tools: Report dependency downloading progress

tools/helpers/src/main/kotlin/DependencyDownloader.kt

@@ -1,13 +1,11 @@
 package org.jetbrains.kotlin.konan
 
-import java.io.File
-import java.io.RandomAccessFile
+import java.io.*
 import java.net.URL
-import java.nio.file.*
-import java.util.*
+import java.util.Properties
+import kotlin.concurrent.thread
 
 // TODO: Try to use some dependency management system (Ivy?)
-// TODO: Show % and size during downloading
 class DependencyDownloader(dependenciesRoot: File, val properties: Properties, val dependencies: List<String>) {
 
     val dependenciesRoot = dependenciesRoot.apply { mkdirs() }
@@ -63,16 +61,65 @@ class DependencyDownloader(dependenciesRoot: File, val properties: Properties, v
         }
     }
 
+    private val Long.humanReadable: String
+        get() {
+            if (this < 0) {
+                return "-"
+            }
+            if (this < 1024) {
+                return "$this bytes"
+            }
+            val exp = (Math.log(this.toDouble()) / Math.log(1024.0)).toInt()
+            val prefix = "kMGTPE"[exp-1]
+            return "%.1f %sB".format(this / Math.pow(1024.0, exp.toDouble()), prefix)
+        }
+
+    private fun updateProgressMsg(url: String, currentBytes: Long, totalBytes: Long) {
+        print("\rDownload dependency: $url (${currentBytes.humanReadable}/${totalBytes.humanReadable}). ")
+    }
+
     private fun download(dependencyName: String): File {
-        val to = File(dependenciesRoot.canonicalPath, "$dependencyName.tar.gz")
-        if (!to.exists()) {
-            val from = URL("$dependenciesUrl/$dependencyName.tar.gz")
-            println("Download dependency: $dependencyName from $from")
-            from.openStream().use {
-                Files.copy(it, Paths.get(to.toURI()), StandardCopyOption.REPLACE_EXISTING)
+        val outputFile = File(dependenciesRoot.canonicalPath, "$dependencyName.tar.gz")
+        if (!outputFile.exists()) {
+            val url = URL("$dependenciesUrl/$dependencyName.tar.gz")
+            val connection = url.openConnection()
+            val totalBytes = connection.contentLengthLong
+
+            var currentBytes = 0L
+            var done = false
+            var downloadError: Throwable? = null
+
+            thread {
+                try {
+                    url.openStream().use { from ->
+                        outputFile.outputStream().use { to ->
+                            val buffer = ByteArray(DEFAULT_BUFFER_SIZE)
+                            var read = from.read(buffer)
+                            while (read != -1) {
+                                to.write(buffer, 0, read)
+                                currentBytes += read
+                                read = from.read(buffer)
+                            }
+                        }
+                    }
+                } catch (e: Throwable) {
+                    downloadError = e
+                }
+                done = true
+            }
+
+            // TODO: Improve console logging
+            var msgLen = 0
+            while (!done) {
+                Thread.sleep(1000) // We can use condition variable here.
+                updateProgressMsg(url.toString(), currentBytes, totalBytes)
+            }
+            println("Done.")
+            if (downloadError != null) {
+                throw RuntimeException("Cannot download dependency: $url", downloadError)
             }
         }
-        return to
+        return outputFile
     }
 
     fun run() {