[add] added DropIndex method (#94) (#96)

* [add] added DropIndex method

* Included DropIndex() example. Extended method description

* [add] Included extra test to cover all DropIndex() conditions

Co-authored-by: 何鸿志 <hehongzhi@njxtc.com>
Co-authored-by: filipecosta90 <filipecosta.90@gmail.com>

redisearch/client.go

@@ -363,6 +363,24 @@ func (i *Client) Drop() error {
 
 }
 
+// Deletes the secondary index and optionally the associated hashes
+//
+// Available since RediSearch 2.0.
+//
+// By default, DropIndex() which is a wrapper for RediSearch FT.DROPINDEX does not delete the document hashes associated with the index.
+// Setting the argument deleteDocuments to true deletes the hashes as well.
+func (i *Client) DropIndex(deleteDocuments bool) error {
+	conn := i.pool.Get()
+	defer conn.Close()
+	var err error = nil
+	if deleteDocuments {
+		_, err = conn.Do("FT.DROPINDEX", i.name, "DD")
+	} else {
+		_, err = conn.Do("FT.DROPINDEX", i.name)
+	}
+	return err
+}
+
 // Delete the document from the index, optionally delete the actual document
 // WARNING: As of RediSearch 2.0 and above, FT.DEL always deletes the underlying document.
 // Deprecated: This function  is deprecated on RediSearch 2.0 and above, use DeleteDocument() instead

redisearch/client_test.go

@@ -894,3 +894,74 @@ func TestClient_CreateIndex(t *testing.T) {
 	assert.Equal(t, "Jon", docs[0].Properties["name"])
 	assert.Equal(t, "John", docs[1].Properties["name"])
 }
+
+func TestClient_DropIndex(t *testing.T) {
+	c := createClient("drop-index-example")
+	version, err := c.getRediSearchVersion()
+	assert.Nil(t, err)
+	if version <= 10699 {
+		// DropIndex() is available for RediSearch 2.0+
+		return
+	}
+
+	// Create a schema
+	schema := NewSchema(DefaultOptions).
+		AddField(NewTextFieldOptions("name", TextFieldOptions{Sortable: true, PhoneticMatcher: PhoneticDoubleMetaphoneEnglish})).
+		AddField(NewNumericField("age"))
+
+	// IndexDefinition is available for RediSearch 2.0+
+	// In this example we will only index keys started by product:
+	indexDefinition := NewIndexDefinition().AddPrefix("drop-index:")
+
+	// Add the Index Definition
+	err = c.CreateIndexWithIndexDefinition(schema, indexDefinition)
+	assert.Nil(t, err)
+
+	// Create docs with a name that has the same phonetic matcher
+	vanillaConnection := c.pool.Get()
+	vanillaConnection.Do("HSET", "drop-index:doc1", "name", "Jon", "age", 25)
+	vanillaConnection.Do("HSET", "drop-index:doc2", "name", "John", "age", 20)
+
+	// Wait for all documents to be indexed
+	info, _ := c.Info()
+	for info.IsIndexing {
+		time.Sleep(time.Second)
+		info, _ = c.Info()
+	}
+
+	// Drop index but keep docs
+	err = c.DropIndex(false)
+	assert.Nil(t, err)
+	// Now that we don't have the index this should raise an error
+	_, err = c.Info()
+	assert.EqualError(t, err, "Unknown Index name")
+	// Assert hashes still exist
+	result, err := vanillaConnection.Do("EXISTS", "drop-index:doc1")
+	assert.Equal(t, int64(1), result)
+	result, err = vanillaConnection.Do("EXISTS", "drop-index:doc2")
+	assert.Equal(t, int64(1), result)
+
+	// Create index again
+	err = c.CreateIndexWithIndexDefinition(schema, indexDefinition)
+
+	// Wait for all documents to be indexed again
+	info, _ = c.Info()
+	for info.IsIndexing {
+		time.Sleep(time.Second)
+		info, _ = c.Info()
+	}
+
+	assert.Nil(t, err)
+	// Drop index but keep docs
+	err = c.DropIndex(true)
+	assert.Nil(t, err)
+	// Now that we don't have the index this should raise an error
+	_, err = c.Info()
+	assert.EqualError(t, err, "Unknown Index name")
+	// Assert hashes still exist
+	result, err = vanillaConnection.Do("EXISTS", "drop-index:doc1")
+	assert.Equal(t, int64(0), result)
+	result, err = vanillaConnection.Do("EXISTS", "drop-index:doc2")
+	assert.Equal(t, int64(0), result)
+
+}

redisearch/example_client_test.go

@@ -107,6 +107,54 @@ func ExampleClient_CreateIndexWithIndexDefinition() {
 	fmt.Printf("Total documents containing \"description\": %d.\n", total)
 }
 
+// The following example illustrates an index creation and deletion.
+// By default, DropIndex() which is a wrapper for RediSearch FT.DROPINDEX does not delete the document hashes associated with the index.
+// Setting the argument deleteDocuments to true deletes the hashes as well.
+// Available since RediSearch 2.0
+func ExampleClient_DropIndex() {
+
+	host := "localhost:6379"
+	password := ""
+	pool := &redis.Pool{Dial: func() (redis.Conn, error) {
+		return redis.Dial("tcp", host, redis.DialPassword(password))
+	}}
+	c := redisearch.NewClientFromPool(pool, "products-from-hashes")
+
+	// Create a schema
+	schema := redisearch.NewSchema(redisearch.DefaultOptions).
+		AddField(redisearch.NewTextFieldOptions("name", redisearch.TextFieldOptions{Sortable: true})).
+		AddField(redisearch.NewTextFieldOptions("description", redisearch.TextFieldOptions{Weight: 5.0, Sortable: true})).
+		AddField(redisearch.NewNumericField("price"))
+
+	// IndexDefinition is available for RediSearch 2.0+
+	// Create a index definition for automatic indexing on Hash updates.
+	// In this example we will only index keys started by product:
+	indexDefinition := redisearch.NewIndexDefinition().AddPrefix("product:")
+
+	// Add the Index Definition
+	c.CreateIndexWithIndexDefinition(schema, indexDefinition)
+
+	// Get a vanilla connection and create 100 hashes
+	vanillaConnection := pool.Get()
+	for productNumber := 0; productNumber < 100; productNumber++ {
+		vanillaConnection.Do("HSET", fmt.Sprintf("product:%d", productNumber), "name", fmt.Sprintf("product name %d", productNumber), "description", "product description", "price", 10.99)
+	}
+
+	// Wait for all documents to be indexed
+	info, _ := c.Info()
+	for info.IsIndexing {
+		time.Sleep(time.Second)
+		info, _ = c.Info()
+	}
+
+	// Delete Index and Documents
+	err := c.DropIndex(true)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+}
+
 // exemplifies the NewClientFromPool function
 func ExampleNewClientFromPool() {
 	host := "localhost:6379"