netsync: Split blockmanager into separate package.

blockdb.go

@@ -244,7 +244,7 @@ func dumpBlockChain(params *chaincfg.Params, b *blockchain.BlockChain) error {
 		progressLogger.LogBlockHeight(bl.MsgBlock(), tipHeight)
 	}
 
-	bmgrLog.Infof("Successfully dumped the blockchain (%v blocks) to %v.",
+	srvrLog.Infof("Successfully dumped the blockchain (%v blocks) to %v.",
 		tipHeight, cfg.DumpBlockchain)
 
 	return nil

docs/json_rpc_api.mediawiki

@@ -549,7 +549,7 @@ the method name for further details such as parameter and return information.
 : Dynamically changes the debug logging level.
 : The levelspec can either be a debug level or of the form <code><subsystem>=<level>,<subsystem2>=<level2>,...</code>
 : The valid debug levels are <code>trace</code>, <code>debug</code>, <code>info</code>, <code>warn</code>, <code>error</code>, and <code>critical</code>.
-: The valid subsystems are <code>AMGR</code>, <code>ADXR</code>, <code>BCDB</code>, <code>BMGR</code>, <code>DCRD</code>, <code>CHAN</code>, <code>DISC</code>, <code>PEER</code>, <code>RPCS</code>, <code>SCRP</code>, <code>SRVR</code>, and <code>TXMP</code>.
+: The valid subsystems are <code>AMGR</code>, <code>ADXR</code>, <code>BCDB</code>, <code>DCRD</code>, <code>CHAN</code>, <code>DISC</code>, <code>PEER</code>, <code>RPCS</code>, <code>SCRP</code>, <code>SRVR</code>, <code>SYNC</code>, and <code>TXMP</code>.
 : Additionally, the special keyword <code>show</code> can be used to get a list of the available subsystems.
 |-
 !Returns
@@ -559,7 +559,7 @@ the method name for further details such as parameter and return information.
 |<code>Done.</code>
 |-
 !Example <code>show</code> Return
-|<code>Supported subsystems [AMGR ADXR BCDB BMGR DCRD CHAN DISC PEER RPCS SCRP SRVR TXMP]</code>
+|<code>Supported subsystems [AMGR ADXR BCDB DCRD CHAN DISC PEER RPCS SCRP SRVR SYNC TXMP]</code>
 |}
 
 ----

internal/fees/estimator.go

@@ -623,11 +623,11 @@ func (stats *Estimator) removeFromMemPool(blocksInMemPool int32, rate feeRate) {
 		// function but not on a previous newMemPoolTx. This leaves the fee db
 		// in an undefined state and should never happen in regular use. If this
 		// happens, then there is a logic or coding error somewhere, either in
-		// the estimator itself or on its hooking to the mempool/blockmanager.
-		// Either way, the easiest way to fix this is to completely delete the
-		// database and start again.
-		// During development, you can use a panic() here and we might return it
-		// after being confident that the estimator is completely bug free.
+		// the estimator itself or on its hooking to the mempool/network sync
+		// manager.  Either way, the easiest way to fix this is to completely
+		// delete the database and start again.  During development, you can use
+		// a panic() here and we might return it after being confident that the
+		// estimator is completely bug free.
 		log.Errorf("Transaction count in bucket index %d and confirmation "+
 			"index %d became < 0", bucketIdx, confirmIdx)
 	}

internal/mining/interface.go

@@ -67,7 +67,7 @@ type blockManagerFacade interface {
 	// best chain.
 	ForceReorganization(formerBest, newBest chainhash.Hash) error
 
-	// IsCurrent returns whether or not the block manager believes it is synced
-	// with the connected peers.
+	// IsCurrent returns whether or not the net sync manager believes it is
+	// synced with the connected peers.
 	IsCurrent() bool
 }

internal/netsync/README.md

@@ -0,0 +1,21 @@
+netsync
+=======
+
+[![Build Status](https://github.com/decred/dcrd/workflows/Build%20and%20Test/badge.svg)](https://github.com/decred/dcrd/actions)
+[![ISC License](https://img.shields.io/badge/license-ISC-blue.svg)](http://copyfree.org)
+[![Doc](https://img.shields.io/badge/doc-reference-blue.svg)](https://pkg.go.dev/github.com/decred/dcrd/internal/netsync)
+
+Package netsync implements a concurrency safe block syncing protocol.
+
+## Overview
+
+The provided implementation of SyncManager communicates with connected peers to
+perform an initial block download, keep the chain in sync, and announce new
+blocks connected to the chain. Currently the sync manager selects a single sync
+peer that it downloads all blocks from until it is up to date with the longest
+chain the sync peer is aware of.
+
+## License
+
+Package netsync is licensed under the [copyfree](http://copyfree.org) ISC
+License.

internal/netsync/doc.go

@@ -0,0 +1,14 @@
+// Copyright (c) 2020 The Decred developers
+// Use of this source code is governed by an ISC
+// license that can be found in the LICENSE file.
+
+/*
+Package netsync implements a concurrency safe block syncing protocol.
+
+The provided implementation of SyncManager communicates with connected peers to
+perform an initial block download, keep the chain in sync, and announce new
+blocks connected to the chain.  Currently the sync manager selects a single sync
+peer that it downloads all blocks from until it is up to date with the longest
+chain the sync peer is aware of.
+*/
+package netsync

internal/netsync/interface.go

@@ -0,0 +1,23 @@
+// Copyright (c) 2020 The Decred developers
+// Use of this source code is governed by an ISC
+// license that can be found in the LICENSE file.
+
+package netsync
+
+import (
+	"github.com/decred/dcrd/chaincfg/chainhash"
+	"github.com/decred/dcrd/dcrutil/v3"
+	"github.com/decred/dcrd/peer/v2"
+)
+
+// PeerNotifier provides an interface to notify peers of status changes related
+// to blocks and transactions.
+type PeerNotifier interface {
+	// AnnounceNewTransactions generates and relays inventory vectors and
+	// notifies websocket clients of the passed transactions.
+	AnnounceNewTransactions(txns []*dcrutil.Tx)
+
+	// UpdatePeerHeights updates the heights of all peers who have announced the
+	// latest connected main chain block, or a recognized orphan.
+	UpdatePeerHeights(latestBlkHash *chainhash.Hash, latestHeight int64, updateSource *peer.Peer)
+}

internal/netsync/log.go

@@ -0,0 +1,22 @@
+// Copyright (c) 2020 The Decred developers
+// Use of this source code is governed by an ISC
+// license that can be found in the LICENSE file.
+
+package netsync
+
+import (
+	"github.com/decred/slog"
+)
+
+// log is a logger that is initialized with no output filters.  This
+// means the package will not perform any logging by default until the caller
+// requests it.
+// The default amount of logging is none.
+var log = slog.Disabled
+
+// UseLogger uses a specified Logger to output package logging info.
+// This should be used in preference to SetLogWriter if the caller is also
+// using slog.
+func UseLogger(logger slog.Logger) {
+	log = logger
+}