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/suggester_completion.go

@@ -0,0 +1,129 @@
+// 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
+
+// CompletionSuggester is a fast suggester for e.g. type-ahead completion.
+// See http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/search-suggesters-completion.html
+// for more details.
+type CompletionSuggester struct {
+	Suggester
+	name           string
+	text           string
+	field          string
+	analyzer       string
+	size           *int
+	shardSize      *int
+	contextQueries []SuggesterContextQuery
+}
+
+// Creates a new completion suggester.
+func NewCompletionSuggester(name string) *CompletionSuggester {
+	return &CompletionSuggester{
+		name:           name,
+		contextQueries: make([]SuggesterContextQuery, 0),
+	}
+}
+
+func (q *CompletionSuggester) Name() string {
+	return q.name
+}
+
+func (q *CompletionSuggester) Text(text string) *CompletionSuggester {
+	q.text = text
+	return q
+}
+
+func (q *CompletionSuggester) Field(field string) *CompletionSuggester {
+	q.field = field
+	return q
+}
+
+func (q *CompletionSuggester) Analyzer(analyzer string) *CompletionSuggester {
+	q.analyzer = analyzer
+	return q
+}
+
+func (q *CompletionSuggester) Size(size int) *CompletionSuggester {
+	q.size = &size
+	return q
+}
+
+func (q *CompletionSuggester) ShardSize(shardSize int) *CompletionSuggester {
+	q.shardSize = &shardSize
+	return q
+}
+
+func (q *CompletionSuggester) ContextQuery(query SuggesterContextQuery) *CompletionSuggester {
+	q.contextQueries = append(q.contextQueries, query)
+	return q
+}
+
+func (q *CompletionSuggester) ContextQueries(queries ...SuggesterContextQuery) *CompletionSuggester {
+	q.contextQueries = append(q.contextQueries, queries...)
+	return q
+}
+
+// completionSuggesterRequest is necessary because the order in which
+// the JSON elements are routed to Elasticsearch is relevant.
+// We got into trouble when using plain maps because the text element
+// needs to go before the completion element.
+type completionSuggesterRequest struct {
+	Text       string      `json:"text"`
+	Completion interface{} `json:"completion"`
+}
+
+// Creates the source for the completion suggester.
+func (q *CompletionSuggester) Source(includeName bool) (interface{}, error) {
+	cs := &completionSuggesterRequest{}
+
+	if q.text != "" {
+		cs.Text = q.text
+	}
+
+	suggester := make(map[string]interface{})
+	cs.Completion = suggester
+
+	if q.analyzer != "" {
+		suggester["analyzer"] = q.analyzer
+	}
+	if q.field != "" {
+		suggester["field"] = q.field
+	}
+	if q.size != nil {
+		suggester["size"] = *q.size
+	}
+	if q.shardSize != nil {
+		suggester["shard_size"] = *q.shardSize
+	}
+	switch len(q.contextQueries) {
+	case 0:
+	case 1:
+		src, err := q.contextQueries[0].Source()
+		if err != nil {
+			return nil, err
+		}
+		suggester["context"] = src
+	default:
+		ctxq := make([]interface{}, 0)
+		for _, query := range q.contextQueries {
+			src, err := query.Source()
+			if err != nil {
+				return nil, err
+			}
+			ctxq = append(ctxq, src)
+		}
+		suggester["context"] = ctxq
+	}
+
+	// TODO(oe) Add completion-suggester specific parameters here
+
+	if !includeName {
+		return cs, nil
+	}
+
+	source := make(map[string]interface{})
+	source[q.name] = cs
+	return source, nil
+}