From 62bd22a379d4cd60a5a744bf7127a562326cc4ca Mon Sep 17 00:00:00 2001
From: Leonard Lyubich <leonard@nspcc.ru>
Date: Tue, 3 Nov 2020 17:24:23 +0300
Subject: [PATCH] [#142] metabase: Fix false-positive select in absence of
 filtered header

Fix a bug in the selection when the object without some filtered header
added to the final result.

Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
---
 pkg/local_object_storage/metabase/select.go   | 34 ++++++++++---------
 .../metabase/select_test.go                   | 32 +++++++++++++++++
 2 files changed, 50 insertions(+), 16 deletions(-)

diff --git a/pkg/local_object_storage/metabase/select.go b/pkg/local_object_storage/metabase/select.go
index c6c051011..741cba8a3 100644
--- a/pkg/local_object_storage/metabase/select.go
+++ b/pkg/local_object_storage/metabase/select.go
@@ -45,16 +45,17 @@ func (db *DB) Select(fs object.SearchFilters) ([]*object.Address, error) {
 			})
 		}
 
-		// keep processed addresses (false if address was added and excluded later)
-		mAddr := make(map[string]bool)
+		// keep processed addresses
+		// value equal to number (index+1) of latest matched filter
+		mAddr := make(map[string]int)
 
-		for _, f := range fs {
-			matchFunc, ok := db.matchers[f.Operation()]
+		for fNum := range fs {
+			matchFunc, ok := db.matchers[fs[fNum].Operation()]
 			if !ok {
-				return errors.Errorf("no function for matcher %v", f.Operation())
+				return errors.Errorf("no function for matcher %v", fs[fNum].Operation())
 			}
 
-			key := f.Header()
+			key := fs[fNum].Header()
 
 			// get bucket with values
 			keyBucket := indexBucket.Bucket([]byte(key))
@@ -63,7 +64,7 @@ func (db *DB) Select(fs object.SearchFilters) ([]*object.Address, error) {
 				return nil
 			}
 
-			fVal := f.Value()
+			fVal := fs[fNum].Value()
 
 			// iterate over all existing values for the key
 			if err := keyBucket.ForEach(func(k, v []byte) error {
@@ -74,13 +75,12 @@ func (db *DB) Select(fs object.SearchFilters) ([]*object.Address, error) {
 					return errors.Wrapf(err, "(%T) could not decode address list", db)
 				}
 
-				for i := range strs {
-					if include {
-						if _, ok := mAddr[strs[i]]; !ok {
-							mAddr[strs[i]] = true
-						}
-					} else {
-						mAddr[strs[i]] = false
+				for j := range strs {
+					if num := mAddr[strs[j]]; num != fNum {
+						// than object does not match some previous filter
+						continue
+					} else if include {
+						mAddr[strs[j]] = fNum + 1
 					}
 				}
 
@@ -90,8 +90,10 @@ func (db *DB) Select(fs object.SearchFilters) ([]*object.Address, error) {
 			}
 		}
 
-		for a, inc := range mAddr {
-			if !inc {
+		fLen := len(fs)
+
+		for a, ind := range mAddr {
+			if ind != fLen {
 				continue
 			}
 
diff --git a/pkg/local_object_storage/metabase/select_test.go b/pkg/local_object_storage/metabase/select_test.go
index ef3e574ea..6362c35d3 100644
--- a/pkg/local_object_storage/metabase/select_test.go
+++ b/pkg/local_object_storage/metabase/select_test.go
@@ -152,3 +152,35 @@ func TestSelectRemoved(t *testing.T) {
 
 	testSelect(t, db, fs, obj2.Address())
 }
+
+func TestMissingObjectAttribute(t *testing.T) {
+	db := newDB(t)
+	defer releaseDB(db)
+
+	// add object w/o attribute
+	obj1 := generateObject(t, testPrm{
+		attrNum: 1,
+	})
+
+	// add object w/o attribute
+	obj2 := generateObject(t, testPrm{})
+
+	a1 := obj1.GetAttributes()[0]
+
+	// add common attribute
+	aCommon := addCommonAttribute(obj1, obj2)
+
+	// write to DB
+	require.NoError(t, db.Put(obj1))
+	require.NoError(t, db.Put(obj2))
+
+	fs := objectSDK.SearchFilters{}
+
+	// 1st filter by common attribute
+	fs.AddFilter(aCommon.GetKey(), aCommon.GetValue(), objectSDK.MatchStringEqual)
+
+	// next filter by attribute from 1st object only
+	fs.AddFilter(a1.GetKey(), a1.GetValue(), objectSDK.MatchStringEqual)
+
+	testSelect(t, db, fs, obj1.Address())
+}