From ca64a122d33008c155c35a9d0e78cfbcafb1820a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C3=A9ter=20Szil=C3=A1gyi?= <peterke@gmail.com>
Date: Sat, 3 Mar 2018 01:52:39 +0200
Subject: [PATCH] eth/downloader: save and load trie sync progress (#16224)

---
 core/database_util.go        | 20 ++++++++++++++++++++
 eth/downloader/downloader.go |  6 +++++-
 eth/downloader/statesync.go  |  4 ++++
 3 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/core/database_util.go b/core/database_util.go
index 61ab701349..8c46989854 100644
--- a/core/database_util.go
+++ b/core/database_util.go
@@ -47,6 +47,7 @@ var (
 	headHeaderKey = []byte("LastHeader")
 	headBlockKey  = []byte("LastBlock")
 	headFastKey   = []byte("LastFast")
+	trieSyncKey   = []byte("TrieSync")
 
 	// Data item prefixes (use single byte to avoid mixing data types, avoid `i`).
 	headerPrefix        = []byte("h") // headerPrefix + num (uint64 big endian) + hash -> header
@@ -146,6 +147,16 @@ func GetHeadFastBlockHash(db DatabaseReader) common.Hash {
 	return common.BytesToHash(data)
 }
 
+// GetTrieSyncProgress retrieves the number of tries nodes fast synced to allow
+// reportinc correct numbers across restarts.
+func GetTrieSyncProgress(db DatabaseReader) uint64 {
+	data, _ := db.Get(trieSyncKey)
+	if len(data) == 0 {
+		return 0
+	}
+	return new(big.Int).SetBytes(data).Uint64()
+}
+
 // GetHeaderRLP retrieves a block header in its raw RLP database encoding, or nil
 // if the header's not found.
 func GetHeaderRLP(db DatabaseReader, hash common.Hash, number uint64) rlp.RawValue {
@@ -374,6 +385,15 @@ func WriteHeadFastBlockHash(db ethdb.Putter, hash common.Hash) error {
 	return nil
 }
 
+// WriteTrieSyncProgress stores the fast sync trie process counter to support
+// retrieving it across restarts.
+func WriteTrieSyncProgress(db ethdb.Putter, count uint64) error {
+	if err := db.Put(trieSyncKey, new(big.Int).SetUint64(count).Bytes()); err != nil {
+		log.Crit("Failed to store fast sync trie progress", "err", err)
+	}
+	return nil
+}
+
 // WriteHeader serializes a block header into the database.
 func WriteHeader(db ethdb.Putter, header *types.Header) error {
 	data, err := rlp.EncodeToBytes(header)
diff --git a/eth/downloader/downloader.go b/eth/downloader/downloader.go
index d13247766a..70febf4cb1 100644
--- a/eth/downloader/downloader.go
+++ b/eth/downloader/downloader.go
@@ -27,6 +27,7 @@ import (
 
 	ethereum "github.com/ethereum/go-ethereum"
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/types"
 	"github.com/ethereum/go-ethereum/ethdb"
 	"github.com/ethereum/go-ethereum/event"
@@ -221,7 +222,10 @@ func New(mode SyncMode, stateDb ethdb.Database, mux *event.TypeMux, chain BlockC
 		quitCh:         make(chan struct{}),
 		stateCh:        make(chan dataPack),
 		stateSyncStart: make(chan *stateSync),
-		trackStateReq:  make(chan *stateReq),
+		syncStatsState: stateSyncStats{
+			processed: core.GetTrieSyncProgress(stateDb),
+		},
+		trackStateReq: make(chan *stateReq),
 	}
 	go dl.qosTuner()
 	go dl.stateFetcher()
diff --git a/eth/downloader/statesync.go b/eth/downloader/statesync.go
index 9cc65a208c..ee6c7b4914 100644
--- a/eth/downloader/statesync.go
+++ b/eth/downloader/statesync.go
@@ -23,6 +23,7 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/core"
 	"github.com/ethereum/go-ethereum/core/state"
 	"github.com/ethereum/go-ethereum/crypto/sha3"
 	"github.com/ethereum/go-ethereum/ethdb"
@@ -466,4 +467,7 @@ func (s *stateSync) updateStats(written, duplicate, unexpected int, duration tim
 	if written > 0 || duplicate > 0 || unexpected > 0 {
 		log.Info("Imported new state entries", "count", written, "elapsed", common.PrettyDuration(duration), "processed", s.d.syncStatsState.processed, "pending", s.d.syncStatsState.pending, "retry", len(s.tasks), "duplicate", s.d.syncStatsState.duplicate, "unexpected", s.d.syncStatsState.unexpected)
 	}
+	if written > 0 {
+		core.WriteTrieSyncProgress(s.d.stateDB, s.d.syncStatsState.processed)
+	}
 }