api: Implement bucket notification. (#2271)

* Implement basic S3 notifications through queues

Supports multiple queues and three basic queue types:

1. NilQueue -- messages don't get sent anywhere
2. LogQueue -- messages get logged
3. AmqpQueue -- messages are sent to an AMQP queue

* api: Implement bucket notification.

Supports two different queue types

- AMQP
- ElasticSearch.

* Add support for redis

vendor/gopkg.in/olivere/elastic.v3/tasks_cancel.go

@@ -0,0 +1,144 @@
+// Copyright 2012-present Oliver Eilhard. All rights reserved.
+// Use of this source code is governed by a MIT-license.
+// See http://olivere.mit-license.org/license.txt for details.
+
+package elastic
+
+import (
+	"fmt"
+	"net/url"
+	"strings"
+
+	"gopkg.in/olivere/elastic.v3/uritemplates"
+)
+
+// TasksCancelService can cancel long-running tasks.
+// It is supported as of Elasticsearch 2.3.0.
+//
+// See http://www.elastic.co/guide/en/elasticsearch/reference/master/tasks-cancel.html
+// for details.
+type TasksCancelService struct {
+	client     *Client
+	pretty     bool
+	taskId     *int64
+	actions    []string
+	nodeId     []string
+	parentNode string
+	parentTask *int64
+}
+
+// NewTasksCancelService creates a new TasksCancelService.
+func NewTasksCancelService(client *Client) *TasksCancelService {
+	return &TasksCancelService{
+		client:  client,
+		actions: make([]string, 0),
+		nodeId:  make([]string, 0),
+	}
+}
+
+// TaskId specifies the task to cancel. Set to -1 to cancel all tasks.
+func (s *TasksCancelService) TaskId(taskId int64) *TasksCancelService {
+	s.taskId = &taskId
+	return s
+}
+
+// Actions is a list of actions that should be cancelled. Leave empty to cancel all.
+func (s *TasksCancelService) Actions(actions []string) *TasksCancelService {
+	s.actions = actions
+	return s
+}
+
+// NodeId is a list of node IDs or names to limit the returned information;
+// use `_local` to return information from the node you're connecting to,
+// leave empty to get information from all nodes.
+func (s *TasksCancelService) NodeId(nodeId []string) *TasksCancelService {
+	s.nodeId = nodeId
+	return s
+}
+
+// ParentNode specifies to cancel tasks with specified parent node.
+func (s *TasksCancelService) ParentNode(parentNode string) *TasksCancelService {
+	s.parentNode = parentNode
+	return s
+}
+
+// ParentTask specifies to cancel tasks with specified parent task id.
+// Set to -1 to cancel all.
+func (s *TasksCancelService) ParentTask(parentTask int64) *TasksCancelService {
+	s.parentTask = &parentTask
+	return s
+}
+
+// Pretty indicates that the JSON response be indented and human readable.
+func (s *TasksCancelService) Pretty(pretty bool) *TasksCancelService {
+	s.pretty = pretty
+	return s
+}
+
+// buildURL builds the URL for the operation.
+func (s *TasksCancelService) buildURL() (string, url.Values, error) {
+	// Build URL
+	var err error
+	var path string
+	if s.taskId != nil {
+		path, err = uritemplates.Expand("/_tasks/{task_id}/_cancel", map[string]string{
+			"task_id": fmt.Sprintf("%d", *s.taskId),
+		})
+	} else {
+		path = "/_tasks/_cancel"
+	}
+	if err != nil {
+		return "", url.Values{}, err
+	}
+
+	// Add query string parameters
+	params := url.Values{}
+	if s.pretty {
+		params.Set("pretty", "1")
+	}
+	if len(s.actions) > 0 {
+		params.Set("actions", strings.Join(s.actions, ","))
+	}
+	if len(s.nodeId) > 0 {
+		params.Set("node_id", strings.Join(s.nodeId, ","))
+	}
+	if s.parentNode != "" {
+		params.Set("parent_node", s.parentNode)
+	}
+	if s.parentTask != nil {
+		params.Set("parent_task", fmt.Sprintf("%v", *s.parentTask))
+	}
+	return path, params, nil
+}
+
+// Validate checks if the operation is valid.
+func (s *TasksCancelService) Validate() error {
+	return nil
+}
+
+// Do executes the operation.
+func (s *TasksCancelService) Do() (*TasksListResponse, error) {
+	// Check pre-conditions
+	if err := s.Validate(); err != nil {
+		return nil, err
+	}
+
+	// Get URL for request
+	path, params, err := s.buildURL()
+	if err != nil {
+		return nil, err
+	}
+
+	// Get HTTP response
+	res, err := s.client.PerformRequest("POST", path, params, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	// Return operation response
+	ret := new(TasksListResponse)
+	if err := s.client.decoder.Decode(res.Body, ret); err != nil {
+		return nil, err
+	}
+	return ret, nil
+}