Implement download helper for properly tracking download progress

Author: BluSpring

gradle.properties

@@ -1,4 +1,4 @@
-unitytranslate_version = 0.4.1
+unitytranslate_version = 0.4.2
 
 # https://github.com/OpenNMT/CTranslate2/blob/master/python/ctranslate2/version.py
 ct2_version = 4.6.0

library/src/main/kotlin/xyz/bluspring/unitytranslate/library/models/argos/ArgosPackageIndex.kt

@@ -4,6 +4,7 @@ import kotlinx.serialization.json.Json
 import xyz.bluspring.unitytranslate.library.UnityTranslateLib
 import xyz.bluspring.unitytranslate.library.models.ModelInfo
 import xyz.bluspring.unitytranslate.library.models.PackageIndex
+import xyz.bluspring.unitytranslate.library.util.DownloadHelper
 import java.net.URI
 import java.nio.file.Path
 import java.util.zip.ZipFile
@@ -62,6 +63,13 @@ class ArgosPackageIndex(path: Path) : PackageIndex<ArgosPackage>(path, "argos")
 
     override suspend fun getOrDownloadModelInfo(pkg: ArgosPackage): ModelInfo {
         val pkgDir = path.resolve("${pkg.code}_${pkg.packageVersion}")
+        val downloadId = "argos_${pkg.code}"
+
+        if (DownloadHelper.getDownloadInfo(downloadId) != null) {
+            while (DownloadHelper.getDownloadInfo(downloadId) != null) {
+                // just keep blocking I guess? idk how else to handle this
+            }
+        }
 
         if (pkgDir.exists()) {
             return ModelInfo(
@@ -78,11 +86,8 @@ class ArgosPackageIndex(path: Path) : PackageIndex<ArgosPackage>(path, "argos")
             try {
                 val url = URI.create(link).toURL()
                 val zipPath = path.resolve("${pkg.code}_${pkg.packageVersion}.argosmodel")
-                url.openStream().use {
-                    zipPath.outputStream().use { o ->
-                        it.copyTo(o)
-                    }
-                }
+
+                DownloadHelper.download(downloadId, url.openConnection(), zipPath)
 
                 val zipFile = ZipFile(zipPath)
                 for (entry in zipFile.entries()) {

library/src/main/kotlin/xyz/bluspring/unitytranslate/library/util/DownloadHelper.kt

@@ -0,0 +1,60 @@
+package xyz.bluspring.unitytranslate.library.util
+
+import java.io.File
+import java.net.URLConnection
+import java.util.*
+
+object DownloadHelper {
+    val runningDownloads: MutableList<DownloadInfo> = Collections.synchronizedList(mutableListOf<DownloadInfo>())
+
+    fun getDownloadInfo(id: String): DownloadInfo? {
+        synchronized(runningDownloads) {
+            return runningDownloads.firstOrNull { it.id == id }
+        }
+    }
+
+    fun getAllDownloadsById(id: String): List<DownloadInfo> {
+        synchronized(runningDownloads) {
+            return runningDownloads.filter { it.id == id }
+        }
+    }
+
+    fun download(id: String, connection: URLConnection, output: File) {
+        val tempOutput = output.parentFile.resolve("${output.name}.tmp")
+        val info = DownloadInfo(id, connection, tempOutput, output)
+
+        if (tempOutput.exists())
+            tempOutput.delete()
+
+        runningDownloads.add(info)
+        try {
+            connection.inputStream.use {
+                tempOutput.outputStream().use { o ->
+                    it.copyTo(o)
+                }
+            }
+
+            if (output.exists())
+                output.delete()
+
+            tempOutput.renameTo(output)
+        } finally {
+            runningDownloads.remove(info)
+        }
+    }
+
+    data class DownloadInfo(val id: String, private val connection: URLConnection, private val tempOutput: File, private val output: File) {
+        val totalLength: Long
+            get() {
+                return connection.contentLengthLong
+            }
+
+        val currentLength: Long
+            get() {
+                return if (tempOutput.exists())
+                    tempOutput.length()
+                else
+                    output.length()
+            }
+    }
+}