From 711962924f85163cfffd039d7d6906316400e894 Mon Sep 17 00:00:00 2001
From: Alex Vanin <alexey@nspcc.ru>
Date: Wed, 30 Jun 2021 19:08:59 +0300
Subject: [PATCH] [#102] container: Make `PutContainerSize` stable for
 simultaneous invocations in one block

Signed-off-by: Alex Vanin <alexey@nspcc.ru>
---
 container/container_contract.go | 67 ++++++++++++++++++++-------------
 1 file changed, 41 insertions(+), 26 deletions(-)

diff --git a/container/container_contract.go b/container/container_contract.go
index a12fd1a..11fb7e9 100644
--- a/container/container_contract.go
+++ b/container/container_contract.go
@@ -54,8 +54,9 @@ const (
 
 	containerIDSize = 32 // SHA256 size
 
-	estimateKeyPrefix = "cnr"
-	cleanupDelta      = 3
+	estimateKeyPrefix   = "cnr"
+	estimatePostfixSize = 10
+	cleanupDelta        = 3
 )
 
 var (
@@ -364,21 +365,12 @@ func PutContainerSize(epoch int, cid []byte, usedSize int, pubKey interop.Public
 		panic("container: only storage nodes can save size estimations")
 	}
 
-	key := estimationKey(epoch, cid)
-	s := getContainerSizeEstimation(ctx, key, cid)
+	key := estimationKey(epoch, cid, pubKey)
 
-	// do not add estimation twice
-	for i := range s.estimations {
-		est := s.estimations[i]
-		if common.BytesEqual(est.from, pubKey) {
-			panic("invalid estimation")
-		}
-	}
-
-	s.estimations = append(s.estimations, estimation{
+	s := estimation{
 		from: pubKey,
 		size: usedSize,
-	})
+	}
 
 	storage.Put(ctx, key, std.Serialize(s))
 
@@ -387,7 +379,13 @@ func PutContainerSize(epoch int, cid []byte, usedSize int, pubKey interop.Public
 
 func GetContainerSize(id []byte) containerSizes {
 	ctx := storage.GetReadOnlyContext()
-	return getContainerSizeEstimation(ctx, id, nil)
+
+	// this `id` expected to be from `ListContainerSizes`
+	// therefore it is not contains postfix, we ignore it in the cut.
+	ln := len(id)
+	cid := id[ln-containerIDSize : ln]
+
+	return getContainerSizeEstimation(ctx, id, cid)
 }
 
 func ListContainerSizes(epoch int) [][]byte {
@@ -400,11 +398,21 @@ func ListContainerSizes(epoch int) [][]byte {
 
 	it := storage.Find(ctx, key, storage.KeysOnly)
 
-	var result [][]byte
+	uniq := map[string]struct{}{}
 
 	for iterator.Next(it) {
-		key := iterator.Value(it).([]byte) // it MUST BE `storage.KeysOnly`
-		result = append(result, key)
+		storageKey := iterator.Value(it).([]byte)
+
+		ln := len(storageKey)
+		storageKey = storageKey[:ln-estimatePostfixSize]
+
+		uniq[string(storageKey)] = struct{}{}
+	}
+
+	var result [][]byte
+
+	for k := range uniq {
+		result = append(result, []byte(k))
 	}
 
 	return result
@@ -574,24 +582,31 @@ func ownerFromBinaryContainer(container []byte) []byte {
 	return container[offset : offset+25] // offset + size of owner
 }
 
-func estimationKey(epoch int, cid []byte) []byte {
+func estimationKey(epoch int, cid []byte, key interop.PublicKey) []byte {
 	var buf interface{} = epoch
 
+	hash := crypto.Ripemd160(key)
+
 	result := []byte(estimateKeyPrefix)
 	result = append(result, buf.([]byte)...)
+	result = append(result, cid...)
 
-	return append(result, cid...)
+	return append(result, hash[:estimatePostfixSize]...)
 }
 
 func getContainerSizeEstimation(ctx storage.Context, key, cid []byte) containerSizes {
-	data := storage.Get(ctx, key)
-	if data != nil {
-		return std.Deserialize(data.([]byte)).(containerSizes)
+	var estimations []estimation
+
+	it := storage.Find(ctx, key, storage.ValuesOnly)
+	for iterator.Next(it) {
+		rawEstimation := iterator.Value(it).([]byte)
+		est := std.Deserialize(rawEstimation).(estimation)
+		estimations = append(estimations, est)
 	}
 
 	return containerSizes{
 		cid:         cid,
-		estimations: []estimation{},
+		estimations: estimations,
 	}
 }
 
@@ -618,8 +633,8 @@ func keysToDelete(ctx storage.Context, epoch int) [][]byte {
 
 	it := storage.Find(ctx, []byte(estimateKeyPrefix), storage.KeysOnly)
 	for iterator.Next(it) {
-		k := iterator.Value(it).([]byte) // it MUST BE `storage.KeysOnly`
-		nbytes := k[len(estimateKeyPrefix) : len(k)-32]
+		k := iterator.Value(it).([]byte)
+		nbytes := k[len(estimateKeyPrefix) : len(k)-containerIDSize-estimatePostfixSize]
 
 		var n interface{} = nbytes