types

Documentation

Index

• type Batch
• type Database
• type Iterator
• type KeyValueWriter
• type Record

Types

type Batch

type Batch interface {
	KeyValueWriter

	// ValueSize retrieves the amount of data queued up for writing.
	ValueSize() int

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

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

	// Replay replays the batch contents.
	Replay(w KeyValueWriter) error
}

type Database

type Database interface {
	Put(key []byte, value []byte) error
	Get(key []byte) ([]byte, error)
	Has(key []byte) (bool, error)
	Delete(key []byte) error
	Close() error
	NewIterator(prefix []byte, start []byte, limit []byte) Iterator
	NewBatch() Batch
}

type Iterator

type Iterator interface {

	// Key returns the key of the current key/value pair, or nil if done.
	// The caller should not modify the contents of the returned slice, and
	// its contents may change on the next call to any 'seeks method'.
	Key() []byte

	// Value returns the value of the current key/value pair, or nil if done.
	// The caller should not modify the contents of the returned slice, and
	// its contents may change on the next call to any 'seeks method'.
	Value() []byte

	// Next moves the iterator to the next key/value pair.
	// It returns false if the iterator is exhausted.
	Next() bool

	// Seek moves the iterator to the first key/value pair whose key is greater
	// than or equal to the given key.
	// It returns whether such pair exist.
	//
	// It is safe to modify the contents of the argument after Seek returns.
	Seek(key []byte) bool
}

Iterator iterates over a DB's key/value pairs in key order.

When encounter an error any 'seeks method' will return false and will yield no key/value pairs. The error can be queried by calling the Error method. Calling Release is still necessary.

An iterator must be released after use, but it is not necessary to read an iterator until exhaustion. Also, an iterator is not necessarily safe for concurrent use, but it is safe to use multiple iterators concurrently, with each in a dedicated goroutine.

type KeyValueWriter

type KeyValueWriter interface {
	// Put inserts the given value into the key-value data store.
	Put(key []byte, value []byte) error

	// Delete removes the key from the key-value data store.
	Delete(key []byte) error
}

KeyValueWriter wraps the Put method of a backing data store.

type Record

type Record struct {
	Key   []byte `json:"hash"`
	Value []byte `json:"block"`
}