fix(189pc): large file upload error (close #4417 in #4438)

drivers/189pc/help.go

@@ -11,6 +11,7 @@ import (
 	"encoding/hex"
 	"encoding/pem"
 	"fmt"
+	"math"
 	"net/http"
 	"regexp"
 	"strings"
@@ -131,3 +132,18 @@ func BoolToNumber(b bool) int {
 	}
 	return 0
 }
+
+// 计算分片大小
+// 对分片数量有限制
+// 10MIB 20 MIB 999片
+// 50MIB 60MIB 70MIB 80MIB ∞MIB 1999片
+func partSize(size int64) int64 {
+	const DEFAULT = 1024 * 1024 * 10 // 10MIB
+	if size > DEFAULT*2*999 {
+		return int64(math.Max(math.Ceil((float64(size)/1999) /*=单个切片大小*/ /float64(DEFAULT)) /*=倍率*/, 5) * DEFAULT)
+	}
+	if size > DEFAULT*999 {
+		return DEFAULT * 2 // 20MIB
+	}
+	return DEFAULT
+}