erigon-pulse/ethdb/kv_abstract.go

package ethdb

import (
	"context"
	"errors"
)

var (
	ErrAttemptToDeleteNonDeprecatedBucket = errors.New("only buckets from dbutils.DeprecatedBuckets can be deleted")
	ErrUnknownBucket                      = errors.New("unknown bucket. add it to dbutils.Buckets")
)

type KV interface {
	View(ctx context.Context, f func(tx Tx) error) error
	Update(ctx context.Context, f func(tx Tx) error) error
	Close()

	Begin(ctx context.Context, parent Tx, writable bool) (Tx, error)
	IdealBatchSize() int
}

type Tx interface {
	Bucket(name string) Bucket

	Commit(ctx context.Context) error
	Rollback()
}

type Bucket interface {
	Get(key []byte) (val []byte, err error)
	Put(key []byte, value []byte) error
	Delete(key []byte) error
	Cursor() Cursor

	Size() (uint64, error)
}

// Interface used for buckets migration, don't use it in usual app code
type BucketMigrator interface {
	Drop() error
	Create() error
	Exists() bool
	Clear() error
}

type Cursor interface {
	Prefix(v []byte) Cursor
	MatchBits(uint) Cursor
	Prefetch(v uint) Cursor
	NoValues() NoValuesCursor

	First() ([]byte, []byte, error)
	Seek(seek []byte) ([]byte, []byte, error)
	Next() ([]byte, []byte, error)
	Last() ([]byte, []byte, error)
	Walk(walker func(k, v []byte) (bool, error)) error

	Put(key []byte, value []byte) error
	Delete(key []byte) error
	Append(key []byte, value []byte) error // Danger: if provided data will not sorted (or bucket have old records which mess with new in sorting manner) - db will corrupt. Method also doesn't tolerate duplicates.
}

type NoValuesCursor interface {
	First() ([]byte, uint32, error)
	Seek(seek []byte) ([]byte, uint32, error)
	Next() ([]byte, uint32, error)
	Walk(walker func(k []byte, vSize uint32) (bool, error)) error
}

type HasStats interface {
	DiskSize(context.Context) (uint64, error) // db size
}

type Backend interface {
	AddLocal([]byte) ([]byte, error)
}

type DbProvider uint8

const (
	Bolt DbProvider = iota
	Remote
	Lmdb
)