minio/cmd/errors.go

123 lines
2.9 KiB
Go

/*
* Minio Cloud Storage, (C) 2016 Minio, Inc.
*
* 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 cmd
import (
"fmt"
"os"
"path/filepath"
"runtime"
"strings"
)
// Holds the current directory path. Used for trimming path in traceError()
var rootPath string
// Figure out the rootPath
func initError() {
// Root path is automatically determined from the calling function's source file location.
// Catch the calling function's source file path.
_, file, _, _ := runtime.Caller(1)
// Save the directory alone.
rootPath = filepath.Dir(file)
}
// Represents a stack frame in the stack trace.
type traceInfo struct {
file string // File where error occurred
line int // Line where error occurred
name string // Name of the function where error occurred
}
// Error - error type containing cause and the stack trace.
type Error struct {
e error // Holds the cause error
trace []traceInfo // stack trace
errs []error // Useful for XL to hold errors from all disks
}
// Implement error interface.
func (e Error) Error() string {
return e.e.Error()
}
// Trace - returns stack trace.
func (e Error) Trace() []string {
var traceArr []string
for _, info := range e.trace {
traceArr = append(traceArr, fmt.Sprintf("%s:%d:%s",
info.file, info.line, info.name))
}
return traceArr
}
// NewStorageError - return new Error type.
func traceError(e error, errs ...error) error {
if e == nil {
return nil
}
err := &Error{}
err.e = e
err.errs = errs
stack := make([]uintptr, 40)
length := runtime.Callers(2, stack)
if length > len(stack) {
length = len(stack)
}
stack = stack[:length]
for _, pc := range stack {
pc = pc - 1
fn := runtime.FuncForPC(pc)
file, line := fn.FileLine(pc)
name := fn.Name()
if strings.HasSuffix(name, "ServeHTTP") {
break
}
if strings.HasSuffix(name, "runtime.") {
break
}
file = strings.TrimPrefix(file, rootPath+string(os.PathSeparator))
name = strings.TrimPrefix(name, "github.com/minio/minio/cmd.")
err.trace = append(err.trace, traceInfo{file, line, name})
}
return err
}
// Returns the underlying cause error.
func errorCause(err error) error {
if e, ok := err.(*Error); ok {
err = e.e
}
return err
}
// Returns slice of underlying cause error.
func errorsCause(errs []error) []error {
cerrs := make([]error, len(errs))
for i, err := range errs {
if err == nil {
continue
}
cerrs[i] = errorCause(err)
}
return cerrs
}