status-im/status-go

package mailserver

import (
    "time"

    "github.com/status-im/status-go/eth-node/types"
)

// every this many seconds check real envelopes count
const envelopeCountCheckInterval = 60

// DB is an interface to abstract interactions with the db so that the mailserver
// is agnostic to the underlying technology used
type DB interface {
    Close() error
    // SaveEnvelope stores an envelope
    SaveEnvelope(types.Envelope) error
    // GetEnvelope returns an rlp encoded envelope from the datastore
    GetEnvelope(*DBKey) ([]byte, error)
    // Prune removes envelopes older than time
    Prune(time.Time, int) (int, error)
    // BuildIterator returns an iterator over envelopes
    BuildIterator(query CursorQuery) (Iterator, error)
}

type Iterator interface {
    Next() bool
    DBKey() (*DBKey, error)
    Release() error
    Error() error
    GetEnvelopeByBloomFilter(bloom []byte) ([]byte, error)
    GetEnvelopeByTopicsMap(topics map[types.TopicType]bool) ([]byte, error)
}

type CursorQuery struct {
    start  []byte
    end    []byte
    cursor []byte
    limit  uint32
    bloom  []byte
    topics [][]byte
}