add tests

weed/storage/needle_map_sorted_file_test.go

@@ -0,0 +1,776 @@
+package storage
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/seaweedfs/seaweedfs/weed/storage/erasure_coding"
+	"github.com/seaweedfs/seaweedfs/weed/storage/idx"
+	"github.com/seaweedfs/seaweedfs/weed/storage/needle_map"
+	. "github.com/seaweedfs/seaweedfs/weed/storage/types"
+)
+
+func TestSortedFileGeneration(t *testing.T) {
+	// Test with the provided test data files
+	testFiles := []string{
+		"../../test/data/iceberg_173",
+		"../../test/data/iceberg_674",
+	}
+
+	for _, baseFileName := range testFiles {
+		t.Run(fmt.Sprintf("TestSortedFileGeneration_%s", filepath.Base(baseFileName)), func(t *testing.T) {
+			testSortedFileGeneration(t, baseFileName)
+		})
+	}
+}
+
+func testSortedFileGeneration(t *testing.T, baseFileName string) {
+	// Open the original idx file
+	idxFile, err := os.OpenFile(baseFileName+".idx", os.O_RDONLY, 0644)
+	if err != nil {
+		t.Fatalf("Failed to open %s.idx: %v", baseFileName, err)
+	}
+	defer idxFile.Close()
+
+	// Generate sorted file
+	sdxFileName := baseFileName + ".sdx"
+	err = erasure_coding.WriteSortedFileFromIdx(baseFileName, ".sdx")
+	if err != nil {
+		t.Fatalf("Failed to generate sorted file for %s: %v", baseFileName, err)
+	}
+	defer os.Remove(sdxFileName) // Clean up
+
+	// Verify the sorted file was created
+	if _, err := os.Stat(sdxFileName); os.IsNotExist(err) {
+		t.Fatalf("Sorted file %s was not created", sdxFileName)
+	}
+
+	// Read original entries
+	originalEntries, err := readIndexFileEntries(idxFile)
+	if err != nil {
+		t.Fatalf("Failed to read original entries from %s: %v", baseFileName, err)
+	}
+
+	// Read sorted entries
+	sdxFile, err := os.OpenFile(sdxFileName, os.O_RDONLY, 0644)
+	if err != nil {
+		t.Fatalf("Failed to open sorted file %s: %v", sdxFileName, err)
+	}
+	defer sdxFile.Close()
+
+	sortedEntries, err := readIndexFileEntries(sdxFile)
+	if err != nil {
+		t.Fatalf("Failed to read sorted entries from %s: %v", sdxFileName, err)
+	}
+
+	// Build final state map from original entries (same logic as readNeedleMap)
+	finalStateMap := make(map[NeedleId]needle_map.NeedleValue)
+	for _, entry := range originalEntries {
+		if !entry.Offset.IsZero() && !entry.Size.IsDeleted() {
+			finalStateMap[entry.Key] = entry
+		} else {
+			delete(finalStateMap, entry.Key)
+		}
+	}
+
+	// Convert map to slice for comparison
+	validOriginalEntries := make([]needle_map.NeedleValue, 0, len(finalStateMap))
+	for _, entry := range finalStateMap {
+		validOriginalEntries = append(validOriginalEntries, entry)
+	}
+
+	// Verify the number of valid entries matches
+	if len(validOriginalEntries) != len(sortedEntries) {
+		t.Fatalf("Valid entry count mismatch: original=%d, sorted=%d", len(validOriginalEntries), len(sortedEntries))
+	}
+
+	// Verify all valid entries are present
+	err = verifyAllEntriesPresent(validOriginalEntries, sortedEntries)
+	if err != nil {
+		t.Fatalf("Data verification failed: %v", err)
+	}
+
+	// Verify the sorted file is actually sorted
+	err = verifySortedOrder(sortedEntries)
+	if err != nil {
+		t.Fatalf("Sorted order verification failed: %v", err)
+	}
+
+	// Test binary search functionality
+	err = testBinarySearch(t, sdxFile, sortedEntries)
+	if err != nil {
+		t.Fatalf("Binary search test failed: %v", err)
+	}
+
+	t.Logf("Successfully verified sorted file generation for %s: %d valid entries out of %d total", baseFileName, len(sortedEntries), len(originalEntries))
+}
+
+func testSortedFileGenerationWithDeletedEntries(t *testing.T, baseFileName string) {
+	// Open the original idx file
+	idxFile, err := os.OpenFile(baseFileName+".idx", os.O_RDONLY, 0644)
+	if err != nil {
+		t.Fatalf("Failed to open %s.idx: %v", baseFileName, err)
+	}
+	defer idxFile.Close()
+
+	// Generate sorted file
+	sdxFileName := baseFileName + ".sdx"
+	err = erasure_coding.WriteSortedFileFromIdx(baseFileName, ".sdx")
+	if err != nil {
+		t.Fatalf("Failed to generate sorted file for %s: %v", baseFileName, err)
+	}
+	defer os.Remove(sdxFileName) // Clean up
+
+	// Verify the sorted file was created
+	if _, err := os.Stat(sdxFileName); os.IsNotExist(err) {
+		t.Fatalf("Sorted file %s was not created", sdxFileName)
+	}
+
+	// Read original entries
+	originalEntries, err := readIndexFileEntries(idxFile)
+	if err != nil {
+		t.Fatalf("Failed to read original entries from %s: %v", baseFileName, err)
+	}
+
+	// Read sorted entries
+	sdxFile, err := os.OpenFile(sdxFileName, os.O_RDONLY, 0644)
+	if err != nil {
+		t.Fatalf("Failed to open sorted file %s: %v", sdxFileName, err)
+	}
+	defer sdxFile.Close()
+
+	sortedEntries, err := readIndexFileEntries(sdxFile)
+	if err != nil {
+		t.Fatalf("Failed to read sorted entries from %s: %v", sdxFileName, err)
+	}
+
+	// Build final state map from original entries (same logic as readNeedleMap)
+	finalStateMap := make(map[NeedleId]needle_map.NeedleValue)
+	for _, entry := range originalEntries {
+		if !entry.Offset.IsZero() && !entry.Size.IsDeleted() {
+			finalStateMap[entry.Key] = entry
+		} else {
+			delete(finalStateMap, entry.Key)
+		}
+	}
+
+	// Convert map to slice for comparison
+	validOriginalEntries := make([]needle_map.NeedleValue, 0, len(finalStateMap))
+	for _, entry := range finalStateMap {
+		validOriginalEntries = append(validOriginalEntries, entry)
+	}
+
+	// Verify the number of valid entries matches
+	if len(validOriginalEntries) != len(sortedEntries) {
+		t.Fatalf("Valid entry count mismatch: original=%d, sorted=%d", len(validOriginalEntries), len(sortedEntries))
+	}
+
+	// Verify all valid entries are present
+	err = verifyAllEntriesPresent(validOriginalEntries, sortedEntries)
+	if err != nil {
+		t.Fatalf("Data verification failed: %v", err)
+	}
+
+	// Verify the sorted file is actually sorted
+	err = verifySortedOrder(sortedEntries)
+	if err != nil {
+		t.Fatalf("Sorted order verification failed: %v", err)
+	}
+
+	// Test binary search functionality
+	err = testBinarySearch(t, sdxFile, sortedEntries)
+	if err != nil {
+		t.Fatalf("Binary search test failed: %v", err)
+	}
+
+	t.Logf("Successfully verified sorted file generation with deleted entries for %s: %d valid entries out of %d total", baseFileName, len(sortedEntries), len(originalEntries))
+}
+
+func TestSortedFileGenerationWith5ByteOffset(t *testing.T) {
+	// Create a test idx file with 5-byte offset entries
+	tempDir := t.TempDir()
+	baseFileName := filepath.Join(tempDir, "test_5bytes")
+
+	// Create test data with both 4-byte and 5-byte compatible entries
+	testEntries := []needle_map.NeedleValue{
+		{Key: NeedleId(1), Offset: ToOffset(1024), Size: Size(100)},
+		{Key: NeedleId(5), Offset: ToOffset(2048), Size: Size(200)},
+		{Key: NeedleId(3), Offset: ToOffset(4096), Size: Size(300)},
+		{Key: NeedleId(7), Offset: ToOffset(8192), Size: Size(400)},
+		{Key: NeedleId(2), Offset: ToOffset(16384), Size: Size(500)},
+	}
+
+	// Create the test idx file
+	err := createTestIdxFile(baseFileName+".idx", testEntries)
+	if err != nil {
+		t.Fatalf("Failed to create test idx file: %v", err)
+	}
+
+	// Test sorted file generation
+	testSortedFileGeneration(t, baseFileName)
+}
+
+func TestSortedFileGenerationWithLargeOffsets(t *testing.T) {
+	// Test with very large offsets that would require 5-byte offset support
+	tempDir := t.TempDir()
+	baseFileName := filepath.Join(tempDir, "test_large_offsets")
+
+	// Create test data with large offsets
+	testEntries := []needle_map.NeedleValue{
+		{Key: NeedleId(1), Offset: ToOffset(1024 * 1024 * 1024), Size: Size(100)},             // 1GB
+		{Key: NeedleId(5), Offset: ToOffset(2 * 1024 * 1024 * 1024), Size: Size(200)},         // 2GB
+		{Key: NeedleId(3), Offset: ToOffset(int64(5) * 1024 * 1024 * 1024), Size: Size(300)},  // 5GB
+		{Key: NeedleId(7), Offset: ToOffset(int64(10) * 1024 * 1024 * 1024), Size: Size(400)}, // 10GB
+		{Key: NeedleId(2), Offset: ToOffset(int64(20) * 1024 * 1024 * 1024), Size: Size(500)}, // 20GB
+	}
+
+	// Create the test idx file
+	err := createTestIdxFile(baseFileName+".idx", testEntries)
+	if err != nil {
+		t.Fatalf("Failed to create test idx file with large offsets: %v", err)
+	}
+
+	// Test sorted file generation
+	testSortedFileGeneration(t, baseFileName)
+
+	t.Logf("Successfully tested sorted file generation with large offsets up to 20GB")
+}
+
+func TestSortedFileGenerationCornerCases(t *testing.T) {
+	tempDir := t.TempDir()
+
+	// Test with empty file
+	t.Run("EmptyFile", func(t *testing.T) {
+		baseFileName := filepath.Join(tempDir, "empty")
+		err := createTestIdxFile(baseFileName+".idx", []needle_map.NeedleValue{})
+		if err != nil {
+			t.Fatalf("Failed to create empty idx file: %v", err)
+		}
+		testSortedFileGeneration(t, baseFileName)
+	})
+
+	// Test with single entry
+	t.Run("SingleEntry", func(t *testing.T) {
+		baseFileName := filepath.Join(tempDir, "single")
+		entries := []needle_map.NeedleValue{
+			{Key: NeedleId(42), Offset: ToOffset(1024), Size: Size(100)},
+		}
+		err := createTestIdxFile(baseFileName+".idx", entries)
+		if err != nil {
+			t.Fatalf("Failed to create single entry idx file: %v", err)
+		}
+		testSortedFileGeneration(t, baseFileName)
+	})
+
+	// Test with deleted entries
+	t.Run("WithDeletedEntries", func(t *testing.T) {
+		baseFileName := filepath.Join(tempDir, "deleted")
+		entries := []needle_map.NeedleValue{
+			{Key: NeedleId(1), Offset: ToOffset(1024), Size: Size(100)},
+			{Key: NeedleId(2), Offset: Offset{}, Size: TombstoneFileSize}, // Deleted
+			{Key: NeedleId(3), Offset: ToOffset(2048), Size: Size(200)},
+		}
+		err := createTestIdxFile(baseFileName+".idx", entries)
+		if err != nil {
+			t.Fatalf("Failed to create idx file with deleted entries: %v", err)
+		}
+		testSortedFileGenerationWithDeletedEntries(t, baseFileName)
+	})
+}
+
+func TestSortedFileNeedleMapIntegration(t *testing.T) {
+	// Test with the provided test data files
+	testFiles := []string{
+		"../../test/data/iceberg_173",
+		"../../test/data/iceberg_674",
+	}
+
+	for _, baseFileName := range testFiles {
+		t.Run(fmt.Sprintf("TestSortedFileNeedleMapIntegration_%s", filepath.Base(baseFileName)), func(t *testing.T) {
+			testSortedFileNeedleMapIntegration(t, baseFileName)
+		})
+	}
+
+	// Also test with valid synthetic data
+	t.Run("SyntheticData", func(t *testing.T) {
+		tempDir := t.TempDir()
+		baseFileName := filepath.Join(tempDir, "synthetic")
+
+		// Create test data with various scenarios
+		testEntries := []needle_map.NeedleValue{
+			{Key: NeedleId(1), Offset: ToOffset(1024), Size: Size(100)},
+			{Key: NeedleId(5), Offset: ToOffset(2048), Size: Size(200)},
+			{Key: NeedleId(3), Offset: ToOffset(4096), Size: Size(300)},
+			{Key: NeedleId(7), Offset: ToOffset(8192), Size: Size(400)},
+			{Key: NeedleId(2), Offset: ToOffset(16384), Size: Size(500)},
+			{Key: NeedleId(10), Offset: Offset{}, Size: TombstoneFileSize}, // Deleted
+			{Key: NeedleId(8), Offset: ToOffset(32768), Size: Size(600)},
+		}
+
+		err := createTestIdxFile(baseFileName+".idx", testEntries)
+		if err != nil {
+			t.Fatalf("Failed to create synthetic test idx file: %v", err)
+		}
+
+		testSortedFileNeedleMapIntegration(t, baseFileName)
+	})
+}
+
+func TestSortedFileNeedleMapIntegration5ByteMode(t *testing.T) {
+	// Test specifically for 5-byte mode functionality with large offsets
+	tempDir := t.TempDir()
+	baseFileName := filepath.Join(tempDir, "test_5byte_integration")
+
+	// Create test data with large offsets that benefit from 5-byte offset support
+	testEntries := []needle_map.NeedleValue{
+		{Key: NeedleId(1), Offset: ToOffset(1024), Size: Size(100)},
+		{Key: NeedleId(100), Offset: ToOffset(int64(5) * 1024 * 1024 * 1024), Size: Size(200)}, // 5GB offset
+		{Key: NeedleId(50), Offset: ToOffset(2048), Size: Size(150)},
+		{Key: NeedleId(200), Offset: ToOffset(int64(10) * 1024 * 1024 * 1024), Size: Size(300)}, // 10GB offset
+		{Key: NeedleId(25), Offset: ToOffset(4096), Size: Size(250)},
+		{Key: NeedleId(75), Offset: Offset{}, Size: TombstoneFileSize},                         // Deleted
+		{Key: NeedleId(150), Offset: ToOffset(int64(2) * 1024 * 1024 * 1024), Size: Size(400)}, // 2GB offset
+	}
+
+	err := createTestIdxFile(baseFileName+".idx", testEntries)
+	if err != nil {
+		t.Fatalf("Failed to create 5-byte test idx file: %v", err)
+	}
+
+	// The test should work regardless of whether we're in 4-byte or 5-byte mode
+	testSortedFileNeedleMapIntegration(t, baseFileName)
+
+	// Additional verification: ensure large offsets are handled correctly
+	idxFile, err := os.OpenFile(baseFileName+".idx", os.O_RDONLY, 0644)
+	if err != nil {
+		t.Fatalf("Failed to open test idx file: %v", err)
+	}
+	defer idxFile.Close()
+
+	sortedMap, err := NewSortedFileNeedleMap(baseFileName, idxFile)
+	if err != nil {
+		t.Fatalf("Failed to create SortedFileNeedleMap for large offset test: %v", err)
+	}
+	defer sortedMap.Close()
+
+	// Test specific large offset entries
+	largeOffsetTests := []struct {
+		key    NeedleId
+		offset Offset
+		size   Size
+	}{
+		{NeedleId(100), ToOffset(int64(5) * 1024 * 1024 * 1024), Size(200)},
+		{NeedleId(200), ToOffset(int64(10) * 1024 * 1024 * 1024), Size(300)},
+		{NeedleId(150), ToOffset(int64(2) * 1024 * 1024 * 1024), Size(400)},
+	}
+
+	for _, test := range largeOffsetTests {
+		value, ok := sortedMap.Get(test.key)
+		if !ok {
+			t.Errorf("Failed to get needle %d with large offset from sorted map", test.key)
+			continue
+		}
+		if value.Offset != test.offset || value.Size != test.size {
+			t.Errorf("Large offset needle %d mismatch: expected (%s, %d), got (%s, %d)",
+				test.key, test.offset.String(), test.size, value.Offset.String(), value.Size)
+		}
+	}
+
+	t.Logf("Successfully verified large offset handling in current mode (NeedleMapEntrySize: %d)", NeedleMapEntrySize)
+}
+
+func testSortedFileNeedleMapIntegration(t *testing.T, baseFileName string) {
+	// Open the original idx file
+	idxFile, err := os.OpenFile(baseFileName+".idx", os.O_RDONLY, 0644)
+	if err != nil {
+		t.Fatalf("Failed to open %s.idx: %v", baseFileName, err)
+	}
+	defer idxFile.Close()
+
+	// Check if the file has a valid size before proceeding
+	stat, err := idxFile.Stat()
+	if err != nil {
+		t.Fatalf("Failed to stat idx file: %v", err)
+	}
+
+	// Skip test files with real data when running in incompatible mode
+	// The test data files iceberg_173.idx and iceberg_674.idx were created with 5-byte offsets
+	if strings.Contains(baseFileName, "iceberg_") {
+		if NeedleMapEntrySize == 16 {
+			t.Skipf("Skipping real test data file %s: created with 5-byte format but running in 4-byte mode", baseFileName)
+			return
+		}
+	}
+
+	if stat.Size()%int64(NeedleMapEntrySize) != 0 {
+		// Check if it would be compatible with the other entry size
+		otherEntrySize := 16
+		if NeedleMapEntrySize == 16 {
+			otherEntrySize = 17 // 5-byte mode
+		} else {
+			otherEntrySize = 16 // 4-byte mode
+		}
+
+		if stat.Size()%int64(otherEntrySize) == 0 {
+			t.Skipf("Skipping test for %s: file size %d is compatible with %d-byte entries but current mode uses %d-byte entries",
+				baseFileName, stat.Size(), otherEntrySize, NeedleMapEntrySize)
+		} else {
+			t.Skipf("Skipping test for %s: file size %d is not a multiple of any known NeedleMapEntrySize (current: %d, alternative: %d)",
+				baseFileName, stat.Size(), NeedleMapEntrySize, otherEntrySize)
+		}
+		return
+	}
+
+	// Create SortedFileNeedleMap which will generate the sorted file
+	sortedMap, err := NewSortedFileNeedleMap(baseFileName, idxFile)
+	if err != nil {
+		t.Fatalf("Failed to create SortedFileNeedleMap: %v", err)
+	}
+	defer sortedMap.Close()
+
+	// Read original entries for verification
+	originalEntries, err := readIndexFileEntries(idxFile)
+	if err != nil {
+		t.Fatalf("Failed to read original entries: %v", err)
+	}
+
+	// Build final state map from original entries (same logic as readNeedleMap)
+	finalStateMap := make(map[NeedleId]needle_map.NeedleValue)
+	for _, entry := range originalEntries {
+		if !entry.Offset.IsZero() && !entry.Size.IsDeleted() {
+			finalStateMap[entry.Key] = entry
+		} else {
+			delete(finalStateMap, entry.Key)
+		}
+	}
+
+	// Test Get operations for all final valid entries
+	validEntries := 0
+	for _, entry := range finalStateMap {
+		validEntries++
+		value, ok := sortedMap.Get(entry.Key)
+		if !ok {
+			t.Errorf("Failed to get needle %d from sorted map", entry.Key)
+			continue
+		}
+		if value.Key != entry.Key || value.Offset != entry.Offset || value.Size != entry.Size {
+			t.Errorf("Needle %d mismatch: expected (%d, %s, %d), got (%d, %s, %d)",
+				entry.Key, entry.Key, entry.Offset.String(), entry.Size,
+				value.Key, value.Offset.String(), value.Size)
+		}
+	}
+
+	t.Logf("Successfully verified %d valid entries out of %d total entries", validEntries, len(originalEntries))
+}
+
+// Helper functions
+
+func readIndexFileEntries(file *os.File) ([]needle_map.NeedleValue, error) {
+	var entries []needle_map.NeedleValue
+
+	err := idx.WalkIndexFile(file, 0, func(key NeedleId, offset Offset, size Size) error {
+		entries = append(entries, needle_map.NeedleValue{
+			Key:    key,
+			Offset: offset,
+			Size:   size,
+		})
+		return nil
+	})
+
+	return entries, err
+}
+
+func verifyAllEntriesPresent(original, sorted []needle_map.NeedleValue) error {
+	// Create maps for efficient lookup
+	originalMap := make(map[NeedleId]needle_map.NeedleValue)
+	sortedMap := make(map[NeedleId]needle_map.NeedleValue)
+
+	for _, entry := range original {
+		originalMap[entry.Key] = entry
+	}
+
+	for _, entry := range sorted {
+		sortedMap[entry.Key] = entry
+	}
+
+	// Verify each original entry is present in sorted
+	for key, originalEntry := range originalMap {
+		sortedEntry, exists := sortedMap[key]
+		if !exists {
+			return fmt.Errorf("entry with key %d missing in sorted file", key)
+		}
+		if originalEntry.Offset != sortedEntry.Offset || originalEntry.Size != sortedEntry.Size {
+			return fmt.Errorf("entry %d data mismatch: original(%s, %d) vs sorted(%s, %d)",
+				key, originalEntry.Offset.String(), originalEntry.Size,
+				sortedEntry.Offset.String(), sortedEntry.Size)
+		}
+	}
+
+	return nil
+}
+
+func verifySortedOrder(entries []needle_map.NeedleValue) error {
+	for i := 1; i < len(entries); i++ {
+		if entries[i-1].Key >= entries[i].Key {
+			return fmt.Errorf("entries not sorted: entry[%d].Key=%d >= entry[%d].Key=%d",
+				i-1, entries[i-1].Key, i, entries[i].Key)
+		}
+	}
+	return nil
+}
+
+func testBinarySearch(t *testing.T, sdxFile *os.File, sortedEntries []needle_map.NeedleValue) error {
+	stat, err := sdxFile.Stat()
+	if err != nil {
+		return err
+	}
+
+	// Test binary search with existing keys
+	for i := 0; i < len(sortedEntries) && i < 10; i++ { // Test first 10 entries
+		key := sortedEntries[i].Key
+		offset, size, err := erasure_coding.SearchNeedleFromSortedIndex(sdxFile, stat.Size(), key, nil)
+		if err != nil {
+			return fmt.Errorf("binary search failed for key %d: %v", key, err)
+		}
+		if offset != sortedEntries[i].Offset || size != sortedEntries[i].Size {
+			return fmt.Errorf("binary search returned wrong values for key %d: expected (%s, %d), got (%s, %d)",
+				key, sortedEntries[i].Offset.String(), sortedEntries[i].Size,
+				offset.String(), size)
+		}
+	}
+
+	// Test binary search with non-existent keys
+	nonExistentKey := NeedleId(999999999)
+	_, _, err = erasure_coding.SearchNeedleFromSortedIndex(sdxFile, stat.Size(), nonExistentKey, nil)
+	if err != erasure_coding.NotFoundError {
+		return fmt.Errorf("expected NotFoundError for non-existent key, got: %v", err)
+	}
+
+	return nil
+}
+
+func createTestIdxFile(filename string, entries []needle_map.NeedleValue) error {
+	file, err := os.OpenFile(filename, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	for _, entry := range entries {
+		bytes := entry.ToBytes()
+		if _, err := file.Write(bytes); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func BenchmarkSortedFileGeneration(b *testing.B) {
+	testFiles := []string{
+		"../../test/data/iceberg_173",
+		"../../test/data/iceberg_674",
+	}
+
+	for _, baseFileName := range testFiles {
+		b.Run(fmt.Sprintf("BenchmarkSortedFileGeneration_%s", filepath.Base(baseFileName)), func(b *testing.B) {
+			// Check if idx file exists before running benchmark
+			if _, err := os.Stat(baseFileName + ".idx"); os.IsNotExist(err) {
+				b.Skipf("Idx file does not exist: %s.idx", baseFileName)
+				return
+			}
+
+			// Cleanup at the end of benchmark
+			defer func() {
+				os.Remove(baseFileName + ".sdx")
+			}()
+
+			for i := 0; i < b.N; i++ {
+				sdxFileName := baseFileName + ".sdx"
+				// Remove existing file if any
+				os.Remove(sdxFileName)
+
+				b.StartTimer()
+				err := erasure_coding.WriteSortedFileFromIdx(baseFileName, ".sdx")
+				b.StopTimer()
+
+				if err != nil {
+					// Clean up before failing
+					os.Remove(sdxFileName)
+					b.Fatalf("Failed to generate sorted file: %v", err)
+				}
+
+				// Clean up immediately after timing
+				os.Remove(sdxFileName)
+			}
+		})
+	}
+
+	// Also benchmark with synthetic data for consistent results
+	b.Run("SyntheticData", func(b *testing.B) {
+		tempDir := b.TempDir()
+		baseFileName := filepath.Join(tempDir, "bench")
+
+		// Create test data for benchmarking
+		testEntries := make([]needle_map.NeedleValue, 1000)
+		for i := 0; i < 1000; i++ {
+			testEntries[i] = needle_map.NeedleValue{
+				Key:    NeedleId(i + 1),
+				Offset: ToOffset(int64((i + 1) * 1024)),
+				Size:   Size(100 + i%900),
+			}
+		}
+
+		err := createTestIdxFile(baseFileName+".idx", testEntries)
+		if err != nil {
+			b.Fatalf("Failed to create benchmark idx file: %v", err)
+		}
+
+		b.ResetTimer()
+		for i := 0; i < b.N; i++ {
+			sdxFileName := baseFileName + ".sdx"
+			os.Remove(sdxFileName)
+
+			b.StartTimer()
+			err := erasure_coding.WriteSortedFileFromIdx(baseFileName, ".sdx")
+			b.StopTimer()
+
+			if err != nil {
+				b.Fatalf("Failed to generate sorted file: %v", err)
+			}
+
+			os.Remove(sdxFileName)
+		}
+	})
+}
+
+func TestSortedFileGenerationConcurrency(t *testing.T) {
+	// Test concurrent sorted file generation
+	tempDir := t.TempDir()
+
+	// Create test data
+	testEntries := []needle_map.NeedleValue{
+		{Key: NeedleId(1), Offset: ToOffset(1024), Size: Size(100)},
+		{Key: NeedleId(5), Offset: ToOffset(2048), Size: Size(200)},
+		{Key: NeedleId(3), Offset: ToOffset(4096), Size: Size(300)},
+		{Key: NeedleId(7), Offset: ToOffset(8192), Size: Size(400)},
+		{Key: NeedleId(2), Offset: ToOffset(16384), Size: Size(500)},
+	}
+
+	baseFileName := filepath.Join(tempDir, "concurrent")
+	err := createTestIdxFile(baseFileName+".idx", testEntries)
+	if err != nil {
+		t.Fatalf("Failed to create test idx file: %v", err)
+	}
+
+	// Test concurrent access to the same source file
+	const numGoroutines = 5
+	errChan := make(chan error, numGoroutines)
+
+	for i := 0; i < numGoroutines; i++ {
+		go func(id int) {
+			concurrentBaseFileName := filepath.Join(tempDir, fmt.Sprintf("concurrent_%d", id))
+			err := createTestIdxFile(concurrentBaseFileName+".idx", testEntries)
+			if err != nil {
+				errChan <- fmt.Errorf("goroutine %d: failed to create idx file: %v", id, err)
+				return
+			}
+
+			// Generate sorted file
+			err = erasure_coding.WriteSortedFileFromIdx(concurrentBaseFileName, ".sdx")
+			if err != nil {
+				errChan <- fmt.Errorf("goroutine %d: failed to generate sorted file: %v", id, err)
+				return
+			}
+
+			// Verify the sorted file
+			sdxFile, err := os.OpenFile(concurrentBaseFileName+".sdx", os.O_RDONLY, 0644)
+			if err != nil {
+				errChan <- fmt.Errorf("goroutine %d: failed to open sorted file: %v", id, err)
+				return
+			}
+			defer sdxFile.Close()
+
+			sortedEntries, err := readIndexFileEntries(sdxFile)
+			if err != nil {
+				errChan <- fmt.Errorf("goroutine %d: failed to read sorted entries: %v", id, err)
+				return
+			}
+
+			if len(sortedEntries) != len(testEntries) {
+				errChan <- fmt.Errorf("goroutine %d: entry count mismatch", id)
+				return
+			}
+
+			// Verify sorted order
+			err = verifySortedOrder(sortedEntries)
+			if err != nil {
+				errChan <- fmt.Errorf("goroutine %d: sorted order verification failed: %v", id, err)
+				return
+			}
+
+			errChan <- nil
+		}(i)
+	}
+
+	// Wait for all goroutines to complete
+	for i := 0; i < numGoroutines; i++ {
+		if err := <-errChan; err != nil {
+			t.Fatal(err)
+		}
+	}
+
+	t.Logf("Successfully tested concurrent sorted file generation with %d goroutines", numGoroutines)
+}
+
+func TestSortedFileErrorHandling(t *testing.T) {
+	tempDir := t.TempDir()
+
+	// Test with non-existent idx file
+	t.Run("NonExistentFile", func(t *testing.T) {
+		baseFileName := filepath.Join(tempDir, "nonexistent")
+		err := erasure_coding.WriteSortedFileFromIdx(baseFileName, ".sdx")
+		if err == nil {
+			t.Fatal("Expected error for non-existent file, got nil")
+		}
+	})
+
+	// Test with empty idx file
+	t.Run("EmptyIdxFile", func(t *testing.T) {
+		baseFileName := filepath.Join(tempDir, "empty")
+		// Create an empty idx file
+		file, err := os.Create(baseFileName + ".idx")
+		if err != nil {
+			t.Fatalf("Failed to create empty idx file: %v", err)
+		}
+		file.Close()
+
+		// Should succeed with empty file
+		err = erasure_coding.WriteSortedFileFromIdx(baseFileName, ".sdx")
+		if err != nil {
+			t.Fatalf("Unexpected error for empty file: %v", err)
+		}
+
+		// Verify empty sorted file was created
+		sdxFile, err := os.OpenFile(baseFileName+".sdx", os.O_RDONLY, 0644)
+		if err != nil {
+			t.Fatalf("Failed to open empty sorted file: %v", err)
+		}
+		defer sdxFile.Close()
+
+		stat, err := sdxFile.Stat()
+		if err != nil {
+			t.Fatalf("Failed to stat empty sorted file: %v", err)
+		}
+
+		if stat.Size() != 0 {
+			t.Fatalf("Expected empty sorted file, got size %d", stat.Size())
+		}
+
+		// Clean up
+		os.Remove(baseFileName + ".sdx")
+	})
+}