database

type Batch interface {
	KeyValueWriterDeleter

	// Size retrieves the amount of data queued up for writing, this includes
	// the keys, values, and deleted keys.
	Size() int

	// Write flushes any accumulated data to disk.
	Write() error

	// Reset resets the batch for reuse.
	Reset()

	// Replay replays the batch contents in the same order they were written
	// to the batch.
	Replay(w KeyValueWriterDeleter) error

	// Inner returns a Batch writing to the inner database, if one exists. If
	// this batch is already writing to the base DB, then itself should be
	// returned.
	Inner() Batch
}

type BatchOp struct {
	Key    []byte
	Value  []byte
	Delete bool
}

type BatchOps struct {
	Ops []BatchOp
	// contains filtered or unexported fields
}

type Batcher interface {
	// NewBatch creates a write-only database that buffers changes to its host db
	// until a final write is called.
	NewBatch() Batch
}

type Compacter interface {
	// Compact the underlying DB for the given key range.
	// Specifically, deleted and overwritten versions are discarded,
	// and the data is rearranged to reduce the cost of operations
	// needed to access the data. This operation should typically only
	// be invoked by users who understand the underlying implementation.
	//
	// A nil start is treated as a key before all keys in the DB.
	// And a nil limit is treated as a key after all keys in the DB.
	// Therefore if both are nil then it will compact entire DB.
	//
	// Note: [start] and [limit] are safe to modify and read after calling Compact.
	Compact(start []byte, limit []byte) error
}

type Database interface {
	KeyValueReaderWriterDeleter
	Batcher
	Iteratee
	Compacter
	io.Closer
	health.Checker
}

type Iteratee interface {
	// NewIterator creates an iterator over the entire keyspace contained within
	// the key-value database.
	NewIterator() Iterator

	// NewIteratorWithStart creates an iterator over a subset of database
	// content starting at a particular initial key.
	NewIteratorWithStart(start []byte) Iterator

	// NewIteratorWithPrefix creates an iterator over a subset of database
	// content with a particular key prefix.
	NewIteratorWithPrefix(prefix []byte) Iterator

	// NewIteratorWithStartAndPrefix creates an iterator over a subset of
	// database content with a particular key prefix starting at a specified
	// key.
	NewIteratorWithStartAndPrefix(start, prefix []byte) Iterator
}

type Iterator interface {
	// Next moves the iterator to the next key/value pair. It returns whether
	// the iterator successfully moved to a new key/value pair.
	// The iterator may return false if the underlying database has been closed
	// before the iteration has completed, in which case future calls to Error()
	// must return [ErrClosed].
	Next() bool

	// Error returns any accumulated error. Exhausting all the key/value pairs
	// is not considered to be an error.
	// Error should be called after all key/value pairs have been exhausted i.e.
	// after Next() has returned false.
	Error() error

	// Key returns the key of the current key/value pair, or nil if done.
	// If the database is closed, must still report the current contents.
	// Behavior is undefined after Release is called.
	Key() []byte

	// Value returns the value of the current key/value pair, or nil if done.
	// If the database is closed, must still report the current contents.
	// Behavior is undefined after Release is called.
	Value() []byte

	// Release releases associated resources. Release should always succeed and
	// can be called multiple times without causing an error.
	Release()
}

type IteratorError struct {
	Err error
}

type KeyValueDeleter interface {
	// Delete removes the key from the key-value data store.
	//
	// Note: [key] is safe to modify and read after calling Delete.
	Delete(key []byte) error
}

type KeyValueReader interface {
	// Has retrieves if a key is present in the key-value data store.
	//
	// Note: [key] is safe to modify and read after calling Has.
	Has(key []byte) (bool, error)

	// Get retrieves the given key if it's present in the key-value data store.
	// Returns ErrNotFound if the key is not present in the key-value data store.
	//
	// Note: [key] is safe to modify and read after calling Get.
	// The returned byte slice is safe to read, but cannot be modified.
	Get(key []byte) ([]byte, error)
}

type KeyValueReaderWriter interface {
	KeyValueReader
	KeyValueWriter
}

type KeyValueReaderWriterDeleter interface {
	KeyValueReader
	KeyValueWriter
	KeyValueDeleter
}

type KeyValueWriter interface {
	// Put inserts the given value into the key-value data store.
	//
	// Note: [key] and [value] are safe to modify and read after calling Put.
	//
	// If [value] is nil or an empty slice, then when it's retrieved
	// it may be nil or an empty slice.
	//
	// Similarly, a nil [key] is treated the same as an empty slice.
	Put(key []byte, value []byte) error
}

type KeyValueWriterDeleter interface {
	KeyValueWriter
	KeyValueDeleter
}