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 <[email protected]>
Co-authored-by: Gary Rong <[email protected]>

Author: jsvisa

core/rawdb/accessors_state.go

@@ -188,37 +188,25 @@ 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 {
-	blob, err := db.Ancient(stateHistoryStorageIndex, id-1)
-	if err != nil {
-		return nil
-	}
-	return blob
+func ReadStateStorageIndex(db ethdb.AncientReaderOp, id uint64, offset, length int) ([]byte, error) {
+	return db.AncientBytes(stateHistoryStorageIndex, id-1, uint64(offset), uint64(length))
 }
 
 // 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 {
-	blob, err := db.Ancient(stateHistoryAccountData, id-1)
-	if err != nil {
-		return nil
-	}
-	return blob
+func ReadStateAccountHistory(db ethdb.AncientReaderOp, id uint64, offset, length int) ([]byte, error) {
+	return db.AncientBytes(stateHistoryAccountData, id-1, uint64(offset), uint64(length))
 }
 
 // ReadStateStorageHistory retrieves the concatenated storage slot data blob for
 // the specified state history. Locations are resolved via the account and
 // 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 {
-	blob, err := db.Ancient(stateHistoryStorageData, id-1)
-	if err != nil {
-		return nil
-	}
-	return blob
+func ReadStateStorageHistory(db ethdb.AncientReaderOp, id uint64, offset, length int) ([]byte, error) {
+	return db.AncientBytes(stateHistoryStorageData, id-1, uint64(offset), uint64(length))
 }
 
 // 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)