Add BF.INFO and BF.RESERVE

Author: gkorland

client.go

@@ -1,7 +1,9 @@
 package redis_bloom_go
 
 import (
+	"errors"
 	"strings"
+	"strconv"
 	"github.com/gomodule/redigo/redis"
 )
 
@@ -33,6 +35,19 @@ func NewClient(addr, name string, authPass *string) *Client {
 	return ret
 }
 
+// Reserve - Creates an empty Bloom Filter with a given desired error ratio and initial capacity. 
+// args:
+// key - the name of the filter
+// error_rate - the desired probability for false positives
+// capacity - the number of entries you intend to add to the filter 
+func (client *Client) Reserve(key string, error_rate float64, capacity uint64) (err error) {
+	conn := client.Pool.Get()
+	defer conn.Close()
+	_, err = conn.Do("BF.RESERVE", key,  strconv.FormatFloat(error_rate, 'g', 16, 64), capacity)
+	return err
+}
+
+
 // Add - Add (or create and add) a new value to the filter
 // args:
 // key - the name of the filter 
@@ -52,3 +67,35 @@ func (client *Client) Exists(key string, item string) (exists bool, err error) {
 	defer conn.Close()
 	return redis.Bool(conn.Do("BF.EXISTS", key, item))
 }
+
+// Info - Return information about key  
+// args:
+// key - the name of the filter 
+func (client *Client) Info(key string) (info map[string]int64, err error) {
+	conn := client.Pool.Get()
+	defer conn.Close()
+	result, err := conn.Do("BF.INFO", key)
+	if err != nil {
+		return nil, err
+	}
+	
+	values, err := redis.Values(result, nil)
+	if err != nil {
+		return nil, err
+	}
+	if len(values)%2 != 0 {
+		return nil, errors.New("Info expects even number of values result")
+	}
+	info = map[string]int64{}
+	for i := 0; i < len(values); i += 2 {
+		key, err = redis.String(values[i], nil)	
+		if err != nil {
+			return nil, err
+		}
+		info[key], err = redis.Int64(values[i+1], nil)
+		if err != nil {
+			return nil, err
+		}
+	}
+	return info, nil				
+}

client_test.go

@@ -41,6 +41,26 @@ func (client *Client) FlushAll() (err error) {
 	return err
 }
 
+func TestReserve(t *testing.T) {
+	client.FlushAll()
+	key := "test_RESERVE"
+	err := client.Reserve(key, 0.1, 1000)
+	assert.Nil(t, err)
+	
+	info, err := client.Info(key)
+	assert.Nil(t, err)
+	assert.Equal(t, info, map[string]int64{
+			"Capacity": 1000,
+			"Expansion rate": 2,
+            "Number of filters": 1,
+            "Number of items inserted": 0,
+            "Size": 932,
+	})
+	
+	err = client.Reserve(key, 0.1, 1000)
+	assert.NotNil(t, err)
+}
+
 func TestAdd(t *testing.T) {
 	client.FlushAll()
 	key := "test_ADD"
@@ -49,6 +69,10 @@ func TestAdd(t *testing.T) {
 	assert.Nil(t, err)
 	assert.True(t, exists)
 
+	info, err := client.Info(key)
+	assert.Nil(t, err)
+	assert.NotNil(t, info)
+	
 	exists, err = client.Add(key, value)
 	assert.Nil(t, err)
 	assert.False(t, exists)