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fix reader_at

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This commit is contained in:
Chris Lu
2020-08-16 00:49:08 -07:00
parent 5d80fc2ec7
commit aec7f32b02
3 changed files with 29 additions and 16 deletions
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30
weed/filer2/reader_at.go
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@@ -19,6 +19,7 @@ type ChunkReadAt struct {
bufferOffset int64
lookupFileId func(fileId string) (targetUrl string, err error)
readerLock sync.Mutex
fileSize int64
chunkCache *chunk_cache.ChunkCache
}
@@ -54,13 +55,14 @@ func LookupFn(filerClient filer_pb.FilerClient) LookupFileIdFunctionType {
}
}
func NewChunkReaderAtFromClient(filerClient filer_pb.FilerClient, chunkViews []*ChunkView, chunkCache *chunk_cache.ChunkCache) *ChunkReadAt {
func NewChunkReaderAtFromClient(filerClient filer_pb.FilerClient, chunkViews []*ChunkView, chunkCache *chunk_cache.ChunkCache, fileSize int64) *ChunkReadAt {
return &ChunkReadAt{
chunkViews: chunkViews,
lookupFileId: LookupFn(filerClient),
bufferOffset: -1,
chunkCache: chunkCache,
fileSize: fileSize,
}
}
@@ -73,9 +75,6 @@ func (c *ChunkReadAt) ReadAt(p []byte, offset int64) (n int, err error) {
readCount, readErr := c.doReadAt(p[n:], offset+int64(n))
n += readCount
err = readErr
if readCount == 0 {
return n, io.EOF
}
}
return
}
@@ -83,8 +82,11 @@ func (c *ChunkReadAt) ReadAt(p []byte, offset int64) (n int, err error) {
func (c *ChunkReadAt) doReadAt(p []byte, offset int64) (n int, err error) {
var found bool
var chunkStart, chunkStop int64
for _, chunk := range c.chunkViews {
if chunk.LogicOffset <= offset && offset < chunk.LogicOffset+int64(chunk.Size) {
// fmt.Printf(">>> doReadAt [%d,%d), chunk[%d,%d), %v && %v\n", offset, offset+int64(len(p)), chunk.LogicOffset, chunk.LogicOffset+int64(chunk.Size), chunk.LogicOffset <= offset, offset < chunk.LogicOffset+int64(chunk.Size))
chunkStart, chunkStop = max(chunk.LogicOffset, offset), min(chunk.LogicOffset+int64(chunk.Size), offset+int64(len(p)))
if chunkStart < chunkStop {
found = true
if c.bufferOffset != chunk.LogicOffset {
c.buffer, err = c.fetchChunkData(chunk)
@@ -96,15 +98,23 @@ func (c *ChunkReadAt) doReadAt(p []byte, offset int64) (n int, err error) {
break
}
}
if !found {
return 0, io.EOF
// fmt.Printf("> doReadAt [%d,%d), buffer:[%d,%d), found:%v, err:%v\n", offset, offset+int64(len(p)), c.bufferOffset, c.bufferOffset+int64(len(c.buffer)), found, err)
if err != nil {
return
}
if err == nil {
n = copy(p, c.buffer[offset-c.bufferOffset:])
if found {
n = int(chunkStart-offset) + copy(p[chunkStart-offset:chunkStop-offset], c.buffer[chunkStart-c.bufferOffset:chunkStop-c.bufferOffset])
return
}
// fmt.Printf("> doReadAt [%d,%d), buffer:[%d,%d)\n", offset, offset+int64(n), c.bufferOffset, c.bufferOffset+int64(len(c.buffer)))
n = len(p)
if offset+int64(n) >= c.fileSize {
err = io.EOF
n = int(c.fileSize - offset)
}
return