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/scroll.go

@@ -0,0 +1,205 @@
+// 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 (
+	"fmt"
+	"net/url"
+	"strings"
+
+	"gopkg.in/olivere/elastic.v3/uritemplates"
+)
+
+// ScrollService manages a cursor through documents in Elasticsearch.
+type ScrollService struct {
+	client    *Client
+	indices   []string
+	types     []string
+	keepAlive string
+	query     Query
+	size      *int
+	pretty    bool
+	scrollId  string
+}
+
+func NewScrollService(client *Client) *ScrollService {
+	builder := &ScrollService{
+		client: client,
+		query:  NewMatchAllQuery(),
+	}
+	return builder
+}
+
+func (s *ScrollService) Index(indices ...string) *ScrollService {
+	if s.indices == nil {
+		s.indices = make([]string, 0)
+	}
+	s.indices = append(s.indices, indices...)
+	return s
+}
+
+func (s *ScrollService) Type(types ...string) *ScrollService {
+	if s.types == nil {
+		s.types = make([]string, 0)
+	}
+	s.types = append(s.types, types...)
+	return s
+}
+
+// Scroll is an alias for KeepAlive, the time to keep
+// the cursor alive (e.g. "5m" for 5 minutes).
+func (s *ScrollService) Scroll(keepAlive string) *ScrollService {
+	s.keepAlive = keepAlive
+	return s
+}
+
+// KeepAlive sets the maximum time the cursor will be
+// available before expiration (e.g. "5m" for 5 minutes).
+func (s *ScrollService) KeepAlive(keepAlive string) *ScrollService {
+	s.keepAlive = keepAlive
+	return s
+}
+
+func (s *ScrollService) Query(query Query) *ScrollService {
+	s.query = query
+	return s
+}
+
+func (s *ScrollService) Pretty(pretty bool) *ScrollService {
+	s.pretty = pretty
+	return s
+}
+
+func (s *ScrollService) Size(size int) *ScrollService {
+	s.size = &size
+	return s
+}
+
+func (s *ScrollService) ScrollId(scrollId string) *ScrollService {
+	s.scrollId = scrollId
+	return s
+}
+
+func (s *ScrollService) Do() (*SearchResult, error) {
+	if s.scrollId == "" {
+		return s.GetFirstPage()
+	}
+	return s.GetNextPage()
+}
+
+func (s *ScrollService) GetFirstPage() (*SearchResult, 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)
+	}
+	if len(indexPart) > 0 {
+		path += strings.Join(indexPart, ",")
+	}
+
+	// Types
+	typesPart := make([]string, 0)
+	for _, typ := range s.types {
+		typ, err := uritemplates.Expand("{type}", map[string]string{
+			"type": typ,
+		})
+		if err != nil {
+			return nil, err
+		}
+		typesPart = append(typesPart, typ)
+	}
+	if len(typesPart) > 0 {
+		path += "/" + strings.Join(typesPart, ",")
+	}
+
+	// Search
+	path += "/_search"
+
+	// Parameters
+	params := make(url.Values)
+	if s.pretty {
+		params.Set("pretty", fmt.Sprintf("%v", s.pretty))
+	}
+	if s.keepAlive != "" {
+		params.Set("scroll", s.keepAlive)
+	} else {
+		params.Set("scroll", defaultKeepAlive)
+	}
+	if s.size != nil && *s.size > 0 {
+		params.Set("size", fmt.Sprintf("%d", *s.size))
+	}
+
+	// Set body
+	body := make(map[string]interface{})
+	if s.query != nil {
+		src, err := s.query.Source()
+		if err != nil {
+			return nil, err
+		}
+		body["query"] = src
+	}
+
+	// Get response
+	res, err := s.client.PerformRequest("POST", path, params, body)
+	if err != nil {
+		return nil, err
+	}
+
+	// Return result
+	searchResult := new(SearchResult)
+	if err := s.client.decoder.Decode(res.Body, searchResult); err != nil {
+		return nil, err
+	}
+
+	return searchResult, nil
+}
+
+func (s *ScrollService) GetNextPage() (*SearchResult, error) {
+	if s.scrollId == "" {
+		return nil, EOS
+	}
+
+	// Build url
+	path := "/_search/scroll"
+
+	// Parameters
+	params := make(url.Values)
+	if s.pretty {
+		params.Set("pretty", fmt.Sprintf("%v", s.pretty))
+	}
+	if s.keepAlive != "" {
+		params.Set("scroll", s.keepAlive)
+	} else {
+		params.Set("scroll", defaultKeepAlive)
+	}
+
+	// Get response
+	res, err := s.client.PerformRequest("POST", path, params, s.scrollId)
+	if err != nil {
+		return nil, err
+	}
+
+	// Return result
+	searchResult := new(SearchResult)
+	if err := s.client.decoder.Decode(res.Body, searchResult); err != nil {
+		return nil, err
+	}
+
+	// Determine last page
+	if searchResult == nil || searchResult.Hits == nil || len(searchResult.Hits.Hits) == 0 || searchResult.Hits.TotalHits == 0 {
+		return nil, EOS
+	}
+
+	return searchResult, nil
+}