Added missing features for source filtering

One can use source filtering now in the Get API.
See http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/docs-get.html#get-source-filtering
for details on source filtering.

Examples:

```go
res, err := client.Get().Index("test").Type("tweet").Id("1").FetchSource(false).Do()
// res.Source should be nil here
```

```go
fsc := NewFetchSourceContext(true).Exclude("message")
res, err := client.Get().Index("test").Type("tweet").Id("1").FetchSourceContext(fsc).Do()
// res.Source should not be nil, but missing the "message" field
```

A more flexible approach is to use the `FetchSourceContext` also used in
the Java API. See
https://github.com/elasticsearch/elasticsearch/blob/master/src/main/java/org/elasticsearch/search/fetch/source/FetchSourceContext.java.
It is available in Elastic as well in
https://github.com/olivere/elastic/blob/master/fetch_source_context.go.

This commit also adds missing fields `version` and `version_type` to the
Get and MGet APIs.

Also fixed the fact that [1.3.8,1.4.0) and 1.4.3+ disabled Groovy
scripting by default. A test in the update API will be skipped for these
versions.

Closes olivere#40

fetch_source_context.go

@@ -1,5 +1,10 @@
 package elastic
 
+import (
+	"net/url"
+	"strings"
+)
+
 type FetchSourceContext struct {
 	fetchSource     bool
 	transformSource bool
@@ -47,3 +52,19 @@ func (fsc *FetchSourceContext) Source() interface{} {
 		"excludes": fsc.excludes,
 	}
 }
+
+// Query returns the parameters in a form suitable for a URL query string.
+func (fsc *FetchSourceContext) Query() url.Values {
+	params := url.Values{}
+	if !fsc.fetchSource {
+		params.Add("_source", "false")
+		return params
+	}
+	if len(fsc.includes) > 0 {
+		params.Add("_source_include", strings.Join(fsc.includes, ","))
+	}
+	if len(fsc.excludes) > 0 {
+		params.Add("_source_exclude", strings.Join(fsc.excludes, ","))
+	}
+	return params
+}

fetch_source_context_test.go

@@ -56,3 +56,33 @@ func TestFetchSourceContextFetchSourceWithIncludesAndExcludes(t *testing.T) {
 		t.Errorf("expected\n%s\n,got:\n%s", expected, got)
 	}
 }
+
+func TestFetchSourceContextQueryDefaults(t *testing.T) {
+	builder := NewFetchSourceContext(true)
+	values := builder.Query()
+	got := values.Encode()
+	expected := ""
+	if got != expected {
+		t.Errorf("expected %q; got: %q", expected, got)
+	}
+}
+
+func TestFetchSourceContextQueryNoFetchSource(t *testing.T) {
+	builder := NewFetchSourceContext(false)
+	values := builder.Query()
+	got := values.Encode()
+	expected := "_source=false"
+	if got != expected {
+		t.Errorf("expected %q; got: %q", expected, got)
+	}
+}
+
+func TestFetchSourceContextQueryFetchSourceWithIncludesAndExcludes(t *testing.T) {
+	builder := NewFetchSourceContext(true).Include("a", "b").Exclude("c")
+	values := builder.Query()
+	got := values.Encode()
+	expected := "_source_exclude=c&_source_include=a%2Cb"
+	if got != expected {
+		t.Errorf("expected %q; got: %q", expected, got)
+	}
+}

get.go

@@ -15,15 +15,19 @@ import (
 )
 
 type GetService struct {
-	client     *Client
-	index      string
-	_type      string
-	id         string
-	routing    string
-	preference string
-	fields     []string
-	refresh    *bool
-	realtime   *bool
+	client                     *Client
+	index                      string
+	_type                      string
+	id                         string
+	routing                    string
+	preference                 string
+	fields                     []string
+	fsc                        *FetchSourceContext
+	refresh                    *bool
+	realtime                   *bool
+	version                    *int64 // see org.elasticsearch.common.lucene.uid.Versions
+	versionType                string // see org.elasticsearch.index.VersionType
+	ignoreErrOnGeneratedFields *bool
 }
 
 func NewGetService(client *Client) *GetService {
@@ -82,6 +86,20 @@ func (b *GetService) Fields(fields ...string) *GetService {
 	return b
 }
 
+func (s *GetService) FetchSource(fetchSource bool) *GetService {
+	if s.fsc == nil {
+		s.fsc = NewFetchSourceContext(fetchSource)
+	} else {
+		s.fsc.SetFetchSource(fetchSource)
+	}
+	return s
+}
+
+func (s *GetService) FetchSourceContext(fetchSourceContext *FetchSourceContext) *GetService {
+	s.fsc = fetchSourceContext
+	return s
+}
+
 func (b *GetService) Refresh(refresh bool) *GetService {
 	b.refresh = &refresh
 	return b
@@ -92,6 +110,22 @@ func (b *GetService) Realtime(realtime bool) *GetService {
 	return b
 }
 
+// Version can be MatchAny (-3), MatchAnyPre120 (0), NotFound (-1),
+// or NotSet (-2). These are specified in org.elasticsearch.common.lucene.uid.Versions.
+// The default is MatchAny (-3).
+func (b *GetService) Version(version int64) *GetService {
+	b.version = &version
+	return b
+}
+
+// VersionType can be "internal", "external", "external_gt", "external_gte",
+// or "force". See org.elasticsearch.index.VersionType in Elasticsearch source.
+// It is "internal" by default.
+func (b *GetService) VersionType(versionType string) *GetService {
+	b.versionType = versionType
+	return b
+}
+
 func (b *GetService) Do() (*GetResult, error) {
 	// Build url
 	urls, err := uritemplates.Expand("/{index}/{type}/{id}", map[string]string{
@@ -119,6 +153,17 @@ func (b *GetService) Do() (*GetResult, error) {
 	if b.refresh != nil {
 		params.Add("refresh", fmt.Sprintf("%v", *b.refresh))
 	}
+	if b.version != nil {
+		params.Add("_version", fmt.Sprintf("%d", *b.version))
+	}
+	if b.versionType != "" {
+		params.Add("_version_type", b.versionType)
+	}
+	if b.fsc != nil {
+		for k, values := range b.fsc.Query() {
+			params.Add(k, strings.Join(values, ","))
+		}
+	}
 	if len(params) > 0 {
 		urls += "?" + params.Encode()
 	}
@@ -129,8 +174,6 @@ func (b *GetService) Do() (*GetResult, error) {
 		return nil, err
 	}
 
-	// No body in get requests
-
 	// Get response
 	res, err := b.client.c.Do((*http.Request)(req))
 	if err != nil {

get_test.go

@@ -5,6 +5,7 @@
 package elastic
 
 import (
+	"encoding/json"
 	"testing"
 )
 
@@ -69,3 +70,68 @@ func TestGet(t *testing.T) {
 		t.Errorf("expected Source == nil; got %v", res.Source)
 	}
 }
+
+func TestGetWithSourceFiltering(t *testing.T) {
+	client := setupTestClientAndCreateIndex(t)
+
+	tweet1 := tweet{User: "olivere", Message: "Welcome to Golang and Elasticsearch."}
+	tweet2 := tweet{User: "olivere", Message: "Another unrelated topic."}
+	tweet3 := tweet{User: "sandrae", Message: "Cycling is fun."}
+
+	// Add all documents
+	_, err := client.Index().Index(testIndexName).Type("tweet").Id("1").BodyJson(&tweet1).Do()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_, err = client.Index().Index(testIndexName).Type("tweet").Id("2").BodyJson(&tweet2).Do()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_, err = client.Index().Index(testIndexName).Type("tweet").Id("3").BodyJson(&tweet3).Do()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_, err = client.Flush().Index(testIndexName).Do()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Get document 1, without source
+	res, err := client.Get().Index(testIndexName).Type("tweet").Id("1").FetchSource(false).Do()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if res.Found != true {
+		t.Errorf("expected Found = true; got %v", res.Found)
+	}
+	if res.Source != nil {
+		t.Errorf("expected Source == nil; got %v", res.Source)
+	}
+
+	// Get document 1, exclude Message field
+	fsc := NewFetchSourceContext(true).Exclude("message")
+	res, err = client.Get().Index(testIndexName).Type("tweet").Id("1").FetchSourceContext(fsc).Do()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if res.Found != true {
+		t.Errorf("expected Found = true; got %v", res.Found)
+	}
+	if res.Source == nil {
+		t.Errorf("expected Source != nil; got %v", res.Source)
+	}
+	var tw tweet
+	err = json.Unmarshal(*res.Source, &tw)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if tw.User != "olivere" {
+		t.Errorf("expected user %q; got: %q", "olivere", tw.User)
+	}
+	if tw.Message != "" {
+		t.Errorf("expected message %q; got: %q", "", tw.Message)
+	}
+}

multi_get.go

@@ -109,15 +109,13 @@ type MultiGetItem struct {
 	id          string
 	routing     string
 	fields      []string
-	version     int64  // see org.elasticsearch.common.lucene.uid.Versions
+	version     *int64 // see org.elasticsearch.common.lucene.uid.Versions
 	versionType string // see org.elasticsearch.index.VersionType
 	fsc         *FetchSourceContext
 }
 
 func NewMultiGetItem() *MultiGetItem {
-	return &MultiGetItem{
-		version: -3, // MatchAny (see Version below)
-	}
+	return &MultiGetItem{}
 }
 
 func (item *MultiGetItem) Index(index string) *MultiGetItem {
@@ -152,7 +150,7 @@ func (item *MultiGetItem) Fields(fields ...string) *MultiGetItem {
 // or NotSet (-2). These are specified in org.elasticsearch.common.lucene.uid.Versions.
 // The default is MatchAny (-3).
 func (item *MultiGetItem) Version(version int64) *MultiGetItem {
-	item.version = version
+	item.version = &version
 	return item
 }
 
@@ -174,25 +172,29 @@ func (item *MultiGetItem) FetchSource(fetchSourceContext *FetchSourceContext) *M
 func (item *MultiGetItem) Source() interface{} {
 	source := make(map[string]interface{})
 
+	source["_id"] = item.id
+
 	if item.index != "" {
 		source["_index"] = item.index
 	}
 	if item.typ != "" {
 		source["_type"] = item.typ
 	}
-	source["_id"] = item.id
-
 	if item.fsc != nil {
 		source["_source"] = item.fsc.Source()
 	}
-
 	if item.fields != nil {
 		source["_fields"] = item.fields
 	}
-
 	if item.routing != "" {
 		source["_routing"] = item.routing
 	}
+	if item.version != nil {
+		source["_version"] = *item.version
+	}
+	if item.versionType != "" {
+		source["_version_type"] = item.versionType
+	}
 
 	return source
 }

update_test.go

@@ -172,6 +172,16 @@ func TestUpdateViaDocAndUpsert(t *testing.T) {
 func TestUpdateViaScriptIntegration(t *testing.T) {
 	client := setupTestClientAndCreateIndex(t)
 
+	// Groovy is disabled for [1.3.8,1.4.0) and 1.4.3+, so skip tests in that case
+	esversion, err := client.ElasticsearchVersion(defaultUrl)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if esversion >= "1.4.3" || (esversion < "1.4.0" && esversion >= "1.3.8") {
+		t.Skip("groovy scripting has been disabled as for [1.3.8,1.4.0) and 1.4.3+")
+		return
+	}
+
 	tweet1 := tweet{User: "olivere", Retweets: 10, Message: "Welcome to Golang and Elasticsearch."}
 
 	// Add a document