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/suggest.go

@@ -0,0 +1,144 @@
+// Copyright 2012-2015 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 (
+	"encoding/json"
+	"fmt"
+	"net/url"
+	"strings"
+
+	"gopkg.in/olivere/elastic.v3/uritemplates"
+)
+
+// SuggestService returns suggestions for text.
+type SuggestService struct {
+	client     *Client
+	pretty     bool
+	routing    string
+	preference string
+	indices    []string
+	suggesters []Suggester
+}
+
+func NewSuggestService(client *Client) *SuggestService {
+	builder := &SuggestService{
+		client:     client,
+		indices:    make([]string, 0),
+		suggesters: make([]Suggester, 0),
+	}
+	return builder
+}
+
+func (s *SuggestService) Index(indices ...string) *SuggestService {
+	s.indices = append(s.indices, indices...)
+	return s
+}
+
+func (s *SuggestService) Pretty(pretty bool) *SuggestService {
+	s.pretty = pretty
+	return s
+}
+
+func (s *SuggestService) Routing(routing string) *SuggestService {
+	s.routing = routing
+	return s
+}
+
+func (s *SuggestService) Preference(preference string) *SuggestService {
+	s.preference = preference
+	return s
+}
+
+func (s *SuggestService) Suggester(suggester Suggester) *SuggestService {
+	s.suggesters = append(s.suggesters, suggester)
+	return s
+}
+
+func (s *SuggestService) Do() (SuggestResult, error) {
+	// Build url
+	path := "/"
+
+	// Indices part
+	indexPart := make([]string, 0)
+	for _, index := range s.indices {
+		index, err := uritemplates.Expand("{index}", map[string]string{
+			"index": index,
+		})
+		if err != nil {
+			return nil, err
+		}
+		indexPart = append(indexPart, index)
+	}
+	path += strings.Join(indexPart, ",")
+
+	// Suggest
+	path += "/_suggest"
+
+	// Parameters
+	params := make(url.Values)
+	if s.pretty {
+		params.Set("pretty", fmt.Sprintf("%v", s.pretty))
+	}
+	if s.routing != "" {
+		params.Set("routing", s.routing)
+	}
+	if s.preference != "" {
+		params.Set("preference", s.preference)
+	}
+
+	// Set body
+	body := make(map[string]interface{})
+	for _, s := range s.suggesters {
+		src, err := s.Source(false)
+		if err != nil {
+			return nil, err
+		}
+		body[s.Name()] = src
+	}
+
+	// Get response
+	res, err := s.client.PerformRequest("POST", path, params, body)
+	if err != nil {
+		return nil, err
+	}
+
+	// There is a _shard object that cannot be deserialized.
+	// So we use json.RawMessage instead.
+	var suggestions map[string]*json.RawMessage
+	if err := s.client.decoder.Decode(res.Body, &suggestions); err != nil {
+		return nil, err
+	}
+
+	ret := make(SuggestResult)
+	for name, result := range suggestions {
+		if name != "_shards" {
+			var sug []Suggestion
+			if err := s.client.decoder.Decode(*result, &sug); err != nil {
+				return nil, err
+			}
+			ret[name] = sug
+		}
+	}
+
+	return ret, nil
+}
+
+type SuggestResult map[string][]Suggestion
+
+type Suggestion struct {
+	Text    string             `json:"text"`
+	Offset  int                `json:"offset"`
+	Length  int                `json:"length"`
+	Options []suggestionOption `json:"options"`
+}
+
+type suggestionOption struct {
+	Text         string      `json:"text"`
+	Score        float64     `json:"score"`
+	Freq         int         `json:"freq"`
+	Payload      interface{} `json:"payload"`
+	CollateMatch bool        `json:"collate_match"`
+}