From 2524563177ac0a4cffd340b58589ee337378b4c9 Mon Sep 17 00:00:00 2001
From: qishenonly <1050026498@qq.com>
Date: Tue, 4 Jul 2023 10:15:49 +0800
Subject: [PATCH] feat: new method--incrByFloat (#135)

---
 structure/string.go      | 28 ++++++++++++++++++++++++++++
 structure/string_test.go | 17 +++++++++++++++++
 2 files changed, 45 insertions(+)

diff --git a/structure/string.go b/structure/string.go
index 3719fcfa..318ef171 100644
--- a/structure/string.go
+++ b/structure/string.go
@@ -213,6 +213,34 @@ func (s *StringStructure) IncrBy(key []byte, amount int, ttl time.Duration) erro
 	return s.Set(key, newValue, ttl)
 }
 
+// IncrByFloat increments the float value of a key by the given amount
+// If the key does not exist, it will be created
+// If the key exists, it will be overwritten
+// If the key is expired, it will be deleted
+// If the key is not expired, it will be updated
+func (s *StringStructure) IncrByFloat(key []byte, amount float64, ttl time.Duration) error {
+	// Get the old value
+	oldValue, err := s.Get(key)
+	if err != nil {
+		return err
+	}
+
+	// Convert the old value to a float
+	oldFloatValue, err := strconv.ParseFloat(string(oldValue), 64)
+	if err != nil {
+		return err
+	}
+
+	// Increment the float value
+	newFloatValue := oldFloatValue + amount
+
+	// Convert the new float value to a byte slice
+	newValue := []byte(strconv.FormatFloat(newFloatValue, 'f', -1, 64))
+
+	// Set the value
+	return s.Set(key, newValue, ttl)
+}
+
 // encodeStringValue encodes the value
 // format: [type][expire][value]
 // type: 1 byte
diff --git a/structure/string_test.go b/structure/string_test.go
index 525ce060..6307d9c0 100644
--- a/structure/string_test.go
+++ b/structure/string_test.go
@@ -139,3 +139,20 @@ func TestStringStructure_IncrBy(t *testing.T) {
 	v2, _ := str.Get(randkv.GetTestKey(1))
 	assert.Equal(t, string(v2), "21")
 }
+
+func TestStringStructure_IncrByFloat(t *testing.T) {
+	str := initdb()
+
+	err = str.Set(randkv.GetTestKey(1), []byte("1"), 0)
+	assert.Nil(t, err)
+
+	err := str.IncrByFloat(randkv.GetTestKey(1), 1.1, 0)
+	assert.Nil(t, err)
+	v1, _ := str.Get(randkv.GetTestKey(1))
+	assert.Equal(t, string(v1), "2.1")
+
+	err = str.IncrByFloat(randkv.GetTestKey(1), 1.1, 0)
+	assert.Nil(t, err)
+	v2, _ := str.Get(randkv.GetTestKey(1))
+	assert.Equal(t, string(v2), "3.2")
+}