blockchain/indexers 模块 ​

// NewManager returns a new index manager with the provided indexes enabled.
//
// The manager returned satisfies the blockchain.IndexManager interface and thus
// cleanly plugs into the normal blockchain processing path.
func NewManager(db database.DB, enabledIndexes []Indexer) *Manager
// Init initializes the enabled indexes.  This is called during chain
// initialization and primarily consists of catching up all indexes to the
// current best chain tip.  This is necessary since each index can be disabled
// and re-enabled at any time and attempting to catch-up indexes at the same
// time new blocks are being downloaded would lead to an overall longer time to
// catch up due to the I/O contention.
//
// This is part of the blockchain.IndexManager interface.
func (m *Manager) Init(chain *blockchain.BlockChain) error
// ConnectBlock must be invoked when a block is extending the main chain.  It
// keeps track of the state of each index it is managing, performs some sanity
// checks, and invokes each indexer.
//
// This is part of the blockchain.IndexManager interface.
func (m *Manager) ConnectBlock(dbTx database.Tx, block *btcutil.Block, view *blockchain.UtxoViewpoint) error
// DisconnectBlock must be invoked when a block is being disconnected from the
// end of the main chain.  It keeps track of the state of each index it is
// managing, performs some sanity checks, and invokes each indexer to remove
// the index entries associated with the block.
//
// This is part of the blockchain.IndexManager interface.
func (m *Manager) DisconnectBlock(dbTx database.Tx, block *btcutil.Block, view *blockchain.UtxoViewpoint) error

// Indexer provides a generic interface for an indexer that is managed by an
// index manager such as the Manager type provided by this package.
type Indexer interface {
	// Key returns the key of the index as a byte slice.
	Key() []byte //这个就是给manager管理用的.

	// Name returns the human-readable name of the index.
	Name() string //给人看的

	// Create is invoked when the indexer manager determines the index needs
	// to be created for the first time.
	Create(dbTx database.Tx) error //初始化数据库

	// Init is invoked when the index manager is first initializing the
	// index.  This differs from the Create method in that it is called on
	// every load, including the case the index was just created. //初始化Indexer
	Init() error 

	// ConnectBlock is invoked when the index manager is notified that a new
	// block has been connected to the main chain. 来了一个新块
	ConnectBlock(dbTx database.Tx, block *btcutil.Block, view *blockchain.UtxoViewpoint) error

	// DisconnectBlock is invoked when the index manager is notified that a
	// block has been disconnected from the main chain. 发生了分叉, 移除一个块
	DisconnectBlock(dbTx database.Tx, block *btcutil.Block, view *blockchain.UtxoViewpoint) error
}