chore: wasmjs ArrayBuffer functions

Author: sureshg

gradle/build-logic/src/main/kotlin/common/CommonExtns.kt

@@ -7,7 +7,6 @@ import java.nio.file.Files
 import java.nio.file.Path
 import java.text.DecimalFormat
 import java.text.NumberFormat
-import kotlin.jvm.optionals.getOrNull
 import kotlin.math.ln
 import kotlin.math.pow
 import kotlin.properties.ReadOnlyProperty
@@ -21,10 +20,6 @@ internal val DEC_FORMAT = DecimalFormat("#.##")
 /** OS temp location */
 val tmp: String = "${System.getProperty("java.io.tmpdir")}${File.separator}"
 
-/** Returns the method name contains this call-site */
-inline val methodName
-  get() = StackWalker.getInstance().walk { it.findFirst().getOrNull()?.methodName }
-
 /** Read the [Class] as [ByteArray] */
 fun <T : Class<*>> T.toBytes() =
     classLoader.getResourceAsStream("${name.replace('.', '/')}.class")?.readBytes()

shared/src/jsMain/kotlin/dev/suresh/Platform.kt

@@ -1,6 +1,8 @@
 package dev.suresh
 
 import kotlinx.browser.window
+import org.khronos.webgl.ArrayBuffer
+import org.khronos.webgl.Int8Array
 
 actual val platform: Platform = JsPlatform
 
@@ -16,3 +18,10 @@ object JsPlatform : Platform {
                 "vendor" to window.navigator.vendor,
             )
 }
+
+/**
+ * Convert JS [ArrayBuffer] to Kotlin [ByteArray]
+ *
+ * [Kotlin-JS-Types](https://kotlinlang.org/docs/js-to-kotlin-interop.html#kotlin-types-in-javascript)
+ */
+fun ArrayBuffer?.asByteArray() = this?.run { Int8Array(this).unsafeCast<ByteArray>() }

shared/src/jvmMain/kotlin/dev/suresh/Extns.kt

@@ -1,6 +1,7 @@
 package dev.suresh
 
 import java.io.File
+import java.lang.StackWalker.Option.RETAIN_CLASS_REFERENCE
 import java.text.DecimalFormat
 import java.text.NumberFormat
 import java.util.concurrent.Semaphore
@@ -16,7 +17,10 @@ val DEC_FORMAT = DecimalFormat("#.##")
 
 /** Returns the method name contains this call-site */
 inline val methodName
-  get() = StackWalker.getInstance().walk { it.findFirst().getOrNull()?.methodName }
+  get() =
+      StackWalker.getInstance(RETAIN_CLASS_REFERENCE).walk {
+        it.findFirst().getOrNull()?.methodName
+      }
 
 /** Read the [Class] as [ByteArray] */
 fun <T : Class<*>> T.toBytes() =

web/wasm/src/wasmJsMain/kotlin/App.kt

@@ -61,7 +61,9 @@ suspend fun main() {
       info?.appendText("Selected files: $files")
       files.forEach { file ->
         val text = file.readAsText()
-        info?.appendText("File content: $text")
+        val buf = file.readAsByteArray()
+        info?.appendText("Text File content: $text")
+        info?.appendText("Binary File content: ${buf?.decodeToString()}")
       }
     }
   }

web/wasm/src/wasmJsMain/kotlin/FilePicker.kt

@@ -23,8 +23,12 @@ suspend fun Document.selectFileFromDisk(accept: String? = null, multiple: Boolea
         this.multiple = multiple
         accept?.let { this.accept = it }
         onchange = {
-          val files = input.files?.asList().orEmpty()
-          cont.resume(files)
+          try {
+            val files = input.files?.asList().orEmpty()
+            cont.resume(files)
+          } catch (e: Exception) {
+            cont.resumeWithException(e)
+          }
         }
       }
       body?.appendChild(input)
@@ -35,9 +39,13 @@ suspend fun Document.selectFileFromDisk(accept: String? = null, multiple: Boolea
 suspend fun File.readAsText() = suspendCoroutine { cont ->
   val reader = FileReader()
   reader.onload = {
-    val target = it.target as? FileReader
-    val result = target?.result as? ArrayBuffer
-    cont.resume(result)
+    try {
+      val target = it.target as? FileReader
+      val result = target?.result?.unsafeCast<JsString>()
+      cont.resume(result?.toString())
+    } catch (e: Exception) {
+      cont.resumeWithException(e)
+    }
   }
 
   reader.onerror = {
@@ -50,3 +58,26 @@ suspend fun File.readAsText() = suspendCoroutine { cont ->
   }
   reader.readAsText(this, "UTF-8")
 }
+
+suspend fun File.readAsByteArray() = suspendCoroutine { cont ->
+  val reader = FileReader()
+  reader.onload = {
+    try {
+      val target = it.target as? FileReader
+      val result = target?.result?.unsafeCast<ArrayBuffer>()
+      cont.resume(result.toByteArray())
+    } catch (e: Exception) {
+      cont.resumeWithException(e)
+    }
+  }
+
+  reader.onerror = {
+    cont.resumeWithException(IllegalStateException("Error reading the file $name"))
+  }
+
+  reader.onprogress = {
+    val percentage = (it.loaded.toDouble() / it.total.toDouble()) * 100
+    log.info { "File loading Progress: $percentage%" }
+  }
+  reader.readAsArrayBuffer(this)
+}

web/wasm/src/wasmJsMain/kotlin/Interop.kt

@@ -1,3 +1,8 @@
+import org.khronos.webgl.ArrayBuffer
+import org.khronos.webgl.Int8Array
+import org.khronos.webgl.get
+import org.khronos.webgl.set
+
 /** JavaScript console class */
 external class Console : JsAny {
   fun log(message: String?)
@@ -11,3 +16,33 @@ external val console: Console
 fun currentTimeMillis(): Long = currentTimeMillisJs().toLong()
 
 private fun currentTimeMillisJs(): Double = js("new Date().getTime()")
+
+fun Int8Array.copyInto(
+    output: ByteArray,
+    inputOffset: Int = 0,
+    outputOffset: Int = 0,
+    length: Int = this.length
+) = repeat(length) { output[outputOffset + it] = this[inputOffset + it] }
+
+fun Int8Array.toByteArray(): ByteArray {
+  val buf = ByteArray(length)
+  copyInto(buf)
+  return buf
+}
+
+fun ByteArray.copyInto(
+    output: Int8Array,
+    inputOffset: Int = 0,
+    outputOffset: Int = 0,
+    length: Int = this.size
+) = repeat(length) { output[outputOffset + it] = this[inputOffset + it] }
+
+fun ByteArray.toInt8Array(): Int8Array {
+  val arr = Int8Array(size)
+  copyInto(arr)
+  return arr
+}
+
+fun ArrayBuffer?.toByteArray() = this?.run { Int8Array(this).toByteArray() }
+
+fun ByteArray.toArrayBuffer() = toInt8Array().buffer