oplog

type AuthorLogstore interface {
	// All AuthorLogstores are Logstores
	Logstore

	// get the id of the oplog that represnts this Logstore's author
	ID() string
	// attribute ownership of the logstore to an author
	// the given id MUST equal the id of a log already in the logstore
	SetID(ctx context.Context, id string) error

	// marshals all logs to a slice of bytes encrypted with the given private key
	FlatbufferCipher(pk crypto.PrivKey) ([]byte, error)
	// decrypt flatbuffer bytes, re-hydrating the store
	UnmarshalFlatbufferCipher(ctx context.Context, pk crypto.PrivKey, ciphertext []byte) error
}

type Journal struct {
	// contains filtered or unexported fields
}

type Log struct {
	ParentID  string // init id of parent Log
	Signature []byte
	Ops       []Op
	Logs      []*Log
	// contains filtered or unexported fields
}

type Logstore interface {
	// MergeLog adds a Log to the store, controlling for conflicts
	// * logs that are already known to the store are merged with a
	//   longest-log-wins strategy, adding all descendants
	// * new top level logs are appended to the store, including all descendants
	// * attempting to add a log with a parent not already in the store MUST fail
	//
	// TODO (b5) - currently a Log pointer doesn't provide a clear method for
	// getting the ID of it's parent, which negates the potential for attempting
	// to merge child log, so we don't need to control for the third point quite
	// yet
	MergeLog(ctx context.Context, l *Log) error

	// Remove a log from the store, all descendant logs must be removed as well
	RemoveLog(ctx context.Context, names ...string) error

	// Logs lists top level logs in the store, that is, the set logs that have no
	// parent. passing -1 as a limit returns all top level logs after the offset
	//
	// The order of logs returned is up to the store, but the stored order must
	// be deterministic
	Logs(ctx context.Context, offset, limit int) (topLevel []*Log, err error)

	// get a log according to a hierarchy of log.Name() references
	// for example, fetching HeadRef(ctx, "foo", "bar", "baz") is a request
	// for the log at the hierarchy foo/bar/baz:
	//   foo
	//     bar
	//       baz
	//
	// HeadRef must return ErrNotFound if any name in the heirarchy is  missing
	// from the store
	// Head references are mutated by adding operations to a log that modifies
	// the name of the initialization model, which means names are not a
	// persistent identifier
	//
	// HeadRef MAY return children of a log. If the returned log.Log value is
	// populated, it MUST contain all children of the log.
	// use Logstore.Children or Logstore.Descendants to populate missing children
	HeadRef(ctx context.Context, names ...string) (*Log, error)

	// get a log according to it's ID string
	// Log must return ErrNotFound if the ID does not exist
	//
	// Log MAY return children of a log. If the returned log.Log value is
	// populated, it MUST contain all children of the log.
	// use Logstore.Children or Logstore.Descendants to populate missing children
	Get(ctx context.Context, id string) (*Log, error)

	// get the immediate descendants of a log, using the given log as an outparam.
	// Children must only mutate Logs field of the passed-in log pointer
	// added Children MAY include decendant logs
	Children(ctx context.Context, l *Log) error
	// get all generations of a log, using the given log as an outparam
	// Descendants MUST only mutate Logs field of the passed-in log pointer
	Descendants(ctx context.Context, l *Log) error

	// ReplaceAll replaces the contents of the entire log
	ReplaceAll(ctx context.Context, l *Log) error
}

type Op struct {
	Type      OpType   // type of operation
	Model     uint32   // data model to operate on
	Ref       string   // identifier of data this operation is documenting
	Prev      string   // previous reference in a causal history
	Relations []string // references this operation relates to. usage is operation type-dependant
	Name      string   // human-readable name for the reference
	AuthorID  string   // identifier for author

	Timestamp int64  // operation timestamp, for annotation purposes only
	Size      int64  // size of the referenced value in bytes
	Note      string // operation annotation for users. eg: commit title
}

type OpType byte

type SparseAncestorsAllDescendantsLogstore interface {
	Logstore
	// GetSparseAncestorsAllDescendants is a fast-path method for getting a
	// log that includes sparse parents & complete descendants. "sparse parents"
	// have the only children given in parent specified
	// AllDescendants include
	// the returned log will match the ID of the request, with parents
	GetSparseAncestorsAllDescendants(ctx context.Context, id string) (*Log, error)
}