如果缓存条件支持206 Partial Content，则第一次加载时自动尝试从分片缓存中读取内容

internal/nodes/http_request_cache.go

@@ -236,6 +236,11 @@ func (this *HTTPRequest) doCacheRead(useStale bool) (shouldStop bool) {
 	if reader == nil {
 		reader, err = storage.OpenReader(key, useStale, false)
 		if err != nil && this.cacheRef.AllowPartialContent {
+			// 尝试读取分片的缓存内容
+			if len(rangeHeader) == 0 {
+				// 默认读取开头
+				rangeHeader = "bytes=0-"
+			}
 			pReader, ranges := this.tryPartialReader(storage, key, useStale, rangeHeader)
 			if pReader != nil {
 				isPartialCache = true