event.go

/*
Copyright 2017 The Nuclio 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 nuclio

import (
	"errors"
	"time"
)

var ErrUnsupported = errors.New("Event does not support this interface")

type SourceInfoProvider interface {

	// get the class of source (sync, async, etc)
	GetClass() string

	// get specific kind of source (http, rabbit mq, etc)
	GetKind() string
}

//
// An event
//

type Event interface {
	GetVersion() int
	GetID() ID
	SetID(id ID)
	SetSourceProvider(sourceInfoProvider SourceInfoProvider)
	GetSource() SourceInfoProvider
	GetContentType() string
	GetBody() []byte
	GetSize() int
	GetHeader(key string) interface{}
	GetHeaderByteSlice(key string) []byte
	GetHeaderString(key string) string
	GetHeaders() map[string]interface{}
	GetField(key string) interface{}
	GetFieldByteSlice(key string) []byte
	GetFieldString(key string) string
	GetFieldInt(key string) (int, error)
	GetFields() map[string]interface{}
	GetTimestamp() time.Time
	GetPath() string
	GetURL() string
	GetMethod() string
}

//
// Abstract implementation of event
//

type AbstractEvent struct {
	sourceInfoProvider SourceInfoProvider
	id                 ID
	emptyByteArray     []byte
	emptyHeaders       map[string]interface{}
	emptyTime          time.Time
}

func (ae *AbstractEvent) GetVersion() int {
	return 0
}

func (ae *AbstractEvent) SetSourceProvider(sourceInfoProvider SourceInfoProvider) {
	ae.sourceInfoProvider = sourceInfoProvider
}

func (ae *AbstractEvent) GetSource() SourceInfoProvider {
	return ae.sourceInfoProvider
}

func (ae *AbstractEvent) GetID() ID {
	return ae.id
}

func (ae *AbstractEvent) SetID(id ID) {
	ae.id = id
}

func (ae *AbstractEvent) GetContentType() string {
	return ""
}

func (ae *AbstractEvent) GetBody() []byte {
	return ae.emptyByteArray
}

func (ae *AbstractEvent) GetSize() int {
	return 0
}

func (ae *AbstractEvent) GetHeader(key string) interface{} {
	return nil
}

func (ae *AbstractEvent) GetHeaderByteSlice(key string) []byte {
	return ae.emptyByteArray
}

func (ae *AbstractEvent) GetHeaderString(key string) string {
	return string(ae.GetHeaderByteSlice(key))
}

func (ae *AbstractEvent) GetHeaders() map[string]interface{} {
	return ae.emptyHeaders
}

func (ae *AbstractEvent) GetTimestamp() time.Time {
	return ae.emptyTime
}

func (ae *AbstractEvent) GetPath() string {
	return ""
}

func (ae *AbstractEvent) GetURL() string {
	return ""
}

func (ae *AbstractEvent) GetMethod() string {
	return ""
}

func (ae *AbstractEvent) GetField(key string) interface{} {
	return nil
}

func (ae *AbstractEvent) GetFieldByteSlice(key string) []byte {
	return nil
}

func (ae *AbstractEvent) GetFieldString(key string) string {
	return ""
}

func (ae *AbstractEvent) GetFieldInt(key string) (int, error) {
	return 0, ErrUnsupported
}

func (ae *AbstractEvent) GetFields() map[string]interface{} {
	return nil
}