From afb83c610cf18ff7b18dd749b66d9ea7c5b35ef3 Mon Sep 17 00:00:00 2001
From: Alex Vanin <alexey@nspcc.ru>
Date: Wed, 23 Dec 2020 16:39:51 +0300
Subject: [PATCH] [#273] service/audit: Add cache of head responses in PoR

Signed-off-by: Alex Vanin <alexey@nspcc.ru>
---
 pkg/services/audit/auditor/context.go | 41 +++++++++++++++++++++++++++
 pkg/services/audit/auditor/por.go     |  3 ++
 2 files changed, 44 insertions(+)

diff --git a/pkg/services/audit/auditor/context.go b/pkg/services/audit/auditor/context.go
index 4097537a..f0ebbf1b 100644
--- a/pkg/services/audit/auditor/context.go
+++ b/pkg/services/audit/auditor/context.go
@@ -34,6 +34,8 @@ type Context struct {
 	}
 
 	cnrNodesNum int
+
+	headResponses map[string]shortHeader
 }
 
 type pairMemberInfo struct {
@@ -48,6 +50,12 @@ type gamePair struct {
 	id *object.ID
 }
 
+type shortHeader struct {
+	tzhash []byte
+
+	objectSize uint64
+}
+
 // ContextPrm groups components required to conduct data audit checks.
 type ContextPrm struct {
 	log *logger.Logger
@@ -114,6 +122,8 @@ func (c *Context) init() {
 
 	c.pairedNodes = make(map[uint64]pairMemberInfo)
 
+	c.headResponses = make(map[string]shortHeader)
+
 	c.log = c.log.With(
 		zap.Stringer("container ID", c.task.ContainerID()),
 	)
@@ -166,3 +176,34 @@ func (c *Context) buildPlacement(id *object.ID) ([]netmap.Nodes, error) {
 
 	return nn, nil
 }
+
+func (c *Context) objectSize(id *object.ID) uint64 {
+	strID := id.String()
+
+	if hdr, ok := c.headResponses[strID]; ok {
+		return hdr.objectSize
+	}
+
+	return 0
+}
+
+func (c *Context) objectHomoHash(id *object.ID) []byte {
+	strID := id.String()
+
+	if hdr, ok := c.headResponses[strID]; ok {
+		return hdr.tzhash
+	}
+
+	return nil
+}
+
+func (c *Context) updateHeadResponses(hdr *object.Object) {
+	strID := hdr.ID().String()
+
+	if _, ok := c.headResponses[strID]; !ok {
+		c.headResponses[strID] = shortHeader{
+			tzhash:     hdr.PayloadHomomorphicHash().Sum(),
+			objectSize: hdr.PayloadSize(),
+		}
+	}
+}
diff --git a/pkg/services/audit/auditor/por.go b/pkg/services/audit/auditor/por.go
index acd9a064..82ade8e6 100644
--- a/pkg/services/audit/auditor/por.go
+++ b/pkg/services/audit/auditor/por.go
@@ -54,6 +54,9 @@ func (c *Context) checkStorageGroupPoR(ind int, sg *object.ID) {
 				continue
 			}
 
+			// update cache for PoR and PDP audit checks
+			c.updateHeadResponses(hdr)
+
 			if len(tzHash) == 0 {
 				tzHash = hdr.PayloadHomomorphicHash().Sum()
 			} else {