From b48521a3e7fdc7e5aacfc737b947f9a5e0de9b04 Mon Sep 17 00:00:00 2001
From: Felix Lange <fjl@twurst.com>
Date: Wed, 31 May 2017 03:53:34 +0200
Subject: [PATCH] eth/downloader: fix vet, megacheck

---
 eth/downloader/metrics.go   |  6 ++--
 eth/downloader/queue.go     | 61 +------------------------------------
 eth/downloader/statesync.go |  2 +-
 3 files changed, 4 insertions(+), 65 deletions(-)

diff --git a/eth/downloader/metrics.go b/eth/downloader/metrics.go
index 0d76c7dfd2..58764ccf06 100644
--- a/eth/downloader/metrics.go
+++ b/eth/downloader/metrics.go
@@ -38,8 +38,6 @@ var (
 	receiptDropMeter    = metrics.NewMeter("eth/downloader/receipts/drop")
 	receiptTimeoutMeter = metrics.NewMeter("eth/downloader/receipts/timeout")
 
-	stateInMeter      = metrics.NewMeter("eth/downloader/states/in")
-	stateReqTimer     = metrics.NewTimer("eth/downloader/states/req")
-	stateDropMeter    = metrics.NewMeter("eth/downloader/states/drop")
-	stateTimeoutMeter = metrics.NewMeter("eth/downloader/states/timeout")
+	stateInMeter   = metrics.NewMeter("eth/downloader/states/in")
+	stateDropMeter = metrics.NewMeter("eth/downloader/states/drop")
 )
diff --git a/eth/downloader/queue.go b/eth/downloader/queue.go
index 9e59522658..8a7735d673 100644
--- a/eth/downloader/queue.go
+++ b/eth/downloader/queue.go
@@ -32,10 +32,7 @@ import (
 	"gopkg.in/karalabe/cookiejar.v2/collections/prque"
 )
 
-var (
-	blockCacheLimit   = 8192 // Maximum number of blocks to cache before throttling the download
-	maxInFlightStates = 8192 // Maximum number of state downloads to allow concurrently
-)
+var blockCacheLimit = 8192 // Maximum number of blocks to cache before throttling the download
 
 var (
 	errNoFetchesPending = errors.New("no fetches pending")
@@ -432,62 +429,6 @@ func (q *queue) ReserveHeaders(p *peer, count int) *fetchRequest {
 	return request
 }
 
-// reserveHashes reserves a set of hashes for the given peer, skipping previously
-// failed ones.
-//
-// Note, this method expects the queue lock to be already held for writing. The
-// reason the lock is not obtained in here is because the parameters already need
-// to access the queue, so they already need a lock anyway.
-func (q *queue) reserveHashes(p *peer, count int, taskQueue *prque.Prque, taskGen func(int), pendPool map[string]*fetchRequest, maxPending int) *fetchRequest {
-	// Short circuit if the peer's already downloading something (sanity check to
-	// not corrupt state)
-	if _, ok := pendPool[p.id]; ok {
-		return nil
-	}
-	// Calculate an upper limit on the hashes we might fetch (i.e. throttling)
-	allowance := maxPending
-	if allowance > 0 {
-		for _, request := range pendPool {
-			allowance -= len(request.Hashes)
-		}
-	}
-	// If there's a task generator, ask it to fill our task queue
-	if taskGen != nil && taskQueue.Size() < allowance {
-		taskGen(allowance - taskQueue.Size())
-	}
-	if taskQueue.Empty() {
-		return nil
-	}
-	// Retrieve a batch of hashes, skipping previously failed ones
-	send := make(map[common.Hash]int)
-	skip := make(map[common.Hash]int)
-
-	for proc := 0; (allowance == 0 || proc < allowance) && len(send) < count && !taskQueue.Empty(); proc++ {
-		hash, priority := taskQueue.Pop()
-		if p.Lacks(hash.(common.Hash)) {
-			skip[hash.(common.Hash)] = int(priority)
-		} else {
-			send[hash.(common.Hash)] = int(priority)
-		}
-	}
-	// Merge all the skipped hashes back
-	for hash, index := range skip {
-		taskQueue.Push(hash, float32(index))
-	}
-	// Assemble and return the block download request
-	if len(send) == 0 {
-		return nil
-	}
-	request := &fetchRequest{
-		Peer:   p,
-		Hashes: send,
-		Time:   time.Now(),
-	}
-	pendPool[p.id] = request
-
-	return request
-}
-
 // ReserveBodies reserves a set of body fetches for the given peer, skipping any
 // previously failed downloads. Beside the next batch of needed fetches, it also
 // returns a flag whether empty blocks were queued requiring processing.
diff --git a/eth/downloader/statesync.go b/eth/downloader/statesync.go
index 73ca97bad0..46c33ad724 100644
--- a/eth/downloader/statesync.go
+++ b/eth/downloader/statesync.go
@@ -291,7 +291,7 @@ func (s *stateSync) process(req *stateReq) (nproc int, err error) {
 	for _, blob := range req.response {
 		hash, err := s.processNodeData(blob, batch)
 		if err != nil && err != trie.ErrNotRequested {
-			return 0, fmt.Errorf("invalid state node %s: %v", err)
+			return 0, fmt.Errorf("invalid state node %s: %v", hash.TerminalString(), err)
 		} else if err == nil {
 			nproc++
 			delete(req.tasks, hash)