Fix reduce network calls count for the target url

entity/cache.go

@@ -0,0 +1,42 @@
+package entity
+
+import (
+	"bytes"
+	"io"
+	"sync"
+)
+
+func NewCache() *Cache {
+	return &Cache{data: make([]byte, 0, 1024*512)}
+}
+
+type Cache struct {
+	mu   sync.RWMutex
+	data []byte
+}
+
+func (c *Cache) Write(p []byte) (n int, err error) {
+	c.mu.Lock()
+	c.data = append(c.data, p...)
+	c.mu.Unlock()
+
+	return len(p), nil
+}
+
+func (c *Cache) Get() []byte {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+
+	return c.data
+}
+
+func (c *Cache) Reader() io.Reader {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+
+	if len(c.data) == 0 {
+		return nil
+	}
+
+	return bytes.NewBuffer(c.data)
+}