refact(csi): use common lib-csi imports (#263)

Signed-off-by: shubham <shubham.bajpai@mayadata.io>

vendor/github.com/openebs/lib-csi/pkg/common/errors/errors.go

@@ -0,0 +1,99 @@
+/*
+Copyright 2019 The OpenEBS Authors
+
+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 errors
+
+import (
+	"fmt"
+)
+
+// New returns an error with the supplied message.
+// New also records the stack trace at the point it was called.
+func New(message string) error {
+	return &err{
+		prefix: stackTraceMessagePrefix,
+		msg:    message,
+		stack:  callers(),
+	}
+}
+
+// Errorf formats according to a format specifier and returns the string
+// as a value that satisfies error.
+// Errorf also records the stack trace at the point it was called.
+func Errorf(format string, args ...interface{}) error {
+	return &err{
+		prefix: stackTraceMessagePrefix,
+		msg:    fmt.Sprintf(format, args...),
+		stack:  callers(),
+	}
+}
+
+// Wrap annotates err with a new message.
+// If err is nil, Wrap returns nil.
+func Wrap(err error, message string) error {
+	if err == nil {
+		return nil
+	}
+	return &wrapper{wrapErrorMessagePrefix, message, err}
+}
+
+// Wrapf annotates err with the format specifier.
+// If err is nil, Wrapf returns nil.
+func Wrapf(err error, format string, args ...interface{}) error {
+	if err == nil {
+		return nil
+	}
+	return &wrapper{wrapErrorMessagePrefix, fmt.Sprintf(format, args...), err}
+}
+
+// WithStack annotates err with a stack trace at the
+// point WithStack was called. If err is nil, WithStack returns nil.
+func WithStack(err error) error {
+	if err == nil {
+		return nil
+	}
+	return &withStack{
+		stackTraceMessagePrefix,
+		err,
+		callers(),
+	}
+}
+
+// Cause returns the underlying cause of the error, if possible.
+// An error value has a cause if it implements the following
+// interface:
+//
+//     type causer interface {
+//            Cause() error
+//     }
+//
+// If the error does not implement Cause, the original error will
+// be returned. If the error is nil, nil will be returned without further
+// investigation.
+func Cause(err error) error {
+	type causer interface {
+		Cause() error
+	}
+
+	for err != nil {
+		cause, ok := err.(causer)
+		if !ok {
+			break
+		}
+		err = cause.Cause()
+	}
+	return err
+}

vendor/github.com/openebs/lib-csi/pkg/common/errors/types.go

@@ -0,0 +1,188 @@
+/*
+Copyright 2019 The OpenEBS Authors
+
+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 errors
+
+import (
+	"fmt"
+	"runtime"
+
+	"github.com/pkg/errors"
+)
+
+const (
+	wrapErrorMessagePrefix  string = "  --  "
+	listErrorMessagePrefix  string = "  -  "
+	stackTraceMessagePrefix string = "      "
+)
+
+// stack represents a stack of program counters.
+type stack []uintptr
+
+// callers returns stack of caller function
+func callers() *stack {
+	const depth = 32
+	var pcs [depth]uintptr
+	n := runtime.Callers(3, pcs[:])
+	var st stack = pcs[0:n]
+	return &st
+}
+
+// err implements error interface that has a message and stack
+type err struct {
+	prefix string
+	msg    string
+	*stack
+}
+
+// Error is implementation of error interface
+func (e *err) Error() string { return e.msg }
+
+// Format is implementation of Formater interface
+func (e *err) Format(s fmt.State, verb rune) {
+	message := wrapErrorMessagePrefix + e.msg
+	switch verb {
+	case 'v':
+		if s.Flag('+') {
+			fmt.Fprint(s, message)
+			for i, pc := range *e.stack {
+				if i > 0 {
+					return
+				}
+				f := errors.Frame(pc)
+				fmt.Fprintf(s, "\n%s%+v", e.prefix, f)
+			}
+			return
+		}
+		fallthrough
+	case 's', 'q':
+		fmt.Fprint(s, message)
+	}
+}
+
+// wrapper implements error interface that has a message and error
+type wrapper struct {
+	prefix string
+	msg    string
+	error
+}
+
+// Error is implementation of error interface
+func (w *wrapper) Error() string { return w.msg }
+
+// Cause is implementation of causer interface
+func (w *wrapper) Cause() error { return w.error }
+
+// Format is implementation of Formater interface
+func (w *wrapper) Format(s fmt.State, verb rune) {
+	switch verb {
+	case 'v':
+		if s.Flag('+') {
+			fmt.Fprintf(s, "%+v\n", w.error)
+			fmt.Fprint(s, w.prefix+w.msg)
+			return
+		}
+		fallthrough
+	case 's', 'q':
+		fmt.Fprintf(s, "%s\n", w.error)
+		fmt.Fprint(s, w.prefix+w.msg)
+	}
+}
+
+// withStack implements error interface that has a stack and error
+type withStack struct {
+	prefix string
+	error
+	*stack
+}
+
+// Format is implementation of Formater interface
+func (ws *withStack) Format(s fmt.State, verb rune) {
+	message := wrapErrorMessagePrefix + fmt.Sprintf("%s", ws.error)
+	switch verb {
+	case 'v':
+		if s.Flag('+') {
+			fmt.Fprint(s, message)
+			for i, pc := range *ws.stack {
+				if i > 0 {
+					return
+				}
+				f := errors.Frame(pc)
+				fmt.Fprintf(s, "\n%s%+v", ws.prefix, f)
+			}
+			return
+		}
+		fallthrough
+	case 's', 'q':
+		fmt.Fprint(s, message)
+	}
+}
+
+// Cause is implementation of causer interface
+func (ws *withStack) Cause() error { return ws.error }
+
+// ErrorList is a wrapper over list of errors
+// It implements error interface
+type ErrorList struct {
+	Errors []error
+	msg    string
+}
+
+// Error is implementation of error interface
+func (el *ErrorList) Error() string {
+	message := ""
+	for _, err := range el.Errors {
+		message += err.Error() + ":"
+	}
+	el.msg = message
+	return message
+}
+
+// Format is implementation of Formater interface
+func (el *ErrorList) Format(s fmt.State, verb rune) {
+	message := ""
+	for _, err := range el.Errors {
+		message += "\n" + listErrorMessagePrefix + err.Error()
+	}
+	fmt.Fprint(s, message)
+
+}
+
+// WithStack annotates ErrorList with a new message and
+// stack trace of caller.
+func (el *ErrorList) WithStack(message string) error {
+	if el == nil {
+		return nil
+	}
+	return &withStack{
+		stackTraceMessagePrefix,
+		Wrap(el, message),
+		callers(),
+	}
+}
+
+// WithStackf annotates ErrorList with the format specifier
+// and stack trace of caller.
+func (el *ErrorList) WithStackf(format string, args ...interface{}) error {
+	if el == nil {
+		return nil
+	}
+	return &withStack{
+		stackTraceMessagePrefix,
+		Wrapf(el, format, args...),
+		callers(),
+	}
+}