Update deps, include cachecontrol

vendor/github.com/pquerna/cachecontrol/cacheobject/warning.go

@@ -0,0 +1,107 @@
+/**
+ *  Copyright 2015 Paul Querna
+ *
+ *  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.
+ *
+ */
+
+package cacheobject
+
+import (
+	"fmt"
+	"net/http"
+	"time"
+)
+
+// Repersents an HTTP Warning: http://tools.ietf.org/html/rfc7234#section-5.5
+type Warning int
+
+const (
+	// Response is Stale
+	// A cache SHOULD generate this whenever the sent response is stale.
+	WarningResponseIsStale Warning = 110
+
+	// Revalidation Failed
+	// A cache SHOULD generate this when sending a stale
+	// response because an attempt to validate the response failed, due to an
+	// inability to reach the server.
+	WarningRevalidationFailed Warning = 111
+
+	// Disconnected Operation
+	// A cache SHOULD generate this if it is intentionally disconnected from
+	// the rest of the network for a period of time.
+	WarningDisconnectedOperation Warning = 112
+
+	// Heuristic Expiration
+	//
+	// A cache SHOULD generate this if it heuristically chose a freshness
+	// lifetime greater than 24 hours and the response's age is greater than
+	// 24 hours.
+	WarningHeuristicExpiration Warning = 113
+
+	// Miscellaneous Warning
+	//
+	// The warning text can include arbitrary information to be presented to
+	// a human user or logged.  A system receiving this warning MUST NOT
+	// take any automated action, besides presenting the warning to the
+	// user.
+	WarningMiscellaneousWarning Warning = 199
+
+	// Transformation Applied
+	//
+	// This Warning code MUST be added by a proxy if it applies any
+	// transformation to the representation, such as changing the
+	// content-coding, media-type, or modifying the representation data,
+	// unless this Warning code already appears in the response.
+	WarningTransformationApplied Warning = 214
+
+	// Miscellaneous Persistent Warning
+	//
+	// The warning text can include arbitrary information to be presented to
+	// a human user or logged.  A system receiving this warning MUST NOT
+	// take any automated action.
+	WarningMiscellaneousPersistentWarning Warning = 299
+)
+
+func (w Warning) HeaderString(agent string, date time.Time) string {
+	if agent == "" {
+		agent = "-"
+	} else {
+		// TODO(pquerna): this doesn't escape agent if it contains bad things.
+		agent = `"` + agent + `"`
+	}
+	return fmt.Sprintf(`%d %s "%s" %s`, w, agent, w.String(), date.Format(http.TimeFormat))
+}
+
+func (w Warning) String() string {
+	switch w {
+	case WarningResponseIsStale:
+		return "Response is Stale"
+	case WarningRevalidationFailed:
+		return "Revalidation Failed"
+	case WarningDisconnectedOperation:
+		return "Disconnected Operation"
+	case WarningHeuristicExpiration:
+		return "Heuristic Expiration"
+	case WarningMiscellaneousWarning:
+		// TODO(pquerna): ideally had a better way to override this one code.
+		return "Miscellaneous Warning"
+	case WarningTransformationApplied:
+		return "Transformation Applied"
+	case WarningMiscellaneousPersistentWarning:
+		// TODO(pquerna): same as WarningMiscellaneousWarning
+		return "Miscellaneous Persistent Warning"
+	}
+
+	panic(w)
+}