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/search_request.go

@@ -0,0 +1,178 @@
+// 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"
+	"strings"
+)
+
+// SearchRequest combines a search request and its
+// query details (see SearchSource).
+// It is used in combination with MultiSearch.
+type SearchRequest struct {
+	searchType   string // default in ES is "query_then_fetch"
+	indices      []string
+	types        []string
+	routing      *string
+	preference   *string
+	requestCache *bool
+	scroll       string
+	source       interface{}
+}
+
+// NewSearchRequest creates a new search request.
+func NewSearchRequest() *SearchRequest {
+	return &SearchRequest{
+		indices: make([]string, 0),
+		types:   make([]string, 0),
+	}
+}
+
+// SearchRequest must be one of "query_then_fetch", "query_and_fetch",
+// "scan", "count", "dfs_query_then_fetch", or "dfs_query_and_fetch".
+// Use one of the constants defined via SearchType.
+func (r *SearchRequest) SearchType(searchType string) *SearchRequest {
+	r.searchType = searchType
+	return r
+}
+
+func (r *SearchRequest) SearchTypeDfsQueryThenFetch() *SearchRequest {
+	return r.SearchType("dfs_query_then_fetch")
+}
+
+func (r *SearchRequest) SearchTypeDfsQueryAndFetch() *SearchRequest {
+	return r.SearchType("dfs_query_and_fetch")
+}
+
+func (r *SearchRequest) SearchTypeQueryThenFetch() *SearchRequest {
+	return r.SearchType("query_then_fetch")
+}
+
+func (r *SearchRequest) SearchTypeQueryAndFetch() *SearchRequest {
+	return r.SearchType("query_and_fetch")
+}
+
+func (r *SearchRequest) SearchTypeScan() *SearchRequest {
+	return r.SearchType("scan")
+}
+
+func (r *SearchRequest) SearchTypeCount() *SearchRequest {
+	return r.SearchType("count")
+}
+
+func (r *SearchRequest) Index(indices ...string) *SearchRequest {
+	r.indices = append(r.indices, indices...)
+	return r
+}
+
+func (r *SearchRequest) HasIndices() bool {
+	return len(r.indices) > 0
+}
+
+func (r *SearchRequest) Type(types ...string) *SearchRequest {
+	r.types = append(r.types, types...)
+	return r
+}
+
+func (r *SearchRequest) Routing(routing string) *SearchRequest {
+	r.routing = &routing
+	return r
+}
+
+func (r *SearchRequest) Routings(routings ...string) *SearchRequest {
+	if routings != nil {
+		routings := strings.Join(routings, ",")
+		r.routing = &routings
+	} else {
+		r.routing = nil
+	}
+	return r
+}
+
+func (r *SearchRequest) Preference(preference string) *SearchRequest {
+	r.preference = &preference
+	return r
+}
+
+func (r *SearchRequest) RequestCache(requestCache bool) *SearchRequest {
+	r.requestCache = &requestCache
+	return r
+}
+
+func (r *SearchRequest) Scroll(scroll string) *SearchRequest {
+	r.scroll = scroll
+	return r
+}
+
+func (r *SearchRequest) SearchSource(searchSource *SearchSource) *SearchRequest {
+	return r.Source(searchSource)
+}
+
+func (r *SearchRequest) Source(source interface{}) *SearchRequest {
+	switch v := source.(type) {
+	case *SearchSource:
+		src, err := v.Source()
+		if err != nil {
+			// Do not do anything in case of an error
+			return r
+		}
+		r.source = src
+	default:
+		r.source = source
+	}
+	return r
+}
+
+// header is used e.g. by MultiSearch to get information about the search header
+// of one SearchRequest.
+// See http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/search-multi-search.html
+func (r *SearchRequest) header() interface{} {
+	h := make(map[string]interface{})
+	if r.searchType != "" {
+		h["search_type"] = r.searchType
+	}
+
+	switch len(r.indices) {
+	case 0:
+	case 1:
+		h["index"] = r.indices[0]
+	default:
+		h["indices"] = r.indices
+	}
+
+	switch len(r.types) {
+	case 0:
+	case 1:
+		h["type"] = r.types[0]
+	default:
+		h["types"] = r.types
+	}
+
+	if r.routing != nil && *r.routing != "" {
+		h["routing"] = *r.routing
+	}
+
+	if r.preference != nil && *r.preference != "" {
+		h["preference"] = *r.preference
+	}
+
+	if r.requestCache != nil {
+		h["request_cache"] = fmt.Sprintf("%v", *r.requestCache)
+	}
+
+	if r.scroll != "" {
+		h["scroll"] = r.scroll
+	}
+
+	return h
+}
+
+// body is used by MultiSearch to get information about the search body
+// of one SearchRequest.
+// See http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/search-multi-search.html
+func (r *SearchRequest) body() interface{} {
+	return r.source
+}