feat: add in memory implementation of HeightIndex Database

database/heightindexdb/memdb/database.go

@@ -0,0 +1,85 @@
+// Copyright (C) 2019-2025, Ava Labs, Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
+package memdb
+
+import (
+	"sync"
+
+	"github.com/ava-labs/avalanchego/database"
+)
+
+var _ database.HeightIndex = (*Database)(nil)
+
+// Database is an in-memory implementation of database.HeightIndex
+type Database struct {
+	mu     sync.RWMutex
+	data   map[uint64][]byte
+	closed bool
+}
+
+// Put stores data in memory at the given height
+func (d *Database) Put(height uint64, data []byte) error {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	if d.closed {
+		return database.ErrClosed
+	}
+
+	if d.data == nil {
+		d.data = make(map[uint64][]byte)
+	}
+
+	if len(data) == 0 {
+		return database.ErrNotFound
+	}
+
+	dataCopy := make([]byte, len(data))
+	copy(dataCopy, data)
+	d.data[height] = dataCopy
+
+	return nil
+}
+
+// Get retrieves data at the given height
+func (d *Database) Get(height uint64) ([]byte, error) {
+	d.mu.RLock()
+	defer d.mu.RUnlock()
+
+	if d.closed {
+		return nil, database.ErrClosed
+	}
+
+	data, ok := d.data[height]
+	if !ok {
+		return nil, database.ErrNotFound
+	}
+
+	dataCopy := make([]byte, len(data))
+	copy(dataCopy, data)
+	return dataCopy, nil
+}
+
+// Has checks if data exists at the given height
+func (d *Database) Has(height uint64) (bool, error) {
+	d.mu.RLock()
+	defer d.mu.RUnlock()
+
+	if d.closed {
+		return false, database.ErrClosed
+	}
+
+	_, ok := d.data[height]
+	return ok, nil
+}
+
+// Close closes the in-memory database
+func (d *Database) Close() error {
+	d.mu.Lock()
+	defer d.mu.Unlock()
+
+	d.closed = true
+	d.data = nil
+	return nil
+}

database/heightindexdb/memdb/database_test.go

@@ -0,0 +1,113 @@
+// Copyright (C) 2019-2025, Ava Labs, Inc. All rights reserved.
+// See the file LICENSE for licensing terms.
+
+package memdb
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/ava-labs/avalanchego/database"
+)
+
+func TestOperationsAfterClose(t *testing.T) {
+	db := &Database{}
+
+	// Close database
+	require.NoError(t, db.Close())
+
+	height := uint64(1)
+	blockData := []byte("test block data")
+
+	tests := []struct {
+		name string
+		fn   func() error
+	}{
+		{
+			name: "Put",
+			fn: func() error {
+				return db.Put(height, blockData)
+			},
+		},
+		{
+			name: "Get",
+			fn: func() error {
+				_, err := db.Get(height)
+				return err
+			},
+		},
+		{
+			name: "Has",
+			fn: func() error {
+				_, err := db.Has(height)
+				return err
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := tt.fn()
+			require.ErrorIs(t, err, database.ErrClosed)
+		})
+	}
+}
+
+func TestPut(t *testing.T) {
+	db := &Database{}
+
+	height := uint64(1)
+	blockData := []byte("test block data")
+	require.NoError(t, db.Put(height, blockData))
+}
+
+func TestGet(t *testing.T) {
+	db := &Database{}
+
+	height := uint64(1)
+	blockData := []byte("test block data")
+	require.NoError(t, db.Put(height, blockData))
+
+	// Read block back
+	retrievedBlock, err := db.Get(height)
+	require.NoError(t, err)
+	require.Equal(t, blockData, retrievedBlock)
+}
+
+func TestHas(t *testing.T) {
+	t.Run("non-existent block", func(t *testing.T) {
+		db := &Database{}
+		exists, err := db.Has(uint64(1))
+		require.NoError(t, err)
+		require.False(t, exists)
+	})
+
+	t.Run("existing block", func(t *testing.T) {
+		db := &Database{}
+		blockData := []byte("test block data")
+		require.NoError(t, db.Put(uint64(1), blockData))
+		exists, err := db.Has(uint64(1))
+		require.NoError(t, err)
+		require.True(t, exists)
+	})
+}
+
+func TestPut_Overwrite(t *testing.T) {
+	db := &Database{}
+
+	height := uint64(1)
+	originalData := []byte("original data")
+	updatedData := []byte("updated data")
+
+	// Write original block
+	require.NoError(t, db.Put(height, originalData))
+
+	// Overwrite with new data
+	require.NoError(t, db.Put(height, updatedData))
+
+	// Verify updated data
+	retrievedBlock, err := db.Get(height)
+	require.NoError(t, err)
+	require.Equal(t, updatedData, retrievedBlock)
+}