triedb, core/rawdb: implement the partial read in freezer (#32132)

This PR implements the partial read functionalities in the freezer, optimizing
the state history reader by resolving less data from freezer.

---------

Signed-off-by: jsvisa <delweng@gmail.com>
Co-authored-by: Gary Rong <garyrong0905@gmail.com>

core/rawdb/accessors_state.go

@@ -188,24 +188,16 @@ func ReadStateAccountIndex(db ethdb.AncientReaderOp, id uint64) []byte {
 // data in the concatenated storage data table. Compute the position of state
 // history in freezer by minus one since the id of first state history starts
 // from one (zero for initial state).
-func ReadStateStorageIndex(db ethdb.AncientReaderOp, id uint64) []byte {
+func ReadStateStorageIndex(db ethdb.AncientReaderOp, id uint64, offset, length int) ([]byte, error) {
-	blob, err := db.Ancient(stateHistoryStorageIndex, id-1)
+	return db.AncientBytes(stateHistoryStorageIndex, id-1, uint64(offset), uint64(length))
-	if err != nil {
-		return nil
-	}
-	return blob
 }
 
 // ReadStateAccountHistory retrieves the concatenated account data blob for the
 // specified state history. Offsets and lengths are resolved via the account
 // index. Compute the position of state history in freezer by minus one since
 // the id of first state history starts from one (zero for initial state).
-func ReadStateAccountHistory(db ethdb.AncientReaderOp, id uint64) []byte {
+func ReadStateAccountHistory(db ethdb.AncientReaderOp, id uint64, offset, length int) ([]byte, error) {
-	blob, err := db.Ancient(stateHistoryAccountData, id-1)
+	return db.AncientBytes(stateHistoryAccountData, id-1, uint64(offset), uint64(length))
-	if err != nil {
-		return nil
-	}
-	return blob
 }
 
 // ReadStateStorageHistory retrieves the concatenated storage slot data blob for
@@ -213,12 +205,8 @@ func ReadStateAccountHistory(db ethdb.AncientReaderOp, id uint64) []byte {
 // storage indexes. Compute the position of state history in freezer by minus
 // one since the id of first state history starts from one (zero for initial
 // state).
-func ReadStateStorageHistory(db ethdb.AncientReaderOp, id uint64) []byte {
+func ReadStateStorageHistory(db ethdb.AncientReaderOp, id uint64, offset, length int) ([]byte, error) {
-	blob, err := db.Ancient(stateHistoryStorageData, id-1)
+	return db.AncientBytes(stateHistoryStorageData, id-1, uint64(offset), uint64(length))
-	if err != nil {
-		return nil
-	}
-	return blob
 }
 
 // ReadStateHistory retrieves the state history from database with provided id.

core/rawdb/chain_freezer.go

@@ -403,6 +403,10 @@ func (f *chainFreezer) AncientRange(kind string, start, count, maxBytes uint64)
 	return f.ancients.AncientRange(kind, start, count, maxBytes)
 }
 
+func (f *chainFreezer) AncientBytes(kind string, id, offset, length uint64) ([]byte, error) {
+	return f.ancients.AncientBytes(kind, id, offset, length)
+}
+
 func (f *chainFreezer) ModifyAncients(fn func(ethdb.AncientWriteOp) error) (int64, error) {
 	return f.ancients.ModifyAncients(fn)
 }

core/rawdb/database.go

@@ -100,6 +100,12 @@ func (db *nofreezedb) AncientRange(kind string, start, max, maxByteSize uint64)
 	return nil, errNotSupported
 }
 
+// AncientBytes retrieves the value segment of the element specified by the id
+// and value offsets.
+func (db *nofreezedb) AncientBytes(kind string, id, offset, length uint64) ([]byte, error) {
+	return nil, errNotSupported
+}
+
 // Ancients returns an error as we don't have a backing chain freezer.
 func (db *nofreezedb) Ancients() (uint64, error) {
 	return 0, errNotSupported

core/rawdb/freezer.go

@@ -202,6 +202,15 @@ func (f *Freezer) AncientRange(kind string, start, count, maxBytes uint64) ([][]
 	return nil, errUnknownTable
 }
 
+// AncientBytes retrieves the value segment of the element specified by the id
+// and value offsets.
+func (f *Freezer) AncientBytes(kind string, id, offset, length uint64) ([]byte, error) {
+	if table := f.tables[kind]; table != nil {
+		return table.RetrieveBytes(id, offset, length)
+	}
+	return nil, errUnknownTable
+}
+
 // Ancients returns the length of the frozen items.
 func (f *Freezer) Ancients() (uint64, error) {
 	return f.frozen.Load(), nil

core/rawdb/freezer_memory.go

@@ -412,3 +412,28 @@ func (f *MemoryFreezer) Reset() error {
 func (f *MemoryFreezer) AncientDatadir() (string, error) {
 	return "", nil
 }
+
+// AncientBytes retrieves the value segment of the element specified by the id
+// and value offsets.
+func (f *MemoryFreezer) AncientBytes(kind string, id, offset, length uint64) ([]byte, error) {
+	f.lock.RLock()
+	defer f.lock.RUnlock()
+
+	table := f.tables[kind]
+	if table == nil {
+		return nil, errUnknownTable
+	}
+	entries, err := table.retrieve(id, 1, 0)
+	if err != nil {
+		return nil, err
+	}
+	if len(entries) == 0 {
+		return nil, errOutOfBounds
+	}
+	data := entries[0]
+
+	if offset > uint64(len(data)) || offset+length > uint64(len(data)) {
+		return nil, fmt.Errorf("requested range out of bounds: item size %d, offset %d, length %d", len(data), offset, length)
+	}
+	return data[offset : offset+length], nil
+}

core/rawdb/freezer_resettable.go

@@ -126,6 +126,15 @@ func (f *resettableFreezer) AncientRange(kind string, start, count, maxBytes uin
 	return f.freezer.AncientRange(kind, start, count, maxBytes)
 }
 
+// AncientBytes retrieves the value segment of the element specified by the id
+// and value offsets.
+func (f *resettableFreezer) AncientBytes(kind string, id, offset, length uint64) ([]byte, error) {
+	f.lock.RLock()
+	defer f.lock.RUnlock()
+
+	return f.freezer.AncientBytes(kind, id, offset, length)
+}
+
 // Ancients returns the length of the frozen items.
 func (f *resettableFreezer) Ancients() (uint64, error) {
 	f.lock.RLock()

core/rawdb/freezer_table.go

@@ -1107,6 +1107,71 @@ func (t *freezerTable) retrieveItems(start, count, maxBytes uint64) ([]byte, []i
 	return output, sizes, nil
 }
 
+// RetrieveBytes retrieves the value segment of the element specified by the id
+// and value offsets.
+func (t *freezerTable) RetrieveBytes(item, offset, length uint64) ([]byte, error) {
+	t.lock.RLock()
+	defer t.lock.RUnlock()
+
+	if t.index == nil || t.head == nil || t.metadata.file == nil {
+		return nil, errClosed
+	}
+	items, hidden := t.items.Load(), t.itemHidden.Load()
+	if items <= item || hidden > item {
+		return nil, errOutOfBounds
+	}
+
+	// Retrieves the index entries for the specified ID and its immediate successor
+	indices, err := t.getIndices(item, 1)
+	if err != nil {
+		return nil, err
+	}
+	index0, index1 := indices[0], indices[1]
+
+	itemStart, itemLimit, fileId := index0.bounds(index1)
+	itemSize := itemLimit - itemStart
+
+	dataFile, exist := t.files[fileId]
+	if !exist {
+		return nil, fmt.Errorf("missing data file %d", fileId)
+	}
+
+	// Perform the partial read if no-compression was enabled upon
+	if t.config.noSnappy {
+		if offset > uint64(itemSize) || offset+length > uint64(itemSize) {
+			return nil, fmt.Errorf("requested range out of bounds: item size %d, offset %d, length %d", itemSize, offset, length)
+		}
+		itemStart += uint32(offset)
+
+		buf := make([]byte, length)
+		_, err = dataFile.ReadAt(buf, int64(itemStart))
+		if err != nil {
+			return nil, err
+		}
+		t.readMeter.Mark(int64(length))
+		return buf, nil
+	} else {
+		// If compressed, read the full item, decompress, then slice.
+		// Unfortunately, in this case, there is no performance gain
+		// by performing the partial read at all.
+		buf := make([]byte, itemSize)
+		_, err = dataFile.ReadAt(buf, int64(itemStart))
+		if err != nil {
+			return nil, err
+		}
+		t.readMeter.Mark(int64(itemSize))
+
+		data, err := snappy.Decode(nil, buf)
+		if err != nil {
+			return nil, err
+		}
+		if offset > uint64(len(data)) || offset+length > uint64(len(data)) {
+			return nil, fmt.Errorf("requested range out of bounds: item size %d, offset %d, length %d", len(data), offset, length)
+		}
+		return data[offset : offset+length], nil
+	}
+}
+
 // size returns the total data size in the freezer table.
 func (t *freezerTable) size() (uint64, error) {
 	t.lock.RLock()

core/rawdb/freezer_table_test.go

@@ -1571,3 +1571,65 @@ func TestTailTruncationCrash(t *testing.T) {
 		t.Fatalf("Unexpected index flush offset, want: %d, got: %d", 26*indexEntrySize, f.metadata.flushOffset)
 	}
 }
+
+func TestFreezerAncientBytes(t *testing.T) {
+	t.Parallel()
+	types := []struct {
+		name   string
+		config freezerTableConfig
+	}{
+		{"uncompressed", freezerTableConfig{noSnappy: true}},
+		{"compressed", freezerTableConfig{noSnappy: false}},
+	}
+	for _, typ := range types {
+		t.Run(typ.name, func(t *testing.T) {
+			f, err := newTable(os.TempDir(), fmt.Sprintf("ancientbytes-%s-%d", typ.name, rand.Uint64()), metrics.NewMeter(), metrics.NewMeter(), metrics.NewGauge(), 1000, typ.config, false)
+			if err != nil {
+				t.Fatal(err)
+			}
+			defer f.Close()
+
+			for i := 0; i < 10; i++ {
+				data := getChunk(100, i)
+				batch := f.newBatch()
+				require.NoError(t, batch.AppendRaw(uint64(i), data))
+				require.NoError(t, batch.commit())
+			}
+
+			for i := 0; i < 10; i++ {
+				full, err := f.Retrieve(uint64(i))
+				require.NoError(t, err)
+
+				// Full read
+				got, err := f.RetrieveBytes(uint64(i), 0, uint64(len(full)))
+				require.NoError(t, err)
+				if !bytes.Equal(got, full) {
+					t.Fatalf("full read mismatch for entry %d", i)
+				}
+				// Empty read
+				got, err = f.RetrieveBytes(uint64(i), 0, 0)
+				require.NoError(t, err)
+				if !bytes.Equal(got, full[:0]) {
+					t.Fatalf("empty read mismatch for entry %d", i)
+				}
+				// Middle slice
+				got, err = f.RetrieveBytes(uint64(i), 10, 50)
+				require.NoError(t, err)
+				if !bytes.Equal(got, full[10:60]) {
+					t.Fatalf("middle slice mismatch for entry %d", i)
+				}
+				// Single byte
+				got, err = f.RetrieveBytes(uint64(i), 99, 1)
+				require.NoError(t, err)
+				if !bytes.Equal(got, full[99:100]) {
+					t.Fatalf("single byte mismatch for entry %d", i)
+				}
+				// Out of bounds
+				_, err = f.RetrieveBytes(uint64(i), 100, 1)
+				if err == nil {
+					t.Fatalf("expected error for out-of-bounds read for entry %d", i)
+				}
+			}
+		})
+	}
+}

core/rawdb/table.go

@@ -62,6 +62,12 @@ func (t *table) AncientRange(kind string, start, count, maxBytes uint64) ([][]by
 	return t.db.AncientRange(kind, start, count, maxBytes)
 }
 
+// AncientBytes is a noop passthrough that just forwards the request to the underlying
+// database.
+func (t *table) AncientBytes(kind string, id, offset, length uint64) ([]byte, error) {
+	return t.db.AncientBytes(kind, id, offset, length)
+}
+
 // Ancients is a noop passthrough that just forwards the request to the underlying
 // database.
 func (t *table) Ancients() (uint64, error) {

ethdb/database.go

@@ -121,6 +121,10 @@ type AncientReaderOp interface {
 	//   - if maxBytes is not specified, 'count' items will be returned if they are present
 	AncientRange(kind string, start, count, maxBytes uint64) ([][]byte, error)
 
+	// AncientBytes retrieves the value segment of the element specified by the id
+	// and value offsets.
+	AncientBytes(kind string, id, offset, length uint64) ([]byte, error)
+
 	// Ancients returns the ancient item numbers in the ancient store.
 	Ancients() (uint64, error)
 

ethdb/remotedb/remotedb.go

@@ -140,6 +140,10 @@ func (db *Database) Close() error {
 	return nil
 }
 
+func (db *Database) AncientBytes(kind string, id, offset, length uint64) ([]byte, error) {
+	panic("not supported")
+}
+
 func New(client *rpc.Client) ethdb.Database {
 	if client == nil {
 		return nil

triedb/pathdb/history_reader.go

@@ -144,25 +144,17 @@ func (r *historyReader) readAccountMetadata(address common.Address, historyID ui
 // readStorageMetadata resolves the storage slot metadata within the specified
 // state history.
 func (r *historyReader) readStorageMetadata(storageKey common.Hash, storageHash common.Hash, historyID uint64, slotOffset, slotNumber int) ([]byte, error) {
-	// TODO(rj493456442) optimize it with partial read
+	data, err := rawdb.ReadStateStorageIndex(r.freezer, historyID, slotIndexSize*slotOffset, slotIndexSize*slotNumber)
-	blob := rawdb.ReadStateStorageIndex(r.freezer, historyID)
+	if err != nil {
-	if len(blob) == 0 {
+		msg := fmt.Sprintf("id: %d, slot-offset: %d, slot-length: %d", historyID, slotOffset, slotNumber)
-		return nil, fmt.Errorf("storage index is truncated, historyID: %d", historyID)
+		return nil, fmt.Errorf("storage indices corrupted, %s, %w", msg, err)
 	}
-	if len(blob)%slotIndexSize != 0 {
-		return nil, fmt.Errorf("storage indices is corrupted, historyID: %d, size: %d", historyID, len(blob))
-	}
-	if slotIndexSize*(slotOffset+slotNumber) > len(blob) {
-		return nil, fmt.Errorf("storage indices is truncated, historyID: %d, size: %d, offset: %d, length: %d", historyID, len(blob), slotOffset, slotNumber)
-	}
-	subSlice := blob[slotIndexSize*slotOffset : slotIndexSize*(slotOffset+slotNumber)]
-
 	// TODO(rj493456442) get rid of the metadata resolution
 	var (
 		m      meta
 		target common.Hash
 	)
-	blob = rawdb.ReadStateHistoryMeta(r.freezer, historyID)
+	blob := rawdb.ReadStateHistoryMeta(r.freezer, historyID)
 	if err := m.decode(blob); err != nil {
 		return nil, err
 	}
@@ -172,17 +164,17 @@ func (r *historyReader) readStorageMetadata(storageKey common.Hash, storageHash
 		target = storageKey
 	}
 	pos := sort.Search(slotNumber, func(i int) bool {
-		slotID := subSlice[slotIndexSize*i : slotIndexSize*i+common.HashLength]
+		slotID := data[slotIndexSize*i : slotIndexSize*i+common.HashLength]
 		return bytes.Compare(slotID, target.Bytes()) >= 0
 	})
 	if pos == slotNumber {
 		return nil, fmt.Errorf("storage metadata is not found, slot key: %#x, historyID: %d", storageKey, historyID)
 	}
 	offset := slotIndexSize * pos
-	if target != common.BytesToHash(subSlice[offset:offset+common.HashLength]) {
+	if target != common.BytesToHash(data[offset:offset+common.HashLength]) {
 		return nil, fmt.Errorf("storage metadata is not found, slot key: %#x, historyID: %d", storageKey, historyID)
 	}
-	return subSlice[offset : slotIndexSize*(pos+1)], nil
+	return data[offset : slotIndexSize*(pos+1)], nil
 }
 
 // readAccount retrieves the account data from the specified state history.
@@ -194,12 +186,11 @@ func (r *historyReader) readAccount(address common.Address, historyID uint64) ([
 	length := int(metadata[common.AddressLength])                                                     // one byte for account data length
 	offset := int(binary.BigEndian.Uint32(metadata[common.AddressLength+1 : common.AddressLength+5])) // four bytes for the account data offset
 
-	// TODO(rj493456442) optimize it with partial read
+	data, err := rawdb.ReadStateAccountHistory(r.freezer, historyID, offset, length)
-	data := rawdb.ReadStateAccountHistory(r.freezer, historyID)
+	if err != nil {
-	if len(data) < length+offset {
 		return nil, fmt.Errorf("account data is truncated, address: %#x, historyID: %d, size: %d, offset: %d, len: %d", address, historyID, len(data), offset, length)
 	}
-	return data[offset : offset+length], nil
+	return data, nil
 }
 
 // readStorage retrieves the storage slot data from the specified state history.
@@ -222,12 +213,11 @@ func (r *historyReader) readStorage(address common.Address, storageKey common.Ha
 	length := int(slotMetadata[common.HashLength])                                                  // one byte for slot data length
 	offset := int(binary.BigEndian.Uint32(slotMetadata[common.HashLength+1 : common.HashLength+5])) // four bytes for slot data offset
 
-	// TODO(rj493456442) optimize it with partial read
+	data, err := rawdb.ReadStateStorageHistory(r.freezer, historyID, offset, length)
-	data := rawdb.ReadStateStorageHistory(r.freezer, historyID)
+	if err != nil {
-	if len(data) < offset+length {
 		return nil, fmt.Errorf("storage data is truncated, address: %#x, key: %#x, historyID: %d, size: %d, offset: %d, len: %d", address, storageKey, historyID, len(data), offset, length)
 	}
-	return data[offset : offset+length], nil
+	return data, nil
 }
 
 // read retrieves the state element data associated with the stateID.