Architecture

Env

Holds configuration taken from the environment, with appropriate defaulting appropriately. Generally passed to the constructor of other components which take their settings from it.

Controller

The central part of the server process initialising and coordinating all the others. Manages resource usage.

LocalRPC

Handles local JSON RPC connections querying ElectrumX-Dime server state. Started when the ElectrumX-Dime process starts.

ElectrumX-Dime

Handles JSON Electrum-Dime client connections over TCP or SSL. One instance per client session. Should be the only component concerned with the details of the Electrum-Dime wire protocol.

Not started until the Block Processor has caught up with dimecoind.

Daemon

Encapsulates the RPC wire protocol with dimecoind for the whole server. Transparently handles temporary dimecoind connection errors, and fails over if necessary.

Notifies the Mempool when the list of mempool transaction hashes is updated.

Block Processor

Responsible for managing block chain state (UTXO set, history, transaction and undo information) and for handling block chain reorganisations.

When caught up, processes new blocks as they are found, and flushes the updates to the Database immediately.

When syncing uses caches for in-memory state updates since the prior flush. Occasionally flushes state to the storage layer when caches get large.

Prefetcher

Cooperates with the Block Processor to asynchronously prefetch blocks from dimecoind. Once it has caught up it additionally asks the Daemon to refresh its view of dimecoind’s mempool transaction hashes. Serves blocks to the Block Processor via a queue.

Mempool

Handles all the details of maintaining a representation of dimecoind’s mempool state. Obtains the list of current mempool transaction hashes from the Daemon when notified by the Prefetcher.

Notifies the Controller that addresses have been touched when the mempool refreshes (or implicitly when a new block is found).

Database

The underlying data store, made up of the DB backend (such as leveldb) and the host filesystem.