diff --git a/content/content.go b/content/content.go index ff17a8417..b7230d88b 100644 --- a/content/content.go +++ b/content/content.go @@ -25,6 +25,26 @@ import ( ocispec "github.com/opencontainers/image-spec/specs-go/v1" ) +// Store combines the methods of content-oriented interfaces into a set that +// are commonly provided by complete implementations. +// +// Overall content lifecycle: +// - Ingester is used to initiate a write operation (aka ingestion) +// - IngestManager is used to manage (e.g. list, abort) active ingestions +// - Once an ingestion is complete (see Writer.Commit), Provider is used to +// query a single piece of content by its digest +// - Manager is used to manage (e.g. list, delete) previously committed content +// +// Note that until ingestion is complete, its content is not visible through +// Provider or Manager. Once ingestion is complete, it is no longer exposed +// through IngestManager. +type Store interface { + Manager + Provider + IngestManager + Ingester +} + // ReaderAt extends the standard io.ReaderAt interface with reporting of Size and io.Closer type ReaderAt interface { io.ReaderAt @@ -42,10 +62,30 @@ type Provider interface { // Ingester writes content type Ingester interface { - // Some implementations require WithRef to be included in opts. + // Writer initiates a writing operation (aka ingestion). A single ingestion + // is uniquely identified by its ref, provided using a WithRef option. + // Writer can be called multiple times with the same ref to access the same + // ingestion. + // Once all the data is written, use Writer.Commit to complete the ingestion. Writer(ctx context.Context, opts ...WriterOpt) (Writer, error) } +// IngestManager provides methods for managing ingestions. An ingestion is a +// not-yet-complete writing operation initiated using Ingester and identified +// by a ref string. +type IngestManager interface { + // Status returns the status of the provided ref. + Status(ctx context.Context, ref string) (Status, error) + + // ListStatuses returns the status of any active ingestions whose ref match + // the provided regular expression. If empty, all active ingestions will be + // returned. + ListStatuses(ctx context.Context, filters ...string) ([]Status, error) + + // Abort completely cancels the ingest operation targeted by ref. + Abort(ctx context.Context, ref string) error +} + // Info holds content specific information // // TODO(stevvooe): Consider a very different name for this struct. Info is way @@ -58,7 +98,7 @@ type Info struct { Labels map[string]string } -// Status of a content operation +// Status of a content operation (i.e. an ingestion) type Status struct { Ref string Offset int64 @@ -94,21 +134,7 @@ type Manager interface { Delete(ctx context.Context, dgst digest.Digest) error } -// IngestManager provides methods for managing ingests. -type IngestManager interface { - // Status returns the status of the provided ref. - Status(ctx context.Context, ref string) (Status, error) - - // ListStatuses returns the status of any active ingestions whose ref match the - // provided regular expression. If empty, all active ingestions will be - // returned. - ListStatuses(ctx context.Context, filters ...string) ([]Status, error) - - // Abort completely cancels the ingest operation targeted by ref. - Abort(ctx context.Context, ref string) error -} - -// Writer handles the write of content into a content store +// Writer handles writing of content into a content store type Writer interface { // Close closes the writer, if the writer has not been // committed this allows resuming or aborting. @@ -131,15 +157,6 @@ type Writer interface { Truncate(size int64) error } -// Store combines the methods of content-oriented interfaces into a set that -// are commonly provided by complete implementations. -type Store interface { - Manager - Provider - IngestManager - Ingester -} - // Opt is used to alter the mutable properties of content type Opt func(*Info) error