Initial commit: SRDB - High-performance LSM-Tree database

- Core engine with MemTable, SST, WAL
- B+Tree indexing for SST files  
- Leveled compaction strategy
- Multi-table database management
- Schema validation and secondary indexes
- Query builder with complex conditions
- Web UI with HTMX for data visualization
- Command-line tools for diagnostics

sst/sst_test.go

@@ -0,0 +1,183 @@
+package sst
+
+import (
+	"os"
+	"testing"
+)
+
+func TestSST(t *testing.T) {
+	// 1. 创建测试文件
+	file, err := os.Create("test.sst")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer os.Remove("test.sst")
+
+	// 2. 写入数据
+	writer := NewWriter(file)
+
+	// 添加 1000 行数据
+	for i := int64(1); i <= 1000; i++ {
+		row := &Row{
+			Seq:  i,
+			Time: 1000000 + i,
+			Data: map[string]interface{}{
+				"name": "user_" + string(rune(i)),
+				"age":  20 + i%50,
+			},
+		}
+		err := writer.Add(row)
+		if err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	// 完成写入
+	err = writer.Finish()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	file.Close()
+
+	t.Logf("Written 1000 rows")
+
+	// 3. 读取数据
+	reader, err := NewReader("test.sst")
+	if err != nil {
+		t.Fatal(err)
+	}
+	defer reader.Close()
+
+	// 验证 Header
+	header := reader.GetHeader()
+	if header.RowCount != 1000 {
+		t.Errorf("Expected 1000 rows, got %d", header.RowCount)
+	}
+	if header.MinKey != 1 {
+		t.Errorf("Expected MinKey=1, got %d", header.MinKey)
+	}
+	if header.MaxKey != 1000 {
+		t.Errorf("Expected MaxKey=1000, got %d", header.MaxKey)
+	}
+
+	t.Logf("Header: RowCount=%d, MinKey=%d, MaxKey=%d",
+		header.RowCount, header.MinKey, header.MaxKey)
+
+	// 4. 查询测试
+	for i := int64(1); i <= 1000; i++ {
+		row, err := reader.Get(i)
+		if err != nil {
+			t.Errorf("Failed to get key %d: %v", i, err)
+			continue
+		}
+		if row.Seq != i {
+			t.Errorf("Key %d: expected Seq=%d, got %d", i, i, row.Seq)
+		}
+		if row.Time != 1000000+i {
+			t.Errorf("Key %d: expected Time=%d, got %d", i, 1000000+i, row.Time)
+		}
+	}
+
+	// 测试不存在的 key
+	_, err = reader.Get(1001)
+	if err == nil {
+		t.Error("Key 1001 should not exist")
+	}
+
+	_, err = reader.Get(0)
+	if err == nil {
+		t.Error("Key 0 should not exist")
+	}
+
+	t.Log("All tests passed!")
+}
+
+func TestHeaderSerialization(t *testing.T) {
+	// 创建 Header
+	header := &Header{
+		Magic:       MagicNumber,
+		Version:     Version,
+		Compression: CompressionSnappy,
+		IndexOffset: 256,
+		IndexSize:   1024,
+		RootOffset:  512,
+		DataOffset:  2048,
+		DataSize:    10240,
+		RowCount:    100,
+		MinKey:      1,
+		MaxKey:      100,
+		MinTime:     1000000,
+		MaxTime:     1000100,
+	}
+
+	// 序列化
+	data := header.Marshal()
+	if len(data) != HeaderSize {
+		t.Errorf("Expected size %d, got %d", HeaderSize, len(data))
+	}
+
+	// 反序列化
+	header2 := UnmarshalHeader(data)
+	if header2 == nil {
+		t.Fatal("Unmarshal failed")
+	}
+
+	// 验证
+	if header2.Magic != header.Magic {
+		t.Error("Magic mismatch")
+	}
+	if header2.Version != header.Version {
+		t.Error("Version mismatch")
+	}
+	if header2.Compression != header.Compression {
+		t.Error("Compression mismatch")
+	}
+	if header2.RowCount != header.RowCount {
+		t.Error("RowCount mismatch")
+	}
+	if header2.MinKey != header.MinKey {
+		t.Error("MinKey mismatch")
+	}
+	if header2.MaxKey != header.MaxKey {
+		t.Error("MaxKey mismatch")
+	}
+
+	// 验证
+	if !header2.Validate() {
+		t.Error("Header validation failed")
+	}
+
+	t.Log("Header serialization test passed!")
+}
+
+func BenchmarkSSTGet(b *testing.B) {
+	// 创建测试文件
+	file, _ := os.Create("bench.sst")
+	defer os.Remove("bench.sst")
+
+	writer := NewWriter(file)
+	for i := int64(1); i <= 10000; i++ {
+		row := &Row{
+			Seq:  i,
+			Time: 1000000 + i,
+			Data: map[string]interface{}{
+				"value": i,
+			},
+		}
+		writer.Add(row)
+	}
+	writer.Finish()
+	file.Close()
+
+	// 打开读取器
+	reader, _ := NewReader("bench.sst")
+	defer reader.Close()
+
+	// 性能测试
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		key := int64(i%10000 + 1)
+		reader.Get(key)
+	}
+}