func()

in oss/filelike.go [295:352]

• 47 lines of code
• 14 McCabe index (conditional complexity)

func (f *ReadOnlyFile) readInternal(offset int64, p []byte) (bytesRead int, err error) {
	defer func() {
		if bytesRead > 0 {
			f.readBufOffset += int64(bytesRead)
			f.seqReadAmount += int64(bytesRead)
		}
	}()

	if offset >= f.sizeInBytes {
		err = io.EOF
		return
	}

	if f.readBufOffset != offset {
		f.readBufOffset = offset
		f.seqReadAmount = 0

		if f.reader != nil {
			f.reader.Close()
			f.reader = nil
		}

		if f.asyncReaders != nil {
			f.numOOORead++
		}

		for _, ar := range f.asyncReaders {
			ar.Close()
		}
		f.asyncReaders = nil
	}

	if f.enablePrefetch && f.seqReadAmount >= f.prefetchThreshold && f.numOOORead < f.oooReadThreshold {
		//swith to async reader
		if f.reader != nil {
			f.reader.Close()
			f.reader = nil
		}

		err = f.prefetch(offset, len(p))
		if err == nil {
			bytesRead, err = f.readFromPrefetcher(offset, p)
			if err == nil {
				return
			}
		}

		// fall back to read serially
		f.seqReadAmount = 0
		for _, ar := range f.asyncReaders {
			ar.Close()
		}
		f.asyncReaders = nil
	}

	bytesRead, err = f.readDirect(offset, p)
	return
}