swarm: localstore hasser (#19230)

swarm/shed/db.go

@@ -123,6 +123,17 @@ func (db *DB) Get(key []byte) (value []byte, err error) {
 	return value, nil
 }
 
+// Has wraps LevelDB Has method to increment metrics counter.
+func (db *DB) Has(key []byte) (yes bool, err error) {
+	yes, err = db.ldb.Has(key, nil)
+	if err != nil {
+		metrics.GetOrRegisterCounter("DB.hasFail", nil).Inc(1)
+		return false, err
+	}
+	metrics.GetOrRegisterCounter("DB.has", nil).Inc(1)
+	return yes, nil
+}
+
 // Delete wraps LevelDB Delete method to increment metrics counter.
 func (db *DB) Delete(key []byte) (err error) {
 	err = db.ldb.Delete(key, nil)

swarm/shed/index.go

@@ -145,6 +145,17 @@ func (f Index) Get(keyFields Item) (out Item, err error) {
 	return out.Merge(keyFields), nil
 }
 
+// Has accepts key fields represented as Item to check
+// if there this Item's encoded key is stored in
+// the index.
+func (f Index) Has(keyFields Item) (bool, error) {
+	key, err := f.encodeKeyFunc(keyFields)
+	if err != nil {
+		return false, err
+	}
+	return f.db.Has(key)
+}
+
 // Put accepts Item to encode information from it
 // and save it to the database.
 func (f Index) Put(i Item) (err error) {

swarm/shed/index_test.go

@@ -49,7 +49,7 @@ var retrievalIndexFuncs = IndexFuncs{
 	},
 }
 
-// TestIndex validates put, get and delete functions of the Index implementation.
+// TestIndex validates put, get, has and delete functions of the Index implementation.
 func TestIndex(t *testing.T) {
 	db, cleanupFunc := newTestDB(t)
 	defer cleanupFunc()
@@ -177,6 +177,41 @@ func TestIndex(t *testing.T) {
 		checkItem(t, got, want)
 	})
 
+	t.Run("has", func(t *testing.T) {
+		want := Item{
+			Address:        []byte("has-hash"),
+			Data:           []byte("DATA"),
+			StoreTimestamp: time.Now().UTC().UnixNano(),
+		}
+
+		dontWant := Item{
+			Address:        []byte("do-not-has-hash"),
+			Data:           []byte("DATA"),
+			StoreTimestamp: time.Now().UTC().UnixNano(),
+		}
+
+		err := index.Put(want)
+		if err != nil {
+			t.Fatal(err)
+		}
+
+		has, err := index.Has(want)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if !has {
+			t.Error("item is not found")
+		}
+
+		has, err = index.Has(dontWant)
+		if err != nil {
+			t.Fatal(err)
+		}
+		if has {
+			t.Error("unwanted item is found")
+		}
+	})
+
 	t.Run("delete", func(t *testing.T) {
 		want := Item{
 			Address:        []byte("delete-hash"),

swarm/storage/localstore/mode_has.go

@@ -0,0 +1,39 @@
+// Copyright 2019 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package localstore
+
+import (
+	"github.com/ethereum/go-ethereum/swarm/chunk"
+)
+
+// Hasser provides Has method to retrieve Chunks
+// from database.
+type Hasser struct {
+	db *DB
+}
+
+// NewHasser returns a new Hasser on database.
+func (db *DB) NewHasser() *Hasser {
+	return &Hasser{
+		db: db,
+	}
+}
+
+// Has returns true if the chunk is stored in database.
+func (h *Hasser) Has(addr chunk.Address) (bool, error) {
+	return h.db.retrievalDataIndex.Has(addressToItem(addr))
+}

swarm/storage/localstore/mode_has_test.go

@@ -0,0 +1,55 @@
+// Copyright 2019 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package localstore
+
+import (
+	"testing"
+)
+
+// TestHas validates that Hasser is returning true for
+// the stored chunk and false for one that is not stored.
+func TestHas(t *testing.T) {
+	db, cleanupFunc := newTestDB(t, nil)
+	defer cleanupFunc()
+
+	chunk := generateTestRandomChunk()
+
+	err := db.NewPutter(ModePutUpload).Put(chunk)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	hasser := db.NewHasser()
+
+	has, err := hasser.Has(chunk.Address())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !has {
+		t.Error("chunk not found")
+	}
+
+	missingChunk := generateTestRandomChunk()
+
+	has, err = hasser.Has(missingChunk.Address())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if has {
+		t.Error("unexpected chunk is found")
+	}
+}