package archiver import ( "context" "github.com/restic/restic/internal/debug" "github.com/restic/restic/internal/restic" tomb "gopkg.in/tomb.v2" ) // Saver allows saving a blob. type Saver interface { SaveBlob(ctx context.Context, t restic.BlobType, data []byte, id restic.ID, storeDuplicate bool) (restic.ID, bool, error) Index() restic.Index } // BlobSaver concurrently saves incoming blobs to the repo. type BlobSaver struct { repo Saver ch chan<- saveBlobJob } // NewBlobSaver returns a new blob. A worker pool is started, it is stopped // when ctx is cancelled. func NewBlobSaver(ctx context.Context, t *tomb.Tomb, repo Saver, workers uint) *BlobSaver { ch := make(chan saveBlobJob) s := &BlobSaver{ repo: repo, ch: ch, } for i := uint(0); i < workers; i++ { t.Go(func() error { return s.worker(t.Context(ctx), ch) }) } return s } // Save stores a blob in the repo. It checks the index and the known blobs // before saving anything. It takes ownership of the buffer passed in. func (s *BlobSaver) Save(ctx context.Context, t restic.BlobType, buf *Buffer) FutureBlob { ch := make(chan saveBlobResponse, 1) select { case s.ch <- saveBlobJob{BlobType: t, buf: buf, ch: ch}: case <-ctx.Done(): debug.Log("not sending job, context is cancelled") close(ch) return FutureBlob{ch: ch} } return FutureBlob{ch: ch, length: len(buf.Data)} } // FutureBlob is returned by SaveBlob and will return the data once it has been processed. type FutureBlob struct { ch <-chan saveBlobResponse length int res saveBlobResponse } // Wait blocks until the result is available or the context is cancelled. func (s *FutureBlob) Wait(ctx context.Context) { select { case <-ctx.Done(): return case res, ok := <-s.ch: if ok { s.res = res } } } // ID returns the ID of the blob after it has been saved. func (s *FutureBlob) ID() restic.ID { return s.res.id } // Known returns whether or not the blob was already known. func (s *FutureBlob) Known() bool { return s.res.known } // Length returns the length of the blob. func (s *FutureBlob) Length() int { return s.length } type saveBlobJob struct { restic.BlobType buf *Buffer ch chan<- saveBlobResponse } type saveBlobResponse struct { id restic.ID known bool } func (s *BlobSaver) saveBlob(ctx context.Context, t restic.BlobType, buf []byte) (saveBlobResponse, error) { id, known, err := s.repo.SaveBlob(ctx, t, buf, restic.ID{}, false) if err != nil { return saveBlobResponse{}, err } return saveBlobResponse{ id: id, known: known, }, nil } func (s *BlobSaver) worker(ctx context.Context, jobs <-chan saveBlobJob) error { for { var job saveBlobJob select { case <-ctx.Done(): return nil case job = <-jobs: } res, err := s.saveBlob(ctx, job.BlobType, job.buf.Data) if err != nil { debug.Log("saveBlob returned error, exiting: %v", err) close(job.ch) return err } job.ch <- res close(job.ch) job.buf.Release() } }