terraform/vendor/github.com/cihub/seelog/dispatch_dispatcher.go

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// Copyright (c) 2012 - Cloud Instruments Co., Ltd.
//
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// 1. Redistributions of source code must retain the above copyright notice, this
// list of conditions and the following disclaimer.
// 2. Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
// ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
// ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
package seelog
import (
"errors"
"fmt"
"io"
)
// A dispatcherInterface is used to dispatch message to all underlying receivers.
// Dispatch logic depends on given context and log level. Any errors are reported using errorFunc.
// Also, as underlying receivers may have a state, dispatcher has a ShuttingDown method which performs
// an immediate cleanup of all data that is stored in the receivers
type dispatcherInterface interface {
flusherInterface
io.Closer
Dispatch(message string, level LogLevel, context LogContextInterface, errorFunc func(err error))
}
type dispatcher struct {
formatter *formatter
writers []*formattedWriter
dispatchers []dispatcherInterface
}
// Creates a dispatcher which dispatches data to a list of receivers.
// Each receiver should be either a Dispatcher or io.Writer, otherwise an error will be returned
func createDispatcher(formatter *formatter, receivers []interface{}) (*dispatcher, error) {
if formatter == nil {
return nil, errors.New("formatter cannot be nil")
}
if receivers == nil || len(receivers) == 0 {
return nil, errors.New("receivers cannot be nil or empty")
}
disp := &dispatcher{formatter, make([]*formattedWriter, 0), make([]dispatcherInterface, 0)}
for _, receiver := range receivers {
writer, ok := receiver.(*formattedWriter)
if ok {
disp.writers = append(disp.writers, writer)
continue
}
ioWriter, ok := receiver.(io.Writer)
if ok {
writer, err := NewFormattedWriter(ioWriter, disp.formatter)
if err != nil {
return nil, err
}
disp.writers = append(disp.writers, writer)
continue
}
dispInterface, ok := receiver.(dispatcherInterface)
if ok {
disp.dispatchers = append(disp.dispatchers, dispInterface)
continue
}
return nil, errors.New("method can receive either io.Writer or dispatcherInterface")
}
return disp, nil
}
func (disp *dispatcher) Dispatch(
message string,
level LogLevel,
context LogContextInterface,
errorFunc func(err error)) {
for _, writer := range disp.writers {
err := writer.Write(message, level, context)
if err != nil {
errorFunc(err)
}
}
for _, dispInterface := range disp.dispatchers {
dispInterface.Dispatch(message, level, context, errorFunc)
}
}
// Flush goes through all underlying writers which implement flusherInterface interface
// and closes them. Recursively performs the same action for underlying dispatchers
func (disp *dispatcher) Flush() {
for _, disp := range disp.Dispatchers() {
disp.Flush()
}
for _, formatWriter := range disp.Writers() {
flusher, ok := formatWriter.Writer().(flusherInterface)
if ok {
flusher.Flush()
}
}
}
// Close goes through all underlying writers which implement io.Closer interface
// and closes them. Recursively performs the same action for underlying dispatchers
// Before closing, writers are flushed to prevent loss of any buffered data, so
// a call to Flush() func before Close() is not necessary
func (disp *dispatcher) Close() error {
for _, disp := range disp.Dispatchers() {
disp.Flush()
err := disp.Close()
if err != nil {
return err
}
}
for _, formatWriter := range disp.Writers() {
flusher, ok := formatWriter.Writer().(flusherInterface)
if ok {
flusher.Flush()
}
closer, ok := formatWriter.Writer().(io.Closer)
if ok {
err := closer.Close()
if err != nil {
return err
}
}
}
return nil
}
func (disp *dispatcher) Writers() []*formattedWriter {
return disp.writers
}
func (disp *dispatcher) Dispatchers() []dispatcherInterface {
return disp.dispatchers
}
func (disp *dispatcher) String() string {
str := "formatter: " + disp.formatter.String() + "\n"
str += " ->Dispatchers:"
if len(disp.dispatchers) == 0 {
str += "none\n"
} else {
str += "\n"
for _, disp := range disp.dispatchers {
str += fmt.Sprintf(" ->%s", disp)
}
}
str += " ->Writers:"
if len(disp.writers) == 0 {
str += "none\n"
} else {
str += "\n"
for _, writer := range disp.writers {
str += fmt.Sprintf(" ->%s\n", writer)
}
}
return str
}