From e9b49f8638618424b3251351558a44c9a79aeed6 Mon Sep 17 00:00:00 2001
From: rene <41963722+renaynay@users.noreply.github.com>
Date: Thu, 30 Sep 2021 13:10:18 +0200
Subject: [PATCH] first draft block store

---
 ipld/read_test.go           |  4 +--
 ipld/write.go               |  6 ++--
 service/block/event.go      |  1 +
 service/block/event_test.go | 58 +++++++++++++++++++++++--------------
 service/block/interface.go  |  5 ++++
 service/block/service.go    |  5 +++-
 service/block/store.go      | 21 ++++++++++++++
 service/block/store_test.go | 30 +++++++++++++++++++
 service/block/types.go      |  5 ++++
 9 files changed, 109 insertions(+), 26 deletions(-)
 create mode 100644 service/block/store.go
 create mode 100644 service/block/store_test.go

diff --git a/ipld/read_test.go b/ipld/read_test.go
index c8a7061e78..2c0518fd45 100644
--- a/ipld/read_test.go
+++ b/ipld/read_test.go
@@ -127,7 +127,7 @@ func TestRetrieveBlockData(t *testing.T) {
 			// // generate EDS
 			eds := generateRandEDS(t, tc.squareSize)
 
-			shares := convertEDStoShares(eds)
+			shares := ConvertEDStoShares(eds)
 
 			in, err := PutData(ctx, shares, dag)
 			require.NoError(t, err)
@@ -158,7 +158,7 @@ func Test_ConvertEDStoShares(t *testing.T) {
 	eds, err := rsmt2d.ComputeExtendedDataSquare(rawshares, rsmt2d.NewRSGF8Codec(), tree.Constructor)
 	require.NoError(t, err)
 
-	resshares := convertEDStoShares(eds)
+	resshares := ConvertEDStoShares(eds)
 	require.Equal(t, rawshares, resshares)
 }
 
diff --git a/ipld/write.go b/ipld/write.go
index 37046b24ca..e4a58a52ad 100644
--- a/ipld/write.go
+++ b/ipld/write.go
@@ -21,7 +21,6 @@ func PutData(ctx context.Context, shares [][]byte, adder ipld.NodeAdder) (*rsmt2
 	batchAdder := NewNmtNodeAdder(ctx, ipld.NewBatch(ctx, adder))
 	// create the nmt wrapper to generate row and col commitments
 	squareSize := uint32(math.Sqrt(float64(len(shares))))
-	fmt.Println("square size when put data", squareSize)
 	tree := wrapper.NewErasuredNamespacedMerkleTree(uint64(squareSize), nmt.NodeVisitor(batchAdder.Visit))
 	// recompute the eds
 	eds, err := rsmt2d.ComputeExtendedDataSquare(shares, rsmt2d.NewRSGF8Codec(), tree.Constructor)
@@ -34,7 +33,10 @@ func PutData(ctx context.Context, shares [][]byte, adder ipld.NodeAdder) (*rsmt2
 	return eds, batchAdder.Commit()
 }
 
-func convertEDStoShares(eds *rsmt2d.ExtendedDataSquare) [][]byte {
+// ConvertEDStoShares converts an ExtendedDataSquare back into its original shares. This
+// is a helper function for circumstances where PutData must be used after the EDS has already
+// been generated.
+func ConvertEDStoShares(eds *rsmt2d.ExtendedDataSquare) [][]byte {
 	origWidth := eds.Width() / 2
 	origShares := make([][]byte, origWidth*origWidth)
 	for i := uint(0); i < origWidth; i++ {
diff --git a/service/block/event.go b/service/block/event.go
index e358ead34a..0f2e9e68b3 100644
--- a/service/block/event.go
+++ b/service/block/event.go
@@ -73,5 +73,6 @@ func (s *Service) handleRawBlock(raw *RawBlock) error {
 		return err
 	}
 	// TODO @renaynay: store extended block
+
 	return nil
 }
diff --git a/service/block/event_test.go b/service/block/event_test.go
index c667a56a6c..b38432ea12 100644
--- a/service/block/event_test.go
+++ b/service/block/event_test.go
@@ -5,15 +5,17 @@ import (
 	"testing"
 
 	"github.com/celestiaorg/celestia-core/testutils"
-	"github.com/celestiaorg/celestia-node/service/header"
+	md "github.com/ipfs/go-merkledag/test"
 	"github.com/stretchr/testify/require"
+
+	"github.com/celestiaorg/celestia-node/service/header"
 )
 
 func Test_listenForNewBlocks(t *testing.T) {
 	mockFetcher := &mockFetcher{
 		mockNewBlockCh: make(chan *RawBlock),
 	}
-	serv := NewBlockService(mockFetcher)
+	serv := NewBlockService(mockFetcher, md.Mock()) // TODO @renaynay: add mock dag service
 
 	ctx, cancel := context.WithCancel(context.Background())
 	t.Cleanup(cancel)
@@ -46,26 +48,40 @@ func (m *mockFetcher) UnsubscribeNewBlockEvent(ctx context.Context) error {
 }
 
 func (m *mockFetcher) generateBlocks(t *testing.T, num int) {
+	t.Helper()
+
 	for i := 0; i < num; i++ {
-		data, err := testutils.GenerateRandomBlockData(1, 1, 1, 1, 40)
-		if err != nil {
-			t.Fatal(err)
-		}
-		rawBlock := &RawBlock{
-			Data: data,
-		}
-		// extend the data to get the data hash
-		extendedData, err := extendBlockData(rawBlock)
-		if err != nil {
-			t.Fatal(err)
-		}
-		dah, err := header.DataAvailabilityHeaderFromExtendedData(extendedData)
-		if err != nil {
-			t.Fatal(err)
-		}
-		rawBlock.Header = header.RawHeader{
-			DataHash: dah.Hash(),
-		}
+		rawBlock, _ := generateRawAndExtendedBlock(t)
 		m.mockNewBlockCh <- rawBlock
 	}
 }
+
+func generateRawAndExtendedBlock(t *testing.T) (*RawBlock, *Block) {
+	t.Helper()
+
+	data, err := testutils.GenerateRandomBlockData(1, 1, 1, 1, 40)
+	if err != nil {
+		t.Fatal(err)
+	}
+	rawBlock := &RawBlock{
+		Data: data,
+	}
+	// extend the data to get the data hash
+	extendedData, err := extendBlockData(rawBlock)
+	if err != nil {
+		t.Fatal(err)
+	}
+	dah, err := header.DataAvailabilityHeaderFromExtendedData(extendedData)
+	if err != nil {
+		t.Fatal(err)
+	}
+	rawBlock.Header = header.RawHeader{
+		DataHash: dah.Hash(),
+	}
+	return rawBlock, &Block{
+		header: &header.ExtendedHeader{
+			DAH: &dah,
+		},
+		data: extendedData,
+	}
+}
diff --git a/service/block/interface.go b/service/block/interface.go
index ad8917e24d..c29b0e8a59 100644
--- a/service/block/interface.go
+++ b/service/block/interface.go
@@ -10,3 +10,8 @@ type Fetcher interface {
 	SubscribeNewBlockEvent(ctx context.Context) (<-chan *RawBlock, error)
 	UnsubscribeNewBlockEvent(ctx context.Context) error
 }
+
+type Store interface {
+	GetBlockByHash(hash []byte) (*Block, error)
+	Store(block *Block) error
+}
diff --git a/service/block/service.go b/service/block/service.go
index 04f33e8cde..c2ea327e18 100644
--- a/service/block/service.go
+++ b/service/block/service.go
@@ -3,6 +3,7 @@ package block
 import (
 	"context"
 
+	ipld "github.com/ipfs/go-ipld-format"
 	logging "github.com/ipfs/go-log/v2"
 )
 
@@ -14,14 +15,16 @@ import (
 // 		4. Serving erasure coded blocks to other `Full` node peers.
 type Service struct {
 	fetcher Fetcher
+	store   ipld.DAGService
 }
 
 var log = logging.Logger("block-service")
 
 // NewBlockService creates a new instance of block Service.
-func NewBlockService(fetcher Fetcher) *Service {
+func NewBlockService(fetcher Fetcher, store ipld.DAGService) *Service {
 	return &Service{
 		fetcher: fetcher,
+		store:   store,
 	}
 }
 
diff --git a/service/block/store.go b/service/block/store.go
new file mode 100644
index 0000000000..7da1ff32be
--- /dev/null
+++ b/service/block/store.go
@@ -0,0 +1,21 @@
+package block
+
+import (
+	"context"
+
+	"github.com/celestiaorg/rsmt2d"
+
+	"github.com/celestiaorg/celestia-core/pkg/da"
+	"github.com/celestiaorg/celestia-node/ipld"
+)
+
+func (s *Service) StoreBlockData(ctx context.Context, data *ExtendedBlockData) error {
+	shares := ipld.ConvertEDStoShares(data)
+	// TODO @renaynay: it's inefficient that we generate the EDS twice
+	_, err := ipld.PutData(ctx, shares, s.store)
+	return err
+}
+
+func (s *Service) GetBlockData(ctx context.Context, dah *da.DataAvailabilityHeader) (*ExtendedBlockData, error) {
+	return ipld.RetrieveData(ctx, dah, s.store, rsmt2d.NewRSGF8Codec())
+}
diff --git a/service/block/store_test.go b/service/block/store_test.go
new file mode 100644
index 0000000000..a42132a879
--- /dev/null
+++ b/service/block/store_test.go
@@ -0,0 +1,30 @@
+package block
+
+import (
+	"context"
+	"testing"
+
+	md "github.com/ipfs/go-merkledag/test"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestService_BlockStore(t *testing.T) {
+	// create mock block service (fetcher is not necessary here)
+	mockStore := md.Mock()
+	serv := NewBlockService(nil, mockStore)
+
+	_, block := generateRawAndExtendedBlock(t)
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	err := serv.StoreBlockData(ctx, block.Data())
+	require.NoError(t, err)
+
+	eds, err := serv.GetBlockData(ctx, block.Header().DAH)
+	require.NoError(t, err)
+	assert.Equal(t, block.data.Width(), eds.Width())
+	assert.Equal(t, block.data.RowRoots(), eds.RowRoots())
+	assert.Equal(t, block.data.ColRoots(), eds.ColRoots())
+}
diff --git a/service/block/types.go b/service/block/types.go
index c8361b1541..a0847f9f4c 100644
--- a/service/block/types.go
+++ b/service/block/types.go
@@ -38,6 +38,11 @@ func (b *Block) LastCommit() *core.Commit {
 	return b.lastCommit
 }
 
+// DataSize returns the size of the ExtendedBlockData.
+func (b *Block) DataSize() uint {
+	return b.data.Width()
+}
+
 // BadEncodingError contains all relevant information to
 // generate a BadEncodingFraudProof.
 type BadEncodingError struct{}