feat(pool): enhance byte pool and add comprehensive tests

- Introduced new benchmarks for GetLarge and GetLargeUnsized methods to evaluate performance with varying buffer sizes.
- Added a new test file for BytesPool, covering various scenarios including sized and unsized buffer retrieval, buffer splitting, and memory safety.
- Improved memory management in the BytesPool implementation to ensure efficient buffer reuse and capacity handling.

internal/utils/synk/pool_bench_test.go

@@ -21,13 +21,25 @@ func BenchmarkBytesPool_MakeSmall(b *testing.B) {
 
 func BenchmarkBytesPool_GetLarge(b *testing.B) {
 	for b.Loop() {
-		bytesPool.Put(bytesPool.GetSized(1024 * 1024))
+		buf := bytesPool.GetSized(DropThreshold / 2)
+		buf[0] = 1
+		bytesPool.Put(buf)
+	}
+}
+
+func BenchmarkBytesPool_GetLargeUnsized(b *testing.B) {
+	for b.Loop() {
+		buf := slices.Grow(bytesPool.Get(), DropThreshold/2)
+		buf = append(buf, 1)
+		bytesPool.Put(buf)
 	}
 }
 
 func BenchmarkBytesPool_MakeLarge(b *testing.B) {
 	for b.Loop() {
-		_ = make([]byte, 1024*1024)
+		buf := make([]byte, DropThreshold/2)
+		buf[0] = 1
+		_ = buf
 	}
 }
 
@@ -37,10 +49,9 @@ func BenchmarkBytesPool_GetAll(b *testing.B) {
 	}
 }
 
-func BenchmarkBytesPoolWithMemory(b *testing.B) {
-	pool := GetBytesPoolWithUniqueMemory()
+func BenchmarkBytesPool_GetAllUnsized(b *testing.B) {
 	for i := range b.N {
-		pool.Put(slices.Grow(pool.Get(), sizes[i%len(sizes)]))
+		bytesPool.Put(slices.Grow(bytesPool.Get(), sizes[i%len(sizes)]))
 	}
 }
 
@@ -49,3 +60,10 @@ func BenchmarkBytesPool_MakeAll(b *testing.B) {
 		_ = make([]byte, sizes[i%len(sizes)])
 	}
 }
+
+func BenchmarkBytesPoolWithMemory(b *testing.B) {
+	pool := GetBytesPoolWithUniqueMemory()
+	for i := range b.N {
+		pool.Put(slices.Grow(pool.Get(), sizes[i%len(sizes)]))
+	}
+}