Checking in vendor folder for ease of using go get.

vendor/github.com/paypal/gorealis/errors.go

@@ -0,0 +1,88 @@
+/**
+ * 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 realis
+
+// Using a pattern described by Dave Cheney to differentiate errors
+// https://dave.cheney.net/2016/04/27/dont-just-check-errors-handle-them-gracefully
+
+// Timeout errors are returned when a function is unable to continue executing due
+// to a time constraint or meeting a set number of retries.
+type timeout interface {
+	Timedout() bool
+}
+
+func IsTimeout(err error) bool {
+	temp, ok := err.(timeout)
+	return ok && temp.Timedout()
+}
+
+// retryErr is a superset of timeout which includes extra context
+// with regards to our retry mechanism. This is done in order to make sure
+// that our retry mechanism works as expected through our tests and should
+// never be relied on or used directly. It is not made part of the public API
+// on purpose.
+type retryErr struct {
+	error
+	timedout   bool
+	retryCount int // How many times did the mechanism retry the command
+}
+
+// Retry error is a timeout type error with added context.
+func (r *retryErr) Timedout() bool {
+	return r.timedout
+}
+
+func (r *retryErr) RetryCount() int {
+	return r.retryCount
+}
+
+// Helper function for testing verification to avoid whitebox testing
+// as well as keeping retryErr as a private.
+// Should NOT be used under any other context.
+func ToRetryCount(err error) *retryErr {
+	if retryErr, ok := err.(*retryErr); ok {
+		return retryErr
+	} else {
+		return nil
+	}
+}
+
+func newRetryError(err error, retryCount int) *retryErr {
+	return &retryErr{error: err, timedout: true, retryCount: retryCount}
+}
+
+// Temporary errors indicate that the action may and should be retried.
+type temporary interface {
+	Temporary() bool
+}
+
+func IsTemporary(err error) bool {
+	temp, ok := err.(temporary)
+	return ok && temp.Temporary()
+}
+
+type TemporaryErr struct {
+	error
+	temporary bool
+}
+
+func (t *TemporaryErr) Temporary() bool {
+	return t.temporary
+}
+
+// Retrying after receiving this error is advised
+func NewTemporaryError(err error) *TemporaryErr {
+	return &TemporaryErr{error: err, temporary: true}
+}