Optimize the Kotlin implementation to double performance

Kotlin/build.gradle

@@ -1,15 +1,15 @@
 
 buildscript {
 
-    ext.kotlin_version = '1.3.72'
+    ext.kotlin_version = '2.0.0'
 
     repositories {
         google()
-        jcenter()
+        mavenCentral()
     }
 
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.5.0'
+        classpath 'com.android.tools.build:gradle:8.5.0'
         classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
     }
 
@@ -19,11 +19,7 @@ allprojects {
 
     repositories {
         google()
-        jcenter()
+        mavenCentral()
     }
 
 }
-
-task clean(type: Delete) {
-    delete rootProject.buildDir
-}

Kotlin/demo/build.gradle

@@ -1,15 +1,14 @@
 apply plugin: 'com.android.application'
 apply plugin: 'kotlin-android'
-apply plugin: 'kotlin-android-extensions'
 
 android {
-
-    compileSdkVersion 29
+    namespace "com.wolt.blurhashapp"
+    compileSdk 34
 
     defaultConfig {
         applicationId "com.wolt.blurhash"
-        minSdkVersion 14
-        targetSdkVersion 29
+        minSdkVersion 21
+        targetSdkVersion 34
         versionCode 1
         versionName "1.0"
     }
@@ -21,9 +20,16 @@ android {
         }
     }
 
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_11
+        targetCompatibility = JavaVersion.VERSION_11
+    }
+    kotlinOptions {
+        jvmTarget = "11"
+    }
 }
 
 dependencies {
-    implementation project(path: ':lib')
-    implementation 'androidx.appcompat:appcompat:1.1.0'
+    implementation project(':lib')
+    implementation 'androidx.appcompat:appcompat:1.7.0'
 }

Kotlin/demo/src/main/AndroidManifest.xml

@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="utf-8"?>
-<manifest xmlns:android="http://schemas.android.com/apk/res/android"
-          package="com.wolt.blurhashapp">
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
 
     <application
         android:allowBackup="true"
@@ -9,7 +8,9 @@
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/AppTheme">
-        <activity android:name="com.wolt.blurhashapp.MainActivity">
+        <activity
+            android:name="com.wolt.blurhashapp.MainActivity"
+            android:exported="true">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN"/>
 

Kotlin/demo/src/main/java/com/wolt/blurhashapp/MainActivity.kt

@@ -2,34 +2,33 @@ package com.wolt.blurhashapp
 
 import android.graphics.Bitmap
 import android.os.Bundle
-import android.os.SystemClock
+import android.view.View
+import android.widget.EditText
+import android.widget.ImageView
+import android.widget.TextView
 import androidx.appcompat.app.AppCompatActivity
 import com.wolt.blurhashkt.BlurHashDecoder
-import kotlinx.android.synthetic.main.activity_main.*
+import kotlin.time.measureTime
 
 class MainActivity : AppCompatActivity() {
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         setContentView(R.layout.activity_main)
+
+        val tvDecode: View = findViewById(R.id.tvDecode)
+        val etInput: EditText = findViewById(R.id.etInput)
+        val ivResult: ImageView = findViewById(R.id.ivResult)
+        val ivResultTime: TextView = findViewById(R.id.ivResultTime)
+
         tvDecode.setOnClickListener {
-            var bitmap: Bitmap? = null
-            val time = timed {
+            val bitmap: Bitmap?
+            val time = measureTime {
                 bitmap = BlurHashDecoder.decode(etInput.text.toString(), 20, 12)
             }
             ivResult.setImageBitmap(bitmap)
-            ivResultTime.text = "Time: $time ms"
+            ivResultTime.text = "Time: ${time.inWholeMilliseconds} ms"
         }
     }
 
 }
-
-/**
- * Executes a function and return the time spent in milliseconds.
- */
-private inline fun timed(function: () -> Unit): Long {
-    val start = SystemClock.elapsedRealtime()
-    function()
-    return SystemClock.elapsedRealtime() - start
-}
-

Kotlin/gradle.properties

@@ -6,9 +6,8 @@
 # http://www.gradle.org/docs/current/userguide/build_environment.html
 # Specifies the JVM arguments used for the daemon process.
 # The setting is particularly useful for tweaking memory settings.
-android.enableJetifier=true
 android.useAndroidX=true
-org.gradle.jvmargs=-Xmx1536m
+org.gradle.jvmargs=-Xmx2048m
 # When configured, Gradle will run in incubating parallel mode.
 # This option should only be used with decoupled projects. More details, visit
 # http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects

Kotlin/gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
-#Mon Jul 01 10:02:38 EEST 2019
+#Sun Jul 07 23:57:08 CEST 2024
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
+distributionUrl=https\://services.gradle.org/distributions/gradle-8.7-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-5.4.1-all.zip

Kotlin/lib/build.gradle

@@ -1,14 +1,13 @@
 apply plugin: 'com.android.library'
-apply plugin: 'kotlin-android-extensions'
 apply plugin: 'kotlin-android'
 
 android {
-
-    compileSdkVersion 29
+    namespace "com.wolt.blurhashkt"
+    compileSdk 34
 
     defaultConfig {
-        minSdkVersion 14
-        targetSdkVersion 29
+        minSdkVersion 21
+        targetSdkVersion 34
         versionCode 1
         versionName "1.0"
 
@@ -22,11 +21,16 @@ android {
         }
     }
 
+    compileOptions {
+        sourceCompatibility = JavaVersion.VERSION_11
+        targetCompatibility = JavaVersion.VERSION_11
+    }
+    kotlinOptions {
+        jvmTarget = "11"
+    }
 }
 
 dependencies {
-    implementation fileTree(dir: 'libs', include: ['*.jar'])
-    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
-    androidTestImplementation 'junit:junit:4.13'
-    androidTestImplementation 'androidx.test:runner:1.2.0'
+    androidTestImplementation 'junit:junit:4.13.2'
+    androidTestImplementation 'androidx.test:runner:1.6.1'
 }

Kotlin/lib/src/androidTest/java/com/wolt/blurhashkt/BlurHashDecoderTest.kt

@@ -1,24 +1,15 @@
 package com.wolt.blurhashkt
 
 import android.graphics.Bitmap
-import com.wolt.blurhashkt.BlurHashDecoder.clearCache
 import com.wolt.blurhashkt.BlurHashDecoder.decode
-import junit.framework.Assert.assertTrue
-import org.junit.Before
+import org.junit.Assert.assertArrayEquals
 import org.junit.Test
 import java.nio.ByteBuffer
-import java.util.*
 
 
 class BlurHashDecoderTest {
-    @Before
-    @Throws(Exception::class)
-    fun setUp() {
-        clearCache()
-    }
-
     @Test
-    fun decode_smallImage_cacheEnabled_shouldGetTheSameBitmapInManyRequests() {
+    fun decode_smallImage_shouldGetTheSameBitmapInManyRequests() {
         val bmp1 = decode("LEHV6nWB2yk8pyo0adR*.7kCMdnj", 20, 12)!!
         val bmp2 = decode("LEHV6nWB2yk8pyo0adR*.7kCMdnj", 20, 12)!!
         val bmp3 = decode("LEHV6nWB2yk8pyo0adR*.7kCMdnj", 20, 12)!!
@@ -28,61 +19,20 @@ class BlurHashDecoderTest {
     }
 
     @Test
-    fun decode_smallImage_differentCache_shouldGetTheSameBitmapInManyRequests() {
-        val bmp1 = decode("LEHV6nWB2yk8pyo0adR*.7kCMdnj", 20, 12)!!
-        val bmp2 = decode("LEHV6nWB2yk8pyo0adR*.7kCMdnj", 20, 12, useCache = false)!!
-        val bmp3 = decode("LEHV6nWB2yk8pyo0adR*.7kCMdnj", 20, 12)!!
-
-        bmp1.assertEquals(bmp2)
-        bmp2.assertEquals(bmp3)
-    }
-
-    @Test
-    fun decode_smallImage_cacheDisabled_shouldGetTheSameBitmapInManyRequests() {
-        val bmp1 = decode("LEHV6nWB2yk8pyo0adR*.7kCMdnj", 20, 12, useCache = false)!!
-        val bmp2 = decode("LEHV6nWB2yk8pyo0adR*.7kCMdnj", 20, 12, useCache = false)!!
-        val bmp3 = decode("LEHV6nWB2yk8pyo0adR*.7kCMdnj", 20, 12, useCache = false)!!
-
-        bmp1.assertEquals(bmp2)
-        bmp2.assertEquals(bmp3)
-    }
-
-    @Test
-    fun decode_bigImage_cacheEnabled_shouldGetTheSameBitmapInManyRequests() {
+    fun decode_bigImage_shouldGetTheSameBitmapInManyRequests() {
         val bmp1 = decode("LEHV6nWB2yk8pyo0adR*.7kCMdnj", 100, 100)!!
         val bmp2 = decode("LEHV6nWB2yk8pyo0adR*.7kCMdnj", 100, 100)!!
         val bmp3 = decode("LEHV6nWB2yk8pyo0adR*.7kCMdnj", 100, 100)!!
 
         bmp1.assertEquals(bmp2)
         bmp2.assertEquals(bmp3)
     }
-
-    @Test
-    fun decode_bigImage_differentCache_shouldGetTheSameBitmapInManyRequests() {
-        val bmp1 = decode("LEHV6nWB2yk8pyo0adR*.7kCMdnj", 100, 100)!!
-        val bmp2 = decode("LEHV6nWB2yk8pyo0adR*.7kCMdnj", 100, 100, useCache = false)!!
-        val bmp3 = decode("LEHV6nWB2yk8pyo0adR*.7kCMdnj", 100, 100)!!
-
-        bmp1.assertEquals(bmp2)
-        bmp2.assertEquals(bmp3)
-    }
-
-    @Test
-    fun decode_bigImage_cacheDisabled_shouldGetTheSameBitmapInManyRequests() {
-        val bmp1 = decode("LEHV6nWB2yk8pyo0adR*.7kCMdnj", 100, 100, useCache = false)!!
-        val bmp2 = decode("LEHV6nWB2yk8pyo0adR*.7kCMdnj", 100, 100, useCache = false)!!
-        val bmp3 = decode("LEHV6nWB2yk8pyo0adR*.7kCMdnj", 100, 100, useCache = false)!!
-
-        bmp1.assertEquals(bmp2)
-        bmp2.assertEquals(bmp3)
-    }
 }
 
 fun Bitmap.assertEquals(bitmap2: Bitmap) {
     val buffer1: ByteBuffer = ByteBuffer.allocate(height * rowBytes)
     copyPixelsToBuffer(buffer1)
     val buffer2: ByteBuffer = ByteBuffer.allocate(bitmap2.height * bitmap2.rowBytes)
     bitmap2.copyPixelsToBuffer(buffer2)
-    val equals = Arrays.equals(buffer1.array(), buffer2.array())
-    assertTrue(equals)
+    assertArrayEquals(buffer1.array(), buffer2.array())
 }