Proposal: kv db base on remote file system

[izouxv]

why i want to do this

kv db base on remote file system.
many rosedb instant can r&w the db file without service.
special for mobile app without backend service.

how do i do it

use afero.Fs to replace os.Fs. it can support local or remote fs, and any other type fs
use Lock interface to replace local file lock. i can support local or remote lock
use db interface to replace struct
split the read write api of db api. write with the lock, read without lock

type DBReadOnly interface {
	Close() error
	Fs() afero.Fs
	Stat() *Stat
	Get(key []byte) ([]byte, error)
	Exist(key []byte) (bool, error)
	Ascend(handleFn func(k []byte, v []byte) (bool, error))
	AscendRange(startKey, endKey []byte, handleFn func(k []byte, v []byte) (bool, error))
	AscendGreaterOrEqual(key []byte, handleFn func(k []byte, v []byte) (bool, error))
	AscendKeys(pattern []byte, filterExpired bool, handleFn func(k []byte) (bool, error))
	Descend(handleFn func(k []byte, v []byte) (bool, error))
	DescendRange(startKey, endKey []byte, handleFn func(k []byte, v []byte) (bool, error))
	DescendLessOrEqual(key []byte, handleFn func(k []byte, v []byte) (bool, error))
	DescendKeys(pattern []byte, filterExpired bool, handleFn func(k []byte) (bool, error))
}
type DB interface {
	DBReadOnly
	Sync() error
	Watch() (<-chan *Event, error)
	Put(key []byte, value []byte) error
	PutWithTTL(key []byte, value []byte, ttl time.Duration) error
	Delete(key []byte) error
	Expire(key []byte, ttl time.Duration) error
	TTL(key []byte) (time.Duration, error)
	Persist(key []byte) error
	DeleteExpiredKeys(timeout time.Duration) error

	NewBatch(options BatchOptions) *Batch

	Merge(reopenAfterDone bool) error
}

type Lock interface {
	TryLock() (bool, error)
	Unlock() error
}

[roseduan]

Thanks for your proposal.

Are you going to use this new feature in your project?

[izouxv]

yes

my project is developing
it is a app that without online server only the remote file system.
this feature can support it

[roseduan]

yes

my project is developing it is a app that without online server only the remote file system. this feature can support it

Thanks, but I think this is not a common feature for most users.
But you can maintain this yourself.
I don`t have enough motivation to add it to main branch.

[izouxv]

ok