1 files changed, 255 insertions, 0 deletions
diff --git a/vendor/github.com/Azure/azure-pipeline-go/pipeline/core.go b/vendor/github.com/Azure/azure-pipeline-go/pipeline/core.go
new file mode 100755
index 000000000..0dde81d72
--- /dev/null
+++ b/vendor/github.com/Azure/azure-pipeline-go/pipeline/core.go
@@ -0,0 +1,255 @@
+package pipeline
+
+import (
+	"context"
+	"net"
+	"net/http"
+	"os"
+	"time"
+)
+
+// The Factory interface represents an object that can create its Policy object. Each HTTP request sent
+// requires that this Factory create a new instance of its Policy object.
+type Factory interface {
+	New(next Policy, po *PolicyOptions) Policy
+}
+
+// FactoryFunc is an adapter that allows the use of an ordinary function as a Factory interface.
+type FactoryFunc func(next Policy, po *PolicyOptions) PolicyFunc
+
+// New calls f(next,po).
+func (f FactoryFunc) New(next Policy, po *PolicyOptions) Policy {
+	return f(next, po)
+}
+
+// The Policy interface represents a mutable Policy object created by a Factory. The object can mutate/process
+// the HTTP request and then forward it on to the next Policy object in the linked-list. The returned
+// Response goes backward through the linked-list for additional processing.
+// NOTE: Request is passed by value so changes do not change the caller's version of
+// the request. However, Request has some fields that reference mutable objects (not strings).
+// These references are copied; a deep copy is not performed. Specifically, this means that
+// you should avoid modifying the objects referred to by these fields: URL, Header, Body,
+// GetBody, TransferEncoding, Form, MultipartForm, Trailer, TLS, Cancel, and Response.
+type Policy interface {
+	Do(ctx context.Context, request Request) (Response, error)
+}
+
+// PolicyFunc is an adapter that allows the use of an ordinary function as a Policy interface.
+type PolicyFunc func(ctx context.Context, request Request) (Response, error)
+
+// Do calls f(ctx, request).
+func (f PolicyFunc) Do(ctx context.Context, request Request) (Response, error) {
+	return f(ctx, request)
+}
+
+// Options configures a Pipeline's behavior.
+type Options struct {
+	HTTPSender Factory // If sender is nil, then the pipeline's default client is used to send the HTTP requests.
+	Log        LogOptions
+}
+
+// LogLevel tells a logger the minimum level to log. When code reports a log entry,
+// the LogLevel indicates the level of the log entry. The logger only records entries
+// whose level is at least the level it was told to log. See the Log* constants.
+// For example, if a logger is configured with LogError, then LogError, LogPanic,
+// and LogFatal entries will be logged; lower level entries are ignored.
+type LogLevel uint32
+
+const (
+	// LogNone tells a logger not to log any entries passed to it.
+	LogNone LogLevel = iota
+
+	// LogFatal tells a logger to log all LogFatal entries passed to it.
+	LogFatal
+
+	// LogPanic tells a logger to log all LogPanic and LogFatal entries passed to it.
+	LogPanic
+
+	// LogError tells a logger to log all LogError, LogPanic and LogFatal entries passed to it.
+	LogError
+
+	// LogWarning tells a logger to log all LogWarning, LogError, LogPanic and LogFatal entries passed to it.
+	LogWarning
+
+	// LogInfo tells a logger to log all LogInfo, LogWarning, LogError, LogPanic and LogFatal entries passed to it.
+	LogInfo
+
+	// LogDebug tells a logger to log all LogDebug, LogInfo, LogWarning, LogError, LogPanic and LogFatal entries passed to it.
+	LogDebug
+)
+
+// LogOptions configures the pipeline's logging mechanism & level filtering.
+type LogOptions struct {
+	Log func(level LogLevel, message string)
+
+	// ShouldLog is called periodically allowing you to return whether the specified LogLevel should be logged or not.
+	// An application can return different values over the its lifetime; this allows the application to dynamically
+	// alter what is logged. NOTE: This method can be called by multiple goroutines simultaneously so make sure
+	// you implement it in a goroutine-safe way. If nil, nothing is logged (the equivalent of returning LogNone).
+	// Usually, the function will be implemented simply like this: return level <= LogWarning
+	ShouldLog func(level LogLevel) bool
+}
+
+type pipeline struct {
+	factories []Factory
+	options   Options
+}
+
+// The Pipeline interface represents an ordered list of Factory objects and an object implementing the HTTPSender interface.
+// You construct a Pipeline by calling the pipeline.NewPipeline function. To send an HTTP request, call pipeline.NewRequest
+// and then call Pipeline's Do method passing a context, the request, and a method-specific Factory (or nil). Passing a
+// method-specific Factory allows this one call to Do to inject a Policy into the linked-list. The policy is injected where
+// the MethodFactoryMarker (see the pipeline.MethodFactoryMarker function) is in the slice of Factory objects.
+//
+// When Do is called, the Pipeline object asks each Factory object to construct its Policy object and adds each Policy to a linked-list.
+// THen, Do sends the Context and Request through all the Policy objects. The final Policy object sends the request over the network
+// (via the HTTPSender object passed to NewPipeline) and the response is returned backwards through all the Policy objects.
+// Since Pipeline and Factory objects are goroutine-safe, you typically create 1 Pipeline object and reuse it to make many HTTP requests.
+type Pipeline interface {
+	Do(ctx context.Context, methodFactory Factory, request Request) (Response, error)
+}
+
+// NewPipeline creates a new goroutine-safe Pipeline object from the slice of Factory objects and the specified options.
+func NewPipeline(factories []Factory, o Options) Pipeline {
+	if o.HTTPSender == nil {
+		o.HTTPSender = newDefaultHTTPClientFactory()
+	}
+	if o.Log.Log == nil {
+		o.Log.Log = func(LogLevel, string) {} // No-op logger
+	}
+	return &pipeline{factories: factories, options: o}
+}
+
+// Do is called for each and every HTTP request. It tells each Factory to create its own (mutable) Policy object
+// replacing a MethodFactoryMarker factory (if it exists) with the methodFactory passed in. Then, the Context and Request
+// are sent through the pipeline of Policy objects (which can transform the Request's URL/query parameters/headers) and
+// ultimately sends the transformed HTTP request over the network.
+func (p *pipeline) Do(ctx context.Context, methodFactory Factory, request Request) (Response, error) {
+	response, err := p.newPolicies(methodFactory).Do(ctx, request)
+	request.close()
+	return response, err
+}
+
+func (p *pipeline) newPolicies(methodFactory Factory) Policy {
+	// The last Policy is the one that actually sends the request over the wire and gets the response.
+	// It is overridable via the Options' HTTPSender field.
+	po := &PolicyOptions{pipeline: p} // One object shared by all policy objects
+	next := p.options.HTTPSender.New(nil, po)
+
+	// Walk over the slice of Factory objects in reverse (from wire to API)
+	markers := 0
+	for i := len(p.factories) - 1; i >= 0; i-- {
+		factory := p.factories[i]
+		if _, ok := factory.(methodFactoryMarker); ok {
+			markers++
+			if markers > 1 {
+				panic("MethodFactoryMarker can only appear once in the pipeline")
+			}
+			if methodFactory != nil {
+				// Replace MethodFactoryMarker with passed-in methodFactory
+				next = methodFactory.New(next, po)
+			}
+		} else {
+			// Use the slice's Factory to construct its Policy
+			next = factory.New(next, po)
+		}
+	}
+
+	// Each Factory has created its Policy
+	if markers == 0 && methodFactory != nil {
+		panic("Non-nil methodFactory requires MethodFactoryMarker in the pipeline")
+	}
+	return next // Return head of the Policy object linked-list
+}
+
+// A PolicyOptions represents optional information that can be used by a node in the
+// linked-list of Policy objects. A PolicyOptions is passed to the Factory's New method
+// which passes it (if desired) to the Policy object it creates. Today, the Policy object
+// uses the options to perform logging. But, in the future, this could be used for more.
+type PolicyOptions struct {
+	pipeline *pipeline
+}
+
+// ShouldLog returns true if the specified log level should be logged.
+func (po *PolicyOptions) ShouldLog(level LogLevel) bool {
+	if po.pipeline.options.Log.ShouldLog != nil {
+		return po.pipeline.options.Log.ShouldLog(level)
+	}
+	return false
+}
+
+// Log logs a string to the Pipeline's Logger.
+func (po *PolicyOptions) Log(level LogLevel, msg string) {
+	if !po.ShouldLog(level) {
+		return // Short circuit message formatting if we're not logging it
+	}
+
+	// We are logging it, ensure trailing newline
+	if len(msg) == 0 || msg[len(msg)-1] != '\n' {
+		msg += "\n" // Ensure trailing newline
+	}
+	po.pipeline.options.Log.Log(level, msg)
+
+	// If logger doesn't handle fatal/panic, we'll do it here.
+	if level == LogFatal {
+		os.Exit(1)
+	} else if level == LogPanic {
+		panic(msg)
+	}
+}
+
+var pipelineHTTPClient = newDefaultHTTPClient()
+
+func newDefaultHTTPClient() *http.Client {
+	// We want the Transport to have a large connection pool
+	return &http.Client{
+		Transport: &http.Transport{
+			Proxy: http.ProxyFromEnvironment,
+			// We use Dial instead of DialContext as DialContext has been reported to cause slower performance.
+			Dial /*Context*/ : (&net.Dialer{
+				Timeout:   30 * time.Second,
+				KeepAlive: 30 * time.Second,
+				DualStack: true,
+			}).Dial, /*Context*/
+			MaxIdleConns:           0, // No limit
+			MaxIdleConnsPerHost:    100,
+			IdleConnTimeout:        90 * time.Second,
+			TLSHandshakeTimeout:    10 * time.Second,
+			ExpectContinueTimeout:  1 * time.Second,
+			DisableKeepAlives:      false,
+			DisableCompression:     false,
+			MaxResponseHeaderBytes: 0,
+			//ResponseHeaderTimeout:  time.Duration{},
+			//ExpectContinueTimeout:  time.Duration{},
+		},
+	}
+}
+
+// newDefaultHTTPClientFactory creates a DefaultHTTPClientPolicyFactory object that sends HTTP requests to a Go's default http.Client.
+func newDefaultHTTPClientFactory() Factory {
+	return FactoryFunc(func(next Policy, po *PolicyOptions) PolicyFunc {
+		return func(ctx context.Context, request Request) (Response, error) {
+			r, err := pipelineHTTPClient.Do(request.WithContext(ctx))
+			if err != nil {
+				err = NewError(err, "HTTP request failed")
+			}
+			return NewHTTPResponse(r), err
+		}
+	})
+}
+
+var mfm = methodFactoryMarker{} // Singleton
+
+// MethodFactoryMarker returns a special marker Factory object. When Pipeline's Do method is called, any
+// MethodMarkerFactory object is replaced with the specified methodFactory object. If nil is passed fro Do's
+// methodFactory parameter, then the MethodFactoryMarker is ignored as the linked-list of Policy objects is created.
+func MethodFactoryMarker() Factory {
+	return mfm
+}
+
+type methodFactoryMarker struct {
+}
+
+func (methodFactoryMarker) New(next Policy, po *PolicyOptions) Policy {
+	panic("methodFactoryMarker policy should have been replaced with a method policy")
+}