feat: mapreduce generic version (#2827)

* feat: mapreduce generic version

* fix: gateway mr type issue

---------

Co-authored-by: kevin.wan <kevin.wan@yijinin.com>

core/mr/mapreduce_fuzzcase_test.go

@@ -54,28 +54,27 @@ func TestMapReduceRandom(t *testing.T) {
 				reducerIdx := rand.Int63n(n)
 				squareSum := (n - 1) * n * (2*n - 1) / 6
 
-				fn := func() (any, error) {
-					return MapReduce(func(source chan<- any) {
+				fn := func() (int64, error) {
+					return MapReduce(func(source chan<- int64) {
 						for i := int64(0); i < n; i++ {
 							source <- i
 							if genPanic && i == genIdx {
 								panic("foo")
 							}
 						}
-					}, func(item any, writer Writer, cancel func(error)) {
-						v := item.(int64)
+					}, func(v int64, writer Writer[int64], cancel func(error)) {
 						if mapperPanic && v == mapperIdx {
 							panic("bar")
 						}
 						writer.Write(v * v)
-					}, func(pipe <-chan any, writer Writer, cancel func(error)) {
+					}, func(pipe <-chan int64, writer Writer[int64], cancel func(error)) {
 						var idx int64
 						var total int64
 						for v := range pipe {
 							if reducerPanic && idx == reducerIdx {
 								panic("baz")
 							}
-							total += v.(int64)
+							total += v
 							idx++
 						}
 						writer.Write(total)
@@ -95,7 +94,7 @@ func TestMapReduceRandom(t *testing.T) {
 				} else {
 					val, err := fn()
 					assert.Nil(t, err)
-					assert.Equal(t, squareSum, val.(int64))
+					assert.Equal(t, squareSum, val)
 				}
 				bar.Increment()
 			})