diff options
Diffstat (limited to 'weed/filer/reader_at.go')
| -rw-r--r-- | weed/filer/reader_at.go | 23 |
1 files changed, 17 insertions, 6 deletions
diff --git a/weed/filer/reader_at.go b/weed/filer/reader_at.go index aeac9b34a..93fa76a2e 100644 --- a/weed/filer/reader_at.go +++ b/weed/filer/reader_at.go @@ -13,6 +13,12 @@ import ( "github.com/seaweedfs/seaweedfs/weed/wdclient" ) +// DefaultPrefetchCount is the default number of chunks to prefetch ahead during +// sequential reads. This value is used when prefetch count is not explicitly +// configured (e.g., WebDAV, query engine, message queue). For mount operations, +// the prefetch count is derived from the -concurrentReaders option. +const DefaultPrefetchCount = 4 + type ChunkReadAt struct { masterClient *wdclient.MasterClient chunkViews *IntervalList[*ChunkView] @@ -20,6 +26,7 @@ type ChunkReadAt struct { readerCache *ReaderCache readerPattern *ReaderPattern lastChunkFid string + prefetchCount int // Number of chunks to prefetch ahead during sequential reads ctx context.Context // Context used for cancellation during chunk read operations } @@ -35,8 +42,9 @@ var _ = io.Closer(&ChunkReadAt{}) // - No high availability (single filer address, no automatic failover) // // For NEW code, especially mount operations, use wdclient.FilerClient instead: -// filerClient := wdclient.NewFilerClient(filerAddresses, grpcDialOption, dataCenter, opts) -// lookupFn := filerClient.GetLookupFileIdFunction() +// +// filerClient := wdclient.NewFilerClient(filerAddresses, grpcDialOption, dataCenter, opts) +// lookupFn := filerClient.GetLookupFileIdFunction() // // This provides: // - Bounded cache with configurable size @@ -56,7 +64,7 @@ func LookupFn(filerClient filer_pb.FilerClient) wdclient.LookupFileIdFunctionTyp var vidCacheLock sync.RWMutex cacheSize := 0 const maxCacheSize = 10000 // Simple bound to prevent unbounded growth - + return func(ctx context.Context, fileId string) (targetUrls []string, err error) { vid := VolumeId(fileId) vidCacheLock.RLock() @@ -123,13 +131,14 @@ func LookupFn(filerClient filer_pb.FilerClient) wdclient.LookupFileIdFunctionTyp } } -func NewChunkReaderAtFromClient(ctx context.Context, readerCache *ReaderCache, chunkViews *IntervalList[*ChunkView], fileSize int64) *ChunkReadAt { +func NewChunkReaderAtFromClient(ctx context.Context, readerCache *ReaderCache, chunkViews *IntervalList[*ChunkView], fileSize int64, prefetchCount int) *ChunkReadAt { return &ChunkReadAt{ chunkViews: chunkViews, fileSize: fileSize, readerCache: readerCache, readerPattern: NewReaderPattern(), + prefetchCount: prefetchCount, ctx: ctx, } } @@ -246,8 +255,10 @@ func (c *ChunkReadAt) readChunkSliceAt(ctx context.Context, buffer []byte, chunk if c.lastChunkFid != "" { c.readerCache.UnCache(c.lastChunkFid) } - if nextChunkViews != nil { - c.readerCache.MaybeCache(nextChunkViews) // just read the next chunk if at the very beginning + if nextChunkViews != nil && c.prefetchCount > 0 { + // Prefetch multiple chunks ahead for better sequential read throughput + // This keeps the network pipeline full with parallel chunk fetches + c.readerCache.MaybeCache(nextChunkViews, c.prefetchCount) } } } |