1 files changed, 62 insertions, 1 deletions
diff --git a/weed/mount/filehandle.go b/weed/mount/filehandle.go
index 6cbc9745e..d3836754f 100644
--- a/weed/mount/filehandle.go
+++ b/weed/mount/filehandle.go
@@ -31,6 +31,11 @@ type FileHandle struct {
 
 	isDeleted bool
 
+	// RDMA chunk offset cache for performance optimization
+	chunkOffsetCache []int64
+	chunkCacheValid  bool
+	chunkCacheLock   sync.RWMutex
+
 	// for debugging
 	mirrorFile *os.File
 }
@@ -84,14 +89,25 @@ func (fh *FileHandle) SetEntry(entry *filer_pb.Entry) {
 		glog.Fatalf("setting file handle entry to nil")
 	}
 	fh.entry.SetEntry(entry)
+	
+	// Invalidate chunk offset cache since chunks may have changed
+	fh.invalidateChunkCache()
 }
 
 func (fh *FileHandle) UpdateEntry(fn func(entry *filer_pb.Entry)) *filer_pb.Entry {
-	return fh.entry.UpdateEntry(fn)
+	result := fh.entry.UpdateEntry(fn)
+	
+	// Invalidate chunk offset cache since entry may have been modified
+	fh.invalidateChunkCache()
+	
+	return result
 }
 
 func (fh *FileHandle) AddChunks(chunks []*filer_pb.FileChunk) {
 	fh.entry.AppendChunks(chunks)
+	
+	// Invalidate chunk offset cache since new chunks were added
+	fh.invalidateChunkCache()
 }
 
 func (fh *FileHandle) ReleaseHandle() {
@@ -111,3 +127,48 @@ func lessThan(a, b *filer_pb.FileChunk) bool {
 	}
 	return a.ModifiedTsNs < b.ModifiedTsNs
 }
+
+// getCumulativeOffsets returns cached cumulative offsets for chunks, computing them if necessary
+func (fh *FileHandle) getCumulativeOffsets(chunks []*filer_pb.FileChunk) []int64 {
+	fh.chunkCacheLock.RLock()
+	if fh.chunkCacheValid && len(fh.chunkOffsetCache) == len(chunks)+1 {
+		// Cache is valid and matches current chunk count
+		result := make([]int64, len(fh.chunkOffsetCache))
+		copy(result, fh.chunkOffsetCache)
+		fh.chunkCacheLock.RUnlock()
+		return result
+	}
+	fh.chunkCacheLock.RUnlock()
+
+	// Need to compute/recompute cache
+	fh.chunkCacheLock.Lock()
+	defer fh.chunkCacheLock.Unlock()
+
+	// Double-check in case another goroutine computed it while we waited for the lock
+	if fh.chunkCacheValid && len(fh.chunkOffsetCache) == len(chunks)+1 {
+		result := make([]int64, len(fh.chunkOffsetCache))
+		copy(result, fh.chunkOffsetCache)
+		return result
+	}
+
+	// Compute cumulative offsets
+	cumulativeOffsets := make([]int64, len(chunks)+1)
+	for i, chunk := range chunks {
+		cumulativeOffsets[i+1] = cumulativeOffsets[i] + int64(chunk.Size)
+	}
+
+	// Cache the result
+	fh.chunkOffsetCache = make([]int64, len(cumulativeOffsets))
+	copy(fh.chunkOffsetCache, cumulativeOffsets)
+	fh.chunkCacheValid = true
+
+	return cumulativeOffsets
+}
+
+// invalidateChunkCache invalidates the chunk offset cache when chunks are modified
+func (fh *FileHandle) invalidateChunkCache() {
+	fh.chunkCacheLock.Lock()
+	fh.chunkCacheValid = false
+	fh.chunkOffsetCache = nil
+	fh.chunkCacheLock.Unlock()
+}