storage

type InsertError struct {
	Duplicates []*openpgp.PrimaryKey
	Errors     []error
}

type Inserter interface {

	// Insert inserts new public keys if they are not already stored. If they
	// are, then nothing is changed.
	Insert([]*openpgp.PrimaryKey) (int, error)
}

type KeyAdded struct {
	Digest string
}

type KeyChange interface {
	InsertDigests() []string
	RemoveDigests() []string
}

type KeyNotChanged struct{}

type KeyReplaced struct {
	OldDigest string
	NewDigest string
}

type Keyring struct {
	*openpgp.PrimaryKey

	CTime time.Time
	MTime time.Time
}

type Notifier interface {
	// Subscribe registers a key change callback function.
	Subscribe(func(KeyChange) error)

	// Notify invokes all registered callbacks with a key change notification.
	Notify(change KeyChange) error

	// RenotifyAll() invokes all registered callbacks with KeyAdded notifications
	// for each key in the Storage.
	RenotifyAll() error
}

type Queryer interface {

	// MatchMD5 returns the matching RFingerprint IDs for the given public key MD5 hashes.
	// The MD5 is calculated using the "SKS method".
	MatchMD5([]string) ([]string, error)

	// MatchID returns the matching RFingerprint IDs for the given public key IDs.
	// Key IDs may be short (last 4 bytes), long (last 10 bytes) or full (20 byte)
	// hexadecimal key IDs.
	Resolve([]string) ([]string, error)

	// MatchKeyword returns the matching RFingerprint IDs for the given keyword search.
	// The keyword search is storage dependant and results may vary among
	// different implementations.
	MatchKeyword([]string) ([]string, error)

	// ModifiedSince returns matching RFingerprint IDs for keyrings modified
	// since the given time.
	ModifiedSince(time.Time) ([]string, error)

	// FetchKeys returns the public key material matching the given RFingerprint slice.
	FetchKeys([]string) ([]*openpgp.PrimaryKey, error)

	// FetchKeyrings returns the keyring records matching the given RFingerprint slice.
	FetchKeyrings([]string) ([]*Keyring, error)
}

type Storage interface {
	io.Closer
	Queryer
	Updater
	Notifier
}

type Updater interface {
	Inserter

	// Update updates the stored PrimaryKey with the given contents, if the current
	// contents of the key in storage matches the given digest. If it does not
	// match, the update should be retried again later.
	Update(pubkey *openpgp.PrimaryKey, priorMD5 string) error
}