mount: add back random read support

avoid too much memory used also

2 files changed, 10 insertions, 1 deletions

diff --git a/weed/filer/filechunk_manifest.go b/weed/filer/filechunk_manifest.go
index d036cfd24..a1f84b38e 100644
--- a/weed/filer/filechunk_manifest.go
+++ b/weed/filer/filechunk_manifest.go
@@ -115,6 +115,15 @@ func fetchWholeChunk(bytesBuffer *bytes.Buffer, lookupFileIdFn wdclient.LookupFi
 	return nil
 }
 
+func fetchChunkRange(buffer []byte, lookupFileIdFn wdclient.LookupFileIdFunctionType, fileId string, cipherKey []byte, isGzipped bool, offset int64) (int, error) {
+	urlStrings, err := lookupFileIdFn(fileId)
+	if err != nil {
+		glog.Errorf("operation LookupFileId %s failed, err: %v", fileId, err)
+		return 0, err
+	}
+	return retriedFetchChunkData(buffer, urlStrings, cipherKey, isGzipped, false, offset)
+}
+
 func retriedFetchChunkData(buffer []byte, urlStrings []string, cipherKey []byte, isGzipped bool, isFullChunk bool, offset int64) (n int, err error) {
 
 	var shouldRetry bool
diff --git a/weed/filer/reader_at.go b/weed/filer/reader_at.go
index 18015e0b3..7d9997761 100644
--- a/weed/filer/reader_at.go
+++ b/weed/filer/reader_at.go
@@ -164,7 +164,7 @@ func (c *ChunkReadAt) doReadAt(p []byte, offset int64) (n int, err error) {
 func (c *ChunkReadAt) readChunkSliceAt(buffer []byte, chunkView *ChunkView, nextChunkViews []*ChunkView, offset uint64) (n int, err error) {
 
 	if c.readerPattern.IsRandomMode() {
-		return c.readerCache.ReadChunkAt(buffer, chunkView.FileId, chunkView.CipherKey, chunkView.IsGzipped, int64(offset), int(chunkView.ChunkSize), chunkView.LogicOffset == 0)
+		return fetchChunkRange(buffer, c.readerCache.lookupFileIdFn, chunkView.FileId, chunkView.CipherKey, chunkView.IsGzipped, int64(offset))
 	}
 
 	n, err = c.readerCache.ReadChunkAt(buffer, chunkView.FileId, chunkView.CipherKey, chunkView.IsGzipped, int64(offset), int(chunkView.ChunkSize), chunkView.LogicOffset == 0)