29 lines
711 B
Go
29 lines
711 B
Go
|
package fs
|
||
|
|
|
||
|
|
import "io"
|
||
|
|
|
||
|
|
// NewCountingReader returns a CountingReader, which will read from the given
|
||
|
|
// reader while keeping track of how many bytes were read.
|
||
|
|
func NewCountingReader(in io.Reader) *CountingReader {
|
||
|
|
return &CountingReader{in: in}
|
||
|
|
}
|
||
|
|
|
||
|
|
// CountingReader holds a reader and a read count of how many bytes were read
|
||
|
|
// so far.
|
||
|
|
type CountingReader struct {
|
||
|
|
in io.Reader
|
||
|
|
read uint64
|
||
|
|
}
|
||
|
|
|
||
|
|
// Read reads from the underlying reader.
|
||
|
|
func (cr *CountingReader) Read(b []byte) (int, error) {
|
||
|
|
n, err := cr.in.Read(b)
|
||
|
|
cr.read += uint64(n)
|
||
|
|
return n, err
|
||
|
|
}
|
||
|
|
|
||
|
|
// BytesRead returns how many bytes were read from the underlying reader so far.
|
||
|
|
func (cr *CountingReader) BytesRead() uint64 {
|
||
|
|
return cr.read
|
||
|
|
}
|