From 6d24155149d9df2469db212026781fc95ca486c1 Mon Sep 17 00:00:00 2001
From: Anton Novojilov <andy@essentialkaos.com>
Date: Tue, 15 Nov 2016 10:54:47 -0500
Subject: [PATCH 1/3] Custom engine support

---
 librato.go | 44 +++++++++++++++++++++++++++++++-------------
 1 file changed, 31 insertions(+), 13 deletions(-)

diff --git a/librato.go b/librato.go
index 2e20cab..bf1e842 100644
--- a/librato.go
+++ b/librato.go
@@ -22,7 +22,7 @@ import (
 // ////////////////////////////////////////////////////////////////////////////////// //
 
 // VERSION contains current version of librato package and used as part of User-Agent
-const VERSION = "3.0.1"
+const VERSION = "4.0.0"
 
 // ////////////////////////////////////////////////////////////////////////////////// //
 
@@ -49,10 +49,10 @@ type Metrics struct {
 	lastSendingDate int64
 	initialized     bool
 	queue           []Measurement
-	engine          *req.Engine
 
 	// Function executed if we have errors while sending data to Librato
 	ErrorHandler func(errs []error)
+	Engine       *req.Engine
 }
 
 // Collector struct
@@ -60,10 +60,10 @@ type Collector struct {
 	period          time.Duration
 	lastSendingDate int64
 	collectFunc     func() []Measurement
-	engine          *req.Engine
 
 	// Function executed if we have errors while sending data to Librato
 	ErrorHandler func(errs []error)
+	Engine       *req.Engine
 }
 
 // Gauge struct
@@ -228,6 +228,12 @@ var (
 // APIEndpoint contians URL of Librato API endpoint
 var APIEndpoint = "https://metrics-api.librato.com"
 
+// Engine is global req.Engine which used for sync requests
+var Engine = &req.Engine{}
+
+// UseGlobalEngine set to true for using global engine for all requests
+var UseGlobalEngine = false
+
 // ////////////////////////////////////////////////////////////////////////////////// //
 
 // List of sources
@@ -237,11 +243,9 @@ var sources []DataSource
 var (
 	errAccessCredentials = []error{errors.New("Access credentials is not set")}
 	errEmptyStreamName   = []error{errors.New("Stream name can't be empty")}
+	errEngineIsNil       = []error{errors.New("Engine is nil")}
 )
 
-// Request engine
-var engine = &req.Engine{}
-
 // ////////////////////////////////////////////////////////////////////////////////// //
 
 // NewMetrics create new metrics struct for async metrics sending
@@ -252,7 +256,12 @@ func NewMetrics(period time.Duration, maxQueueSize int) (*Metrics, error) {
 		initialized:     true,
 		queue:           make([]Measurement, 0),
 		lastSendingDate: -1,
-		engine:          &req.Engine{},
+	}
+
+	if UseGlobalEngine {
+		metrics.Engine = Engine
+	} else {
+		metrics.Engine = &req.Engine{}
 	}
 
 	err := validateMetrics(metrics)
@@ -277,7 +286,6 @@ func NewCollector(period time.Duration, collectFunc func() []Measurement) *Colle
 		period:          period,
 		collectFunc:     collectFunc,
 		lastSendingDate: -1,
-		engine:          &req.Engine{},
 	}
 
 	if sources == nil {
@@ -285,6 +293,12 @@ func NewCollector(period time.Duration, collectFunc func() []Measurement) *Colle
 		go sendingLoop()
 	}
 
+	if UseGlobalEngine {
+		collector.Engine = Engine
+	} else {
+		collector.Engine = &req.Engine{}
+	}
+
 	sources = append(sources, collector)
 
 	return collector
@@ -318,7 +332,7 @@ func AddMetric(m ...Measurement) []error {
 		}
 	}
 
-	return execRequest(engine, req.POST, APIEndpoint+"/v1/metrics/", data)
+	return execRequest(Engine, req.POST, APIEndpoint+"/v1/metrics/", data)
 }
 
 // AddAnnotation synchronously send annotation to librato
@@ -333,7 +347,7 @@ func AddAnnotation(stream string, a Annotation) []error {
 		return []error{err}
 	}
 
-	return execRequest(engine, req.POST, APIEndpoint+"/v1/annotations/"+stream, a)
+	return execRequest(Engine, req.POST, APIEndpoint+"/v1/annotations/"+stream, a)
 }
 
 // DeleteAnnotations synchronously remove annotation stream on librato
@@ -342,7 +356,7 @@ func DeleteAnnotations(stream string) []error {
 		return errEmptyStreamName
 	}
 
-	return execRequest(engine, req.DELETE, APIEndpoint+"/v1/annotations/"+stream, nil)
+	return execRequest(Engine, req.DELETE, APIEndpoint+"/v1/annotations/"+stream, nil)
 }
 
 // ////////////////////////////////////////////////////////////////////////////////// //
@@ -396,7 +410,7 @@ func (mt *Metrics) Send() []error {
 
 	mt.queue = make([]Measurement, 0)
 
-	errs := execRequest(mt.engine, req.POST, APIEndpoint+"/v1/metrics/", data)
+	errs := execRequest(mt.Engine, req.POST, APIEndpoint+"/v1/metrics/", data)
 
 	mt.execErrorHandler(errs)
 
@@ -433,7 +447,7 @@ func (cl *Collector) Send() []error {
 	cl.lastSendingDate = time.Now().Unix()
 
 	data := convertMeasurementSlice(measurements)
-	errs = execRequest(cl.engine, req.POST, APIEndpoint+"/v1/metrics/", data)
+	errs = execRequest(cl.Engine, req.POST, APIEndpoint+"/v1/metrics/", data)
 
 	cl.execErrorHandler(errs)
 
@@ -549,6 +563,10 @@ func convertMeasurementSlice(data []Measurement) measurements {
 
 // execRequest create and execute request to API
 func execRequest(engine *req.Engine, method, url string, data interface{}) []error {
+	if engine == nil {
+		return errEngineIsNil
+	}
+
 	if engine.UserAgent == "" {
 		engine.SetUserAgent("go-ek-librato", VERSION)
 	}

From 27828d890588efbb235c32805b3ef9dadef23bd3 Mon Sep 17 00:00:00 2001
From: Anton Novojilov <andy@essentialkaos.com>
Date: Tue, 15 Nov 2016 10:58:24 -0500
Subject: [PATCH 2/3] Updated TravisCI config and examples

---
 .travis.yml                     | 2 +-
 examples/annotations_example.go | 2 +-
 examples/async_example.go       | 2 +-
 examples/basic_example.go       | 2 +-
 examples/collector_example.go   | 2 +-
 5 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index dc18493..9523a35 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -23,7 +23,7 @@ matrix:
 before_install:
   - go get pkg.re/essentialkaos/ek.v5
   - mkdir -p $GOPATH/src/pkg.re/essentialkaos
-  - ln -sf $GOPATH/src/github.com/essentialkaos/librato $GOPATH/src/pkg.re/essentialkaos/librato.v3
+  - ln -sf $GOPATH/src/github.com/essentialkaos/librato $GOPATH/src/pkg.re/essentialkaos/librato.v4
 
 script:
   - go build examples/annotations_example.go
diff --git a/examples/annotations_example.go b/examples/annotations_example.go
index c511411..a992d59 100644
--- a/examples/annotations_example.go
+++ b/examples/annotations_example.go
@@ -6,7 +6,7 @@ import (
 	"fmt"
 	"time"
 
-	"pkg.re/essentialkaos/librato.v3"
+	"pkg.re/essentialkaos/librato.v4"
 )
 
 // ////////////////////////////////////////////////////////////////////////////////// //
diff --git a/examples/async_example.go b/examples/async_example.go
index b33624f..f71ac9d 100644
--- a/examples/async_example.go
+++ b/examples/async_example.go
@@ -8,7 +8,7 @@ import (
 
 	"pkg.re/essentialkaos/ek.v5/rand"
 
-	"pkg.re/essentialkaos/librato.v3"
+	"pkg.re/essentialkaos/librato.v4"
 )
 
 // ////////////////////////////////////////////////////////////////////////////////// //
diff --git a/examples/basic_example.go b/examples/basic_example.go
index 7c47dfb..56e386e 100644
--- a/examples/basic_example.go
+++ b/examples/basic_example.go
@@ -8,7 +8,7 @@ import (
 
 	"pkg.re/essentialkaos/ek.v5/rand"
 
-	"pkg.re/essentialkaos/librato.v3"
+	"pkg.re/essentialkaos/librato.v4"
 )
 
 // ////////////////////////////////////////////////////////////////////////////////// //
diff --git a/examples/collector_example.go b/examples/collector_example.go
index 9f81517..e03f279 100644
--- a/examples/collector_example.go
+++ b/examples/collector_example.go
@@ -8,7 +8,7 @@ import (
 
 	"pkg.re/essentialkaos/ek.v5/rand"
 
-	"pkg.re/essentialkaos/librato.v3"
+	"pkg.re/essentialkaos/librato.v4"
 )
 
 // ////////////////////////////////////////////////////////////////////////////////// //

From 4096e17dfd3ba674261f35b5421ecc46f09fbaa7 Mon Sep 17 00:00:00 2001
From: Anton Novojilov <andy@essentialkaos.com>
Date: Tue, 15 Nov 2016 17:11:49 -0500
Subject: [PATCH 3/3] Readme updated

---
 readme.md | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/readme.md b/readme.md
index e6d9cfc..e5317e7 100644
--- a/readme.md
+++ b/readme.md
@@ -1,17 +1,17 @@
-# Librato [![GoDoc](https://godoc.org/pkg.re/essentialkaos/librato.v3?status.svg)](https://godoc.org/pkg.re/essentialkaos/librato.v3) [![Build Status](https://travis-ci.org/essentialkaos/librato.svg?branch=master)](https://travis-ci.org/essentialkaos/librato) [![codebeat badge](https://codebeat.co/badges/f82e704d-67a7-4c6f-9e5d-1acf058c937b)](https://codebeat.co/projects/github-com-essentialkaos-librato)
+# Librato [![GoDoc](https://godoc.org/pkg.re/essentialkaos/librato.v4?status.svg)](https://godoc.org/pkg.re/essentialkaos/librato.v4) [![Build Status](https://travis-ci.org/essentialkaos/librato.svg?branch=master)](https://travis-ci.org/essentialkaos/librato) [![codebeat badge](https://codebeat.co/badges/f82e704d-67a7-4c6f-9e5d-1acf058c937b)](https://codebeat.co/projects/github-com-essentialkaos-librato)
 
 Package for working with [Librato Metrics](https://www.librato.com) API from Go code.
 
 ## Installation
 
 ````
-go get pkg.re/essentialkaos/librato.v3
+go get pkg.re/essentialkaos/librato.v4
 ````
 
 For update to latest stable release, do:
 
 ````
-go get -u pkg.re/essentialkaos/librato.v3
+go get -u pkg.re/essentialkaos/librato.v4
 ````
 
 ## Examples