Function DefaultOptions

options.go:120–175

DefaultOptions sets a list of recommended options for good performance. Feel free to modify these to suit your needs with the WithX methods.

(path string)

// DefaultOptions sets a list of recommended options for good performance.
// Feel free to modify these to suit your needs with the WithX methods.
func DefaultOptions(path string) Options {
	return Options{
		Dir:                 path,
		ValueDir:            path,
		LevelOneSize:        256 << 20,
		LevelSizeMultiplier: 10,
		TableLoadingMode:    options.MemoryMap,
		ValueLogLoadingMode: options.MemoryMap,
		// table.MemoryMap to mmap() the tables.
		// table.Nothing to not preload the tables.
		MaxLevels:               7,
		MaxTableSize:            64 << 20,
		NumCompactors:           2, // Compactions can be expensive. Only run 2.
		NumLevelZeroTables:      5,
		NumLevelZeroTablesStall: 10,
		NumMemtables:            5,
		BloomFalsePositive:      0.01,
		BlockSize:               4 * 1024,
		SyncWrites:              true,
		NumVersionsToKeep:       1,
		CompactL0OnClose:        true,
		KeepL0InMemory:          false,
		VerifyValueChecksum:     false,
		Compression:             options.None,
		MaxCacheSize:            0,
		MaxBfCacheSize:          0,
		LoadBloomsOnOpen:        true,
		// The following benchmarks were done on a 4 KB block size (default block size). The
		// compression is ratio supposed to increase with increasing compression level but since the
		// input for compression algorithm is small (4 KB), we don't get significant benefit at
		// level 3.
		// no_compression-16              10	 502848865 ns/op	 165.46 MB/s	-
		// zstd_compression/level_1-16     7	 739037966 ns/op	 112.58 MB/s	2.93
		// zstd_compression/level_3-16     7	 756950250 ns/op	 109.91 MB/s	2.72
		// zstd_compression/level_15-16    1	11135686219 ns/op	   7.47 MB/s	4.38
		// Benchmark code can be found in table/builder_test.go file
		ZSTDCompressionLevel: 1,

		// Nothing to read/write value log using standard File I/O
		// MemoryMap to mmap() the value log files
		// (2^30 - 1)*2 when mmapping < 2^31 - 1, max int32.
		// -1 so 2*ValueLogFileSize won't overflow on 32-bit systems.
		ValueLogFileSize: 1<<30 - 1,

		ValueLogMaxEntries:            1000000,
		ValueThreshold:                1 << 10, // 1 KB.
		Truncate:                      false,
		Logger:                        defaultLogger(INFO),
		LogRotatesToFlush:             2,
		EncryptionKey:                 []byte{},
		EncryptionKeyRotationDuration: 10 * 24 * time.Hour, // Default 10 days.
		DetectConflicts:               true,
		KeepBlocksInCache:             false,
		KeepBlockIndicesInCache:       false,
	}
}

func buildTableOptions(opt Options) table.Options {