diff options
| -rw-r--r-- | weed/filer2/reader_at.go | 49 |
1 files changed, 24 insertions, 25 deletions
diff --git a/weed/filer2/reader_at.go b/weed/filer2/reader_at.go index 600788f9c..75a0a0655 100644 --- a/weed/filer2/reader_at.go +++ b/weed/filer2/reader_at.go @@ -15,8 +15,6 @@ import ( type ChunkReadAt struct { masterClient *wdclient.MasterClient chunkViews []*ChunkView - buffer []byte - bufferFileId string lookupFileId func(fileId string) (targetUrl string, err error) readerLock sync.Mutex fileSize int64 @@ -71,49 +69,50 @@ func (c *ChunkReadAt) ReadAt(p []byte, offset int64) (n int, err error) { defer c.readerLock.Unlock() glog.V(4).Infof("ReadAt [%d,%d) of total file size %d bytes %d chunk views", offset, offset+int64(len(p)), c.fileSize, len(c.chunkViews)) - for n < len(p) && err == nil { - readCount, readErr := c.doReadAt(p[n:], offset+int64(n)) - n += readCount - err = readErr - } - return + return c.doReadAt(p[n:], offset+int64(n)) } func (c *ChunkReadAt) doReadAt(p []byte, offset int64) (n int, err error) { - var startOffset = offset + var buffer []byte + startOffset, remaining := offset, int64(len(p)) for i, chunk := range c.chunkViews { - if startOffset < min(chunk.LogicOffset, int64(len(p))+offset) { - gap := int(min(chunk.LogicOffset, int64(len(p))+offset) - startOffset) + if remaining <= 0 { + break + } + if startOffset < chunk.LogicOffset { + gap := int(chunk.LogicOffset - startOffset) glog.V(4).Infof("zero [%d,%d)", n, n+gap) n += gap - startOffset = chunk.LogicOffset + startOffset, remaining = chunk.LogicOffset, remaining-int64(gap) + if remaining <= 0 { + break + } } // fmt.Printf(">>> doReadAt [%d,%d), chunk[%d,%d)\n", offset, offset+int64(len(p)), chunk.LogicOffset, chunk.LogicOffset+int64(chunk.Size)) - chunkStart, chunkStop := max(chunk.LogicOffset, offset), min(chunk.LogicOffset+int64(chunk.Size), offset+int64(len(p))) + chunkStart, chunkStop := max(chunk.LogicOffset, startOffset), min(chunk.LogicOffset+int64(chunk.Size), startOffset+remaining) if chunkStart >= chunkStop { continue } - glog.V(4).Infof("read [%d,%d), %d chunk %s [%d,%d)", chunkStart, chunkStop, i, chunk.FileId, chunk.LogicOffset-chunk.Offset, chunk.LogicOffset-chunk.Offset+int64(chunk.Size)) - c.buffer, err = c.fetchWholeChunkData(chunk) + glog.V(4).Infof("read [%d,%d), %d/%d chunk %s [%d,%d)", chunkStart, chunkStop, i, len(c.chunkViews), chunk.FileId, chunk.LogicOffset-chunk.Offset, chunk.LogicOffset-chunk.Offset+int64(chunk.Size)) + buffer, err = c.readFromWholeChunkData(chunk) if err != nil { glog.Errorf("fetching chunk %+v: %v\n", chunk, err) return } - c.bufferFileId = chunk.FileId bufferOffset := chunkStart - chunk.LogicOffset + chunk.Offset - copied := copy(p[chunkStart-offset:chunkStop-offset], c.buffer[bufferOffset:bufferOffset+chunkStop-chunkStart]) + copied := copy(p[chunkStart-startOffset:chunkStop-startOffset], buffer[bufferOffset:bufferOffset+chunkStop-chunkStart]) n += copied - startOffset += int64(copied) + startOffset, remaining = startOffset + int64(copied), remaining-int64(copied) } - // fmt.Printf("> doReadAt [%d,%d), buffer %s:%d, found:%v, err:%v\n", offset, offset+int64(len(p)), c.bufferFileId, int64(len(c.buffer)), found, err) + glog.V(4).Infof("doReadAt [%d,%d), n:%v, err:%v", offset, offset+int64(len(p)), n, err) - if startOffset < min(c.fileSize, int64(len(p))+offset) { - gap := int(min(c.fileSize, int64(len(p))+offset) - startOffset) - glog.V(4).Infof("zero2 [%d,%d)", n, n+gap) - n += gap + if remaining > 0 { + glog.V(4).Infof("zero2 [%d,%d)", n, n+int(remaining)) + n += int(remaining) } + if offset+int64(n) >= c.fileSize { err = io.EOF } @@ -123,9 +122,9 @@ func (c *ChunkReadAt) doReadAt(p []byte, offset int64) (n int, err error) { } -func (c *ChunkReadAt) fetchWholeChunkData(chunkView *ChunkView) (chunkData []byte, err error) { +func (c *ChunkReadAt) readFromWholeChunkData(chunkView *ChunkView) (chunkData []byte, err error) { - glog.V(4).Infof("fetchWholeChunkData %s offset %d [%d,%d) size at least %d", chunkView.FileId, chunkView.Offset, chunkView.LogicOffset, chunkView.LogicOffset+int64(chunkView.Size), chunkView.ChunkSize) + glog.V(4).Infof("readFromWholeChunkData %s offset %d [%d,%d) size at least %d", chunkView.FileId, chunkView.Offset, chunkView.LogicOffset, chunkView.LogicOffset+int64(chunkView.Size), chunkView.ChunkSize) chunkData = c.chunkCache.GetChunk(chunkView.FileId, chunkView.ChunkSize) if chunkData != nil { |