mirror of
https://github.com/octoleo/restic.git
synced 2024-11-16 18:15:20 +00:00
190d8e2f51
This inlines the io.LimitedReader into the LimitedReadCloser body to achieve fewer allocations. Results on linux/amd64: name old time/op new time/op delta Backend/BenchmarkLoadPartialFile-8 412µs ± 4% 413µs ± 4% ~ (p=0.634 n=17+17) Backend/BenchmarkLoadPartialFileOffset-8 455µs ±13% 441µs ±10% ~ (p=0.072 n=20+18) name old speed new speed delta Backend/BenchmarkLoadPartialFile-8 10.2GB/s ± 3% 10.2GB/s ± 4% ~ (p=0.817 n=16+17) Backend/BenchmarkLoadPartialFileOffset-8 9.25GB/s ±12% 9.54GB/s ± 9% ~ (p=0.072 n=20+18) name old alloc/op new alloc/op delta Backend/BenchmarkLoadPartialFile-8 888B ± 0% 872B ± 0% -1.80% (p=0.000 n=15+15) Backend/BenchmarkLoadPartialFileOffset-8 888B ± 0% 872B ± 0% -1.80% (p=0.000 n=15+15) name old allocs/op new allocs/op delta Backend/BenchmarkLoadPartialFile-8 18.0 ± 0% 17.0 ± 0% -5.56% (p=0.000 n=15+15) Backend/BenchmarkLoadPartialFileOffset-8 18.0 ± 0% 17.0 ± 0% -5.56% (p=0.000 n=15+15)
60 lines
1.6 KiB
Go
60 lines
1.6 KiB
Go
package backend
|
|
|
|
import (
|
|
"bytes"
|
|
"context"
|
|
"io"
|
|
|
|
"github.com/restic/restic/internal/restic"
|
|
)
|
|
|
|
// LoadAll reads all data stored in the backend for the handle into the given
|
|
// buffer, which is truncated. If the buffer is not large enough or nil, a new
|
|
// one is allocated.
|
|
func LoadAll(ctx context.Context, buf []byte, be restic.Backend, h restic.Handle) ([]byte, error) {
|
|
err := be.Load(ctx, h, 0, 0, func(rd io.Reader) error {
|
|
// make sure this is idempotent, in case an error occurs this function may be called multiple times!
|
|
wr := bytes.NewBuffer(buf[:0])
|
|
_, cerr := io.Copy(wr, rd)
|
|
if cerr != nil {
|
|
return cerr
|
|
}
|
|
buf = wr.Bytes()
|
|
return nil
|
|
})
|
|
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
|
|
return buf, nil
|
|
}
|
|
|
|
// LimitedReadCloser wraps io.LimitedReader and exposes the Close() method.
|
|
type LimitedReadCloser struct {
|
|
io.Closer
|
|
io.LimitedReader
|
|
}
|
|
|
|
// LimitReadCloser returns a new reader wraps r in an io.LimitedReader, but also
|
|
// exposes the Close() method.
|
|
func LimitReadCloser(r io.ReadCloser, n int64) *LimitedReadCloser {
|
|
return &LimitedReadCloser{Closer: r, LimitedReader: io.LimitedReader{R: r, N: n}}
|
|
}
|
|
|
|
// DefaultLoad implements Backend.Load using lower-level openReader func
|
|
func DefaultLoad(ctx context.Context, h restic.Handle, length int, offset int64,
|
|
openReader func(ctx context.Context, h restic.Handle, length int, offset int64) (io.ReadCloser, error),
|
|
fn func(rd io.Reader) error) error {
|
|
rd, err := openReader(ctx, h, length, offset)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
err = fn(rd)
|
|
if err != nil {
|
|
rd.Close() // ignore secondary errors closing the reader
|
|
return err
|
|
}
|
|
return rd.Close()
|
|
}
|