+4
+9
+2
+4
+13
+3
+5
+6
+3
+6
+5
+4
+9
+6
+3
+5
+7
+3
+6
+6
+4
+3
+10
+6
+3
+221
+3
+5
+3
+6
+4
+8
+5
+3
+6
+4
+4
+2
+54
+5
+6
+11
+3
+3
+4
+4
+4
+3
+7
+3
+11
+11
+7
+10
+6
+13
+223
+213
+15
+231
+7
+3
+7
+228
+2
+3
+4
+4
+5
+6
+7
+4
+13
+3
+4
+5
+3
+6
+4
+6
+7
+2
+4
+3
+4
+3
+3
+6
+3
+7
+3
+5
+18
+5
+6
+8
+10
+3
+3
+3
+2
+4
+2
+4
+4
+5
+6
+6
+4
+10
+13
+3
+12
+5
+12
+16
+8
+4
+19
+11
+2
+4
+5
+6
+8
+5
+6
+4
+18
+10
+4
+2
+216
+6
+6
+6
+2
+4
+12
+8
+3
+11
+5
+6
+14
+5
+3
+13
+4
+5
+4
+5
+3
+28
+6
+3
+7
+219
+3
+9
+7
+3
+10
+6
+3
+4
+19
+5
+7
+11
+6
+15
+19
+4
+13
+11
+3
+7
+5
+10
+2
+8
+11
+2
+6
+4
+6
+24
+6
+3
+3
+3
+3
+6
+18
+4
+11
+4
+2
+5
+10
+8
+3
+9
+5
+3
+4
+5
+6
+2
+5
+7
+4
+4
+14
+6
+4
+4
+5
+5
+7
+2
+4
+3
+7
+3
+3
+6
+4
+5
+4
+4
+4
+3
+3
+3
+3
+8
+14
+2
+3
+5
+3
+2
+4
+5
+3
+7
+3
+3
+18
+3
+4
+4
+5
+7
+3
+3
+3
+13
+5
+4
+8
+211
+5
+5
+3
+5
+2
+5
+4
+2
+655
+6
+3
+5
+11
+2
+5
+3
+12
+9
+15
+11
+5
+12
+217
+2
+6
+17
+3
+3
+207
+5
+5
+4
+5
+9
+3
+2
+8
+5
+4
+3
+2
+5
+12
+4
+14
+5
+4
+2
+13
+5
+8
+4
+225
+4
+3
+4
+5
+4
+3
+3
+6
+23
+9
+2
+6
+7
+233
+4
+4
+6
+18
+3
+4
+6
+3
+4
+4
+2
+3
+7
+4
+13
+227
+4
+3
+5
+4
+2
+12
+9
+17
+3
+7
+14
+6
+4
+5
+21
+4
+8
+9
+2
+9
+25
+16
+3
+6
+4
+7
+8
+5
+2
+3
+5
+4
+3
+3
+5
+3
+3
+3
+2
+3
+19
+2
+4
+3
+4
+2
+3
+4
+4
+2
+4
+3
+3
+3
+2
+6
+3
+17
+5
+6
+4
+3
+13
+5
+3
+3
+3
+4
+9
+4
+2
+14
+12
+4
+5
+24
+4
+3
+37
+12
+11
+21
+3
+4
+3
+13
+4
+2
+3
+15
+4
+11
+4
+4
+3
+8
+3
+4
+4
+12
+8
+5
+3
+3
+4
+2
+220
+3
+5
+223
+3
+3
+3
+10
+3
+15
+4
+241
+9
+7
+3
+6
+6
+23
+4
+13
+7
+3
+4
+7
+4
+9
+3
+3
+4
+10
+5
+5
+1
+5
+24
+2
+4
+5
+5
+6
+14
+3
+8
+2
+3
+5
+13
+13
+3
+5
+2
+3
+15
+3
+4
+2
+10
+4
+4
+4
+5
+5
+3
+5
+3
+4
+7
+4
+27
+3
+6
+4
+15
+3
+5
+6
+6
+5
+4
+8
+3
+9
+2
+6
+3
+4
+3
+7
+4
+18
+3
+11
+3
+3
+8
+9
+7
+24
+3
+219
+7
+10
+4
+5
+9
+12
+2
+5
+4
+4
+4
+3
+3
+19
+5
+8
+16
+8
+6
+22
+3
+23
+3
+242
+9
+4
+3
+3
+5
+7
+3
+3
+5
+8
+3
+7
+5
+14
+8
+10
+3
+4
+3
+7
+4
+6
+7
+4
+10
+4
+3
+11
+3
+7
+10
+3
+13
+6
+8
+12
+10
+5
+7
+9
+3
+4
+7
+7
+10
+8
+30
+9
+19
+4
+3
+19
+15
+4
+13
+3
+215
+223
+4
+7
+4
+8
+17
+16
+3
+7
+6
+5
+5
+4
+12
+3
+7
+4
+4
+13
+4
+5
+2
+5
+6
+5
+6
+6
+7
+10
+18
+23
+9
+3
+3
+6
+5
+2
+4
+2
+7
+3
+3
+2
+5
+5
+14
+10
+224
+6
+3
+4
+3
+7
+5
+9
+3
+6
+4
+2
+5
+11
+4
+3
+3
+2
+8
+4
+7
+4
+10
+7
+3
+3
+18
+18
+17
+3
+3
+3
+4
+5
+3
+3
+4
+12
+7
+3
+11
+13
+5
+4
+7
+13
+5
+4
+11
+3
+12
+3
+6
+4
+4
+21
+4
+6
+9
+5
+3
+10
+8
+4
+6
+4
+4
+6
+5
+4
+8
+6
+4
+6
+4
+4
+5
+9
+6
+3
+4
+2
+9
+3
+18
+2
+4
+3
+13
+3
+6
+6
+8
+7
+9
+3
+2
+16
+3
+4
+6
+3
+2
+33
+22
+14
+4
+9
+12
+4
+5
+6
+3
+23
+9
+4
+3
+5
+5
+3
+4
+5
+3
+5
+3
+10
+4
+5
+5
+8
+4
+4
+6
+8
+5
+4
+3
+4
+6
+3
+3
+3
+5
+9
+12
+6
+5
+9
+3
+5
+3
+2
+2
+2
+18
+3
+2
+21
+2
+5
+4
+6
+4
+5
+10
+3
+9
+3
+2
+10
+7
+3
+6
+6
+4
+4
+8
+12
+7
+3
+7
+3
+3
+9
+3
+4
+5
+4
+4
+5
+5
+10
+15
+4
+4
+14
+6
+227
+3
+14
+5
+216
+22
+5
+4
+2
+2
+6
+3
+4
+2
+9
+9
+4
+3
+28
+13
+11
+4
+5
+3
+3
+2
+3
+3
+5
+3
+4
+3
+5
+23
+26
+3
+4
+5
+6
+4
+6
+3
+5
+5
+3
+4
+3
+2
+2
+2
+7
+14
+3
+6
+7
+17
+2
+2
+15
+14
+16
+4
+6
+7
+13
+6
+4
+5
+6
+16
+3
+3
+28
+3
+6
+15
+3
+9
+2
+4
+6
+3
+3
+22
+4
+12
+6
+7
+2
+5
+4
+10
+3
+16
+6
+9
+2
+5
+12
+7
+5
+5
+5
+5
+2
+11
+9
+17
+4
+3
+11
+7
+3
+5
+15
+4
+3
+4
+211
+8
+7
+5
+4
+7
+6
+7
+6
+3
+6
+5
+6
+5
+3
+4
+4
+26
+4
+6
+10
+4
+4
+3
+2
+3
+3
+4
+5
+9
+3
+9
+4
+4
+5
+5
+8
+2
+4
+2
+3
+8
+4
+11
+19
+5
+8
+6
+3
+5
+6
+12
+3
+2
+4
+16
+12
+3
+4
+4
+8
+6
+5
+6
+6
+219
+8
+222
+6
+16
+3
+13
+19
+5
+4
+3
+11
+6
+10
+4
+7
+7
+12
+5
+3
+3
+5
+6
+10
+3
+8
+2
+5
+4
+7
+2
+4
+4
+2
+12
+9
+6
+4
+2
+40
+2
+4
+10
+4
+223
+4
+2
+20
+6
+7
+24
+5
+4
+5
+2
+20
+16
+6
+5
+13
+2
+3
+3
+19
+3
+2
+4
+5
+6
+7
+11
+12
+5
+6
+7
+7
+3
+5
+3
+5
+3
+14
+3
+4
+4
+2
+11
+1
+7
+3
+9
+6
+11
+12
+5
+8
+6
+221
+4
+2
+12
+4
+3
+15
+4
+5
+226
+7
+218
+7
+5
+4
+5
+18
+4
+5
+9
+4
+4
+2
+9
+18
+18
+9
+5
+6
+6
+3
+3
+7
+3
+5
+4
+4
+4
+12
+3
+6
+31
+5
+4
+7
+3
+6
+5
+6
+5
+11
+2
+2
+11
+11
+6
+7
+5
+8
+7
+10
+5
+23
+7
+4
+3
+5
+34
+2
+5
+23
+7
+3
+6
+8
+4
+4
+4
+2
+5
+3
+8
+5
+4
+8
+25
+2
+3
+17
+8
+3
+4
+8
+7
+3
+15
+6
+5
+7
+21
+9
+5
+6
+6
+5
+3
+2
+3
+10
+3
+6
+3
+14
+7
+4
+4
+8
+7
+8
+2
+6
+12
+4
+213
+6
+5
+21
+8
+2
+5
+23
+3
+11
+2
+3
+6
+25
+2
+3
+6
+7
+6
+6
+4
+4
+6
+3
+17
+9
+7
+6
+4
+3
+10
+7
+2
+3
+3
+3
+11
+8
+3
+7
+6
+4
+14
+36
+3
+4
+3
+3
+22
+13
+21
+4
+2
+7
+4
+4
+17
+15
+3
+7
+11
+2
+4
+7
+6
+209
+6
+3
+2
+2
+24
+4
+9
+4
+3
+3
+3
+29
+2
+2
+4
+3
+3
+5
+4
+6
+3
+3
+2
+4

vendor/github.com/beorn7/perks/quantile/stream.go

+// Package quantile computes approximate quantiles over an unbounded data
+// stream within low memory and CPU bounds.
+//
+// A small amount of accuracy is traded to achieve the above properties.
+//
+// Multiple streams can be merged before calling Query to generate a single set
+// of results. This is meaningful when the streams represent the same type of
+// data. See Merge and Samples.
+//
+// For more detailed information about the algorithm used, see:
+//
+// Effective Computation of Biased Quantiles over Data Streams
+//
+// http://www.cs.rutgers.edu/~muthu/bquant.pdf
+package quantile
+
+import (
+	"math"
+	"sort"
+)
+
+// Sample holds an observed value and meta information for compression. JSON
+// tags have been added for convenience.
+type Sample struct {
+	Value float64 `json:",string"`
+	Width float64 `json:",string"`
+	Delta float64 `json:",string"`
+}
+
+// Samples represents a slice of samples. It implements sort.Interface.
+type Samples []Sample
+
+func (a Samples) Len() int           { return len(a) }
+func (a Samples) Less(i, j int) bool { return a[i].Value < a[j].Value }
+func (a Samples) Swap(i, j int)      { a[i], a[j] = a[j], a[i] }
+
+type invariant func(s *stream, r float64) float64
+
+// NewLowBiased returns an initialized Stream for low-biased quantiles
+// (e.g. 0.01, 0.1, 0.5) where the needed quantiles are not known a priori, but
+// error guarantees can still be given even for the lower ranks of the data
+// distribution.
+//
+// The provided epsilon is a relative error, i.e. the true quantile of a value
+// returned by a query is guaranteed to be within (1±Epsilon)*Quantile.
+//
+// See http://www.cs.rutgers.edu/~muthu/bquant.pdf for time, space, and error
+// properties.
+func NewLowBiased(epsilon float64) *Stream {
+	ƒ := func(s *stream, r float64) float64 {
+		return 2 * epsilon * r
+	}
+	return newStream(ƒ)
+}
+
+// NewHighBiased returns an initialized Stream for high-biased quantiles
+// (e.g. 0.01, 0.1, 0.5) where the needed quantiles are not known a priori, but
+// error guarantees can still be given even for the higher ranks of the data
+// distribution.
+//
+// The provided epsilon is a relative error, i.e. the true quantile of a value
+// returned by a query is guaranteed to be within 1-(1±Epsilon)*(1-Quantile).
+//
+// See http://www.cs.rutgers.edu/~muthu/bquant.pdf for time, space, and error
+// properties.
+func NewHighBiased(epsilon float64) *Stream {
+	ƒ := func(s *stream, r float64) float64 {
+		return 2 * epsilon * (s.n - r)
+	}
+	return newStream(ƒ)
+}
+
+// NewTargeted returns an initialized Stream concerned with a particular set of
+// quantile values that are supplied a priori. Knowing these a priori reduces
+// space and computation time. The targets map maps the desired quantiles to
+// their absolute errors, i.e. the true quantile of a value returned by a query
+// is guaranteed to be within (Quantile±Epsilon).
+//
+// See http://www.cs.rutgers.edu/~muthu/bquant.pdf for time, space, and error properties.
+func NewTargeted(targets map[float64]float64) *Stream {
+	ƒ := func(s *stream, r float64) float64 {
+		var m = math.MaxFloat64
+		var f float64
+		for quantile, epsilon := range targets {
+			if quantile*s.n <= r {
+				f = (2 * epsilon * r) / quantile
+			} else {
+				f = (2 * epsilon * (s.n - r)) / (1 - quantile)
+			}
+			if f < m {
+				m = f
+			}
+		}
+		return m
+	}
+	return newStream(ƒ)
+}
+
+// Stream computes quantiles for a stream of float64s. It is not thread-safe by
+// design. Take care when using across multiple goroutines.
+type Stream struct {
+	*stream
+	b      Samples
+	sorted bool
+}
+
+func newStream(ƒ invariant) *Stream {
+	x := &stream{ƒ: ƒ}
+	return &Stream{x, make(Samples, 0, 500), true}
+}
+
+// Insert inserts v into the stream.
+func (s *Stream) Insert(v float64) {
+	s.insert(Sample{Value: v, Width: 1})
+}
+
+func (s *Stream) insert(sample Sample) {
+	s.b = append(s.b, sample)
+	s.sorted = false
+	if len(s.b) == cap(s.b) {
+		s.flush()
+	}
+}
+
+// Query returns the computed qth percentiles value. If s was created with
+// NewTargeted, and q is not in the set of quantiles provided a priori, Query
+// will return an unspecified result.
+func (s *Stream) Query(q float64) float64 {
+	if !s.flushed() {
+		// Fast path when there hasn't been enough data for a flush;
+		// this also yields better accuracy for small sets of data.
+		l := len(s.b)
+		if l == 0 {
+			return 0
+		}
+		i := int(math.Ceil(float64(l) * q))
+		if i > 0 {
+			i -= 1
+		}
+		s.maybeSort()
+		return s.b[i].Value
+	}
+	s.flush()
+	return s.stream.query(q)
+}
+
+// Merge merges samples into the underlying streams samples. This is handy when
+// merging multiple streams from separate threads, database shards, etc.
+//
+// ATTENTION: This method is broken and does not yield correct results. The
+// underlying algorithm is not capable of merging streams correctly.
+func (s *Stream) Merge(samples Samples) {
+	sort.Sort(samples)
+	s.stream.merge(samples)
+}
+
+// Reset reinitializes and clears the list reusing the samples buffer memory.
+func (s *Stream) Reset() {
+	s.stream.reset()
+	s.b = s.b[:0]
+}
+
+// Samples returns stream samples held by s.
+func (s *Stream) Samples() Samples {
+	if !s.flushed() {
+		return s.b
+	}
+	s.flush()
+	return s.stream.samples()
+}
+
+// Count returns the total number of samples observed in the stream
+// since initialization.
+func (s *Stream) Count() int {
+	return len(s.b) + s.stream.count()
+}
+
+func (s *Stream) flush() {
+	s.maybeSort()
+	s.stream.merge(s.b)
+	s.b = s.b[:0]
+}
+
+func (s *Stream) maybeSort() {
+	if !s.sorted {
+		s.sorted = true
+		sort.Sort(s.b)
+	}
+}
+
+func (s *Stream) flushed() bool {
+	return len(s.stream.l) > 0
+}
+
+type stream struct {
+	n float64
+	l []Sample
+	ƒ invariant
+}
+
+func (s *stream) reset() {
+	s.l = s.l[:0]
+	s.n = 0
+}
+
+func (s *stream) insert(v float64) {
+	s.merge(Samples{{v, 1, 0}})
+}
+
+func (s *stream) merge(samples Samples) {
+	// TODO(beorn7): This tries to merge not only individual samples, but
+	// whole summaries. The paper doesn't mention merging summaries at
+	// all. Unittests show that the merging is inaccurate. Find out how to
+	// do merges properly.
+	var r float64
+	i := 0
+	for _, sample := range samples {
+		for ; i < len(s.l); i++ {
+			c := s.l[i]
+			if c.Value > sample.Value {
+				// Insert at position i.
+				s.l = append(s.l, Sample{})
+				copy(s.l[i+1:], s.l[i:])
+				s.l[i] = Sample{
+					sample.Value,
+					sample.Width,
+					math.Max(sample.Delta, math.Floor(s.ƒ(s, r))-1),
+					// TODO(beorn7): How to calculate delta correctly?
+				}
+				i++
+				goto inserted
+			}
+			r += c.Width
+		}
+		s.l = append(s.l, Sample{sample.Value, sample.Width, 0})
+		i++
+	inserted:
+		s.n += sample.Width
+		r += sample.Width
+	}
+	s.compress()
+}
+
+func (s *stream) count() int {
+	return int(s.n)
+}
+
+func (s *stream) query(q float64) float64 {
+	t := math.Ceil(q * s.n)
+	t += math.Ceil(s.ƒ(s, t) / 2)
+	p := s.l[0]
+	var r float64
+	for _, c := range s.l[1:] {
+		r += p.Width
+		if r+c.Width+c.Delta > t {
+			return p.Value
+		}
+		p = c
+	}
+	return p.Value
+}
+
+func (s *stream) compress() {
+	if len(s.l) < 2 {
+		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 = s.l[:len(s.l)-1]
+			xi -= 1
+		} else {
+			x = c
+			xi = i
+		}
+		r -= c.Width
+	}
+}
+
+func (s *stream) samples() Samples {
+	samples := make(Samples, len(s.l))
+	copy(samples, s.l)
+	return samples
+}

vendor/github.com/beorn7/perks/quantile/stream_test.go

+package quantile
+
+import (
+	"math"
+	"math/rand"
+	"sort"
+	"testing"
+)
+
+var (
+	Targets = map[float64]float64{
+		0.01: 0.001,
+		0.10: 0.01,
+		0.50: 0.05,
+		0.90: 0.01,
+		0.99: 0.001,
+	}
+	TargetsSmallEpsilon = map[float64]float64{
+		0.01: 0.0001,
+		0.10: 0.001,
+		0.50: 0.005,
+		0.90: 0.001,
+		0.99: 0.0001,
+	}
+	LowQuantiles  = []float64{0.01, 0.1, 0.5}
+	HighQuantiles = []float64{0.99, 0.9, 0.5}
+)
+
+const RelativeEpsilon = 0.01
+
+func verifyPercsWithAbsoluteEpsilon(t *testing.T, a []float64, s *Stream) {
+	sort.Float64s(a)
+	for quantile, epsilon := range Targets {
+		n := float64(len(a))
+		k := int(quantile * n)
+		if k < 1 {
+			k = 1
+		}
+		lower := int((quantile - epsilon) * n)
+		if lower < 1 {
+			lower = 1
+		}
+		upper := int(math.Ceil((quantile + epsilon) * n))
+		if upper > len(a) {
+			upper = len(a)
+		}
+		w, min, max := a[k-1], a[lower-1], a[upper-1]
+		if g := s.Query(quantile); g < min || g > max {
+			t.Errorf("q=%f: want %v [%f,%f], got %v", quantile, w, min, max, g)
+		}
+	}
+}
+
+func verifyLowPercsWithRelativeEpsilon(t *testing.T, a []float64, s *Stream) {
+	sort.Float64s(a)
+	for _, qu := range LowQuantiles {
+		n := float64(len(a))
+		k := int(qu * n)
+
+		lowerRank := int((1 - RelativeEpsilon) * qu * n)
+		upperRank := int(math.Ceil((1 + RelativeEpsilon) * qu * n))
+		w, min, max := a[k-1], a[lowerRank-1], a[upperRank-1]
+		if g := s.Query(qu); g < min || g > max {
+			t.Errorf("q=%f: want %v [%f,%f], got %v", qu, w, min, max, g)
+		}
+	}
+}
+
+func verifyHighPercsWithRelativeEpsilon(t *testing.T, a []float64, s *Stream) {
+	sort.Float64s(a)
+	for _, qu := range HighQuantiles {
+		n := float64(len(a))
+		k := int(qu * n)
+
+		lowerRank := int((1 - (1+RelativeEpsilon)*(1-qu)) * n)
+		upperRank := int(math.Ceil((1 - (1-RelativeEpsilon)*(1-qu)) * n))
+		w, min, max := a[k-1], a[lowerRank-1], a[upperRank-1]
+		if g := s.Query(qu); g < min || g > max {
+			t.Errorf("q=%f: want %v [%f,%f], got %v", qu, w, min, max, g)
+		}
+	}
+}
+
+func populateStream(s *Stream) []float64 {
+	a := make([]float64, 0, 1e5+100)
+	for i := 0; i < cap(a); i++ {
+		v := rand.NormFloat64()
+		// Add 5% asymmetric outliers.
+		if i%20 == 0 {
+			v = v*v + 1
+		}
+		s.Insert(v)
+		a = append(a, v)
+	}
+	return a
+}
+
+func TestTargetedQuery(t *testing.T) {
+	rand.Seed(42)
+	s := NewTargeted(Targets)
+	a := populateStream(s)
+	verifyPercsWithAbsoluteEpsilon(t, a, s)
+}
+
+func TestTargetedQuerySmallSampleSize(t *testing.T) {
+	rand.Seed(42)
+	s := NewTargeted(TargetsSmallEpsilon)
+	a := []float64{1, 2, 3, 4, 5}
+	for _, v := range a {
+		s.Insert(v)
+	}
+	verifyPercsWithAbsoluteEpsilon(t, a, s)
+	// If not yet flushed, results should be precise:
+	if !s.flushed() {
+		for φ, want := range map[float64]float64{
+			0.01: 1,
+			0.10: 1,
+			0.50: 3,
+			0.90: 5,
+			0.99: 5,
+		} {
+			if got := s.Query(φ); got != want {
+				t.Errorf("want %f for φ=%f, got %f", want, φ, got)
+			}
+		}
+	}
+}
+
+func TestLowBiasedQuery(t *testing.T) {
+	rand.Seed(42)
+	s := NewLowBiased(RelativeEpsilon)
+	a := populateStream(s)
+	verifyLowPercsWithRelativeEpsilon(t, a, s)
+}
+
+func TestHighBiasedQuery(t *testing.T) {
+	rand.Seed(42)
+	s := NewHighBiased(RelativeEpsilon)
+	a := populateStream(s)
+	verifyHighPercsWithRelativeEpsilon(t, a, s)
+}
+
+// BrokenTestTargetedMerge is broken, see Merge doc comment.
+func BrokenTestTargetedMerge(t *testing.T) {
+	rand.Seed(42)
+	s1 := NewTargeted(Targets)
+	s2 := NewTargeted(Targets)
+	a := populateStream(s1)
+	a = append(a, populateStream(s2)...)
+	s1.Merge(s2.Samples())
+	verifyPercsWithAbsoluteEpsilon(t, a, s1)
+}
+
+// BrokenTestLowBiasedMerge is broken, see Merge doc comment.
+func BrokenTestLowBiasedMerge(t *testing.T) {
+	rand.Seed(42)
+	s1 := NewLowBiased(RelativeEpsilon)
+	s2 := NewLowBiased(RelativeEpsilon)
+	a := populateStream(s1)
+	a = append(a, populateStream(s2)...)
+	s1.Merge(s2.Samples())
+	verifyLowPercsWithRelativeEpsilon(t, a, s2)
+}
+
+// BrokenTestHighBiasedMerge is broken, see Merge doc comment.
+func BrokenTestHighBiasedMerge(t *testing.T) {
+	rand.Seed(42)
+	s1 := NewHighBiased(RelativeEpsilon)
+	s2 := NewHighBiased(RelativeEpsilon)
+	a := populateStream(s1)
+	a = append(a, populateStream(s2)...)
+	s1.Merge(s2.Samples())
+	verifyHighPercsWithRelativeEpsilon(t, a, s2)
+}
+
+func TestUncompressed(t *testing.T) {
+	q := NewTargeted(Targets)
+	for i := 100; i > 0; i-- {
+		q.Insert(float64(i))
+	}
+	if g := q.Count(); g != 100 {
+		t.Errorf("want count 100, got %d", g)
+	}
+	// Before compression, Query should have 100% accuracy.
+	for quantile := range Targets {
+		w := quantile * 100
+		if g := q.Query(quantile); g != w {
+			t.Errorf("want %f, got %f", w, g)
+		}
+	}
+}
+
+func TestUncompressedSamples(t *testing.T) {
+	q := NewTargeted(map[float64]float64{0.99: 0.001})
+	for i := 1; i <= 100; i++ {
+		q.Insert(float64(i))
+	}
+	if g := q.Samples().Len(); g != 100 {
+		t.Errorf("want count 100, got %d", g)
+	}
+}
+
+func TestUncompressedOne(t *testing.T) {
+	q := NewTargeted(map[float64]float64{0.99: 0.01})
+	q.Insert(3.14)
+	if g := q.Query(0.90); g != 3.14 {
+		t.Error("want PI, got", g)
+	}
+}
+
+func TestDefaults(t *testing.T) {
+	if g := NewTargeted(map[float64]float64{0.99: 0.001}).Query(0.99); g != 0 {
+		t.Errorf("want 0, got %f", g)
+	}
+}

vendor/github.com/cloudfoundry-community/go-cfenv/.gitignore

+# Compiled Object files, Static and Dynamic libs (Shared Objects)
+*.o
+*.a
+*.so
+
+# Folders
+_obj
+_test
+
+# Architecture specific extensions/prefixes
+*.[568vq]
+[568vq].out
+
+*.cgo1.go
+*.cgo2.c
+_cgo_defun.c
+_cgo_gotypes.go
+_cgo_export.*
+
+_testmain.go
+
+*.exe
+vendor
+Godeps

vendor/github.com/cloudfoundry-community/go-cfenv/.travis.yml

+language: go
+sudo: false
+go:
+    - 1.6.2
+
+before_install:
+  - go get -u golang.org/x/tools/cmd/cover
+  - go get -u github.com/alecthomas/gometalinter
+  - go get -u github.com/mitchellh/mapstructure
+  - go get -u github.com/onsi/ginkgo
+  - go get -u github.com/onsi/gomega
+  - export PATH=$HOME/gopath/bin:$PATH
+  - gometalinter --install
+
+script:
+  - gometalinter --disable-all --enable=vet --enable=vetshadow --enable=golint --enable=ineffassign --exclude=comment --tests .
+  - go test -race .
+  - go test -cover .

vendor/github.com/cloudfoundry-community/go-cfenv/LICENSE

+Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "{}"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright {yyyy} {name of copyright owner}
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+

vendor/github.com/cloudfoundry-community/go-cfenv/README.md

+# Go CF Environment Package [![Build Status - Master](https://travis-ci.org/cloudfoundry-community/go-cfenv.svg?branch=master)](https://travis-ci.org/cloudfoundry-community/go-cfenv)
+
+### Overview
+
+[![GoDoc](https://godoc.org/github.com/cloudfoundry-community/go-cfenv?status.png)](https://godoc.org/github.com/cloudfoundry-community/go-cfenv)
+
+`cfenv` is a package to assist you in writing Go apps that run on [Cloud Foundry](http://cloudfoundry.org). It provides convenience functions and structures that map to Cloud Foundry environment variable primitives (http://docs.cloudfoundry.org/devguide/deploy-apps/environment-variable.html).
+
+### Usage
+
+`go get github.com/cloudfoundry-community/go-cfenv`
+
+```go
+package main
+
+import (
+	"github.com/cloudfoundry-community/go-cfenv"
+)
+
+func main() {
+	appEnv, _ := cfenv.Current()
+
+	fmt.Println("ID:", appEnv.ID)
+	fmt.Println("Index:", appEnv.Index)
+	fmt.Println("Name:", appEnv.Name)
+	fmt.Println("Host:", appEnv.Host)
+	fmt.Println("Port:", appEnv.Port)
+	fmt.Println("Version:", appEnv.Version)
+	fmt.Println("Home:", appEnv.Home)
+	fmt.Println("MemoryLimit:", appEnv.MemoryLimit)
+	fmt.Println("WorkingDir:", appEnv.WorkingDir)
+	fmt.Println("TempDir:", appEnv.TempDir)
+	fmt.Println("User:", appEnv.User)
+	fmt.Println("Services:", appEnv.Services)
+}
+```
+
+### Contributing
+
+Pull requests welcomed.