Issue search support elasticsearch (#9428)

* Issue search support elasticsearch

* Fix lint

* Add indexer name on app.ini

* add a warnning on SearchIssuesByKeyword

* improve code

vendor/github.com/olivere/elastic/v7/msearch.go

@@ -0,0 +1,169 @@
+// 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 (
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"net/url"
+	"strings"
+)
+
+// MultiSearch executes one or more searches in one roundtrip.
+type MultiSearchService struct {
+	client *Client
+
+	pretty     *bool       // pretty format the returned JSON response
+	human      *bool       // return human readable values for statistics
+	errorTrace *bool       // include the stack trace of returned errors
+	filterPath []string    // list of filters used to reduce the response
+	headers    http.Header // custom request-level HTTP headers
+
+	requests              []*SearchRequest
+	indices               []string
+	maxConcurrentRequests *int
+	preFilterShardSize    *int
+}
+
+func NewMultiSearchService(client *Client) *MultiSearchService {
+	builder := &MultiSearchService{
+		client: client,
+	}
+	return builder
+}
+
+// Pretty tells Elasticsearch whether to return a formatted JSON response.
+func (s *MultiSearchService) Pretty(pretty bool) *MultiSearchService {
+	s.pretty = &pretty
+	return s
+}
+
+// Human specifies whether human readable values should be returned in
+// the JSON response, e.g. "7.5mb".
+func (s *MultiSearchService) Human(human bool) *MultiSearchService {
+	s.human = &human
+	return s
+}
+
+// ErrorTrace specifies whether to include the stack trace of returned errors.
+func (s *MultiSearchService) ErrorTrace(errorTrace bool) *MultiSearchService {
+	s.errorTrace = &errorTrace
+	return s
+}
+
+// FilterPath specifies a list of filters used to reduce the response.
+func (s *MultiSearchService) FilterPath(filterPath ...string) *MultiSearchService {
+	s.filterPath = filterPath
+	return s
+}
+
+// Header adds a header to the request.
+func (s *MultiSearchService) Header(name string, value string) *MultiSearchService {
+	if s.headers == nil {
+		s.headers = http.Header{}
+	}
+	s.headers.Add(name, value)
+	return s
+}
+
+// Headers specifies the headers of the request.
+func (s *MultiSearchService) Headers(headers http.Header) *MultiSearchService {
+	s.headers = headers
+	return s
+}
+
+func (s *MultiSearchService) Add(requests ...*SearchRequest) *MultiSearchService {
+	s.requests = append(s.requests, requests...)
+	return s
+}
+
+func (s *MultiSearchService) Index(indices ...string) *MultiSearchService {
+	s.indices = append(s.indices, indices...)
+	return s
+}
+
+func (s *MultiSearchService) MaxConcurrentSearches(max int) *MultiSearchService {
+	s.maxConcurrentRequests = &max
+	return s
+}
+
+func (s *MultiSearchService) PreFilterShardSize(size int) *MultiSearchService {
+	s.preFilterShardSize = &size
+	return s
+}
+
+func (s *MultiSearchService) Do(ctx context.Context) (*MultiSearchResult, error) {
+	// Build url
+	path := "/_msearch"
+
+	// Parameters
+	params := url.Values{}
+	if v := s.pretty; v != nil {
+		params.Set("pretty", fmt.Sprint(*v))
+	}
+	if v := s.human; v != nil {
+		params.Set("human", fmt.Sprint(*v))
+	}
+	if v := s.errorTrace; v != nil {
+		params.Set("error_trace", fmt.Sprint(*v))
+	}
+	if len(s.filterPath) > 0 {
+		params.Set("filter_path", strings.Join(s.filterPath, ","))
+	}
+	if v := s.maxConcurrentRequests; v != nil {
+		params.Set("max_concurrent_searches", fmt.Sprintf("%v", *v))
+	}
+	if v := s.preFilterShardSize; v != nil {
+		params.Set("pre_filter_shard_size", fmt.Sprintf("%v", *v))
+	}
+
+	// Set body
+	var lines []string
+	for _, sr := range s.requests {
+		// Set default indices if not specified in the request
+		if !sr.HasIndices() && len(s.indices) > 0 {
+			sr = sr.Index(s.indices...)
+		}
+
+		header, err := json.Marshal(sr.header())
+		if err != nil {
+			return nil, err
+		}
+		body, err := sr.Body()
+		if err != nil {
+			return nil, err
+		}
+		lines = append(lines, string(header))
+		lines = append(lines, body)
+	}
+	body := strings.Join(lines, "\n") + "\n" // add trailing \n
+
+	// Get response
+	res, err := s.client.PerformRequest(ctx, PerformRequestOptions{
+		Method:  "GET",
+		Path:    path,
+		Params:  params,
+		Body:    body,
+		Headers: s.headers,
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	// Return result
+	ret := new(MultiSearchResult)
+	if err := s.client.decoder.Decode(res.Body, ret); err != nil {
+		return nil, err
+	}
+	return ret, nil
+}
+
+// MultiSearchResult is the outcome of running a multi-search operation.
+type MultiSearchResult struct {
+	TookInMillis int64           `json:"took,omitempty"` // search time in milliseconds
+	Responses    []*SearchResult `json:"responses,omitempty"`
+}