feat: improve write performance and update benckmark

Author: adrielcafe

README.md

@@ -256,14 +256,43 @@ puffer.apply {
 
 ## Benchmark
 
+### Write & Read
 |  | Write 1k strings (ms) | Read 1k strings (ms) |
 |-------------------|-----------------------|----------------------|
-| **PufferDB** | **28** | **9** |
-| [SharedPreferences](https://developer.android.com/training/data-storage/shared-preferences) | 291 | 14 |
-| [MMKV](https://github.com/Tencent/MMKV) | 16 | 10 |
-| [Paper](https://github.com/pilgr/Paper) | 780 | 170 |
-| [Binary Prefs](https://github.com/yandextaxitech/binaryprefs) | 65 | 9 |
-| [Hawk](https://github.com/orhanobut/hawk) | 12053 | 192 |
+| **PufferDB** | **20** | **5** |
+| [SharedPreferences](https://developer.android.com/training/data-storage/shared-preferences) | 278 | 7 |
+| [MMKV](https://github.com/Tencent/MMKV) | 13 | 8 |
+| [Paper](https://github.com/pilgr/Paper) | 818 | 169 |
+| [Binary Prefs](https://github.com/yandextaxitech/binaryprefs) | 121 | 9 |
+| [Hawk](https://github.com/orhanobut/hawk) | 15183 | 207 |
+
+|  | Write 100k strings (ms) | Read 100k strings (ms) |
+|-------------------|-----------------------|----------------------|
+| **PufferDB** | **259** | **32** |
+| [SharedPreferences](https://developer.android.com/training/data-storage/shared-preferences) | 💥 | 💥 |
+| [MMKV](https://github.com/Tencent/MMKV) | 871 | 516 |
+| [Paper](https://github.com/pilgr/Paper) | 💥 | 💥 |
+| [Binary Prefs](https://github.com/yandextaxitech/binaryprefs) | 1082 | 101 |
+| [Hawk](https://github.com/orhanobut/hawk) | 💥 | 💥 |
+
+### File size
+|  | 1k strings (kb) |
+|-------------------|-----------------------|
+| **PufferDB** | **25** |
+| [SharedPreferences](https://developer.android.com/training/data-storage/shared-preferences) | 20 |
+| [MMKV](https://github.com/Tencent/MMKV) | 40 |
+| [Paper](https://github.com/pilgr/Paper) | 61 |
+| [Binary Prefs](https://github.com/yandextaxitech/binaryprefs) | 53 |
+| [Hawk](https://github.com/orhanobut/hawk) | 27 |
+
+|  | 100k strings (kb) |
+|-------------------|-----------------------|
+| **PufferDB** | **2.907** |
+| [SharedPreferences](https://developer.android.com/training/data-storage/shared-preferences) | 💥 |
+| [MMKV](https://github.com/Tencent/MMKV) | 4.104 |
+| [Paper](https://github.com/pilgr/Paper) | 💥 |
+| [Binary Prefs](https://github.com/yandextaxitech/binaryprefs) | 5.175 |
+| [Hawk](https://github.com/orhanobut/hawk) | 💥 |
 
 *Tested on Moto Z2 Plus*
 

core/src/main/kotlin/cafe/adriel/pufferdb/core/PufferDB.kt

@@ -10,20 +10,20 @@ import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.GlobalScope
 import kotlinx.coroutines.Job
+import kotlinx.coroutines.async
+import kotlinx.coroutines.coroutineScope
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.drop
 import kotlinx.coroutines.flow.flowOn
 import kotlinx.coroutines.flow.launchIn
 import kotlinx.coroutines.flow.onEach
-import kotlinx.coroutines.flow.onStart
 import kotlinx.coroutines.isActive
-import kotlinx.coroutines.launch
 import kotlinx.coroutines.sync.Mutex
 import kotlinx.coroutines.sync.withLock
 
 class PufferDB private constructor(
     private val pufferFile: File,
-    private val scope: CoroutineScope,
+    scope: CoroutineScope,
     private val dispatcher: CoroutineContext
 ) : Puffer {
 
@@ -43,17 +43,18 @@ class PufferDB private constructor(
     private var writeJob: Job? = null
 
     init {
+        loadProto()
+
         stateFlow
             .drop(1)
-            .onStart { loadProto() }
             .onEach { saveProto(state) }
             .flowOn(dispatcher)
             .launchIn(scope)
     }
 
     @Suppress("UNCHECKED_CAST")
     override fun <T : Any> get(key: String, defaultValue: T?): T = try {
-        val value = state.getOrDefault(key, null)
+        val value = state[key]
         if (value == null) {
             throw PufferException("The key '$key' has no value saved")
         } else {
@@ -124,9 +125,9 @@ class PufferDB private constructor(
             }
             .toMap()
 
-    private fun saveProto(state: Map<String, Any>) {
+    private suspend fun saveProto(state: Map<String, Any>) = coroutineScope {
         writeJob?.cancel()
-        writeJob = scope.launch(dispatcher) {
+        writeJob = async(dispatcher) {
             writeMutex.withLock {
                 if (isActive) {
                     val newNest = state.mapValues { it.value.getProtoValue() }

sample/src/main/kotlin/cafe/adriel/pufferdb/sample/Benchmark.kt

@@ -9,6 +9,7 @@ import com.ironz.binaryprefs.BinaryPreferencesBuilder
 import com.orhanobut.hawk.Hawk
 import com.tencent.mmkv.MMKV
 import io.paperdb.Paper
+import java.io.File
 import kotlin.system.measureTimeMillis
 
 class Benchmark(context: Context) {
@@ -21,11 +22,20 @@ class Benchmark(context: Context) {
     private val keys = Array(REPEAT_COUNT) { "Key $it" }
     private val values = Array(REPEAT_COUNT) { "Value $it" }
 
+    private val pufferFile = AndroidPufferDB.getInternalFile("puffer.db")
     private val puffer = AndroidPufferDB.withDefault()
+
+    private val sharedPreferencesDir = File(context.filesDir, "preferences")
     private val sharedPreferences = PreferenceManager.getDefaultSharedPreferences(context)
+
+    private val mmkvDir = File(MMKV.getRootDir())
     private val mmkv = MMKV.defaultMMKV()
+
     private val paper = Paper.book()
-    private val binaryPrefs = BinaryPreferencesBuilder(context).build()
+    private val paperDir = File(paper.path)
+
+    private val binaryPrefsDir = File(context.filesDir, "binaryPrefs")
+    private val binaryPrefs = BinaryPreferencesBuilder(context).customDirectory(binaryPrefsDir).build()
 
     fun run() {
         reset()
@@ -170,4 +180,9 @@ class Benchmark(context: Context) {
         }
         Log.i("HAWK READ", "$duration ms")
     }
+
+    private fun File.lengthRecursively(): Long =
+        walk().fold(0L) { acc, file ->
+            acc + file.length()
+        }
 }